Duke U nîvers ity Med ical Center Libi 
 Historical Collection 
 
 IjIÜKAK y 
 
 JOHNS HOPKINS UNIVERSITY 
 
 MEDICAL SCHOOL COLLECTION 
 
Digitized by the Internet Archive 
 in 2016 
 
 https://archive.org/details/manualofgenerald3183meck 
 
J. F. MECKEL, 
 
 It 
 
 Professor of Anatomy at Halle, &c. ice. &c. 
 
 TRANSLATED FROM THE GERMAN INTO FRENCH, 
 WITH ADDITIONS AND NOTES, 
 
 BY 
 
 A. J. L. JOURDAN, 
 
 Member of the Royal Academy of Medicine at Paris, &c. &c. &c. 
 
 G. BRESCHET, 
 
 Adjunct Professor of Anatomy at the School of Medicine, &c. &c. &c. 
 TRANSLATED FROM THE FRENCH, 
 WITH NOTES, 
 
 BY A. SIDNEY DOANE, A. M„ M. D. 
 
 IN THREE VOLUMES. 
 VOLUME III. 
 
 PHILADELPHIA: 
 
 CAREY & LEA— CHESTNUT STREET. 
 
 1832 . 
 
\ Y i eate-L u 
 V. 3 
 
 I 2 3 3u 
 
 Institut« 
 
 11 Entered, according to act of Congress, in the year 1832, by Henry C. Sleight, in the 
 office of the Clerk of the District Court of the Southern District of New York ” 
 
 
 SLEIGHT AND ROBINSON, PRINTERS, 
 
 No. Ill Nassau St., New- York. 
 
MANUAL 
 
 OF 
 
 GENERAL, DESCRIPTIVE, AND PATHOLOGICAL 
 
 ANATOMY. 
 
 DESCRIPTIVE ANATOMY. 
 
 SECTION II. 
 
 OF THE PERIPHERY OF THE NERVOUS SYSTEM. 
 
 § 1809. The periphery of the nervous system, comprehending the 
 nerves properly so called, is divided into three sections : the nerves of 
 the spinal marrow or the spinal nerves, the nerves of the brain or the en- 
 cephalic nerves, and the ganglionnary or great sympathetic nerve. The 
 number of these nerves, including the last, is forty-three pairs. But 
 anatomists do not divide them in the same manner, for several cerebral 
 nerves have been blended which are now considered as distinct pairs ; 
 and farther, some consider as cerebral nerves those which others refer 
 to the spinal pairs. 
 
 We shall point out the differences arising from the first of these 
 sources in our general remarks on the cerebral nerves. Those which 
 arise from the second depend principally upon the division of the 
 central mass of the nervous system. If the medulla oblongata be 
 considered as the summit of the spinal marrow, we must naturally 
 arrange the nerves arising from it among the spinal pairs ; hence their 
 number is increased, while that of the cerebral pairs is diminished. 
 
 Vol. III. 2 
 
6 
 
 DESCRIPTIVE ANATOMY. 
 
 Thus Gordon admits only eight pairs of cerebral nerves and thirty- 
 four pairs of spinal nerves. Bichat makes three classes, the first com- 
 prising two nerves of the cerebrum, the second six of the mesoce- 
 phalon, and the third thirty-four spinal nerves. Others with Portal, 
 tacitly admit another intermediate class in which the accessory nerve 
 is placed, which in the geneial method belongs to that of the cerebral 
 nerves. Others as Sabatier, Bichat, and Cloquet, following Willis, 
 exclude the first nerves of the spinal marrow from the number of spinal 
 pairs, and consider them as the most inferior cerebral nerves. 
 
 This last method is the least natural of all, for although the upper 
 pair of the spinal nerves is often between the cerebral and spinal nerves 
 in character, as may be seen from the description, still it is more like 
 the latter than the former. The want of exactness in considering the 
 last four cerebral nerves as the first spinal pairs, is also proved by the con- 
 tradiction between the general characters of these four nerves and those 
 of the spinal marrow, and it then becomes impossible to generalize 
 about these last. This classification is farther very inconvenient, since 
 a slight examination demonstrates that certain nerves (for instance, the 
 auditory and external motor nerves) arise from the same region of the 
 central part of the nervous system ; and with a little care and patience 
 this may be proved of most of the others. The same reasons which im- 
 pelled us to separate the medulla oblongata from the spinal marrow, and 
 to consider it as a portion of the encephalon, have obliged us to place 
 the nerves derived from it among the cerebral. The characters of these 
 nerves, which resemble those of the cerebral rather than those of the 
 spinal nerves, demonstrate also the superiority of our method. 
 
 We shall first examine the spinal nerves, not only because we have 
 already treated of the spinal marrow when describing the cervical part 
 of the nervous system, but because from the cerebral nerves, which 
 will be mentioned last, we shall naturally pass to the organs of sense, 
 and from them to the more complex organs, with which we shall' close 
 the treatise. 
 
 CHAPTER I. 
 
 NERVES OF THE SPINAL MARROW. 
 
 § 1810. We have already mentioned the general characters of the 
 nerves of the spinal marrow :(1) they are divided into as many sec- 
 tions as there are regions in the vertebral column, consequently into 
 cervical , thoracic , lumbar , and sacral nerves. 
 
 We shall first describe the thoracic nerves, except the first one, 
 because they are more simple and arise the first ; next the nerves of 
 the limbs, those of the inferior extremities arising from most of the 
 
 (1) J. J. Huber, Dc medulla spinali, speeialim de nervis ab cil provenienlibufi ) 
 Gottingen, 1741. — G. Frotscher, De medullâ spinali cj usrjue nervis, Erlange», 1786. 
 
 * 
 
OF THE NERVOUS SYSTEM. 
 
 1 
 
 sacral and lumbar nerves, those of the superior from the first dorsal 
 and the last four cervical ; finally, the four superior cervical nerves, 
 which lead by a remarkable transition to the cerebral nerves. 
 
 Before describing minutely the nerves of these different regions, we 
 ought to make known the following characters which belong to them 
 in common, and which are important in regard to their topography. 
 
 1st. There is no constant difference between the nerves of the right 
 and those of the left sides. 
 
 2d. The nerves are not perfectly symmetrical ; one is often situated 
 higher than another, and the number of cords is frequently greater by 
 two or three on one side than on the other. But this difference is 
 almost always compensated for, because then the adjacent pairs vary 
 in the opposite manner. 
 
 3d. The upper and lower pairs are much nearer each other than the 
 central. The latter also after the last dorsal nerve, are so near each 
 other that they do not seem like separate nerves. They are also much 
 nearer in the early periods of existence, and even during the first years 
 of life, than at subsequent periods. This propinquity in the superior 
 and inferior regions, is owing to the disproportion between the size of 
 the nerves and the shortness of that part of the spinal marrow from 
 whence they arise. Hence why the smaller thoracic nerves, which 
 arise not much above the place from whence they leave the spinal 
 marrow, are farther from each other, and the reason of the greater 
 distance between the spinal nerves in animals whose necks are longer, 
 and in whom too the spinal marrow descends lower than in man. 
 
 4th. The ganglions formed by the posterior roots are situated in the 
 intervertebral foramina, except those of the sacral nerves which are 
 found in the cavity of the sacrum. 
 
 These ganglions are not all of the same size in all regions, and their 
 development is not in a direct ratio with that of the nerves. In fact, a 
 ganglion which is usually large, is not unfrequently replaced by another 
 very small, and vice versa. The ganglions of the dorsal nerves are 
 generally the largest, and those of the sacral nerves, especially the 
 last, the smallest. 
 
 5th. All the spinal nerves divide soon after coming from the verte- 
 bral column into two branches, an anterior and a posterior, the first of 
 which is often larger than the other, excepting always those of the 
 second cervical nerve, which presents a contrary arrangement. The 
 anterior branches turn first outward, then forward and inward, and 
 terminate near or upon the anterior median line. The posterior go 
 directly backward, and are distributed to the muscles which fill the 
 groove between the spinous and transverse processes of the vertebra?, 
 or in those which correspond to them in the cranium and the skin of 
 this region. The first are distributed to the anterior muscles, which 
 represent these dorsal muscles on the sides and anteriorly, and in those 
 of the extremities. 
 
8 
 
 DESCRIPTIVE ANATOMY. 
 
 6th. All the spinal nerves communicate together very constantly by 
 one or several larger or smaller branches which they give off soon 
 after leaving the vertebral canal, and which anastomose with those 
 analogous. 
 
 The anastomosing branches usually arise from the anterior part of 
 the nerves, or belong only to their anterior branches, and go before the 
 transverse processes on the sides of the bodies of the vertebræ. The 
 brachial, lumbar, and sacral plexuses, are formed entirely in this man- 
 ner ; their arrangement, however, differs from that usually seen, being 
 more complex, since the anastomosing branches produce others winch 
 anastomose several times with those near. Nerves composed of fila- 
 ments from several trunks of different origins, arise from these points of 
 union whether single or multiple. 
 
 One or more anastomosing branches communicate at the same time 
 with the branches of the ganglionnary system in the limiting gan- 
 glions. 
 
 Besides these anterior anastomosing branches which form along the 
 vertebral column, a series of plexuses, corresponding in number to that 
 of the vertebræ, the posterior branches also anastomose in an ana logous 
 manner, especially at the upper region of the neck, although this ar- 
 rangement is less general posteriorly than anteriorly. 
 
 § 1811. The dorsal, thoracic, costal, or intercostal nerves (JV. tho 
 racici, s. dorsales , s. costales , s. intercostales) are like the dorsal ver- 
 tebræ, twelve in number. Some anatomists, however, as Haller,(l) 
 count only eleven, and annex to the lumbar nerves that usually re- 
 garded as the twelfth. We shall examine only the eleven inferior 
 nerves, as it is more convenient to describe the first with the four 
 inferior cervical nerves. 
 
 The general characters of these nerves are as follow : 
 
 1st. They make part of the smaller nerves of the spinal marrow, 
 and are particularly smaller than the inferior cervical, the lumbar, and 
 the superior sacral nerves. 
 
 2d. Most of them, especially the inferior, are those spinal nerves 
 which arise farthest from each other. Still the superior are nearer 
 to each other than the superior cervical nerves are. 
 
 3d. Most of them communicate only by intermediate filaments in 
 the vertebral canal. Still we have often found between the first and 
 second pairs, as between the second and third, a filament, proceeding 
 obliquely from above downward, and from within outward, from the su- 
 
 ARTICLE FIRST. 
 
 DORSAL NERVES. 
 
 (1) El.phys., lib. x. not. 38. 
 
OF THE NERVOUS SYSTEM, 
 
 perior edge of the inferior nerve to the inferior edge of the nerve situated 
 immediately above. They have always seemed smaller between the 
 second and third pair than between the first and second. 
 
 4th. Their trunk furnishes on emerging, and immediately after, some 
 thin short branches which go forward and enter either into the nearest 
 limiting ganglion of the ganglionnary nerve, or more rarely into the fila- 
 ment of communication between two of these adjacent ganglions. It 
 then divides soon after emerging into two branches, one anterior , inter- 
 costal, or subcostal (R. intercostalis, s. subcostalis ), the other posterior 
 or dorsal ( R . dorsalis ). 
 
 The anterior branch proceeds under the rib, below which the trunk 
 comes from the vertebral canal, between the external and internal 
 intercostales muscles, and advances as far as these last extend. It 
 accompanies the intercostal vessels lodged more or less immediately 
 in the groove of the rib. In its course it gradually leaves the superior 
 rib, so that its anterior part is nearer the rib below than that above. It 
 then perforates the intercostales muscles near the sternum, and be- 
 comes external. Proceeding, it gives branches to these muscles, the 
 upper part of the abdominal muscles, and to the skin which covers the 
 intercostales muscles. These last filaments called the external thoracic 
 nerves {R. pectorales externi ), successively perforate the intercostales 
 muscles from behind forward, but all arise very far from the place 
 where they emerge. 
 
 Each anterior branch near its origin, sends off posteriorly several 
 branches, of which the internal are usually numerous, and go, inde- 
 pendently of those coming from the trunk, to the limiting ganglions of 
 the ganglionnary nerve and their filaments of union, and anastomose 
 in this place with the analogous branches of the adjacent dorsal nerves, 
 while the external which are simple, pass on the internal face of the 
 ribs, and communicate with those of the two adjacent dorsal nerves 
 which go to meet them. These last are sometimes deficient in the 
 middle pairs : but then absence is not always observed, as they not 
 unfrequently occur there, although they are more developed in the 
 upper and lower pairs. 
 
 The posterior branch proceeds backward between the transverse 
 processes of the vertebrae, between which it arises under the multifidus 
 spinæ muscle, and there usually divides into external and internal 
 branches, the latter of which are smaller and are deficient when the 
 division does not take place. 
 
 The internal branches are distributed to the multifidus spinæ, the 
 semispinalis, the spinalis, the internal belly of the sacro-lumbalis, the 
 digastricus nuchæ, the complexi, the transversalis, the inferior portion 
 of the splenius, the rhomboidei, the trapezius, and the latissimus 
 dorsi muscles. 
 
 The external branches proceed outwardly, emerge between the 
 scalenus muscle and the internal belly of the sacro-spinalis, and in this 
 place penetrate between the two bellies of the latter muscle, to which 
 they are distributed and also to the superficial muscles of the back. 
 
ÏO 
 
 DESCRIPTIVE ANATOMY. 
 
 Besides, these two branches usually, but not always, extend to the 
 skin. 
 
 All the dorsal nerves are not of the same size. Except the first, 
 which is the largest, they go on increasing in size much from the 
 second to the last. However, they do not enlarge uniformly ; Haller(l) 
 and Sœmmerring have observed, and the results of our numerous dis- 
 sections also coincide with their opinion, that the the fourth, sixth, and 
 eighth, are smaller than the fifth, seventh, and ninth. 
 
 § 1812. The differences in the distribution of the thoracic nerves, 
 depend principally on their anterior or intercostal branches. 
 
 The first is remarkably distinguished from the others. It soon goes 
 upward and outward above the first rib, toward the brachial plexus, 
 and opposite to this rib divides into two branches. One which is pro- 
 portionally very small, goes forward and proceeds below the first rib 
 like the anterior branches of the other thoracic nerves.. The second 
 is much larger, and ascends and corresponds to the small anastomosing 
 branches of the other thoracic nerves ; it immediately unites with the 
 brachial plexus, with which we shall describe its farther progress. 
 
 The anterior branches of the second and third' thoracic nerve, to- 
 gether furnish to the skin of the arm an inferior branch, which may 
 be called the brachial nerve. Both then send some filaments to the 
 intercostales muscles, penetrate the external, then descend to the in- 
 teguments at the axilla and unite, but not always uniformly, with 
 the internal cutaneous nerve of the arm, and expand in the superior 
 and internal part of the integuments of the arm, so that their filaments, 
 especially those of the second pair, descend to the elbow. 
 
 Anteriorly, the anterior branches of these two nerves terminate in the 
 anterior part of the pectoralis major and the triangularis sternqmuscle. 
 In their passage they furnish no constant branches to the abdominal 
 muscles. 
 
 The anterior extremities of the anterior branches, and of the 
 second, third, fourth, fifth, sixth, and seventh thoracic nerves, are 
 distributed also in these two muscles, the skin of this region, and 
 the thymus gland. The external pectoral twigs of these branches 
 penetrate Into the upper part of the obliquus externus and rectus ab- 
 dominis muscles, also in the skin which covers them. 
 
 The anterior extremities of the anterior branches of the eighth, 
 ninth, tenth, and eleventh thoracic pairs, pass above the costal digi- 
 tations of the diaphragm, glide between the obliquus internus and 
 transversalis abdominis muscles, distribute filaments to these muscles, 
 and then go to the posterior face of the rectus muscle and to the skin 
 which covers it. 
 
 The external pectoral twigs of these branches are distributed in 
 the upper part of the obliquus abdominis internus muscle and the skin 
 near it. 
 
 (1) Depart, c urp. hum., vol. viii. p. 399. 
 
OF THE NERVOUS SYSTEM. 
 
 II 
 
 The eleventh thoracic nerve gives filaments to the posterior part of 
 the diaphragm. 
 
 The twelfth, described by Haller as the first lumbar nerve, anasto- 
 moses by a large branch with the first lumbar pair, and sends filaments 
 to the diaphragm, then passes before the superior part of the quadratus 
 lumborum muscle, between it and the posterior tendon of the transver- 
 salis, gives off filaments and divides at its external edge into superficial 
 and deep abdominal branches. The former pass between the trans- 
 versalis and obliquus internus abdominis muscles, and terminate there, 
 and also in the lower part of the rectus and pyramidalis muscles. The 
 second go between the two oblique muscles, pass through the external, 
 and are distributed to the integuments of the abdomen as far as the 
 ossa ilia. 
 
 ARTICLE SECOND. 
 
 LUMBAR AND SACRAL NERVES. 
 
 §1813. The description of the lumbar and sacral (\ ) nerves ought 
 to follow that of the thoracic, because by then describing the cervical, 
 we proceed from below upward to the explanation of the encephalic 
 nerves. We shall combine our observations in regard to these two 
 orders of spinal nerves, because they resemble each other in their most 
 essential characters, and particularly as they unite to form the nerves 
 of the inferior extremities. 
 
 The five lumbar nerves and the sacral nerves, which are also five 
 and sometimes six in number, arise near each other from the inferior 
 prominence of the spinal marrow. They emerge from the medullary 
 canal, the lumbar passing out through the intervertebral foramina, 
 situated between the lumbar vertebrae as between the last one and the 
 upper surface of the sacrum. The sacral nerves form the sacral 
 foramina, except the last, which passes between the sacrum and the 
 first piece of the coccyx. Not only the anterior and posterior roots of 
 each pair, but the different pairs themselves are closely united to each 
 other from their origin to the ganglions formed by their posterior 
 branches ; but neither the first nor second communicate by inter- 
 mediate filaments. The sacral nerves differ from all other spinal 
 nerves by the situation of their ganglions, which do not anastomose 
 when coming from the nerve, but in the channel of the vertebral 
 column, and are as much more distant from the sacral foramina the 
 lower the origins of the nerves to which they belong, so that the an- 
 terior and posterior roots of these last unite even within the medullary 
 canal. The trunks resulting from their union divide near their origin, 
 and also within the vertebral canal, into anterior and posterior branches, 
 
 (1) J.L. Fischer, Descriptio anatomica nervorum himbalium, sacralium el cxtre- 
 mitalum infer iorum, Leipsic, 1791. 
 
12 
 
 UESCKXI'TIVE ANATOMY. 
 
 which do not usually anastomose together in this canal, hut emerge, 
 the first through the anterior sacral foramina, the others through the 
 posterior sacral foramina. The union of the anterior and posterior 
 roots of the sacral nerves in the medullary canal, undoubtedly corres- 
 ponds to the fusion of the false sacral vertebræ in a single bone, and 
 it takes place after the same type so evident in the vascular system. 
 Perhaps, also, it partially depends on the greater distance between the 
 point from whence the nerves originate, and that whence they emerge. 
 One circumstance favors this conjecture, viz. that the place where the 
 posterior and anterior roots unite, is farther in the inferior nerves where 
 the trunk is proportionally longer. But this circumstance also favors 
 the opinion first proposed, since the inferior false sacral vertebrae unite 
 also sooner than the superior. 
 
 The anterior branches of these ten nerves which enlarge very much, 
 form a plexus which may be called the femoral or crural plexus ( plexus 
 femoralis). This plexus, like the brachial and cervical, is produced by 
 the increase and multiplication of the anastomoses between the anterior 
 branches, which is in proportion to the increase of volume of the 
 nerves, and which takes place in breadth, and from without inward, 
 and in thickness or from behind forward. 
 
 We may consider separately the superior and inferior parts of this 
 plexus, the first as the lumbar or lumbo-abdominal(l) plexus, the se- 
 cond as the sacral or sciatic plexus , since from each of these two parts, 
 which are formed, the first by the lumbar, the second by the sacral 
 nerves, arise nerves which are distributed differently. Still as the 
 principal nerves which come from it are all distributed to the lower 
 extremities, it is more convenient to regard them as forming one plexus 
 only, as the inferior lumbar nerves mostly form the sacral plexus and 
 the nerves which come from it. 
 
 This plexus is indicated in the dorsal region by the much smaller 
 anastomosis between the anterior branches, and which are constantly 
 developed in the inferior thoracic pairs. 
 
 Of the nerves which form it, the upper suddenly enlarge very much 
 from above downward, and the lower from below upward. 
 
 The last two sacral nerves are the smallest, and the last es- 
 pecially is the smallest of all the spinal nerves. Next comes the first 
 lumbar, then the third sacral ; the second lumbar is a little larger, 
 being about the same size as the second sacral ; the third and fourth 
 lumbar which are almost equal, are a little larger than the preceding. 
 The fifth lumbar and the first sacral are much the largest. 
 
 Dorsal branches which are much smaller arise from all these nerves 
 which unite to form the crural plexus, commencing before the union of 
 their anterior branches, when they emerge from the foramina : these 
 go directly backward between the transverse processes of the lumbar 
 vertebræ and the sacrum, passing there through the posterior sacral 
 
 (1) J. A. Schmidt, De plexu lumbali, de nervis lumbaliqus corumque ylexu com- 
 mcntarius anatomko-patkologicus, Vienna, 1794. 
 
OF THE NERVOUS SYSTEM. 
 
 13 
 
 foramina. These branches are distributed to the posterior part of the 
 muscles of the back, to the gluteus maximus and the skin which 
 covers them. 
 
 The posterior branches, the dorsal or lumbar (R. postici, s. dorsales , 
 s. lumbales ), of the lumbar nerves diminish considerably in volume from 
 the first to the last, so that the last two rarely extend to the skin, but 
 are distributed only in the common belly of the sacro-lumbalis and 
 multifidus spinæ muscles. From the first sacral nerve to the fourth, 
 the posterior branches again enlarge much. That of the fourth is the 
 largest ; the fifth is smaller, while the sixth is much more minute. 
 
 § 1814. The anterior or abdominal branches {R. antici, s. abdcnni- 
 nales ) of the lumbar nerves pass behind the psoas magnus muscle, unite 
 not only with each other, but beside the first with the anterior branch of 
 the last dorsal, the last with the anterior branch of the first sacral, to 
 form the lumbar plexus, the lumbar ganglion of the ganglionnary 
 nerve, and produce the nerves we are about to describe. The anterior 
 branches of the sacral nerves, principally the first, second, third, and 
 fourth, concur in the same manner to form the sacral plexus to which 
 the fifth contributes least, and the sixth takes no part when it exists. 
 
 Some ramifications arise from the anterior twigs after their union, 
 some of which, the smaller ones, are usually formed by the filaments 
 of a single nerve, while others which are larger, arise from the union of 
 fasciculi from several nerves. 
 
 The first are principally the external pudic nerve, several branches 
 for the muscles in the lumbar region, the skin of this region and the 
 common integuments of the inguinal region, the gluteal nerves and the 
 inferior and middle hemorrhoidal nerves. 
 
 The second are the three nerves of the lower- extremities, the obtu- 
 rator, the crural, and the gluteal nerve. 
 
 A. SMALL NERVES WHICH ARISE FROM THE ANTERIOR BRANCHES OF 
 THE LUMBAR AND SACRAL NERVES. 
 
 § 1815. First and second lumbar nerve. From the first and second 
 lumbar nerve, especially from the inferior extremity of the plexus be- 
 tween them, arises the external pudic or the genitocrural nerve (N. 
 pudendus externus , s. spermaticus externus , s. inguinalis , s. genito-cru- 
 ralis ), which passes between the superior digitations of the psoas mus- 
 cle, arives at the anterior face of this muscle, on which it goesfrom behind 
 forward and from above downward, and divides within the pelvis into 
 branches which all emerge from the inguinal ring. Among these, the 
 most considerable which are always the continuation of the trunk, 
 arrive at the spermatic vessels, and are distributed in the male in the 
 cremaster muscle and its coats, and in the female in the round liga- 
 ment of the uterus, and anastomosing with the inferior pudic nerves, 
 terminate in the glands and integuments of the inguinal region. The 
 external passes under the crural arch, penetrates the aponeurosis, is dis- 
 
 Vol. III. 3 
 
14 
 
 DESCRIPTIVE ANATOMY, 
 
 tributed in the skin to the middle of the internal face of the thigh, and 
 anastomoses with some filaments of the crural nerve. 
 
 Besides there arise from the first lumbar nerve and its anastomosis 
 with the second, branches designed for the psoas, the quadratus lum- 
 borum, and' the transversalis abdominis muscles, and for the integuments 
 of the lumbar and inguinal regions. One of these branches, which is 
 large, penetrates the psoas muscle, goes forward between the obliquus 
 internus and transversalis along the crest of the ilium, and terminates 
 in the inferior part of the large abdominal muscles and skin of this 
 region and of the scrotum. 
 
 Several filaments come from the second lumbar nerve and are 
 distributed to the psoas and quadratus lumborum muscles and the skin 
 of the lumbar and inguinal regions : usually there arise one or two 
 distinct branches which are longer {nerfi lio-scrotal, Ch.), which passing 
 through the psoas muscle, proceed outwardly before the quadratus 
 lumborum, penetrate the transversalis, then the obliquus internus, to 
 which they give filaments, go forward along the crest of the ilium, 
 perforate the aponeurosis of the obliquus externus, and are distributed 
 to the skin of the inguinal region and scrotum. 
 
 3d. The third lumbar nerve usually gives off a cutaneous nerve 
 which unites to the preceding one or replaces it either partially or 
 wholly, descends between the psoas and iliacus muscles, emerges from 
 the pelvis, passing under the outward extremity of the crural arch and 
 is distributed to the external and anterior extremities of the integuments 
 of the thigh to the neighborhood of the knee. There it is the infe- 
 rior branch of the crural plexus of Bichat, the inguino-cutané of 
 Chaussier. 
 
 4th. The fourth lumbar nerve usually gives branches only to- the 
 iliacu3 muscle. 
 
 5th. The anterior branches of the fourth and fifth lumbar nerve unite 
 to form a very considerable trunk, the lombo-sacral nerve of Bichat 
 (JV. lumbo-sacralis ), which is much larger than the crural, and give 
 origin in the very cavity of the small pelvis, but always before uniting 
 with the first sacral nerve, to the superior gluteal nerve (JY. glutæus 
 superior ), which emerges from the pelvis below the upper edge of the 
 sciatic notch, is distributed to the gluteus médius and minimus, and 
 penetrates even forward to the tensor vaginæ femoris. 
 
 6th. From the second and third sacral nerve, come some fasciculi 
 which unite, then give filaments to the pyramidalis muscle, and coming 
 from the pelvis below it, go to form the inferior gluteal nerve. 
 
 Before these fasciculi, a very considerable nerve arises from these 
 same nerves farther below and forward, sometimes also from the fourth 
 sacral nerve, called the external common hemorrhoidal nerve (JY. pu- 
 dendo-hœmorrhoidalis communis externus ), which re-enters into the 
 pelvis, between the two sacro-sciatic ligaments, and divides into two 
 branches, the external pudic , and the inferior hemorrhoidal nerve. 
 
 The external or superior pudic nerve, ischio-pénien or ischio-clitori- 
 dien , Ch. ( N . pudendus externus , s. superior), goes along the ascending 
 
OF THE NERVOUS SYSTEM. 
 
 15 
 
 branch of the ischium and the descending branch of the pubis, pro- 
 ceeding on gives branches to the obturator internus and bulbo-caver- 
 nosus muscles, then passes under the symphysis pubis to go forward, 
 as the dorsal nerve of the penis (JY. dorsalis penis) in the male, and 
 that of the nerve of the clitoris (JY. clitoridcus , s. pudendus superior) 
 in the female, proceeds along the penis and clitoris, sends filaments to 
 the skin which covers them, and also to the mons veneris and mucous 
 membrane of the urethra, and terminates finally in the glans. 
 
 The inferior hemorrhoidal nerve, called also the inferior pudic (JY. 
 hœmorrhoideus, s. pudendus inferior ), partly accompanies the pre- 
 ceding, then goes upward between the bulbo- and ischio-cavernosus 
 muscle, is distributed to the integuments and in all the muscles of the 
 perineum to the inferior extremity of the rectum, the skin of the scro- 
 tum and mucous membrane of the urethra, and anastomoses with the 
 external pudic, the inguinal and internal hemorrhoidal nerves. 
 
 From the difference in size between the penis and clitoris, the external 
 pudic is the larger of these two branches in the male, while the internal 
 hemorrhoidal is the larger in the female. 
 
 7th. The third and the fourth sacral nerves also give off the middle 
 hemorrhoidal nerves (JY. hcemorrhoidales medii), which are smaller, 
 and not united at then - origin ; but this term is not exact for they 
 are distributed partly to the rectum, the levator and sphincter ani mus- 
 cles, and proceed on the side of this intestine to be distributed from be- 
 low upward in the walls of the bladder, at the commencement of the 
 urethra, uterus, and vagina, the prostate gland and vesiculæ séminales 
 in the male, and frequently anastomose with the lower part of the 
 great sympathetic nerve to give origin to the hypogastric plexus. 
 
 8th. The fifth and sixth lumbar nerves, when they exist, are in fact 
 connected with the crural plexus, but do not contribute to form the 
 nerves which come from them. Their anterior branches are distributed 
 to the sacro-coccygeal, the levator, and sphincter ani muscles. Their 
 posterior are distributed in the integuments of the posterior part of the 
 anus and perineum. 
 
 B.. LARGE NERVES WHICH ARISE FROM THE ANTERIOR BRANCHES OF 
 THE LUMBAR AND SACRAL NERVES, OR NERVES OF THE INFERIOR 
 EXTREMITIES. 
 
 I. OBTURATOR NERVE. 
 
 § 1816. The obturator nerve, sous-pubiofémoral, Ch. (JY. obtura- 
 torius),(l) the smallest of those belonging to this division, arises from 
 the most anterior fasciculi of the second, third, and fourth lumbar nerves, 
 rarely from the first, by an equal and sometimes greater number of 
 
 (1) See in regard to this and the following nerve, M. C. Styx, Descript, anat. 
 nervi cruralis et obturatorii, Jena 1782. 
 
16 
 
 DESCRIPTIVE ANATOMY. 
 
 roots, which meet at acute angles. It descends into the lower pelvis, 
 before the following nerve, is covered by the psoas muscle, goes for- 
 ward along the linea innominata, accompanied by the vessels of the 
 same name, comes out through the obturator foramen, and divides into 
 two branches, an anterior superficial and large and a posterior deeper 
 and smaller. 
 
 The anterior branch is distributed to the gracilis, the adductorlongus, 
 and brevis muscles, and sends to the internal saphena nerve some 
 branches which are sometimes so large that this last seems to arise 
 from it rather than from the crural. 
 
 The posterior branch is distributed in the obturator muscles, particu- 
 larly the externus, and in the adductor magnus muscle, even descend- 
 ing to near its inferior extremity. 
 
 II. CRUIiAL NERVE. 
 
 § 1817. The crural nerve, férnoro-pré tibial , Ch. (JY. cruralis), is 
 larger than the preceding, behind which it is situated, arises from the 
 posterior part of the first, second, third, and fourth lumbar nerves, 
 descends along the posterior and external side of the crural artery, be- 
 tween the psoas and iliacus muscles, gives several branches to these 
 two muscles, but principally to the second, and furnishes one conside- 
 rable which sometimes come off higher than the branches destined 
 to the iliacus muscle, anastomoses near the crural arch with another 
 branch which arises in this place, comes sometimes also from the 
 fourth lumbar nerve, and then is distributed in the integuments of the 
 anterior and internal face of the thigh. This branch is called the 
 superior or the small saphena nerve (JY. saphenus superior , s. minor). 
 
 A branch is generally given off a little below the crural arch which 
 proceeds from within outward, and goes to the common lower ex- 
 tremity of the iliacus and psoas muscles. 
 
 The nerve then divides generally below the crural arch into two 
 branches, an external larger, and an internal smaller, above. 
 
 The external branch also soon divides into several twigs, which go 
 to the four heads of the extensor of the leg, to the crurceus, and to 
 the tensor vaginæ femoris muscle. These branches descend to the 
 articulation of the knee and penetrate into its capsule. 
 
 The internal branch gives to the sartorius muscle many twigs, most 
 of which enter its middle and inferior part. It gives them also to the 
 skin of the internal face of the thigh. But the largest of all the 
 branches which come from it is the internal saphena nerve, tibio-cu- 
 t ané, Ch. (JY. saphenus internus ). This nerve accompanies the in- 
 ternal saphena vein, which it surrounds at several different parts, 
 distributes some filaments to the integuments of this region, descends 
 on the back of the foot, and extends even to the great toe. 
 
OF THE NERVOUS SYSTEM. 
 
 17 
 
 III. SCIATIC NERVE. 
 
 § 1818. The sciatic nerve, grand femoro-poplité, Ch. (JY. ischiadi- 
 cus),( 1 ) the largest of all the nerves, not only of the inferior members, 
 but even of the whole body, arises from the inferior half of the fourth 
 lumbar nerve, and from all the fifth, also from the three superior sacral ; 
 the anterior branches unite to form the sciatic or sacral plexus ( plexus 
 sacralis , s. ischiadicus ), which is only the inferior part of the crural 
 plexus, although we usually consider this the only plexus of nerves of 
 the lower extremities. 
 
 § 1819. The sciatic nerve sometimes, partially or wholly, gives off 
 the superior gluteal nerve and always the inferior either wholly or 
 partially. This last emerges sometimes above and sometimes below 
 the pyramidalis muscle, anastomoses with a branch of the sciatic 
 nerve which arises a little lower, and is distributed with it in the 
 gluteus maximus muscle. 
 
 § 1820. The sciatic nerve emerges from the sacral plexus through 
 the sciatic notch, between the pyramidalis and gemelli muscles. 
 
 There it sends to the obturator internus a considerable branch which 
 penetrates from without inward between the large and small sciatic 
 ligaments, and enters from below upward into this muscle. 
 
 Then it gives a second, which descends before the gemelli and the 
 tendon of the obturator internus, distributes filaments to the first two 
 of these muscles, and is distributed in the quadratus femoris muscle. 
 
 Still lower a large branch leaves its posterior part, and unites to the 
 inferior gluteal nerve (§ 1788), with which it goes to the gluteus 
 maximus muscle. 
 
 The trunk first gives branches to the flexor muscles of the thigh ; 
 then to the long head of the biceps ; then to the semitendinosus ; far- 
 ther on, to the semimembranosus muscle ; finally, to the short head of 
 the biceps. The filament of the semimembranosus is distributed also 
 to the adductor magnus muscle. 
 
 Farther on it gives off the middle posterior cutaneous nerve (JY. 
 cutaneus posterior médius ), which descends under the skin of the pos- 
 terior face of the thigh and leg to the calf, and anastomoses with some 
 filaments of the superior and inferior nerves. 
 
 The inferior posterior cutaneous nerve (JY. cutaneus posterior infe- 
 rior) is given off below this branch ; it proceeds in part hke the former 
 one, and is partially expanded hi the posterior part of the capsular liga- 
 ment of the knee. 
 
 § 1821. The sciatic nerve then divides into two branches : the in- 
 ternal, the larger, is the tibial nerve, and the external, the smaller, the 
 peroneal nerve. This division usually takes place at the middle of the 
 thigh, often higher up, and even above the sciatic tuberosity, so that 
 the two branches are separated from each other by the pyramid- 
 alis muscle. 
 
 (1) J. H. Joerdens, Descriptio nervi ischiadici, Erlangen, 1788. 
 
18 
 
 DESCRIPTIVE ANATOMY. 
 
 When the bifurcation occurs higher than usual, it is analogous to 
 the arrangement of the sciatic nerve in the mammalia. 
 
 Rosenmuller mentions a national difference in regard to the height 
 of this division, viz. that the sciatic nerves divide very high in the 
 inhabitants of the north of Europe, while in those of the south it bifur- 
 cates very low not far from the ham.(l) We have not observed this 
 difference. 
 
 When the nerve divides high, the two branches are separated by the 
 pyramidalis muscle, and they descend, the external behind, the internal 
 before it. 
 
 The popliteal nerve (JV. popliteus ) rarely or never exists. (2) At 
 most the name of the internal and the external popliteal nerve may be 
 given to the upper part of the two terminating branches of the sciatic 
 nerve, from their origin to the femoro-tibial articulation. 
 
 a. Peroneal nerve. 
 
 § 1822. The peroneal or external popliteal nerve (JV. peroneus ) often 
 gives origin to the posterior, inferior, and middle cutaneous nerves. It 
 descends from within outward on the internal side of the biceps femo- 
 ris muscle, passes between the extensor longus digitorum communis 
 and peroneus longus muscles, sends filaments to these muscles, and 
 likewise to the tibialis anticus, and divides very high up into two 
 branches, the superficial and the deep peroneal nerves. 
 
 § 1823. The superficial peroneal , or the muscular cutaneous nerve, 
 prétibio-digital , Ch. (JV. peroneus superficialis ), soon divides into two 
 branches, an external superficial and small, the other internal, which 
 is deeper and larger. 
 
 The first, or the cutaneous peroneal nerve, which might more pro- 
 perly be called the middle cutaneous nerve of the back of the foot , or the 
 external branch of the peroneal nerve (JV. cutaneus peroneus , s. cuta- 
 neus médius dorsi pedis, s. cutaneus peroneus externus ), descends on the 
 peroneus brevis muscle, passes on the crucial ligaments of the tarsus, 
 is distributed to the skin of the external part of the back of the foot, and 
 terminates by filaments which are the tibial nerve of the little toe, the 
 dorsal nerves of the fourth toe, and the peroneal nerve of the third toe. 
 
 The second, the anterior nerve of the back of the foot (JV. dorsi pedis 
 anticus communis, s. peroneus anticus, s. pedalis anticus), is situated 
 before the former, also near the surface, and is distributed partly to the 
 internal half of the back of the foot, partly to the skin of the external 
 and anterior faces of the leg, and terminates by producing' the dorsal 
 nerves of the two external toes and the peroneal nerve of the third. 
 
 § 1824. The deep peroneal or anterior tibial nerve, prélibio-sus-plan- 
 iaire , Ch. (JV. peroneus profundus ), descends deeply between the 
 
 (1) In Neer Journal der Erfindungen in der Natur-und Arzneywissenschqft, part 
 
 ii., p. 100. 
 
 (2) Coopmans has made the remark (Neurol., ed. 2, p. 198. 
 
OF THE NERVOUS SYSTEM. 
 
 19 
 
 muscles on the anterior face of the tibia, at the side of the anterioi 
 tibial artery, but does not pass with it from the posterior to the anterior 
 face of the leg, between the two bones, for the whole trunk of the 
 peroneal nerve is situated and divides on the external face of the fibula. 
 
 Such at least is always the arrangement of the deep peroneal 
 nerve according to our observations. Although we have made many 
 careful dissections, yet we have never seen it pursue the course of the 
 anterior tibial artery. Thus, although this authority is sanctioned by 
 a great name,(l) it certainly is not the usual arrangement, and should 
 be considered as a very rare anomaly, more especially as many 
 writers, Coopmans(2) among others, do not sanction it, or speak only 
 of the first. 
 
 This nerve gives filaments to the peroneus longus, and to the 
 extensor longus digitorum communis muscle, to the tibialis anticus, 
 and to the extensor hallucis proprius, passes under the crucial liga- 
 ment of the tarsus, and arrives on the back of the foot, where it termi- 
 nates in the extensor digitorum brevis, the first interosseous muscle, and 
 the internal part of the skin of this region, by anastomosing with some 
 branches ofthe cutaneous nerve around the foot, so that the dorsal nerves 
 of the large toe more properly arise from this than from the latter. 
 
 We have always found the peroneal nerve distributed in this man- 
 ner, but we have never found that of the two branches into which it 
 divides at the upper extremity of the fibula, one was the external cu- 
 taneous nerve, the other, the common trunk of the anterior tibial and 
 internal cutaneous nerves ;(3) Sabatier, (4) Coopmans,(5) andReil,(6) 
 state the same distribution as ourselves : this arrangement then should 
 be regarded as the most constant. 
 
 b. Tibial nerve. 
 
 § 1825. The tibial or internal •popliteal nerve (A', tibialis ), the 
 largest and most internal of the two terminating branches of the sciatic 
 nerve, may be called the popliteal ( JV. popliteus), from the bifurcation to 
 the calf of the leg, although this term is not perfectly exact. It gives 
 off first a considerable cutaneous nerve, the long posterior cutaneous 
 nerve of the foot and the leg , or rather the external cutaneous tibial 
 nerve of the foot { N . cutaneus longus posterior tibiae , s. cutaneus pedis 
 externus , s. tibialis), which nevertheless often comes from the peroneal 
 nerve, or at least especially when the sciatic nerve bifurcates high up> 
 is partially replaced either by the posterior and inferior branch of this 
 latter, or even by its inferior and middle cutaneous nerve. 
 
 (1) Sœmmerring, Hirn-und Nervenlehre, p. 312. 
 
 (2) Neurologia, p. 203. 
 
 (3) Sœmmerring-, Ncrvenlehre, p. 309. 
 
 (4) TV. complet d’anat. ed. 3. vol. iii. p. 328. 
 
 (5V Neurologia, p. 201, 203. 
 
 (6) Anat. descript, vol. iii. p. 309. 
 
20 
 
 DESCRIPTIVE ANATOMY. 
 
 The external cutaneous tibial nerve of the foot descends behind the 
 muscles of the foot, goes outward below the external malleolus, pro- 
 ceeds along the external edge of the foot and the fibular edge of the 
 fifth toe, constituting its dorsal peroneal nerve, and proceeds to the 
 top of it. 
 
 The tibial nerve then gives off a small branch to the posterior part 
 of the capsule of the articulation of the knee. This branch is some- 
 times given off higher or as high as the preceding. 
 
 Farther on, the trunk of the tibial nerve gives external and internal 
 branches to the three heads of the triceps, the plantaris, the popliteus, 
 the tibialis posticus, and the flexor hallucis longus. 
 
 § 1826. The tibial nerve then goes forward between the upper two 
 heads of the triceps suræ muscle, descends between the tendo achillis, 
 the tibialis posticus and the flexor hallucis longus, passes behind the 
 malleolus internus, and goes to the sole of the foot. 
 
 Behind the malleolus it divides into three branches, one superficial 
 and two deep. 
 
 § 1827. The superficial branch or the external tibial nerve (JV. 
 tibialis exterior ), more properly the proper cutaneous plantar nerve 
 (JV. cutaneus plantaris proprius ), is distributed to the skin below the 
 malleolus internus, and at the posterior part of the sole of the foot. 
 
 § 1828. The two deep branches are the internal and the external 
 plantar nerve. 
 
 The internal plantar nerve (JV. plantaris internus ) is usually a little 
 larger and more superficial than the other ; it goes forward under the 
 long head of the adductor hallucis, between it and the flexor communis 
 digitorum brevis, and divides far back into two branches, an internal 
 and an external: the latter is the larger. 
 
 The internal branch having given filaments to the adductor hallucis, 
 becomes the first plantar nerve of the toes ( N. . digitorum plantaris 
 primus ), the tibio-plantar nerve or the internal nerve of the great toe 
 (JV. plantaris internus , s. tibialis hullucis). 
 
 The external branch also subdivides into two others, the external of 
 which is also the larger. 
 
 The internal or the third plantar nerve of the toes also divides into 
 the external plantar nerve of the second toe , and the internal plantar 
 nerve of the third toe. 
 
 The external or the fourth plantar nerve of the toes divides into 
 the external plantar nerve of the third toe , and the internal plantar 
 nerve of the fourth. 
 
 Thus this trunk distributes its branches to the internal half of the 
 skin of the foot, to the two sides of the three internal toes, and to the 
 internal side of the fourth. 
 
 § 1829. The external plantar nerve (JV. plantaris externus ) goes 
 forward and outward between the flexor communis digitorum brevis, 
 and the tendon of the flexor longus, and divides before the tuberosity 
 of the calcanéum into three branches. 
 
OF THE NERVOUS SYSTEM. 
 
 21 
 
 The internal branch, the fifth plantar nerve of the toes, which is en- 
 tirely cutaneous, goes forward to the anterior extremity of the tarsus, 
 where it divides into the plantar nerve of the fourth toe, and the in- 
 ternal plantar nerve of the fifth. 
 
 The external branch, the musculo-cutaneous nerve, goes forward 
 along the fibular edge of the sole of the foot, gives filaments to the 
 abductor minimi digiti muscle, and becoming the external plantar 
 nerve of the fifth toe, advances to its extremity, where as in the great 
 toe, it receives at its external edge a distinct branch, an arrangement 
 which is worthy of notice, as it contributes to the lateral symmetry. 
 
 This nerve forms the sixth plantar nerve of the toes. 
 
 The middle, deep, or muscular trunk is the largest. It goes ob- 
 liquely inward and forward, penetrates between the tendons of the 
 extensor longus digitorum communis and the deep muscles of the sole 
 of the foot, and distributes itself in the lumbricales, the adductor and 
 flexor hallucis muscles, and in almost all the internal part of the 
 interossei muscles, and the small muscles of the fifth toe. 
 
 ARTICLE THIRD. 
 
 OF THE CERVICAL NERVES. 
 
 § 1830. Till the time of Willis, eight cervical nerves, tracheliens 
 Ch. (N. cervicales, s. N. colli)( 1) were admitted, but this anatomist 
 and many after him, have mentioned only seven : as they consider the 
 first cervical as the last encephalic nerve, an opinion less correct than 
 the ancient. The general characters of these eight nerves are : 
 
 1st. Of all the spinal nerves they have the least extent in the verte- 
 bral column from their origin to the place where they penetrate the 
 dura-mater, and emerge through the intervertebral foramina. 
 
 2d. The interna] extremities of their roots are closer to each other 
 than those of the thoracic nerves, but farther than those of the lumbar 
 and sacral nerves. 
 
 3d. The different pairs are united together by anastomoses ; these 
 are usually simple, and extend from the inferior edge of the root of the 
 superior nerve, to the upper edge of that of the lower nerve, and form 
 the upper part of this last. The anastomosing filaments of the posterior 
 roots are more constant than those of the anterior ; the latter usually 
 exist only between the second and third pairs, and the third and fourth, 
 and are deficient between all the others. On the contrary, the anas- 
 tomosing filaments of the anterior roots exist in almost every part, but 
 are sometimes deficient between the lower pairs. They are very 
 seldom met with between the last cervical and the first dorsal nerve. 
 
 We, however, should observe that the anastomosing filaments often 
 do not exist between the middle cervical pairs, although found between 
 the superior and the inferior nerves. 
 
 (1) J. Bang-, Nervorum cervicalium anatomc ; in Ludwig, Se. neur, 
 
 Vol. III. 4 
 
22 
 
 DESCRIPTIVE ANATOMY. 
 
 The arrangement of these filaments is not always exactly the 
 same ; we usually see a filament which goes a little obliquely upward 
 and outward from the internal extremity of the upper edge of the 
 lower nerve, towards the external extremity of the lower edge of the 
 upper nerve. But sometimes this filament descends directly from the 
 lower edge of the upper nerve, to the upper edge of the lower nerve. 
 
 Between this arrangement and the preceding is one which is inter- 
 mediate, where the most superior fasciculus of the lower nerve divides 
 at its centre into two parts, the upper of which goes to the upper 
 nerve in the first .of the two modes mentioned above, while the lower 
 proceeds in the direction of the fasciculus, forming the most upper part 
 of the lower nerve. Sometimes one or two thin fasciculi are found 
 between two pairs of nerves, and usually a little nearer the lower than 
 the upper. When there is only one fasciculus, this divides into two ; 
 when two, they arise immediately one at the side of the other. In 
 both cases either the fasciculi primitively distinct, or the two branches 
 of the single fasciculus separate from below upward immediately after 
 arising, and form, one the most inferior fasciculus, the other the most 
 superior of the pairs between which they are situated. Sometimes 
 they are united together by superior and inferior fasciculi, and after- 
 ward by a transverse filament. 
 
 The first arrangement usually exists between the inferior cervical 
 nerves, the third between the middle, the second between the superior, 
 and the fourth between the first two, counting from above downward. 
 
 The cervical nerves may be divided into two groups ; the first com- 
 prises the four lower pairs, the other the four upper pairs, for the first 
 differ much from the second, as they enlarge to give origin to the nerves 
 of the upper extremities. 
 
 A. INFERIOR CERVICAL NERVES AND FIRST DORSAL NERVE, OR NERVES 
 OF THE UPPER EXTREMITIES. 
 
 § 1831. The nerves of the upper extremities ( JY . brachiales , s. ex- 
 tremitatis superior is) ( 1 ) arise from the first dorsal and the four in- 
 ferior cervical nerves, which unite at some distance from their foramina 
 to form the brachial plexus, so that a greater number of trunks comes 
 afterward from the latter, each of which is formed from the fasciculi 
 coming from several of the carrying nerves. The first dorsal nerve 
 emerges below the first dorsal vertebra, the eighth cervical below the 
 seventh cervical vertebra, the seventh below the sixth, the sixth below 
 the fifth, and the fifth below the fourth. That nerve which usually 
 occupies the centre of the group, that is the seventh cervical nerve, is 
 the largest : the first dorsal and the fifth cervical nerves are the 
 smallest : the fifth cervical nerve is smaller than the first dorsal, and 
 the sixth and eighth dorsal are about the same size. 
 
 (1) J. J. Klint, De nervis brachii, Gottingen ,1784. — P. Camper, Demonst. anal, 
 pathol., 1. i. Amsterdam, 1760. 
 
OF THE NERVOUS SYSTEM. 
 
 23 
 
 The nerves which usually emerge from the brachial plexus are the 
 thoracic , the scapular, the axillary, the radial, the external cutaneous, 
 the median, the ulnar, and the internal cutaneous nerves. 
 
 § 1832. Before uniting, the five nerves which form the brachial 
 plexus give off much smaller posterior branches, which go to the deep 
 dorsal muscles of this region. The brachial nerves are then only the 
 enlarged anterior branches of the superior dorsal and the four inferior 
 cervical nerves. 
 
 § 1833. These anterior branches descend from within outward, pass 
 between the scalenus anticus and médius muscles, and soon unite to 
 form the brachial plexus ( plexus brachialis).{\ ) The two superior and 
 two inferior usually unite before the middle with the adjacent branches. 
 
 The fifth and the sixth usually imite the first. 
 
 Two nerves arise from their union. 
 
 The superior after passing several inches divides into two branches, 
 one of which is the axillary or circumflex nerve, the other is large and 
 unites with the large posterior fasciculi of the seventh and eighth cer- 
 vical nerves to form the radial nerve. 
 
 The inferior, having proceeded two or three inches, unites with one 
 or two anterior fasciculi of the seventh cervical nerve, and thus pro- 
 duces a more or less complicated plexus,' whence the external cu- 
 taneous or the musculo-cutaneous nerve wholly, and the median par- 
 tially arise. 
 
 The seventh cervical nerve divides two or three inches from its 
 emerging from the spinal canal into an anterior and a posterior branch, 
 of which the second is larger. 
 
 The posterior branch blends -with the upper posterior branch of the 
 eighth cervical nerve in a small trunk, which soon joins the posterior 
 branch of the trunk formed by the union of the fifth and sixth cervical 
 nerves, and gives origin to the radial nerve. 
 
 From the anterior branch and the common trunk formed by the 
 union of the fifth and sixth cervical nerves, several anterior thoracic 
 nerves arise and then the musculo-cutaneous nerve ; it gives rise with 
 the eighth cervical and the first dorsal nerves to the median nerve. 
 
 The eighth cervical nerve divides into two branches, one posterior, 
 thinner but longer, the other anterior, shorter but much thicker. 
 
 The posterior unites to some branches of the fifth, sixth, and seventh 
 cervical nerves to form the radial nerve. 
 
 The anterior joins the first dorsal nerve. 
 
 The common trunk formed by this last union, divides into two 
 branches, a superior and an inferior. 
 
 The superior, united with the fasciculi of the fifth, sixth, and seventh 
 cervical nerves, becomes the median nerve. 
 
 The inferior forms the ulnar nerve. 
 
 The first dorsal nerve divides into two other branches, both of which 
 unite with the eighth cervical nerve. 
 
 Cl) Bang 1 (toe. cit.) has figured the brachial plexus— Prochaska De struct, nerv., 
 Vienna, 1779, tab. iv. v. — Scarpa. Annot. anat ., B. 1. lab. fi. 
 
24 
 
 DESCRIPTIVE ANATOMY. 
 
 The superior assists to produce the radial nerve. 
 
 The inferior concurs to form the ulnar nerve, and sometimes alone 
 produces the internal cutaneous nerve. 
 
 I. THORACIC NERVES. 
 
 § 1834. The thoracic nerves , sterno-tlioraciques, Ch. (JV. tlioracici) 
 may be distinguished into posterior and anterior. 
 
 The posterior arise from the branches of the fifth and sixth, some- 
 times also from the seventh cervical nerve, which are mostly united in 
 a nerve which descends on the external face of the serratus major 
 muscle, and is distributed in that muscle. 
 
 The anterior arise from the anterior trunk formed by the union of 
 the fifth and sixth cervical nerves, and also from the anterior branch of 
 the seventh and eighth, descend from behind forward, and give filaments 
 to the subclavius, the pectoralis major and minor muscles, the thymous 
 gland, and the skin of the anterior and superior part of the chest and 
 shoulder, where they anastomose with some filaments of the fourth 
 cervical and axillary nerves. 
 
 II. SCAPULAR NSRVE. 
 
 § 1835. The scapular nerve (JV*. scapularis ), which is rather large 
 often comes from the fifth cervical nerve before it joins with the follow- 
 ing. When it arises only after the union, it commences almost in the 
 place where it is, passes through the coracoid notch of the scapula, 
 arrives thus on the posterior face of the scapula, sends filaments to the 
 supraspinatus muscle, goes downward over the neck of the scapula, 
 and arrives at the infraspinal fossa, where it is distributed to the 
 infraspinatus and teres minor muscles. 
 
 HI. AXILLARY NERVE. 
 
 § 1836. The axillary nerve, scapulo-humeral , Ch. ( JV. axillaris , s. 
 circumflexus brachii), or more properly the circumflex nerve, arises 
 from the posterior and superior branch coming from the division of the 
 common trunk formed by the union of the fifth and sixth cervical 
 nerves. It first sends branches to the infraspinatus muscle, which 
 often receives a large one from the common trunk mentioned above, it 
 then gives some to the teres minor and major muscles, then passing 
 between these two muscles and the long head of the triceps extensor, 
 it is reflected outward and backward on the head of the humerus, ex- 
 pands in the deltoides muscle, and finally becoming the cutaneous 
 nerve of the shoulder (JV. cutaneus humeri ), together with the fourth 
 cervical nerve sends filaments to the integuments of this region. 
 
OF THE NERVOUS SYSTEM. 
 
 25 
 
 IY. RADIAL NERVE. 
 
 § 1837. The radial nerve, radio-digital, Ch. (JV. radialis), is much 
 larger than the preceding, arises from fasciculi of all the brachial nerves 
 by three branches, which come one from the seventh cervical nerve 
 only, the second from the fifth and sixth, and the third from the eighth 
 cervical and the first dorsal nerves. Soon after its origin, it gives a 
 large branch to the latissimus dorsi and filaments to the triceps ex- 
 tensor muscles. A little below the middle of the arm it turns on the 
 humerus, often reappearing on its anterior face between the brachialis 
 intemus and the supinator longus muscles. 
 
 In turning on the humerus it gives a long and thin cutaneous 
 branch, the superior external cutaneous nerve (JV. cutaneus externus 
 superior). This nerve descends along the radial edge and the inner 
 face of the fore-arm, and interlaces with the cutaneous branch of the 
 musculo-cutaneous nerve, extends a greater or less distance to the 
 middle of the fore-arm, to the carpus, and even the thumb. 
 
 The trunk of the radial nerve then gives branches to the supinator 
 longus and the extensor carpi longus radialis muscles. It divides at 
 the lower extremity of the fore-arm into two branches, a superficial or 
 cutaneous and a deep or muscular. 
 
 The superficial branch (R. superficialis dorsalis, s. cutaneus) de- 
 scends along the anterior edge of the radius between the supinator 
 longus and the radiales muscles, arrives at the outer face of the fore- 
 arm, passing below the tendons of the first of these three muscles, and 
 divides usually some inches below the inferior extremity of the fore-arm 
 into two almost equal branches, the anterior being a little the larger, 
 which distribute filaments to the anterior region of the integuments 
 of the back of the hand, and to the dorsal face of the three anterior 
 fingers. 
 
 The anterior branch anastomoses in several places with'those of the 
 cutaneous branch of the musculo-cutaneous nerve, sends filaments to 
 the skin of the radial side of the carpus and metacarpus, and divides 
 on the carpus into two small branches, the clo7'sal «erres ofi the thumb 
 (JV. cutanei pollicis dorsales), which descend on its dorsal side along 
 the radial and ulnar edges to its anterior extremity, furnish filaments 
 to its dorsal face, and anastomose together and with the palmar nerves 
 of the thumb. 
 
 The posterior branch usually divides soon after arising into two 
 principal ramuscules, an anterior and posterior. 
 
 The anterior goes to the skin between the thumb and index finger, 
 and arrived at the radial side of the last finger becomes the radio- 
 dorsal nerve of the index finger (JV. dorsalis radialis indicus). 
 
 The posterior soon subdivides into two filaments, one of which pro- 
 duces the cubito-dorsal nerve of the index finger and the radio-dorsal 
 nerve of the middle finger, while the second is the cubito-dorsal nerve 
 of the middle finger. 
 
26 
 
 DESCRIPTIVE ANATOMY. 
 
 All these ramifications frequently anastomose with each other or 
 with those of the ulnar nerve, and thus give rise to a plexus called the 
 dorsal arch of the hand ( rete , s. arcus dorsalis manus ). 
 
 The deeper or larger muscular branch gives off branches for the ra- 
 dialis brevis and the supinator brevis muscles ; it then turns over these 
 muscles and engages itself between their fibres, penetrates between 
 the extensor digitorum communis muscle, arrives at the posterior sur- 
 face of the fore-arm, gives off some large branches, some of which are 
 recurrent to the extensor digitorum communis, to the extensor minimi 
 digiti, and to the ulnaris internus and externus muscles. Then as the 
 external interosseus nerve ( JY. interosseous externus), it descends on the 
 extensor and the adductor pollicis longus muscles, to which it sends 
 filaments, as also to the extensor indicis proprius muscle, and is finally 
 lost in the capsule of the wrist-joint. 
 
 V. EXTERNAL CUTANEOUS NERVE. 
 
 § 1838. The external cutaneous nerve, or muscido-cutaneous nerve, 
 or the perforating nerve of Casserius, radio-cutané , Ch. (JY. cutaneus 
 externus, s. musculo-cutaneus, s. perforons Casserii), is much smaller 
 than the preceding, although it descends almost as low as it. It arises 
 from the fasciculi of the fifth, sixth, and seventh cervical nerves. It 
 sometimes comes from the median nerve. 
 
 It frequently but not always penetrates the coraco-brachialis muscle. 
 When this is not the case, it passes on the internal edge of this muscle, 
 being joined to it only at its surface. It divides high up in the arm 
 into two branches, the one muscular and small, the other cutaneous 
 and larger. 
 
 The muscular branch gives filaments to the coraco-brachialis 
 muscle, to the two heads of [the biceps, and to the bracliialis internus 
 muscle. 
 
 The cutaneous branch passing between the biceps and the brachialis 
 internus muscle, arrives at the anterior edge of the arm, descends on the 
 radial side in the aponeurosis,' accompanying the cephalic vein. It anas- 
 tomoses frequently above with the external cutaneous nerve, and below 
 with the dorsal branch of the radial nerve ; it is distributed to the skin 
 of the posterior surface of the fore-arm and the hand, and terminates at 
 the thumb. 
 
 VI. MEDIAN NERVE. 
 
 § 1839. The median nerve, mcdio-digital , Ch. (JY. mcdianus ), the 
 largest nerve of the upper extremity, comes also from the brachial 
 plexus. It descends on the inside of the arm near its lower extremity 
 without giving off any branch, unless it be sometimes the external 
 cuianeous nerve. 
 
OF TKB NERVOUS SYSTEM. 
 
 27 
 
 Some inches below the elbow-joint it gives several small muscular 
 branches to the pronator teres, to the upper part of the radialis internus, 
 the palmaris longus, and to the upper part of the flexor digitorum brevis 
 muscles. Near the elbow it gives off a considerable branch, the inter- 
 nal interrosseus nerve (N. interrosseus internus ), which descends before 
 the flexor communis digitorum profundus, distributes branches to this 
 muscle and to the flexor pollicis longus, is reflected on the anterior 
 edge of the pronator quadratus, arrived thus at the posterior face of the 
 fore-arm, it terminates in this muscle. 
 
 The trunk descends before the flexor digitorum profundus, between 
 the bones of the fore-arm, gives off filaments to this muscle and to the 
 palmaris longus, and gives a cutaneous branch which is distributed in 
 the integuments of the palmar face of the carpus, where it anasto- 
 moses with the branches of the musculo-cutaneous nerve and the ulnar 
 nerve. It then divides near the lower third of the fore-arm into two 
 branches, an anterior or radial and a posterior or ulnar ; the first is the 
 larger. 
 
 These branches descend without giving any twig to the fore-arm 
 between the tendons of the flexors, with which they pass under the 
 ligaments of the carpus, where they usually unite by some transverse 
 fibres. At the palm of the hand they separate. 
 
 The radial branch divides at the carpus into an anterior and posterior 
 twig. 
 
 The anterior very soon divides into three filaments, the radio-palmar 
 and the cubito-palmar nerves of the thumb, and the radio-palmar nerve of 
 the index finger , these frequently anastomose together, extend to the 
 extremities of these two fingers, and terminate by considerable 
 branches, and give filaments to the first lumbiicalis muscle. 
 
 The posterior then sends a large branch to the adductor brevis, to 
 its opponens muscle and the flexor pollicis brevis, after which it be- 
 comes the cubito-palmar nerve of the index finger. 
 
 § 1840. The cubital branch divides at the commencement of the 
 carpus into two twigs. 
 
 The anterior which is smaller sends filaments to the second lum- 
 bricalis muscle, and becomes the radio-palmar nerve of the third finger. 
 
 The posterior which is larger sends filaments to the integuments of 
 the hand, soon divides into two ramuscules, the cubito-palmar nerve of 
 the third finger and the radio-palmar nerve of the fourth. 
 
 VII. ULNAE OR CUBITAL NERVE. 
 
 § 1841. The ulnar nerve,- cubito-digital ( JY . ulnar is. s. cubitalis), is 
 a little smaller than the preceding, and arises from the three inferior 
 nerves of the brachial plexus. It descends inward and backward, gives 
 off no branches along the arm except sometimes the internal cutaneous 
 nerve, and arrives at the ulnar side of the fore-arm, passing imme- 
 
28 
 
 DESCRIPTIVE ANATOMY. 
 
 diately behind the internal condyle of the humerus, where it may be 
 easily compressed. 
 
 Arrived at the fore-arm, it first gives off ramifications to the flexor 
 digitorum profundus and to the flexor carpi ulnaris, and then sends 
 under the skin along the basilic vein a small branch, called the long 
 palmar nerve (JV. ulnaris longus palmaris), which anastomoses in the 
 carpus with an analogous branch coming from the median nerve ; 
 about the middle of the fore-arm, it divides into two branches, a dorsal 
 and a palmar. 
 
 The dorsal branch (JV. ulnaris dorsalis ) passes between the ulna 
 and the tendon of the flexor carpi ulnaris muscle, comes on the back 
 of the fore-arm, where it subdivides into two twigs. 
 
 The posterior or ulnar supplies the skin of the ulnar side of the hand, 
 and becomes the cubito-dorsal nerve of the fifth finger. 
 
 The anterior or the radial also soon divides into two principal fila- 
 ments, one of which is the radio-dorsal nerve of the fifth finger and the 
 cubito-dorsal nerve of the fourth , the other is the radio-dorsal nerve of 
 the fourth finger. 
 
 This dorsal branch is distributed like the dorsal branch of the radial 
 nerve. 
 
 The palmar branch ( JV. ulnaris palmaris ) which is larger, descends 
 between the tendons of the ulnaris internus and the flexor digitorum 
 communis muscles, and divides on the ulnar edge of the carpus into a 
 superficial and a deep twig. 
 
 The deep or muscular twig goes downward and forward between 
 the adductor and flexor minimi digiti muscles, passes across to the 
 radial side of the hand, going between the tendons of the flexor com- 
 munis and interossei muscles, and sends numerous twigs to the mus- 
 cles of the little finger, to the interossei and lumbricales, and to the 
 adductor pollicis muscles. 
 
 The superficial or cutaneous branch is smaller than the preceding, 
 anastomoses by one or several filaments with the cubito-palmar branch 
 of the median nerve (from this union we have a superficial palmar 
 arch), and soon divides into two filaments, an anterior and a posterior. 
 
 The anterior soon divides into the cubito-palmar nerve of the fifth 
 finger and the common trunk of the cubito-palmar nerve of the fourth , 
 and the radio palmar nerve of the fifth. 
 
 Each finger receives two palmar and two dorsal branches, the first 
 of which are the largest. They proceed along the radial and ulnar edges 
 of the finger directly at the side of the digito-palmar artery, more in- 
 ward and downward than it, that is, nearer the palmar face, as like- 
 wise the superficial palmar arch is nearer the surface than their trunk. 
 They go to the extremity of the fingers. In this passage they give 
 off several large branches, distribute some small twigs to the palmar 
 face of the finger, when they anastomose with each other. 
 
or THE NERVOUS SYSTEM. 
 
 29 
 
 VIII. INTERNAL CUTANEOUS NERVE. 
 
 § 1842. The internal cutuneous nerve, cubito-cutané, Ch. (JV. cu- 
 taneus internus ), usually arises from the first dorsal by several roots ; 
 it sometimes though rarely comes from the ulnar, being the first branch. 
 It descends directly below the skin at the side of the basilic vein in the 
 arm. From its upper part arises the superior cutaneous nerve (A’. 
 cutaneus internus superior ), which sometimes comes from the ulnar 
 nerve, and is distributed to the triceps extensor muscle and the skin 
 which covers it. A little lower it gives off the inferior internal cutaneous 
 nerve (A*. cutaneus internus inferior ), which distributes its branches to 
 the lower part of the triceps extensor muscle, to the skin of the elbow, 
 to the integuments of the ulnar edge of the fore-arm, and to the carpus, 
 and which terminates on the cubital edge of the hand and little finger, 
 descending along the basilic vein, and anastomosing with the branches 
 of the ulnar nerve, which it meets in its course. 
 
 In the whole course of this nerve its different branches anastomose 
 frequently with each other and with those of the external cutaneous 
 nerve on the posterior side of the fore-arm. 
 
 B. SUPERIOR CERVICAL NERVES. 
 
 § 1843. The four superior cervical nerves are smaller than the 
 inferior. Like the latter their size increases progressively from above 
 downward, so that the second and third are the largest. They form 
 with the lower ones an uninterrupted series ; and like them their an- 
 terior branches immediately after their trunks have come from the 
 intervertebral foramina, give off twigs which anastomose with the 
 adjacent branches and form the cervical plexus , trachélo-sous-cutané, 
 Ch. ( plexus cervicalis). This plexus descends along the corresponding 
 vertebrae, below the sterno-cleido-mastoideus muscle, outside of the in- 
 ternal jugular vein, carotid artery, and pneumogastric nerve, on the 
 scalenus posticus muscle. It anastomoses below with the brachial 
 plexus, within with the superior and middle cervical ganglions of the 
 great sympathetic nerve. We have as much reason to think the dif- 
 ferent branches of the cervical nerves are derived from them as that 
 they arise from the cervical pairs themselves. 
 
 Some modern anatomists, among whom are Bichat(l) and Clo- 
 quet, (2) have adopted this method, and describe separately only the 
 posterior branches and the commencement of the anterior, and consider 
 the cervical plexus as the origin of all the nerves which arise after the 
 union of the anterior branches. But we shall not follow them, as the 
 
 (1) Anat. descript., vol. iii. p. 234-246. 
 
 (2) Tr. d'anat., vol. ii. p. 633-641. 
 
 5 
 
 VOL. III. 
 
30 
 
 DESCRIPTIVE ANATOMY. 
 
 nerves of which they treat seem to arise from some particular pairs 
 which are not seen in the other plexiform nerves of the spinal marrow. 
 
 The diaphragmatic nerve is the only one to be considered sepa- 
 rately, because produced not only by several pairs of the cervical 
 plexus but also of the brachial plexus, so that it seems to belong in 
 common to the superior and inferior section of the cervical nerves. 
 
 I. DIAPHRAGMATIC NERVE. 
 
 § 1844. The diaphragmatic or phrenic nerve (JV. diaphragmati- 
 ons , s. phrenicus){l ) arises by several branches from the lower extre- 
 mity of the brachial plexus. The largest branch is always furnished 
 by the anterior branch of the fourth pair, but a smaller one always 
 arises from the third and often from the second, and about three from 
 the brachial plexus. This nerve sometimes joins the ascending branch 
 of the hypoglossal nerve. 
 
 The diaphragmatic nerve descends on the side of the neck between 
 the rectus capitis anticus and the scalenus muscle, gives branches to 
 these muscles and to the thymous gland, anastomoses by a few filaments 
 with the inferior and middle cervical ganglions of the great sympa- 
 thetic nerve, enters the chest between the subclavian artery and vein, 
 then goes forward, descends before the pulmonary vessels, and lastly 
 passes between the internal wall of the external sac of the pleura and 
 the pericardium, applied very exactly to the surface of this last mem- 
 brane, and is finally distributed to the diaphragm. A little before 
 arriving at this muscle, it divides into several branches which are 
 united by intermediate filaments, some of which go to the convex face 
 of the diaphragm and others pass through its costal portion and its 
 central tendon, accompany the ascending vena-cava on the right, with 
 which they emerge through the foramen quadratum, come into the 
 abdomen, where they not only expand on the inferior face of the mus- 
 cle, but also anastomose by several filaments with the solar plexus of 
 the great sympathetic and with the gastric branch of the pneumo-gas- 
 tric nerve. These anastomotic filaments almost always project at in- 
 tervals, and these projections often form real ganglions. 
 
 The left diaphragmatic nerve is situated farther back, and is longer 
 than the right, as it turns around on the summit of the heart. Be- 
 sides the filaments it gives to the diaphragm, it sends some also to the 
 lower part of the esophagus. 
 
 (1) Kruger, De nervo phrenico, Leipsic, 1758. 
 
OF THE NERVOUS SYSTEM. 
 
 31 
 
 It. FOURTH CERVICAL NERVE. 
 
 § 1845. The fourth cervical nerve(l) is a little smaller than the two 
 adjacent. It emerges through the third intervertebral foramen, be- 
 tween the anterior and posterior intertransversarii muscles, and imme- 
 diately divides into an anterior and a posterior branch. 
 
 The posterior is the smaller and deeper : it anastomoses with a 
 branch of the third cervical nerve, gives a twig to the complexus 
 muscle, passes transversely between this muscle and the semispinalis 
 colli, to which also it sends large filaments, also to the multifidus 
 spinæ, then penetrates between the complexus and trapezius muscles, 
 and expands in the corresponding skin of the neck. 
 
 The anterior branch, which is the larger, first gives off a filament 
 to the rectus capitis major anticus muscle : then it sends one of anas- 
 tomosis to the cervical portion of the great sympathetic nerve, or to its 
 superior cervical ganglion. It usually gives off also a twig to the 
 descending branch of the hypoglossal nerve, and constantly sends fila- 
 ments to the levator anguli scapulæ muscle. 
 
 It then sends an ascending anastomotic twig to the anterior branch 
 of the third cervical, and forms with it the third cervical nervous plexus , 
 then divides into three or four twigs which also proceed from above 
 downward, and are called the supraclavicular nerves (JY. supra-clavi- 
 culares). The latter are distributed principally to the skin which 
 covers the clavicle and the shoulder. 
 
 The anterior (JY. supra-clavicidares anteriores ) are distributed to the 
 skin which covers the first piece of the sternum and the sternal ex- 
 tremity of the clavicle to the mamma, anastomose with the anterior 
 thoracic nerves coming from the fifth cervical, and send filaments also 
 to the subclavius muscle. 
 
 The middle (JY. supra-clavicidares medii ) are distributed to the tra- 
 pezius muscle and the posterior belly of the omo-hyoideus muscle, and 
 also to the skin which covers the body of the clavicle, its scapular 
 extremity, and the scapula. 
 
 The posterior (JY. supra-claviculares posteriores ) go to the skin of 
 the neck and of the shoulder. 
 
 A small ascending branch generally arises from the anterior or 
 the middle nerve ; this forms a very broad plexus by anastomosing 
 with the middle subcutaneous cervical nerve, which comes from the 
 third pair. 
 
 The middle and the posterior anastomose with the accessory nerve 
 partly in the skin, and partly in the trapezius muscle. 
 
 (1) G. F. Peipers, Diss. sistens tertii et quarti nervorum cervicalium descrip- 
 tionem , cut accedit succincta eorundcm nervorum quinti , nervi phrenici , prœsertim 
 ratione originis nervi duri ejusque prœsertim rami inferioris , nervi hypoglossi et 
 occipitalis maximi a secundo cervicalium nervo adumbratio, Halle, 1793. 
 
32 
 
 DESCRIPTIVE ANATOMY. 
 
 III. THIRD CERVICAL NERVE. 
 
 § 1S46. The third cervical nerve( 1) is larger than the preceding. 
 It emerges from the spinal canal between the second and the third 
 cervical vertebne, and divides into two branches, a posterior and an 
 anterior. 
 
 The posterior branch is much smaller than the anterior ; it proceeds 
 from before backward between the anterior and posterior intertrans- 
 versarii muscles, gives filaments to these two muscles and also to the 
 transversalis colli and the complexus minor muscles, goes backward 
 passing on this latter, sends anastomosing filaments to the posterior 
 branch of the second and third cervical nerves, and also to the small 
 occipital nerve which comes from the anterior branch of the third pair, 
 glides below the biventer cervicis nuchæ and the complexus major 
 muscles, which receive considerable filaments from it, and goes directly 
 to the trapezius muscle in which it is distributed, and also in the middle 
 region of the skin of the neck. 
 
 The anterior branch sends first small twigs to the rectus capitis 
 major anticus and to the longus colli muscles, then proceeds from above 
 downward and divides into two branches, a descending and an as- 
 cending. 
 
 The descending branch, the superficial cervical nerve, the 
 submental nerve, Ch. ( JV. superficialis colli, s. profundus, JV. sub-cu- 
 taneus colli médius) turns on the posterior edge of the sterno- 
 cleido-mastoideus muscle, to go to the outer face of this muscle, to 
 which it gives filaments, sends others which anastomose with the 
 ascending branch, and terminates first, by descending ramifications 
 called the middle and inferior subcutaneous cervical nerves ( JV. subcu- 
 tanei colli medii et inferiores), in the middle and lower part of the skin 
 of the neck ; second, by ascending twigs which anastomose fiequently, 
 both with each other and with the final twigs of the facial nerve in the 
 skin which covers the ascending and horizontal branches of the lower 
 jaw from the lobe of the ear to the chin, and thus form the superior 
 subcutaneous cervical nerves (JV. subcidanei colli superiores). 
 
 The highest and most posterior portion of this descending branch, or 
 the great auricidar nerve, the zygomato-auricular nerve, Ch. (JV. 
 auricularis magnus , s. cervicalis), goes directly upward, and passing 
 behind the ascending branch of the lower jaw arrives at the exter- 
 nal ear. Its ramifications are distributed from behind forward and 
 from below upward in the integuments and posterior muscles of the 
 external ear, and also in the skin of the auditory foramen. 
 
 The uscending branch goes backward and upward, gives off first an 
 ascending anastomosing filament which unites to a descending filament 
 of the third pair to form the second cervical nervous plexus, and often 
 sends off immediately the great auricular nerve. In this case its pos- 
 
 (1) Peipers, loc. til. — Vic-d’Azyr, Mêmoiré sur les nerfs de la seconde et de la troi- 
 séme paire cervicale ; in the Mém. de Paris, 1777, p. 21-40. 
 
OF THE NERVOUS SYSTEM. 
 
 33 
 
 tenor part, and when the great auricular nerve comes from the de- 
 scending branch, its entire trunk becomes the small or the anterior 
 occipital nerve (JV. occipitalis minor, s. anterior ), which most generally 
 soon divides into several filaments, ascends on the complexus minor 
 and splenius capitis muscles and expands in the skin of the occiput, 
 in that of the mastoid process, in that of the posterior and superior part 
 of the external ear between the superior and posterior auricular 
 muscles, farther forward than the large occipital nerve given off by the 
 second cervical pair, although anastomosing frequently with this latter, 
 as with the filaments of the facial nerve. 
 
 IV. SECOND CERVICAL NERVE. 
 
 § 1847. The second cervical nerve(l) emerges from the spinal canal 
 between the first and second cervical vertebra. It is larger than the 
 third, and divides into an anterior and a posterior branch, directly below 
 the ganglion. 
 
 The posterior branch, the great occipital nerve (JV. occipitalis maxi- 
 mus ), is much larger than the anterior, which is contrary to the ar- 
 rangement of the inferior cervical nerves except the first, and to that 
 of all the other spinal nerves. It goes directly backward below the 
 complexus minor muscle, first sends, filaments to the obliquus capitis 
 inferior muscle, gives off others which pass on this muscle to anasto- 
 mose with the first and third cervical nerves, also gives them to the 
 upper part of the two splenii muscles, to the biventer cervicis, the 
 complexus and trapezius muscles under which it proceeds, to the mul- 
 tifidus spinse and to the skin of the neck, approaches the median line, 
 and arrives at the occipital bone ; it there forms most of the nerves in 
 this region, ramifies to the lambdoidal suture, where its filaments ex- 
 pand in the skin and occipitalis muscle, and anastomose with those of 
 the facial and small occipital nerve. 
 
 The anterior branch is smaller than the preceding ; it goes forward 
 and outward under the obliquus capitis superior muscle, and soon di- 
 vides into two anastomotic branches, a superior, ascending (JV'. anasto 
 moticus adscendens ), and an inferior, descending (JV'. anastomoticns 
 descendais), which unite, the first with the anterior branch of the first 
 cervical nerve, to form the first cervical nervous plexus ; the other with 
 the anterior branch of the third, to form the second cervical nervous 
 'plexus. 
 
 From the upper branch arise filaments which enter the superior cer- 
 vical ganglion of the great sympathetic, the sublingual, and the 
 pneumo-gastric nerve : one arises even from the bifurcation and goes 
 into the superior cervical ganglion ; finally the inferior branch produces 
 one which is larger, which descends from behind forward and anasto- 
 moses with a similar twig from the anterior branch of the third cervical 
 nerve, and with the descending branch of the sublingual nerve. 
 
 (1) Vicq-d’Azyr, loc. cit. 
 
34 
 
 DESCRIPTIVE ANATOMY. 
 
 V. FIRST CERVICAL NERVE. 
 
 § 1848. The first cervical nerve, called also the suboccipital or the 
 tenth encephalic nerve (JV. cervicalis primus , s. supremus, s. occipitalis , 
 s. infra-occipitalis, s. decimus cerebri), (1) is frequently the smallest of 
 all the spinal nerves, since it is not unfrequently smaller than the last 
 sacral nerve ; at least it is always smaller than the other nerves of the 
 spinal marrow, except the last. By its situation, origin, and direction, 
 it makes the transition from the spinal to the encephalic nerves, for it 
 frequently in the same and still more so in different subjects resembles 
 the former in some characters, the latter in others. 
 
 Hence for a long time, that is, since Willis lived, it has been consi- 
 dered as an encephalic nerve, the tenth cerebral nerve. It is not till 
 lately that it has been generally admitted among the spinal nerves, to 
 which it is more similar than to the cerebral nerves. 
 
 It arises out of the skull from the upper extremity of the spinal 
 marrow between the occipital portion of the basilar bone and the first 
 cervical vertebra. 
 
 Very often, perhaps even most generally, although Huber considers 
 the existence of two roots as a constant fact, (2) it arises by one an- 
 terior root which, like that of the sublingual nerve, comes from the an- 
 terior cord of the spinal marrow. (3) 
 
 Even when a posterior root exists, the anterior is much larger than 
 it, and is composed of from two or three to seven fasciculi, rarely of 
 eight, more commonly of two or three. These fasciculi, situated one 
 above another, are also formed of smaller filaments. The posterior root 
 presents only from one to three, and rarely four filaments which are 
 much smaller, the inferior of which, a remarkable fact, is generally 
 much larger than the others : these filaments commonly unite in two 
 fasciculi which proceed the superior outward, the inferior upward. 
 
 Even when the posterior root exists, the nerve however is most 
 generally formed anteriorly by but one root, the anterior, for the latter 
 ascends more than the posterior. 
 
 The posterior root is generally situated behind the accessory nerve ; 
 sometimes, however, but very rarely (we have never observed it), it 
 passes before. It is then in this latter case unusually near the ante- 
 rior, although the ligamentum centiculatum even then always sepa- 
 rates it from them. Farther it is constantly nearer the anterior face 
 than are the posterior roots of the other spinal nerves. 
 
 (1) G. T. Asch, De primo pare nervorum medullas spinalis, Gottingen, 1750. — Sa- 
 batier, Sur les nerfs de la dixième paire ; in the Mém. présentés, vol. vit., p. 553. 
 
 (2) De medulla spinali, Gottingen, 1741, § 12. 
 
 (3) Morgagni (Ep. anat., vol. xvi. 8vo.) also says : Septies ab eo tempore ex quo 
 semel anteriores tantam reperi, posteriores illas fibr as quœsivi. Bis dubius hœsi. 
 Q uater procvl omni dubio nullas omnino fuisse deprehendi. Semel a dextris.... 
 sed ne in eo quidem ipso.... ullam prorsus fibram e sinistris. — See also Vicq-d’Azyr, 
 Mém. de Paris, 1781, p. 596. — Gordon, p. 214. — Cloquet, p. 631. 
 
OF THE NERVOUS SYSTEM, 
 
 35 
 
 The posterior root most generally anastomoses with the accessory 
 nerve. This is sometimes, although more rarely, the case with the 
 anterior. Sometimes the posterior does not unite with the anterior ; it 
 goes only to the accessory nerve, in which case the latter after forming 
 a small ganglion which however does not constantly exist, sends one 
 or two filaments to the anterior root of the second cervical nerve. 
 
 Sometimes instead of the posterior root we find only a plexus which 
 anastomoses with the accessory nerve, the filaments of which go 
 towards the opening destined for the passage of the first cervical 
 nerve.(l). 
 
 When the posterior root and the accessory nerve do not anastomose, 
 we generally find a filament which extends from this root to the pos- 
 terior root of the second cervical nerve ; but this filament is not con- 
 stant. 
 
 The direction of the first cervical nerve is most generally transverse 
 from its origin to its emerging from the spinal canal. It not unfre- 
 quently proceeds in a direction opposite to that of the other cervical 
 nerves, that is, it proceeds a little more from below upward and from 
 within outward like the cerebral nerves. 
 
 The superior filaments of the posterior root rarely go upward, and 
 the inferior downward. Still more rarely the inferior filaments of the 
 two roots have a direction from above downward, while on the con- 
 trary the superior commonly follow this direction. 
 
 It is easy to observe that the smallness, the frequent absence and 
 the anterior situation of the posterior root, its separation from the an- 
 terior, the anastomosis of the latter with the accessory or the second 
 cervical nerve, and the direction of the whole nerve, establish a great 
 analogy between the latter and the cerebral nerves, while the frequent 
 existence also of the roots and their place of origin, establish a 
 resemblance with the spinal nerves. 
 
 § 1849. The trunk of the first cervical nerve passes between the 
 occipital portion of the basilar bone and the transverse process of the 
 atlas, in the lateral groove of the vertebra below the vertebral artery, 
 after forming a very elongated, more or less apparent, and often almost 
 imperceptible ganglion. It divides, as usual, opposite the posterior 
 edge of the atlas into an anterior and a posterior branch. 
 
 The posterior is larger, and proceeds obliquely backward and up- 
 ward, and divides into seven or eight radiating filaments which go to 
 the obliquus capitis minor, the obliquus capitis major, the rectus 
 capitis major and minor, and the complexus muscles. Some pene- 
 trate within the mastoid process. 
 
 The anterior is smaller, goes first from behind forward along the 
 vertebral artery to the place where this vessel leaves the vertebral 
 canal, it then immediately ascends between the transverse process of 
 
 (1) Vicq-d’Azyr, loc. cit., p. 296. 
 
36 
 
 DESCRIPTIVE ANATOMY. 
 
 the atlas and the mastoid process. It then divides into four or five 
 branches. 
 
 The first turns around on the transverse process of the atlas, pro- 
 ceeding from above downward, and anastomoses with one or two as- 
 cending filaments of the anterior branch of the second pair. It gives 
 off some filaments which unite with the pneumo-gastric, the hypo- 
 glossal, and the great sympathetic nerve. 
 
 The second goes to the temporalis muscle. 
 
 The third enters the vertebral canal, is distributed to the vertebral 
 artery, and sends filaments to the second cervical nerve. 
 
 The fourth and fifth arise before the transverse process of the first 
 cervical vertebra, and are distributed in the rectus capitis major and 
 minor muscles. 
 
 The peculiarity in the distribution of this nerve, is, that being situ- 
 ated very deeply, it sends off filaments only to these muscles and these 
 vessels, and does not extend to the skin. 
 
 CHAPTER II. 
 
 ENCEPHALIC NERVES. 
 
 § 1850. The following are usually mentioned as general characters 
 of the encephalic nerves(l) to distinguish them from the spinal nerves. 
 
 1st. They arise by a single root. 
 
 2d. On leaving the dura-mater they do not produce any special 
 ganglion without the concurrence of another nerve. 
 
 3d. They pass through foramina in the bones of the skull, or through 
 very irregular fissures formed in them. 
 
 4th. They expand in parts other than the muscles of the skin, par- 
 ticularly in the organs of sense and the viscera. (2) 
 
 But of all these characters only the first is with difficulty of general 
 application. The fifth pair is an exception to the second, as its semi- 
 lunar ganglion is formed without the concurrence of any other nerve : 
 we can even to a certain extent mention the olfactory nerve in this 
 respect. The glosso-pharyngeal and the pneumo-gastric with the ac- 
 cessory nerve, also produce a considerable ganglion shortly after 
 leaving the cranium. In fact , these latter unite to give rise to the 
 ganglion : but first, the anomaty resulting from it disappears, when it 
 is considered that these three nerves should be regarded as forming but 
 one : second, almost all the cervical nerves anastomose with each 
 
 (1) J. D. Santorini, Obs. anat ., cap. iii. — A. Bergen, Dé nereis quibusdam cranii 
 ad novem paria hactenus nun rélalis, Erfort, 1738.' — Morgagni, Ep. anal., xvi. — 
 Sœmmerring, De basi cncephali et originibus nervorum e cranio egredienlium , 
 Gottingen, 1778.— Id., Tabula baseos encepliali , Francfort, 1799. — Stieck, De quin- 
 que prioribus encepliali nereis , Gottingen, 1791. 
 
 (2) Huber, De medulla spinali, Gottingen, 1741, p. 8, 9. — Ascii, De primo pare 
 mcdullœ spinalis, Gottingen, 1750, §xxvii. 
 
OF THE NERVOU-S SYSTEM. 
 
 37 
 
 other within the dura-mater by intermediate filaments, before that 
 each produces its ganglion. As to the third character, it does not 
 depend on the nerves, but only on the difference in the size and con- 
 nections of the bones of the skull and the vertebrae. Besides, it is not 
 so exclusive as has been asserted, since we not only sometimes find 
 an opening in the first cervical vertebra for the first cervical nerve, but 
 also the sacral nerves constantly pass through the foramina of a bone 
 originally composed of several pieces immoveably articulated to- 
 gether. In animals we find foramina for the passage of the corres- 
 ponding cervical nerves, not only in the first cervical vertebra, in all 
 the mammalia except some apes, but also in the second, but even in 
 several of the following in some of these animals, particularly the 
 hog. 
 
 The insufficiency of the latter character seems no less evident when 
 we consider, first, that the spinal nerves necessarily cannot go to 
 parts which are not yet formed : second, that the lumbar and sacral 
 nerves are distributed to the genital and urinary organs, and also to 
 the latter portion of the intestinal canal. 
 
 It follows then that the distinction between the spinal and the ence- 
 phalic nerves is not so well marked as we should be tempted to think 
 at first view, and from the assertions of anatomists. Far from it : we 
 shall demonstrate that it is very easy to refer the second to the first, 
 and to show that they are both constructed after the same type. 
 
 § 1851. We have already mentioned the principal differences in 
 authors in respect to the number of the encephalic pairs they establish, 
 and demonstrated that they depend on the different manner of bounding 
 the different portions of the centre of the nervous system. But there 
 are others depending on the fact, that some cerebral nerves have been 
 regarded sometimes as distinct pairs, sometimes only as portions of 
 pairs. . 
 
 The old anatomists followed the first course, while the moderns, 
 adopting the second, have increased the number of cerebral pairs, 
 which has gradually risen from seven to twelve, and even according 
 to Malacarne,(l) to fifteen.(2) 
 
 The twelve cerebral nerves most generally admitted now, are, pro- 
 ceeding from behind forward, 1st, the sublingual ; 2d, the accessory ; 
 3d, the pneumo- gastric ; 4th, the glosso-pharyngœal ; 5th, the facial ; 
 6th, the auditory ; 7th, the external or posterior motor ; 8th, the trifa- 
 cial : 9th, the internal or superior motor ; 10th, the common motor ; 
 11th, the optic ; 12th, the olfactory nerve. 
 
 The reasons for admitting a smaller number of nerves are, first, the 
 olfactory nerve was long considered, till the time of Massa, not as a 
 nerve, but as a portion of the cerebrum : second, till the time of Achil- 
 lini, the common external motor nerve of the eye was considered 
 as part of the fifth : third, the auditory and the facial nerves have been 
 
 (1) Neuro -encephalotarnia, Pavia, 1791. 
 
 (2) Malacarne numbers, properly speaking', seventeen ; but the seventeenth is the 
 posterior root of the suboccipital nerve, and the eleventh the sympathetic nerve. 
 
 Vol. Ill 6 
 
38 
 
 DESCRIPTIVE ANATOMY. 
 
 considered as one till the time of Sœmmeriing ; fourth and fifth, 
 till the time of Andersch, the glosso-pharyngceal and the accessory- 
 nerves have been considered only as portions of the pneumo-gastric 
 nerve. Certain anatomists, however, and even before the preceding 
 division was established by Scemmerring’s publication, had considered 
 a greater or less number of the nerves mentioned, as distinct pairs. 
 
 Malacarne states the number of the encephalic nerves to be fifteen : 
 first and second, by admitting an accessory nerve to the common motor 
 and to the superior motor nerve ; third and fourth, by considering the 
 three branches of the trifacial as so many distinct nerves, which would 
 make sixteen pairs, if instead of distinguishing the glosso-pharyngceal, 
 it had not been united to the pneumo-gastric nerve. But this method 
 is very objectionable, for even when Malacarne had cause to admit his 
 accessory nerves to the motors, he could regard them only as the roots 
 of these latter, to the trunks of which they unite : second, the three 
 branches of the trifacial nerve arise by a common nervous trunk : third, 
 the glosso-pharyngceal nerve deserves to be separated from the adja- 
 cent nerves, and considered as a distinct pair more than any which 
 Malacarne insulates. 
 
 Farther, we shall have occasion hereafter to show that it would be 
 more convenient to diminish than to increase the number of cerebral 
 nerves, but at present we shall follow the common division. 
 
 The principle of the nomenclature of the nerves is not the same in 
 all. Formerly the respective situation of their origin was taken for 
 them, and they were numbered from before backward. Still later 
 this method was preserved, but names drawn from their distribu- 
 tion and their uses were applied. This latter mode is undoubtedly the 
 best, and we follow it much more willingly, because the first does not 
 entirely agree with our mode of considering the nerves, commencing 
 at the spinal marrow. 
 
 § 1852 The cerebral nerves of man differ considerably in respect to 
 volume, form, and origin. 
 
 1st. Volume. The cerebral nerves generally diminish in size in the 
 following older;, the trifacial, the optic, the olfactory, the auditory, the 
 common motor, the pneumo-gastric, the glosso-pharyngceal, the facial, 
 the external motor, the accessory, the hypoglossal, and the superior 
 motor. 
 
 Form. Here we may consider, 
 
 1st. The shape. Most of these nerves are round; the external motor 
 however is slightly flattened, and the olfactory is triangular. 
 
 2d. Texture. Almost all are fibrous from their origin ; in the olfactory 
 nerve alone there are no distinct fibres. In some, the fibres continue 
 separate longer than in others, and they are the more so, the more pos- 
 terior the origin of the nerves. They generally unite in fasciculi of 
 various sizes before they blend in one trunk. These fasciculi are more 
 numorous, and are more similar in size the more posteriorly the nerves 
 are situated. The two anterior nerves form only one trunk on leaving 
 the cerebrum. 
 
OF THE NERVOUS SYSTEM. 
 
 39 
 
 We must mention here the differences in their substance and solidity. 
 The eleven posterior cerebral nerves are composed, like the spinal 
 nerves, of white substance ; the olfactory, on the contrary, contains 
 some which is gray. This nerve and the auditory are much softer 
 than the others. 
 
 3d. Origin. In this respect, 
 
 a. The cerebral nerves succeed each other from behind forward. 
 
 b. All arise from the inferior part of the cerebrum. Some, particu- 
 larly the hypoglossal, the accessory, the pneumo-gastric, the glosso- 
 pharyngeal, the posterior motor, the trifacial, the common motor, and 
 the olfactory, come from its lower face. The others arise more or less 
 from its upper face. 
 
 c. The origins of some, as the trifacial and the common motor, are 
 deeply concealed in the substance of the parts of the cerebrum from 
 the surface of which they emerge-. On the contrary, most of the others 
 cannot be traced beyond the surface. 
 
 4th. Direction and progress. All go forward ; but they differ from 
 each other in this respect, that the direction of the posterior ten is for- 
 ward and outward, while the optic nerve proceeds forward and inward 
 at its posterior part, unites with that of the opposite side, and does not 
 go outward till after this union. The course of the olfactory nerve 
 is obliquely inward and forward. 
 
 I. HYPOGLOSSAL NERVE. 
 
 § 1853. The hypoglossal nerve, hyoglossien, Ch. the ninth cerebral 
 pair, the tivelfth of the usual method ( JV. lingualis médius , Haller ; 
 gustalorius , Winslow ; lingualis, Vicq-d’Azyr ; hypoglossus , Wins- 
 low),^) arises from the anterior face of the medulla oblongata, passes 
 through the anterior condyloid foramen, and is distributed principally 
 to the muscles of the tongue. 
 
 It commences by several fasciculi placed after each other from above 
 downward. These fasciculi, arranged in a single series about half an 
 inch long, describe a curved line, which is convex outward, as the 
 superior and inferior are placed a little farther outward than the central. 
 They come from the groove between the pyramid and the olivary 
 body. The inferior arise below this latter eminence ; the superior 
 begin a little above the centre of the groove. All are situated a little 
 farther outward than the anterior roots of the first cervical nerve, the 
 lowest of which are about two lines distant from above downward. 
 
 The whole series of these fasciculi corresponds with much exact- 
 ness to the origin of the glosso-phaijmgeal, and the pneumogastric 
 nerves, and to that portion of the accessory nerve which arises from the 
 medulla oblongata. 
 
 (1) J. F. G. Bœhmer, De nono pare nervorum cerebri, Gottingen, 1777. — H. F. 
 Kilian, Untersuchung über dus neunte Hirnnervenpaar , Perth, 1822. 
 
40 
 
 DESCRIPTIVE ANATOMY. 
 
 They are always very distinctly separated from each other at their 
 origin, and commence by several radicles, which are themselves gene- 
 rally composed of other smaller radicles. 
 
 They vary in their number and situation. We admit from four to 
 eight of them. They usually succeed each other uninterruptedly, so 
 that the smallest radicles of the different fasciculi touch each other. 
 Sometimes, however, we observe some which are more remote from 
 the others, and even about a line distant from them, so that this ar- 
 rangement divides them into two or three bundles of different sizes. 
 
 These fasciculi reunite in cords which are generally two and some- 
 times three in number, each of which passing through a special open- 
 ing in the dura-mater, proceeds from behind forward, from below up- 
 ward, and from within outward, towards the posterior orifice of the 
 anterior condyloid foramen. They rarely unite in a single trunk 
 before they enter the dura-mater. Sometimes even an osseous septum 
 divides them for the whole extent of the condyloid canal, into at least 
 two halves, which unite only at the external orifice of this canal. 
 
 On leaving the cranium the trunk goes downward, proceeding on 
 the upper part of the condyle, and covered outward in the extent of 
 about an inch, by that of the pneumo-gastric nerve, with which it is 
 generally united by filaments, it passes on the internal carotid artery, 
 and descends from behind forward between the laryngœal branch of 
 the pneumo-gastric and the accessory nerve. 
 
 In this place it unites at first near the summit of the transverse 
 process of the first cervical vertebra forward and upward by a con- 
 siderable filament, with the pneumo-gastric nerve downward and 
 backward, with the first cervical nerve and the great sympathetic 
 nerve by another filament which ascends from the anterior branch of 
 the first, and from the superior cervical ganglion, before which it is 
 situated. It then descends, covered outward by the pneumo-gastric 
 nerve, the posterior belly of the digastricus muscle, the stylo-glossus 
 muscle, and the internal jugular vein, inward by the internal carotid 
 artery, and gives ramifications to the submaxillary gland. When as 
 high as the third cervical vertebra, it passes before the external carotid 
 artery, and forming a large arch, which is convex downward, it goes 
 from behind forward and from below upward, towards the genio-glossus 
 muscle, along the inside of the posterior and inferior hyoid bone. 
 
 At the origin of its arch it gives off a considerable and very con- 
 stant branch, the descending serviced nerve (R. descendons noni ), 
 which goes downward and forward, first along the anterior face of the 
 external carotid artery, where it is intimately united to the trunk of 
 the pneumo-gastric nerve by cellular tissue, then to the inner side of 
 the internal jugular vein, passes above the superior thyroid artery, 
 goes still farther forward on leaving this point, gives off forward and 
 inward a branch which terminates in the anterior belly of the omo- 
 hyoideus muscle, sends others to the muscles of the larynx, and again 
 uniting in the middle of the neck with the descending nerve which 
 comes from the anterior branches of the second and third cervical 
 
OF THE NERVOUS SYSTEM. 
 
 41 
 
 nerves, thus forms an arch, the convexity of which is well marked and 
 turned forward. 
 
 The convexity of this arch usually gives rise to two branches, which 
 descend along the anterior side of the internal jugular vein. The 
 superior is smaller, and retrogrades to go to the anterior belly of the 
 omo-hyoideus muscle. The inferior is larger, passes under the anterior 
 belly of this muscle, goes downward and forward to the external face 
 of the sterno-thyroideus muscle, distributes several filaments in this 
 muscle and the sterno-hyoideus muscle, and anastomoses in this place 
 by a small but constant filament, with the diaphragmatic nerve. Some 
 ramifications of this branch enter the chest, particularly on the left 
 side, and extend to the upper part of the pericardium. 
 
 The trunk of the hypoglossal nerve immediately gives off some 
 branches which go downward into the thyro-hyoideus muscle. Thence 
 it rises again, first below the tendon of the digastricus muscle, then on 
 the external face of the hyoglossus muscle, gives filaments, of which 
 the upper anastomose frequently from its upper and lower parts, but 
 principally from this latter to the muscles of the larynx, then to the 
 hyoglossus, to the genio-hyoideus, and to the genio-glossus muscle, 
 unites with the lingual nerve of the third branch of the trifacial in the 
 upper and anterior part of the hyoglossus muscle, by two or three con- 
 siderable filaments, and afterwards extends almost to the point of the 
 tongue by ramifications which proceed between the fibres of the hyo- 
 glossus muscle. 
 
 At the body of the hyoid bone the trunk of the nerve turns on the 
 lingual artery,, and enters the genio-glossus muscle, in which it ter- 
 minates by branches, some of which go to the lower face of the point 
 of the tongue. 
 
 We cannot follow the filaments of the hypoglossal nerve into the 
 integuments of the tongue ; they stop in the muscles of this organ. 
 From this circumstance we might deduce the very probable conclusion 
 that it serves only to excite the motions of the muscles, and that it is 
 not the proper gustatory nerve, although it communicates by very 
 large anastomoses with the lingual branch of the trifacial nerve, the 
 ramifications of which penetrate distinctly into the integuments of the 
 tongue. Another circumstance gives more weight to this conjecture, 
 viz. the analogy between it and the motory nerves of the other organs 
 of the senses which receive both nerves of sensation and of motion. 
 That these two orders of nerves fulfill different functions, is demon- 
 strated by the observation, that alterations, the primitive or accidental 
 destruction of one of them, is attended only with the loss of one of the 
 two faculties of the tongue, that of the taste when the affection is 
 situated in the lingual branch of the trifacial nerve, and that of motility 
 when the hypoglossal nerve is affected.(l) The loss of taste in one 
 
 (1) The sense of taste is lost in trisma, but the levator muscles of the lower jaw 
 receive their nerves from the fifth pair and not from the hypoglossal nerve (HaÜer, 
 El.phys ., vol. v. p. 112). The congenital absence of taste has been observed in a 
 patient where the lingual branch went to the occiput and not to the tongue (Colombo, 
 De re anat., Paris, 1762, p. 486.) 
 
42 
 
 DESCRIPTIVE ANATOMY. 
 
 case where the hypoglossal nerve was injured(l) even when this 
 lesion would not have been admitted as probable, would not prove 
 that the two nerves concurred in the function of taste, for on one side 
 the lesion might produce this effect only from the connections between 
 the two nerves ; and secondly a case cited by Heuermann would 
 farther prove that it cannot be admitted, since on account of the distri- 
 bution of the hypoglossal nerve and of the lingual branch of the 
 trifacial nerve, the hypoglossal nerve could not alone be the nerve of 
 taste, as should be concluded from this fact, considered as a peremp- 
 tory argument in favor of the power attributed by the author to the 
 nervous trunk supposed to be injured. 
 
 But the difference of function between the two nerves is not proved 
 by the cases where the loss of the motion of the tongue without that 
 of taste, or the loss of taste without that of the motion of the tongue(2) 
 in general, have been observed, since the same phenomenon is seen 
 in other parts which receive only one nerve, and which cannot conse- 
 quently be explained in the same manner. 
 
 II. ACCESSORY NERVE. 
 
 § 1854. The accessory nerve, (3) trachelo dorsal , Ch. (JY. spinalis 
 ad par vagum accessorius , accessorius Willisii),(4) arises by numerous 
 filaments from the posterior part of the lateral face of the posterior cord 
 of the spinal marrow, ascends between the posterior roots of the upper 
 six cervical nerves and the ligamentum denticulatum, nearer the for- 
 mer than the latter, consequently also nearer the posterior than the 
 anterior roots of the cervical nerves, penetrates into the skull through 
 the occipital foramen behind the vertebral artery, receives some fila- 
 ments from the latter parts of the medulla oblongata, is situated below 
 near the pneumo -gastric nerve, with which it emerges from the skull 
 through the posterior foramen lacerum, and is distributed partly in 
 the upper region of the pharynx, partly also in some muscles of the 
 back. 
 
 Its lowest and smallest root usually arises at the height of the supe- 
 rior filament of the posterior roots of the seventh cervical pair ; the 
 second at that of the upper part of the posterior root of the fifth ; the 
 third and fourth at that of the upper part of the fourth ; the fifth oppo- 
 site that of the third ; the sixth between the second and third ; and the 
 seventh opposite the posterior root of the second. Many of these roots 
 
 (1) Heuermann, .Physiologie, vol. ii. p.295. 
 
 (2) Sœmmerring, Nervenlehre, p. 262. — Scarpa, Tab. neurol., Pavia, 1794, p. 
 16-17. Two cases. 
 
 (3) Often termed the accessory nerve of Willis , but wrongly, as it had previously 
 been figured by Eustachius and described by Coiter. 
 
 (4) J. P. Lobstein, De nervo spinali ad par vagum accessorio, Strasburg, 1760. — 
 A. Scarpa, Uber den zum achten Paare der Gehirnnerven hinlaufenden Beinerven 
 des Rückenmarncs ; in the Abhandl. der Josephsakad, vol. i. p. 385. — Its origin has 
 been described perfectly by Huber, De medulla spinali , specialim de nervis ab eâ 
 provenientibus, Gottingen, 1741, § vii-xi. 
 
OF THE NERVOUS SYSTEM. 
 
 43 
 
 sometimes communicate in one or several points with the anastomotic 
 filaments of the middle and superior cervical pairs. 
 
 Usually no root of the accessory nerve arises from a higher point of 
 the spinal marrow. 
 
 Sometimes, however, the whole posterior root of the first cervical 
 nerve joins it and forms with it a small ganglion. But this ganglion 
 is not constant when the nerves unite, and we should even think it 
 extremely rare, since it has never been observed by Haller, Ash, 
 Lobstein, and Scarpa, who have remarked only a slight thickening of 
 the nerve. (1) We have never seen it but a few times, notwithstanding 
 our numerous researches. 
 
 Three or four roots generally arise within the skull from the lateral 
 face of the posterior cord of the medulla oblongata ; these are behind 
 the roots of the hypoglossal nerve. 
 
 These ten or eleven roots gradually become longer and thicker 
 from below upward, and go towards the trunk of the nerve at angles 
 which are more acute the lower their origins. The lowest is in great 
 part concealed in the pia-mater, through which it only penetrates. 
 The spinal roots also are usually single, while those arising from the 
 medulla oblongata are generally composed of two short radicles united 
 at an acute angle, each of which is formed by three or four filaments. 
 These radicles, one of which is superior, the other inferior, and the se- 
 cond of which ascends in a more perpendicular direction, soon reunite. 
 In considering the whole series of roots, we recognize that they gra- 
 dually become more anterior from below upward. 
 
 The nerve enlarges as it ascends, goes imperceptibly outward, and 
 is attached above by short filaments to the trunk of the pneumo-gastric 
 nerve. 
 
 The accessory nerve never arises lower than the point indicated. 
 On the contrary it often commences higher, opposite the sixth cervical 
 vertebra, sometimes even but more rarely opposite the fifth. In some 
 subjects it receives from the spinal marrow only two or three roots, 
 which are then proportionally thicker. 
 
 The number of the filaments from the medulla oblongata is some- 
 times less than we have mentioned : it is rarely and perhaps never 
 greater. Sometimes they resemble by being single those which arise 
 from the spinal marrow. 
 
 So likewise the accessory nerve does not always arise exactly in the 
 same place. 
 
 It is very rarely united by a filament with the posterior root of the 
 second cervical nerve. (2) 
 
 It does not anastomose with the hypoglossal nerve within the 
 skull. (3) 
 
 (1) Scarpa, loc. cit., p. 396. 
 
 (2) Scarpa, loc. cit., p. 395. This anatomist has observed this union only twice in 
 his numerous dissections We have found it only once. 
 
 (3) Scarpa, loc. cit., p. 397, does not admit this assertion of Winslow. We have 
 never seen the anastomosis mentioned by this latter. 
 
44 
 
 DESCRIPTIVE ANATOMY. 
 
 It generally passes through the dura-mater in connection with the 
 pneumo-gastric nerve : but sometimes also it emerges through a spe- 
 cial opening behind the latter, with which however it reunites. 
 
 All these differences are observed not only in different persons, but 
 frequently in the same person on different sides of the body. 
 
 In passing through the dura-mater the accessory nerve is inclosed in 
 a sheath with the pneumo-gastric nerve ; but before emerging through 
 the posterior foramen lacer um it divides into an internal and an ex- 
 ternal branch. 
 
 The internal branch gives off first two branches which unite with 
 each other and with a third which descends from the pneumo-gastric 
 nerve, and produces the superior pharyngœal nerve. It then receives 
 some filaments from the pneumo-gastric nerve, sometimes communi- 
 cates with the hypoglossal nerve, then reunites with the trunk of the 
 pneumo-gastric nerve to form a ganglion. 
 
 The external branch proceeds for about two inches descending 
 deeply behind the internal jugular vein, at first between this vessel and 
 the occipital artery, then between it and the sterno-cleido-mastoideus 
 muscle. It turns a little on this muscle and goes forward, sometimes 
 passes through it, gives to it filaments which anastomose with those 
 of the third cervical nerve, then continues to descend but from before 
 backward, passing on the internal jugular vein, enlarges considerably 
 by uniting with two anastomosing branches, the upper of which arises 
 from the anterior branch of the second' cervical nerve and the lower 
 from that of the third, passes on the levator anguli scapulae muscle, 
 anastomoses with the ramifications of the fourth and fifth cervical 
 nerves, and comes to the internal face of the trapezius, in which it is 
 distributed. No other muscles receive filaments from it. 
 
 III. PNEUMO-GASTRIC NERVE. 
 
 § 1855. The pneumo-gastric , the par vagum , the middle sympa- 
 thetic, the pulmonary , the vocal nerve, the eighth, or according to the 
 new calculation, the tenth pair (JV. pneumo gastricus, Chaussier ; JV. 
 vagus, JY. sympathicus médius, Winslow; JV. pulmonalis , Bartels ;(1) 
 par octavum, Willis ;(2) decimum, Andersch),(3) arises from the 
 side of the posterior prolongation of the cerebellum between the acces- 
 sory and the glosso-pharyngœal nerves, emerges from the skull 
 through the posterior foramen lacerum, and descending is distributed 
 
 (1) Respiration , p. 210. 
 
 (2) This term, however, includes the following' or the glosso-pharyngeal nerve. 
 
 (3) Neubauer, Descript, nerv. cardiac. — Andcrsch, in the Nov. comm. Gott. vol. ii. 
 published in Haase, Cerebri nervorumque anal., Leipsic, 1781, and in Ludwig, 
 Script, neural, min. vol. ii. — Walter, De nerv, abdom., Berlin, 1800.— Wrisberg, Da 
 gonglio plexuque semilunari, &c. sect, ii., De pari octavo ; in the same Comment. 
 vol. i. 1800. — Scarpa, Tab. neurolog., Pavia, 1794. 
 
OP THE NERVOUS SYSTEM, 
 
 45 
 
 in the upper part of the alimentary canal, the stomach ; second in the 
 organs of respiration ; hence the term pneumo-gastric. 
 
 § 1856, It arises by from ten to sixteen filaments from the lower 
 part of the lateral face of the posterior prolongations of the cerebellum. 
 The inférior are situated far behind the anterior, and form a series 
 which is generally single and five or six lines long. Sometimes, how- 
 ever, several are more anterior than the others ;(1) this is particularly 
 the case with those at the top of the series, although there is no dis- 
 position indicating any tendency to produce distinct roots. On the 
 contrary, in this formation the pneumo-gastric nerve is similar to 
 the formation of the anterior cerebral nerves, as its origin is thus more 
 rounded, which form is remarkable in several of the mammalia, parti- 
 cularly the ruminantia. These filaments arise principally towards the 
 anterior and inferior edge of the posterior prolongation of the cerebel- 
 lum, in the groove between this prolongation and the olivary body. 
 They do not extend so high as this latter, and terminate below long 
 before those of the hypoglossal nerve. Some of them frequently anas- 
 tomose with the transverse medullary striae on the floor of the calamus 
 scriptorius, and hence these striae seem to concur in their formation. (3) 
 Others, particularly some of the inferior, come from the lower extremity 
 of the olivary body. (4) 
 
 These filaments are generally single, and not cleft at their internal 
 part. They are sometimes separated and sometimes united from their 
 origin in three or four fasciculi. The inferior are commonly very inti- 
 mately connected with the accessory nerve. The superior most gene- 
 rally communicate by a transverse filament with the glosso-pharyngceal 
 nerve even within the skull. 
 
 These filaments and fasciculi unite in a flattened trunk about one 
 line and a half broad, one quarter or one fifth of a line thick, and al- 
 ways larger at its upper part where they are interlaced with each 
 other. This trunk goes outward and backward. It is inclosed in a 
 small canal of the dura-mater, through which it comes from the cranium, 
 through the anterior part of the foramen lacerum, before the origin of 
 the internal jugular vein. It is separated from this vein by a promi- 
 nence of bone which comes from the petrous portion of the temporal 
 bone or from the occipital bone, or from both, and from the accessory 
 and the glosso-pharyngceal nerves by the dura-mater. 
 
 The fasciculi hitherto distinct do not entirely unite in a rounded 
 cord except within this canal. The rounded cord on leaving the fora- 
 men lacerum is united very intimately by mucous tissue with the 
 
 (1) Coopmans, Neurol., p. 118. — Soemmerringr, p. 102. 
 
 (2) Santorini, Septemdecim tabulae , p. 27. — Girardi, ibid.— Vicq-d’Azyr, in the 
 Mém. de Paris , 1784, p. 594. 
 
 (3) Desmoulins, Sur le rapport qui unit le développement du nerf pneumogas- 
 trique à celui des parois du quatrième ventricule ; in the Journ. de phys. expérimen- 
 tale, vol. iii., p. 362. 
 
 (4) Vicq-d’Azyr, loc. cit., p. 594. 
 
46 
 
 DESCRIPTIVE ANATOMY. 
 
 glosso-pharyngœal nerve, the hypoglossal and the ascending branch of 
 the superior cervical ganglion. It is situated at first behind the glosso- 
 pharyngœal and before the hypoglossal nerve, but it soon passes be- 
 hind this latter, is separated from the glosso-pharyngceal nerve by the 
 internal jugular vein, leaves the hypoglossal nerve on the transverse 
 process of the first cervical vertebra, and descends outward and a little 
 backward before the primitive carotid artery, between it and the in- 
 ternal jugular vein, intimately united to these two vessels by a mucous 
 tissue destitute of fat and more loosely connected to the intermediate 
 filaments of the sympathetic nerve which are situated behind it and 
 placed in the rectus capitis major anticus and the longus colli mus- 
 cles.(l) 
 
 In passing through the foramen lacerum the pneumo-gastric nerve 
 anastomoses by some filaments with the accessory nerve, and shortly 
 after leaving this opening it communicates also with the glosso-pharyn- 
 goeal nerve and the superior cervical ganglion. It then gives off a 
 branch which unites with two filaments from the inner branch of the 
 accessory nerve, and gives rise to the pharyngœal or superior pharyn- 
 gœal nerve (JY. pliaryngœus, s. pliaryngœus superior , s. primus.) 
 
 This nerve goes obliquely from above downward and from without 
 inward on the inside of the internal carotid artery, sends an anasto- 
 mosing filament to the glosso-pharyngœal nerve, bulges a little, and 
 forms at the height of the middle constrictor of the pharynx a consi- 
 derable plexus termed the pharyngœal ( plexus pliaryngœus). This 
 plexus receives filaments from the laryngceal, the glosso-pharyngœal 
 nerves, and from the superior cervical ganglion ; its filaments are dis- 
 tributed principally in the middle constrictor, but some go to the upper 
 constrictor of the pharynx : a few descend along the primitive carotid 
 artery, where they anastomose with the ramifications of the glosso- 
 pharyngœal and the superficial cardiac nerves. 
 
 The inferior pharyngœal nerve (JY. pliaryngœus inferior , s. minor), 
 which also is not constant, arises directly below the superior pharyn- 
 gœal nerve. This nerve soon anastomoses with the preceding, and 
 also with one or several of the anterior filaments of the superior cer- 
 vical ganglion, sends filaments to the pharyngœal plexus, and is dis- 
 tributed in the middle constrictor of the pharynx. 
 
 At the place where the pharyngœal nerves are given off and some- 
 times also a little higher, the trunk of the pneumo-gastric nerve be- 
 comes much thicker and its texture is closer for about an inch : its 
 fasciculi separate very much, and a reddish gelatinous substance is 
 deposited between them. A real ganglionnary plexus then forms. The 
 remnant of the internal branch of the accessory nerve after sending an 
 anastomotic twig to the pharyngœal nerve enters this plexus at about 
 its centre, sometimes in one branch, sometimes also in several filaments 
 which ramify and interlace differently, so that this branch forms the 
 
 (1) J. H. Haase, De nervo phrenico dex'lri lateris duplki par isque vagi per collum 
 decursu, Leipsic, 1790. 
 
OF THE NERVOUS SYSTEM, 
 
 47 
 
 lower part of the plexus, and seems also to belong to the pneumo-gas- 
 trie nerve. 
 
 The trunk of the pneûmo-gastric nerve is in fact directly attached to 
 this ganglion from before backward ; but it is sometimes, although 
 rarely, connected with it only by some filaments of communication. 
 
 A more distinct development of this plexiform dilatation of the nerve 
 occurs when it divides into two portions which unite only at the lower 
 part of the neck ; but such an arrangement is extremely rare : it has 
 been observed only once in five hundred cases, and this was on the 
 right side.(l) 
 
 The superior laryngœal nerve (JY. laryngœus superior ), which is 
 commonly larger than the inferior, usually arises from the upper part 
 of this ganglion. 
 
 This nerve descends between the internal carotid artery and the su- 
 perior cervical ganglion, most generally anastomoses by one or several 
 filaments with this latter, the pharyngeeal plexus, and the hypoglossal 
 nerve, and divides into an external and an internal branch. 
 
 The external goes inward, and sends filaments to the inferior con- 
 strictor muscle of the pharynx, the crico-thyroideus, the sterno-thy- 
 roideus, and the hyo-thyroideus muscles, to the thyroid gland, and to 
 the membrane of the pharynx ; these filaments enter the cavity of the 
 larynx between the cricoid and thyroid cartilages. 
 
 The internal branch passes through the hyo-thyroid membrane be- 
 tween the hyoid bone and the thyroid cartilage. It distributes soft 
 and thick filaments in the membrane and glands of the epiglottis, the 
 mucous membranes of the pharynx and larynx, several small muscles 
 of the larynx, particularly the arytenoideus and the crico-thyroideus, 
 and anastomoses with the filaments of the inferior and recurrent laryn- 
 gœal nerve. 
 
 After the superior laryngœal nerve, we see arise either from the 
 ganglionnary plexus or directly below it some filaments which are not 
 constant ; these unite to the descending branch of the hypoglossal 
 nerve, and also to the first cervical nerve, and to the soft nerves which 
 go to the internal carotid artery. 
 
 After giving off these branches, the trunk of the pneumo-gastric 
 nerve becomes more compact, and descends in the manner mentioned 
 above, but gives off no ramifications. It then represents a cord com- 
 posed of less distinct fasciculi and which is generally uneven by a kind 
 of indentation, but its surface is surrounded here and there by very 
 minute filaments which interlace like a plexus. (2) It gives off about 
 an inch or an inch and a half above the origin of the primitive carotid 
 artery (but an inch higher on the right than on the left side), and 
 at about the centre of the neck, on both sides, the cardiac nerves (R. 
 cardiaci). These descend from within outward and from behind for- 
 
 (1) Wrisberg, De nervis pharyngis ; in Ludwig, toc. cit., vol. iii., p. 57. 
 
 (2) Prochaska, De struc. nerv., tab. ii., fig. 7, 7, ee. — Reil, De struct, nerv., tab. i., 
 fig. 2, 3, 4. 
 
48 
 
 DESCRIPTIVE ANATOMY, 
 
 ward in the carotid artery and the innominata trunk, anastomose with 
 the superficial cardiac nerves, and are distributed to the arch of the 
 aorta. We generally find three or four on the right side, the upper of 
 which is the largest and most constant. There are one or two on the 
 left side. 
 
 The trunk of the pneumo-gastric nerve goes forward, is situated 
 behind the innominata vein, passing on the right before the subclavian 
 artery, on the left before the arch of the aorta, thus comes into the 
 chest, enlarges considerably, and divides into two halves, of which the 
 lower and larger is the continuation of the trunk, and the upper is 
 smaller, and is termed the inferior laryngœal ascending or recurrent 
 nerve, tracheal, Ch. (JV. recurrens , s. adscendens, s. laryngeus in- 
 ferior). 
 
 The two recurrent nerves arise within the chest, the left much 
 lower than that of the right side. They ascend first from before back- 
 ward, then vertically, send some filaments to the cardiac nerves which 
 come from the pneumo-gastric, the middle and inferior cardiac nerves 
 which come from the ganglionnary nerves, form with them a plexus, 
 then turn from before backward, the right on the right subclavian 
 artery, the left on the extremity of the arch of the aorta, and are 
 placed behind the primitive carotid and inferior thyroid artery, between 
 the trachea and the esophagus, and rise to the larynx. In this 
 course they give off first the branches called the superior tracheal 
 nerves (R. tracheales superiores), which descend before the trachea 
 and anastomose with the preceding, arrive at the bronchia and the 
 pulmonary plexus of their side, are distributed in the membrane of the 
 trachea, the pharynx, and the thyroid gland, and communicate with 
 some filaments of the cervical portion of the sympathetic nerve. 
 
 Finally, when as high as the larynx the recurrent nerve is distri- 
 buted in the inferior constrictor of the pharynx and the cricoarytenoid 
 muscles, enters the cavity of the larynx between the cricoid and 
 thyroid cartilages, and terminates in the thyroid cartilage, the arytenoid 
 muscle, and the mucous membrane of the larynx, by anastomosing 
 by several branches with the superior laryngœal nerve. 
 
 The recurrent nerve is sometimes double, but this is rare, and when 
 it occurs it is always on the right side, if we judge from observations 
 made hitherto. The unusual nerve is smaller than the other, and 
 arises from the trunk some lines below it, turns like it on the sub- 
 clavian artery, ascends between the esophagus and the trachea, anas- 
 tomoses by a large twig with the normal recurrent nerve, and is dis- 
 tributed with the latter.(l) 
 
 This anomaly seems to indicate an effort to establish a perfect simi- 
 larity between the right and left sides, since the recurrent nerve 
 always arises lower than that of the right side. 
 
 It is very probable that the recurrent nerve results from the plexi- 
 form division of the trunk of the pneumo-gastric, and that its existence 
 
 (1) Wrisberg'j De nervis abdominis, Gottingen, 1780. 
 
OF THF NERVOUS SYSTEM. 
 
 49 
 
 is connected with the primitive shortness of the neck, since the larynx 
 is much nearer its origin in the early periods of life than subsequently. 
 This hypothesis would explain its arrangement in the same manner 
 as the high origin and long course of the spermatic vessels. Farther, 
 it is impossible to deny the analogy between the distribution of the 
 nerves and vessels in this region of the body, since the superior and 
 inferior laryngoeal nerves and the superior and inferior thyroid arteries 
 manifestly correspond. 
 
 § 1857. The trunk of the pneumo-gastric nerve having given off 
 the recurrent nerve, goes backward on the posterior face of the trachea. 
 
 There it supplies first five or six inferior tracheal nerves ( V. tra- 
 chéales inferiores ), some of which proceed before, others behind the 
 trachea. The former anastomose with the filaments of the superior 
 tracheal nerves and with others coming from the inferior cervical 
 ganglion. Some descend before on the ramifications of the bronchiæ 
 and of the pulmonary artery. Others enter the muscular and mucous 
 tunics of the trachea, bronchia, and esophagus, and terminate in the 
 pulmonary plexus {plexus pulmonalis ) . 
 
 This plexus commences directly above the bronchia of each side. 
 It is formed principally by the fasciculi of the trunk of the pneumo- 
 gastric nerve, between which there is a very vascular mucous tissue. 
 It extends behind the bronchiæ into the substance of the lungs, 
 surrounding the finest ramifications of the bronchial tree, to the mus- 
 cular tunic, and even to the mucous membrane to which it sends fila- 
 ments. Beside the trunk of the pneumo-gastric nerve which develops 
 itself to give rise to it, it also receives some filaments which are less 
 numerous, from the superior thoracic and from the inferior cervical 
 ganglion of the great sympathetic nerve. 
 
 Five or six fasciculi on the right side and only two or three on the 
 left, arise from the lower part of each of these two pulmonary plexuses. 
 These fasciculi are first situated very far from each other, but fre- 
 quently anastomose by intermediate filaments. After passing some 
 lines they unite on each side in a cord, which is the continuation of 
 the trunk of the pneumo-gastric nerve, and the right of which is larger 
 than the left. These cords descend, that of the left before, that of the 
 right behind, and at the side of the esophagus. 
 
 In their course they frequently anastomose principally by anterior 
 filaments which descend from the right cord, send filaments to the 
 esophagus, and others which are smaller to the aorta, and enter the 
 abdomen with the esophagus, passing through the esopahgœan fissure 
 of the diaphragm. 
 
 The pneumo-gastric nerve terminates in the stomach. That of the 
 right side which is the largest, goes to the right portion and the pos- 
 terior face of the viscus ; that of the left side is distributed in its left 
 part and on its anterior face. 
 
 The right forms around the cardiac orifice a large plexus, from 
 which numerous filaments arise, some of which are distributed to the 
 posterior face of the stomach ; others situated behind the coronary 
 
50 
 
 DESCRIPTIVE ANATOMY. 
 
 artery of the stomach, proceed along its small curve to the pylorus, 
 and there anastomose with those of the left nerve and with the superior 
 gastric plexus of the great sympathetic nerve : finally, some which do 
 not belong to the stomach pass behind it, arrive at the right portion of 
 the solar plexus and also the plexuses which come from this latter on 
 the right side, and are distributed to the hepatic artery and its branches, 
 to the vena-portæ, the duodenum, and the pancreas. 
 
 The left divides at the cardiac orifice into several branches which 
 separate in rays, communicate less frequently, follow the small curve 
 of the stomach from left to right, send ramifications to the anterior face 
 of this viscus, anastomose near the pylorus with the filaments of the 
 right pneumo-gastric nerve, and leaving the stomach, terminate anteri- 
 orly before the pylorus, in the hepatic plexus formed by the ganglion- 
 nary nerve. 
 
 IV. GLOSSO-PHARYNGŒAL NERVE. 
 
 § 1858. The glosso-pharyngceal nerve (N. glosso-pharyngœus, Hal- 
 ler; s. lingtiulis pnewnogastrici, Vicq-d’Azyr; s. octavus, Andersch), 
 has been considered until lately as the anterior part of the pneumo- 
 gastric nerve. In fact, if we regard its origin, the communications 
 between it and this nerve, both, within the skull and at its passage 
 through the posterior foramen laeerum, finally the manner in which it 
 is distributed, we discover that it really forms a part of the pneumo- 
 gastric nerve, but it is so largely developed that it may be considered a 
 proper and distinct nerve. It arises by five or six filaments, which 
 may be easily separated from each other, and the anterior of which are 
 generally smaller than the posterior. It arises between the pneumo- 
 gastric and facial nerves, some distance behind the latter, but directly 
 before the upper filaments of the first, from which its own cannot be 
 separated. It comes from the upper part of the lower face of the 
 inferior prolongation of the cerebellum, from the depression between 
 this cord, the olivary bodies, and the posterior edge of the annular pro- 
 tuberance, directly behind the latter, from which several of its filaments 
 sometimes emanate. It goes outward and at first a little forward, covered 
 by the fourth lobe of the cerebellum, usually anastomoses within the 
 skull by a large branch with the pneumo-gastric nerve,(l) and after 
 proceeding five or six lines, passes through the arachnoid membrane. 
 It is round and about a half or three quarters of a line thick, and 
 emerges from the skull through the anterior part of the posterior fora- 
 men laeerum, directly before the pneumo-gastric nerve, but inclosed in 
 a special canal of the dura-mater. About four or six lines from its 
 entrance into this canal, it becomes a small, oblong, rounded, and gene- 
 rally very distinct ganglion about five lines long, which extends into 
 the canal of the dura-mater and the anterior part of the foramen 
 laeerum. 
 
 (1) Anderscli, F'ragm. descripl. nerv. cardiac., in Ludwig, loo. cit., vol. ii. p. 115. 
 
OF THE NERVOUS SYSTEM, 
 
 51 
 
 This ganglion gives off, above, a filament, which enters into the 
 cavity of the tympanum, and then divides into two branches ; one 
 ascends along the promontory, gives off a small filament to the mem- 
 brane of the foramen rotundum, and passes through the petrous por- 
 tion of the temporal bone to the superficial temporal nerve, and the 
 other passes below the osseous portion of the Eustachian tube, and 
 goes to the carotid canal, where it anastomoses with the great sym- 
 pathetic nerve.(l) 
 
 The ganglion also gives off other filaments, which passthrough the 
 canal of the dura-mater to go to the trunk of the pneumo-gastric, to 
 the accessory, and the great sympathetic nerves. 
 
 After emerging from the posterior foramen lacerum, 'the glosso- 
 pharyngeal nerve is separated from the pneumo-gastric trunk by the 
 internal jugular vein, before which it is situated. Thence it goes 
 downward and forward, passing on the internal carotid artery, descends 
 situated at first closely on the outside, then on the anterior part of this 
 artery, between it, the external carotid artery, and the stylo- pharyngceus 
 muscle, passes between this muscle and the glosso-pharyngceus muscle, 
 then between this latter and the hyoglossus, and thus comes to the 
 lower and posterior part of the tongue. 
 
 On leaving the skull it sends a filament of anastomosis to the stylo- 
 hyoid branch or to the digastric branch of the facial nerve and another 
 to the trunk of the pneumo-gastric nerve. It then gives off one or two 
 which descend along the internal and the primitive carotid arteries, 
 anastomose first with the pharyngœal branch of the pneumo-gastric 
 nerve, and then going to the lower part of the neck communicate with 
 some filaments of the sympathetic nerve particularly with the super- 
 ficial or even the middle cardiac nerves. Still farther on, it sends off 
 three or four filaments to the stylo-pharyngeus muscle, and also to the 
 middle and superior constrictors of the pharynx and to the amygdalæ, 
 and some which enter the pharyngœal plexus of the pneumo-gastric 
 and the ganglionnary nerve. 
 
 The glosso-pharyngceal nerve then passes between the styloglossus 
 and hyoglossus muscles ; then situated in the tongue below the 
 lingual nerve of the fifth pair and above the hypoglossal nerve, both 
 larger than it and with which it does not communicate at least by very 
 evident filaments, it is distributed partly in the muscles of the tongue, 
 the membrane of the soft palate and the amygdalæ by several ramifi- 
 cations which interlace like a plexus ; partly in the integuments of the 
 base of the tongue, its large papillæ, and the mucous membrane of the 
 epiglottis by other filaments which are situated lower and nearer the 
 median line than the preceding, and pass from below upward through 
 the substance of the tongue. 
 
 (1) Rosenmuller, Handbuch der Anatomic, 1816. p. 407. — Jacobson, in the Acta reg. 
 societ. Hqfniensis medicæ, vol. v. Copenhagen, 1818. p. 292.— This anastomosis has 
 been doubted by Kilian, but is admitted by Lobstein. 
 
52 
 
 DESCRIPTIVE ANATOMY, 
 
 V. AUDITORY NERVE. 
 
 § 1859. The auditory or acoustic nerve, labyrinthique , Ch., the soft 
 portion of the seventh pair ( JY . auditorius , s. acusticus , s. portio mollis 
 nervi acustici),(l ) is very soft, but harder than the olfactory and the por- 
 tion of the optic nerve behind the decussation ; it generally communicates 
 so evidently with all the white striæ of the floor of the calamus scrip - 
 torms, or at least with several of them, that it may be said to arise 
 partially from it. 
 
 Its upper and external part is formed by these striæ. The fibres 
 connected with it follow one another from before backward and are 
 separated by unequal and inconstant spaces ; they turn on the inferior 
 prolongations of the cerebellum, on the surface of which they are inti- 
 mately connected. Their direction is forward and downward, the 
 anterior proceeding transversely, the posterior obliquely from below 
 upward. 
 
 The inner part of the nerve is larger than the external portion, but 
 they are not separated ; it arises below and farther forward than it from 
 the lateral face of the spinal prolongation of the cerebellum, directly 
 before and above the glosso-pliaryngœal nerve and the upper part of 
 the pneumo-gastric nerve. 
 
 The trunk of the nerve then goes forward, outward and downward 
 on the posterior edge of the transverse prolongation of the cerebellum, 
 and is united to its upper face so intimately for about three lines, that it 
 may properly be considered as arising from this part of the encephalon. 
 It is slightly covered outward by the fourth lobe of the cerebellum, being 
 often attached in this place to its medullary substance, so that we may 
 admit also that it partially arises there, which is worthy of note but 
 not astonishing, on account of the analogy resulting from it with what 
 is seen in the other two nerves, the optic and olfactory, which are only 
 nerves of sense. 
 
 Its internal face is grooved lengthwise, and receives the facial nerve. 
 It is soft at its origin, and we do not perceive there distinct fibres, but 
 on leaving the encephalon it evidently becomes fibrous and still more 
 solid. 
 
 On leaving its origin the auditory nerve goes obliquely forward, 
 outward, and upward, and soon penetrates the internal auditory fora- 
 men, which is much larger than it. It then divides into two branches, 
 which continue united externally to its base ; the anterior enters the 
 cochlea and the posterior , the vestibule and the semicircular canals. 
 We shall describe these branches when speaking of the ear. 
 
 (1) J. F. Meckel, Obs. anat. sur la glande pineale, sur la cloison transparente et 
 sur Vorigine de la septième paire , in the Mêm. de Berlin , 1765. p. 91—100.— A. 
 Scarpa, De nervo auditorio , in his Anat. disquis. de auditu et otfadu, Pavia, 1789, 
 sect. ii. cap. iii. 
 
OF THE NERVOUS SYSTEM. 
 
 53 
 
 VI. FACIAL NERVE. 
 
 § I860. The facial or small sympathetic nerve, the hard portion of 
 the seventh nerve, the seventh pair, th eseventh cerebral nerve (JV. facialis, 
 s. sympathicus minor , s. communis facili, s. portio dura septimi, s. 
 nervus primus septimi paris, s. par septimum){ 1) is much smaller than 
 the auditory nerve ; it arises by two roots which are generally distinct, 
 although placed one against the other. One is external and posterior, 
 the other much larger is internal and anterior. It arises within, below, 
 and before the auditory nerve, which receives it in a groove situated 
 along its internal face, directly at the side of this nerve and before the 
 glosso-pharyngæal nerve. It arises from the posterior edge of the 
 annular protuberance, from the uppermost part of the lower face of the 
 rachidian prolongation of the cerebellum ; sometimes, also, according 
 to Malacarne, by several filaments from the floor of the fourth Ven- 
 tricle, that is, from the most anterior transverse medullary striae. The 
 filaments from the annular protuberance, particularly the internal, seem 
 to come only from this tubercle ; but examining them attentively, we 
 see that they are separated from the principal root only by the pos- 
 terior fibres of the protuberance existing between this latter and 
 them.(2) Very possibly, however, from this reason they are in fact 
 separated from the principal root, and first arise from the pons Varolii. 
 The external root of the nerve, which is much smaller than the in- 
 ternal, is always formed of three or four filaments which unite anteri- 
 orly in one or two fasciculi. It is situated between the internal root and 
 the auditory nerve, and some of its filaments frequently seem, at least 
 in situation, to belong to the auditory nerve rather than to it. 
 
 The nerve leaves the annular protuberance at about the centre of 
 the space between the anterior and posterior edges of this latter, goes 
 forward and outward to arrive at the internal auditory passage, through 
 which it proceeds above and before the auditory nerve to the canal of 
 Fallopius, which it exactly fills, and passes entirely through it. Its 
 direction is consequently first outward and backward, then downward 
 behind and above the cavity of the tympanum, and it emerges through 
 the stylo-mastoid foramen, to be distributed in a considerable portion of 
 the skin and of the muscles of the head. 
 
 In its course along the canal of Fallopius, it gives off first down- 
 ward and forward, a filament which reunites with the superior branch 
 of the recurrent nerve given off by the second branch of the fifth pair, 
 to form the superficial petrous nerve ( JV. petrosus superficialis). 
 
 (1) J. H. Meckel, De quinto pare nervorum cerebri, Gottingen, 1748, for the por- 
 tion of the facial nerve contained in the Fallopian canal. — J. F. Meckel, Dissertation, 
 anatomique sur les nerfs de la face, in the Mém. de Berlin, vol. vii. 1752.— See also 
 Bock, Beschreibung des fünf ten Nervenpaares, Leipsic, 1817. tab. i. ii. 
 
 (2) Gall, loc. cit . , p. 206. r 
 
 Yql. III. 
 
 8 
 
DESCRIPTIVE ANATOMY. 
 
 A4 
 
 It then gives off a little downward and outward, behind the cavity 
 of the tympanum, one or several filaments for the muscles of the little 
 bones of the ear. 
 
 A little lower, some distance above the stylo-mastoid foramen, it 
 sends off a considerable branch, the cord of the tympanum ( chorda 
 tympan; ), which descends at first along the trunk, then goes outward 
 and upward, passes through the posterior wall of the cavity of the 
 tympanum, enters this cavity at the side of the pyramid, descends 
 from behind forward between the malleus and incus situated on the 
 former bone : it anastomoses by one or more filaments with the tym- 
 panitic nerves of the fifth pair, but gives no ramification to the mem- 
 brane of the tympanum, leaves the tympanum through the fissure of 
 Glaser, descends on the inside of the ascending branch of the jaw, and 
 gradually becoming thicker, anastomoses at an acute angle with a 
 twig of the lingual branch of the trifacial nerve which meets it. 
 
 It does not seem to us probable, from our dissections, that the 
 superficial petrous nerve and the cord of the tympanum, are only 
 a filament of the fifth pair, which is fitted to the facial nerve, and 
 which does not really anastomose with it,( 1 ) although we consider 
 the lower and prominent portion of the cord of the tympanum, as be- 
 longing to the branch of the trifacial nerve. 
 
 After leaving the stylo-mastoid foramen, the facial nerve gives off 
 the following branches: 
 
 1st. One single or double branch, termed the posterior, inferior , or 
 deep auricular nerve (JV. auricularis posterior , profundus inferior ) , 
 which sends one or more inconstant filaments into the mastoid process, 
 then goes upward and backward and divides into two branches, an 
 anterior and a posterior, the former of which is the larger. 
 
 The posterior, which sometimes forms the first branch of the facial 
 nerve, ascends on the mastoid process, is distributed in the skin which 
 covers it, extends to the occipitalis muscle, to which it distributes fila- 
 ments, and anastomoses with the ramifications of the small occipital 
 nerve. 
 
 The anterior arrives at the lower and posterior part of the cartila- 
 ginous portion of the auditory foramen, and of the external ear, sends 
 some filaments to the skin of this region, and also to the posterior 
 auricular muscle, and passing through the cartilage, is distributed in 
 the integuments of the auditory passage. 
 
 2d. The stylo-hyoid nerve (JY. stylo- hyoidcus) which is distributed 
 partly in the upper portion of the muscles attached to the styloid pro- 
 cess, and the posterior part of the digastricus muscle of the jaw, and 
 partly sends several anastomosing filaments to the upper part of the 
 ganglionnary nerve, and to the middle cutaneous nerve, given off by 
 the third cervical nerve. 
 
 3d. A branch termed the digastric (R. digastricus ), which passes 
 through the posterior belly of the digastricus muscle, and anastomoses 
 
 (1) Cloquet, Tr. d’anat., vol. ii'- p. 610. 
 
OF THE NERVOUS SYSTEM, 
 
 65 
 
 with the ramifications of the glosso-pharyngceal, the pneumo-gastric, 
 and the accessory nerves. 
 
 4th, Sometimes a filament which anastomoses with the posterior 
 twig of the inferior auricular nerve, and with the filaments of the 
 anterior branch of the third and fourth cervical nerves. This filament 
 exists particularly when the inferior auricular nerve is small. 
 
 After giving off these ramifications, the trunk of the facial nerve, 
 passing under the ear, enters the parotid gland from above downward 
 and from behind forward, assumes in this gland a direction which is 
 oblique from below upward, still continuing to go forward, and forms 
 within it a considerable plexus, the parotid 'plexus (plexus par otideus). 
 This plexus i formed by the nerve dividing at the posterior edge of the 
 ascending branch of the jaw, into from two to five branches, which may 
 always be referred to two which vary in direction and distribution. Of 
 these branches, one is superior, the other inferior, and smaller than the 
 former. They anastomose frequently together, and thus form a 
 polygon convex forward, upward and downward, whence arise the 
 other ramifications of the nerve, which are distributed in the 
 6kin of the upper, middle, and lower portions of the face, in that of the 
 upper part of the neck and in most of the muscles of the face. 
 
 Several considerable branches constantly unite posteriorly with this 
 plexus ; they come from the superficial temporal nerves which arise 
 from the third branch of the trifacial nerve, and which turn from be- 
 hind forward on the posterior edge of the ascending branch of the 
 jaw. 
 
 By examining this plexus from above downward and from behind 
 forward, we observe that it gives off some ascending, some anterior, 
 and some descending branches, which frequently anastomose together 
 by intermediate twigs, equally distant from the edge of the parotid 
 
 gland. 
 
 I. ASCENDING BRANCHES. 
 
 § 1861. The ascending branches are the temporal and the malar 
 nerves (JV*. temporales et malares). Chaussier terms them collectively 
 the temporo facial branch. 
 
 a. Temporal nerves. 
 
 § 1862. We find, 
 
 5th, 6th, 7th. Two or three temporal nerves, which give some small 
 filaments to the parotid gland, ascend on the malar bone, anastomose 
 between them with the superficial and deep temporal branches of the 
 submaxillary nerve posteriorly, and with the frontal and lacrymal twigs 
 of the first branch of the trifacial nerve, are distributed on the temporalis 
 muscle, and send ramifications to the skin of the temples, to that of 
 the anterior part of the external ear, the anterior auricular muscle, 
 
56 
 
 DESCRIPTIVE ANATOMY. 
 
 and the external and upper part of the orbicularis palpebrarum 
 muscle. 
 
 When only two temporal nerves exist, the anterior is larger than 
 the other. 
 
 b. Malar nerves. 
 
 § 1863. 8th and 9th. These are usually two nerves ; they proceed 
 more forward and upward than the preceding, and passing on the 
 malar bone, they are distributed in the skin which covers this bone and 
 the external edge of the orbit, in the outer part of the eyelids, in the 
 external and lower part of the orbicularis palpebrarum muscle, finally 
 in the posterior part of the zygomatici muscles. 
 
 IL. ANTERIOR BRANCHES OR BUCCAL NERVES. 
 
 § 1864. There are usually three, more rarely two, anterior branches 
 or buccal nerves (JV. buccales). 
 
 The central one is the largest. 
 
 They go almost directly forward on the upper and middle portion of 
 the masseter muscle, beyond its anterior edge. The middle is situated 
 directly on the excretory canal of the parotid gland. 
 
 The superior, passing under the zygomatici muscles, to which it 
 gives filaments, ascends towards the lower eyelid, and goes to the 
 inner angle of the eye, where it often anastomoses with the infra- 
 trochlear nerve given off by the fifth pair. 
 
 The central divides into ascending and anterior twigs. 
 
 The ascending twigs arrive at the lower part of the orbicularis 
 palpebrarum muscle, the muscles of the sides of the nose, and the skin 
 which covers them, anastomose with some filaments of the infraorbitar 
 nerve which come from the fifth pair, particularly with the external, 
 and terminate in the levator muscles of the upper lip, the orbicularis 
 oris, and the skin of the upper lip. 
 
 The inferior go directly forward, are distributed in the buccinator 
 muscle, the skin of this region and that of the lower lip. They anas- 
 tomose wfith the buccal nerve which comes from the third branch of 
 the fifth pair. 
 
 III. DESCENDING BRANCHES. 
 
 § 1865. The descending branches, cervico-faciales, Ch., arise from 
 the lower and smaller trunk, which commonly anastomoses at its origin 
 by some filaments with the superior. 
 
 This trunk generally divides into two branches. 
 
 The superior goes forward on the lower part of the masseter muscle, 
 anastomoses with the inferior buccal nerve, and is distributed in the 
 skin of the lower bp, the depressor labii inferioris, and the buccinator 
 muscle. 
 
OF THE NERVOUS SYSTEM, 
 
 57 
 
 The inferior descends towards the lower angle of the jaw, and 
 divides near the angle of this bone, into a superior and an inferior 
 twig. 
 
 The superior twig, the marginal nerve (N. marginalia), proceeds 
 above and along the edge of the lower jaw, goes forward and upward, 
 distributes its filaments in the muscles which depress the lower lip and 
 in the skin of the chin, and anastomoses with the inferior labial nerves 
 of the third branch of the trifacial nerve. 
 
 The inferior divides in turn into two or three ramuscules, the su- 
 perior cutaneous cervical or submaxillary nerves (JV. subcutanei colli su- 
 periores ), which descend under the jaw, are distributed in the upper 
 part of the skin of the neck and in the platysma myoides muscle, and 
 anastomose frequently with the ascending twigs of the anterior branch 
 of the third cervical nerve. 
 
 VII. EXTERNAL MOTOR NERVE. 
 
 § 1866. The external motor nerve, the sixth pair, the external oculo- 
 muscular nerve ( JY. '. oculo-muscularis externus, s. posterior, s. abducens, 
 s. par sextum),{\) is flat, and arises by two very distinct roots, an 
 internal and an external which is usually four times the size of the 
 former, from the upper extremity of the pyramid, from the posterior 
 edge and the posterior extremity of the lower face of the annular pro- 
 tuberance, about two lines from the median line, and four or five lines 
 inside of the facial nerve. From the inferior face of the annular protu- 
 berance only the inner root generally arises, which sometimes does not 
 extend to the posterior edge, but terminates two lines from this edge 
 and arises only from the external face of this protuberance, although 
 we cannot follow it farther either backward or forward. The ex- 
 ternal root generally arises also from the anterior extremity of the pyra- 
 mid. These two roots, particularly the internal, are formed of several 
 fasciculi which are easily detached from each other. 
 
 It is very rare that the internal root is the larger, (2) or that the 
 filaments by which the nerve arises do not unite in two distinct roots. 
 
 Sometimes the nerve arises only from the pyramid. Not unfre- 
 quently it comes in part from the olivary body and the transverse band 
 which is often found between the summits of the two pyramids. (3) 
 
 We can, however, generally demonstrate particularly by compara- 
 tive anatomy, that it arises from the medulla oblongata between the 
 olivary bodies and the pyramids, much lower than it comes from them 
 and that the different filaments coming from the olivary bodies, the 
 small transverse striæ, and the pons Yarolii, are either supplementary, 
 or as is true particularly of those from the annular protuberance, ap- 
 
 (1) Zinn, Desc. oculi humani, Gottingen, 1755, tab. vi. 
 
 (2) We have rarely seen this. Vicq-d'Azyr {Mém. de Paris, 1781, p. 589) observes 
 also that this arrangement is rare. 
 
 (3) Vicq-d’Azyr, Toe. tit., p. 689. 
 
68 
 
 DESCRIPTIVE ANATOMY. 
 
 pear to be distinct roots only because the fibres of the principal root of 
 the nerve are separated from each other at their upper part by the pos- 
 terior fibres of the pons Varolii.(l) 
 
 The two roots generally unite before passing through the dura-ma- 
 ter : sometimes, however, each passes through a special opening in 
 this membrane and also proceeds three or four lines and even glides 
 under a special fibrous bridge entirely distinct from the dura-rnater 
 before they join. In the cases where we have seen this arrangement 
 it has ahuaijs appeared on the left side alone , and the external fasci- 
 culus was the smaller. 
 
 These facts, compared with those adduced by Sœmmerring, seem 
 much in favor of the opinion that the ganglionnary nerve comes from 
 the centre of the nervous system, and that the cerebral nerves appear 
 to be more numerous than they truly are by the enlargement of some 
 branches. If proved that the external motor nerve always divides on 
 the left side, it would be important on account of the analogy which it 
 establishes with the vascular system. 
 
 On leaving the encephalon the nerve becomes fibrous, is covered 
 with a neurilemma and goes directly forward and outward, passes 
 through the dura-mater below the posterior clinoid process, enters the 
 cavernous sinus within which it is attended a short distance by the 
 arachnoid membrane, being separated from the blood by the inner 
 membrane of the sinus, and is situated on the outside of the internal 
 carotid artery to which it is attached by compact cellular tissue. In 
 passing above the anterior orifice of the carotid canal it anastomoses 
 with the ganglionnary nerve by some filaments which form an acute 
 angle with its trunk. Farther forward it communicates also by a fila- 
 ment with the spheno-palatine ganglion, or the recurrent nerve of the 
 second branch of the trifacial nerve. It goes to the orbit through the 
 sphenoid fissure through a special opening in the dura-mater, enters 
 this cavity between the fasciculi of the rectus oculi externus muscle, 
 intimately united in this place with the common motor nerve and the 
 nasal nerve of the first branch of the tiifacial nerve, and coming on 
 the inside of the rectus externus muscle is entirely distributed to it. 
 
 The external motor nerve goes then only to one muscle. It very 
 rarely gives off the nasal branch of the fifth pair, (2) but more fre- 
 quently sends a filament to the opthalmic ganglion. (3) This latter 
 arrangement makes the transition from that commonly found to the 
 first. This anastomotic filament, however, undoubtedly belongs at 
 least in part to the ganglionnary system. 
 
 t 
 
 (1) Gall, loc. cit., p. 204. 
 
 (2) Otto, Seltne Wahrnchmungén, 1816, p. 103. 
 
 (3) Petit, Mein, de Paris, 1727. 
 
OF THE NERVOUS SYSTEM. 
 
 59 
 
 VIII. TRIFACIAL NERVE. 
 
 § 1867. The trifacial nerve, the fifth pair , (N. trigeminus , s. di- 
 visas, s. mixtus , Gj.11, s. pur quintum nervorum), ( 1) is very large: it 
 appears ab 3 at six lines before the posterior edge of the inferior prolon- 
 gation of the cerebellum, three behind the anterior edge of this prolon- 
 gation, and nine from the median line of the pons Varolii. There it is 
 manifestly composed of three more or less distinct roots, a posterior, a 
 central, and an anterior. The posterior is situated farther backward 
 and higher than the central, and the anterior below and on the inside 
 of it. These roots were first correctly described by Santorini, (2) and 
 after him by Wrisbsrg,(3) Palletta,(4) and Niemeyer.(5) 
 
 § 1833. Tne central root is always much larger than the other two, 
 for it is more than a line and a half in diameter after it emerges, while 
 each of the others is only about half a line. Its fasciculi are more 
 numerous : but they are smaller than those of the other two roots. 
 
 At the place where it emerges it is a little depressed from above 
 downward, but soon enlarges, becomes round, and again contracts. 
 
 The fibres of the annular protuberance evidently separate at their 
 base, so that we may judge from a superficial examination that the 
 root does not arise in this place but from a deeper part. 
 
 This middle root is composed of thirty or forty fasciculi of various 
 sizes. The number of filaments which form these fasciculi is about 
 one hundred : some authors assert less ; but they probably have de- 
 scribed the fasciculi simply as filaments, or have neglected to decom- 
 pose several of them. 
 
 It is principally by following the central root that we can demon- 
 strate very evidently that the nerve arises from a deeper part than 
 where it leaves the annular protuberance. Santorini has stated per- 
 fectly its true origin ;(6) his observations have been confirmed and 
 
 (1) J. P. Merkel, De quinto pare nervorum, Gottingen, 1748. — A. B. R. Hirsch, 
 Paris quinti nervorum encephali disquisitio anaiomica , Vienna, 1765. — H. A. W'ris- 
 berg, Observations anatomicce de quinto pare nervorum et de nervis , qui ex rodem 
 duram matremingredifalso dicuntur, Gottingen, 1777. — A. C. Rock, Beischreibung 
 der fünften Nervenpaares und seiner Verbindung mit andern Nerven, vorzüglich 
 dem Gangliensystem, Meissen, 1617. — G. K. Treviranus, Sur les nerfs de la cin- 
 quième paire, considérés comme organes ou conducteurs de sensations ; in the Journ. 
 compl. du diet, des sc. méd. vol. xv. p. 207. — Magendie, Sur les fonctions de la 
 cinquième paire de nerfs ; in the Journ. de phy. exp., vol. iv. p. 176 and 302. 
 
 (2) Obs. anal., Venice, 1724, p. 65. 
 
 (31 Loc. cit. 
 
 (4) De nervo crotophilico et buccin a'orio, Milan, 1784. 
 
 (5) De origine paris quinti nervorum cerebri , Hales, 1812. 
 
 (6) Loc. cit., p. 65. T. he honor of this discovery then belongs to Santorini. 
 Niemeyer seems to attribute it to Winslow, and is consequently wrong, for the 
 Anatomy of Winslow appeared first in 1732, while Santorini’s observations were pub- 
 lished in 1724. 
 
60 
 
 DESCRIPTIVE ANATOMY. 
 
 rendered still more exact by the labors of Winslow,(l) Sœmmer- 
 ring,(2) Gall, (3) and Niemeyer.(4) 
 
 Here also the posterior part and the proper origin of the nerve are 
 covered by the considerable development of the cerebral parts. On 
 leaving the place where it appears, it enters from without inward, from 
 before backward, and from below upward in the fissure of the central 
 prolongation of the cerebellum, and is more or less completely divided 
 into several cords by the transverse fibres of the annular protuberance, 
 thus comes behind the union of the three peduncles of the cerebellum 
 directly below the floor of the fourth ventricle, passes under the pos- 
 terior prolongation of the cerebellum, almost the length of the exteinal 
 edge of the annular protuberance, and proceeds towards the groove 
 between the restiform and the olivary bodies ; its strongest root arises 
 there partly from the groove and partly from the olivary eminences. 
 
 From this point to where it passes between the posterior and lateral 
 prolongations of the cerebellum it is not fibrous, and is surrounded by 
 gray substance ; but from this second point to its emerging from the 
 annular protuberance it is formed of very apparent fibres, and is sur- 
 rounded by a thin membrane. In its whole extent from its origin to a 
 little before its emerging on the external face of the inferior prolonga- 
 tion of the cerebellum it gradually becomes thicker, but before leaving 
 the pons Yarolii it slightly contracts and enlarges considerably after 
 emerging. 
 
 The fasciculi of the nerve are then more distinct and surrounded with 
 neurilemma, and occupy the w’hole circumference of the pons Varolii. 
 They enlarge partly by the separation and partly by the increase of 
 their substance. When once emerged, the nerve is at first round but 
 gradually becoming flatter, goes forward towards the upper end of the 
 petrous portion of the temporal bone. At first it is loose in the skull, 
 being loosely surrounded by a broad prolongation of the arachnoid 
 membrane, but at the upper edge of the petrous portion of the temporal 
 bone it enters a rounded and oblong sheath of the dura-mater which 
 generally is entirely separated from the cavernous sinus. This sheath is 
 at first loose, but afterwards is placed strongly on its surface. It thus 
 goes from before downward and from behind forward on the anterior 
 face of the petrous portion of the temporal bone. 
 
 In this course the trifacial nerve examined externally seems formed 
 only by fasciculi placed one at the side of another. These fasciculi, 
 however, communicate their whole extent, by small intermediate fila- 
 ments. This union and the ramification of fasciculi which resultsfiom it, 
 become more and more marked from behind forward, and for about a line 
 and a half to two lines the breadth of the fasciculi divide into very minute 
 
 (1) Exp. anat., 1732, vol. iv. p. 182. 
 
 (2) Loc. cit., p. 267. 
 
 (3) Lieber das Organ des Seele, Koenigsberg, 1796, p. 36. 
 
 (4) Loc. cit., p. 211. 
 
OF. THE NERVOUS SYSTEM. 
 
 61 
 
 filaments, and interlace perpetually with each other near its anterior 
 extremity. The trunk of the nerve which here touches outward the 
 last curve of the internal carotid artery anastomoses with some fila- 
 ments of the great sympathetic nerve. 
 
 The anterior extremity of this large principal root suddenly differs 
 in appearance from the other parts, and the different branches of the 
 nerves. 
 
 In fact at the anterior extremity of the upper face of the petrous 
 portion of the temporal bone it forms a semicircular prominence, the 
 concave edge of which is turned upward and backward and the convex 
 edge downward and forward. This prominence which reaches be- 
 yond the trunk of the nerve in every direction is six to ten lines long 
 from before backward, one broad from within outward, and a line and a 
 half high. It is termed the semilunar ganglion or gangliform plexus 
 {ganglion semilunare , plexus ganglioformis , Vieussens ; intumescentia 
 ganglio ajfinis, Scarpa ; plexus retiformis, Santorini ; tarda nervosa , 
 Haller ; intumescentia semi-lunaris , Wrisberg ; Jigger lunatus, Neu- 
 bauer ; Armilla , Malacarne). It is transparent and reddish, and for 
 about a quarter to half a line has no determinate texture, if we except 
 some filaments which pass over its two faces, particularly the inner 
 part of the inferior : but it then reassumes its fibrous appearance, so 
 that in the mode directly the opposite of that over the plexus the fila- 
 ments unite from above downward in larger threads, and thus produce 
 fasciculi, still forming a trunk from one and a half to two lines broad, 
 which immediately divides into three principal branches, the upper of 
 which forms with the crural a very acute angle, and the latter a 
 slightly obtuse angle with the posterior. The branches, the fasciculi 
 of which still interlace with each other, are at first broad, but they 
 gradually become round in approaching the openings through which 
 they pass. 
 
 The plexiform filaments of the nerve are not generally continuous 
 with the inferior, but terminate in a channel grooved on the upper and 
 concave edge of the ganglion. The inferior arise from all the circum- 
 ference of the ganglion, and most generally extend to the upper and 
 concave edge externally. The substance of the ganglion is homo- 
 geneous internally, and precisely similar to that of the proper nervous 
 ganglions. 
 
 § 1869. The small roots of the trifacial nerve do not contribute to 
 form the prominence of the ganglion, although there is on the lower 
 face of this latter, and of the large root, a groove formed by their pas- 
 sage. 
 
 The superior penetrates through a special fissure into the inferior pro- 
 longation of the cerebellum from one fourth of a line to two lines dis- 
 tant from the great middle root. When the two roots are very near each 
 other they seem to enter through the same fissure : but in attentively 
 examining we perceive this is rarely the case, even if it ever happens. 
 The direction of the superior root in the inferior prolongations of the 
 cerebellum is the same as that of the preceding, which proceeds below 
 
 Vol. Ill 9 
 
62 
 
 DESCRIPTIVE ANATOMY. 
 
 it; we however cannot trace the former as far. Soon after emerging', 
 it turns on the upper face and the inner edge of the large root, arrives 
 at its lower face, and continuing to pass on, it goes gradually outward 
 where it reunites, after passing about half an inch, with the small in- 
 ferior roots. It is formed of from three to six fasciculi of different sizes. 
 
 The small inferior root is generally nearer the central than the su- 
 perior, being often only a fourth of a line and seldom more than one 
 line distant from it, and the rule mentioned by Palletta that they are 
 always several lines distant cannot be admitted. They often evidently 
 arise from the same groove. The part of the small inferior root which 
 is contained in the cerebral substance always proceeds below the large 
 in the same direction with it, and less distant from it than is the upper 
 root. It is generally formed of a greater number of fasciculi than the 
 upper, as there are about from six to eight. It leaves the annular 
 protuberance on the lower face of the large root, and reunites with the 
 small superior root in the manner stated, most generally, three or four 
 lines behind the ganglionnary prominence of the large root. The trunk 
 of the temporo-buccal nerve (N. crotciphito-buccinalorius), formed by this 
 union, passes first under the large root, then under the ganglionnary 
 prominence and the third branch of the fifth pair, thus goes outward 
 and forward, and anastomosing in this course only by some inconstant 
 filaments, first with this trunk, then with the third branch of the fifth 
 pair, often but not always enlarges longitudinally under the plexiform 
 ganglion, and after passing through the foramen rotundum of the ba- 
 silar bone proceeds to form the temporal and buccal nerves. 
 
 These two small roots form the small portion of the fifth pair, which 
 is whiter and harder than the large. 
 
 Their separation with the ganglion formed by the large portion is 
 extremely curious, as it presents a repetition of the formation peculiar 
 to the nerves of the spinal marrow. 
 
 A. FIRST PRINCIPAL BRANCH. 
 
 § 1870. The first branch , the superior or ophthalmic branch of the 
 fif III pair (R. primus , s. superior , s. ophthalmicus), (1) is much smaller 
 than the other two, and arises from the upper part of the ganglion. 
 Its direction is from below upward and from behind forward on the 
 outer side of the cavernous sinus towards the orbit, into which it pene- 
 trates from within outward, on the outside of the common motor and 
 below the superior motor nerve. 
 
 In this course it gives off no branches, except nearer or farther from 
 its origin a tolerably constant twig which unites to the superior motor 
 nerve, and another less constant which goes to the ganglionnary nerve. 
 
 (1) Rinn, DcscripLlo oculi humani, tab. vi.— Soœnnnening, in Demeura, Traite 
 des maladies des yeux, vol. i v., p. 32, pl. vi., fi g. I. 
 
OF THE NERVOUS SYSTEM. 
 
 63 
 
 But it is united in all its extent by very compact cellular tissue with 
 the superior motor nerve. 
 
 Just before entering the orbit it generally divides into two and more 
 rarely into three twigs, which aie the nasal , the lachrymal, and the 
 frontal nerves. In the first case, the second blanch, which is larger 
 than the other, is the common trunk of the lachrymal and frontal 
 nerves. 
 
 1st. The nasal or nnso-ciliary nerve (N. naso-ocularis , s. naso- 
 ciliaris), which in respect to size is between the other two, anasto- 
 moses posteriorly with some filaments of the great sympathetic nerve, 
 and divides into two branches generally before entering the orbit. 
 
 The external branch (R. ciliaris, s. ad ganglion ) is the smaller, and 
 goes to the lenticular or ciliary ganglion ( ganglion lenticulare, s. 
 ciliare ), which is situated on the outside of the optic nerve and forms 
 its long root. Sometimes it anastomoses previously by one or two fila- 
 ments with the common motor nerve.(l) It rarely gives off a ciliary 
 nerve. 
 
 The internal branch is larger and proceeds forward and inward on 
 the optic nerve, with which it is connected. It not unfrequently gives 
 off some ciliary nerves which proceed along the optic nerve to the eye 
 and enter its capsule at its posterior part, proceed between the fibrous 
 envelop and the choroid membrane to the iris, in which they are distri- 
 buted with analogous but more numerous filaments which come from 
 the lenticular ganglion, forming with them from five to ten nerves which 
 generally divide again into two, more rarely into three fasciculi, which 
 we shall describe when speaking of the eye. Several filaments from 
 the ganglionnary nerve enter the ganglion. (2) 
 
 The nerve then passes below the rectus oculi superior and obliquus 
 major muscles, continues B to proceed inward and forward, situated 
 against the internal wall of the orbit, and soon divides into two 
 branchés, the ethmoidal and the infra-trochlear nerves. 
 
 The ethmoidal or internal nasal nerve (N. cthmoidalis, s. nasalis, 
 Winslow, s. ophthalmicus, Willis, s. nasalis internus ), re-enters the 
 skull through the internal and anterior orbitar foramen, afterwards 
 emerges from this cavity through one of the anterior foramina of the 
 cribriform plate of the ethmoid bone, proceeds to the nasal fossa, sends 
 filaments to the mucous membrane of the superior turbinated bone and 
 of the septum, sends others to that of the frontal sinus, then glides in a 
 groove of the nasal spine of the frontal and of the proper nasal bones, 
 descends along the anterior edge of the cartilaginous septum of the 
 nose to the nasal fossee, emerges, and terminates at the tip of the nose 
 sending filaments to its alæ, at the end of which it anastomoses 
 
 (1) Bock, loc. cit., p. 11. 
 
 (2) Kibes, Sur quelques parties de l’œil ; in the Mêm. de la soc. méd. d’êm., vol. 
 vii., p. 86. — Bock, loc. cit., p. 12. 
 
64 
 
 DESCRITTIVE ANATOMY. 
 
 with some twigs of the second branch of the fifth and the seventh 
 pairs.(l) 
 
 The ethmoidal nerve sometimes divides into an anterior and a pos- 
 terior trunk, the latter of which passes through the internal and pos- 
 terior orbitar foramen, and remains in the nasal fossa. (2) 
 
 The infra-trochlear or external nasal nerve ( N . infra-irochlearis), 
 advances below the rectus and obliquas superior oculi muscles, along 
 the inner wall of the orbit, passes directly below the pully, and gives off 
 a small filament to the mucous bursa in this place, leaves the orbit, and 
 divides in the internal angle of the eye into two principal branches, a 
 superior and an inferior. These branches soon subdivide into twigs by 
 which the nerve is distributed in the tunica conjunctiva, the caruncula 
 lachrymalis, the lachrymal sac, the orbicularis palpebrarum and the 
 frontalis muscles, and the skin of the back of the nose. It anastomoses 
 above with the supra-trochlear nerve, then with some filaments of the 
 facial nerve, and farther forward with the second branch of the fifth pair. 
 
 Sometimes the long root of the lenticular ganglion does not come 
 from the nasal nerve, but from the third pair. Analogous to this ar- 
 rangement but much more rare is the case where the nasal nerve 
 comes from the sixth(3) and not from the fifth pair. 
 
 2d. The frontal branch or nerve (N. frontalis ), the largest of the 
 three branches of the ophthalmic nerve, proceeds between the other 
 two from behind forward and from without inward on the levator pal- 
 pebræ superioris muscle directly below the arch of the orbit. It is at 
 first intimately united with the superior motor nerve. 
 
 At about its centre it sends off inward and forward a small branch 
 which anastomoses with the infra-trochlear nerve, and which sends 
 filaments into the frontal sinus, either directly, or indirectly by a small 
 ganglion. 
 
 It then sends off a larger filament, the supra-trochlear nerve (N. 
 supratrochlearis ), which proceeds along the internal wall of the orbit, 
 passes above the pully of the obliquus major muscle, and emerges from 
 the cavity of the orbit. This nerve, called also the internal frontal 
 nerve, is reflected from below upward, distributes its twigs in the 
 corrugator supercilii muscle, the internal and upper part of the orbicu- 
 aris palpebrarum, the frontalis muscle and the skin which covers it, and 
 anastomoses with some filaments of the infra-trochlear and the proper 
 frontal nerve. 
 
 The continuation of the trunk, the proper frontal nerve, gives off no 
 branch within the orbit, leaves this cavity sometimes in one root but 
 sometimes divided into several, through one or more supra-orbitar fora- 
 mina, is soon reflected from below upward on the upper edge of the 
 orbit, and is distributed in the skin of the forehead and the vertex. 
 
 (3) Hunter, Observations on different parts of animal economy , London, 1792 .—A 
 description of some branches of the fifth pair of nerves , p. 265. 
 
 (2) Bock, loc. cit., p. 18. 
 
 (3) Otto, Seltne Beobachtungen , Breslau, 1816, p. 108. 
 
OF THE NERVOUS SYSTEM. 
 
 65 
 
 3d. The lachrymal nerve, (N. lachrymalis) which is between the 
 other two in size, and is the most external of the three twigs of the 
 first branch of the fifth pair, goes forward and outward, being also 
 situated against the orbitar plate, and soon divides into an external 
 and an internal branch. 
 
 The external reunites with a twig of the subcutaneous malar nerve, 
 which comes from the second principal branch of the fifth pair. From 
 this trunk we generally see a filament depart which is sometimes 
 double, and which passing directly to the anterior extremity of the 
 inferior orbitar fissure, between the malar and sphenoid bones, goes 
 outward in the temporal fossa, where it anastomoses with a malar 
 branch of the facial nerve, more rarely with the superficial temporal 
 nerve which comes from the second principal branch of the fifth 
 pair.(l) 
 
 This external branch sometimes sends a filament to the ciliary 
 nerves, which come directly from the nasal nerve. (2) 
 
 The internal branch divides into several twigs, which anastomose 
 with each other like a plexus, and enter the lachrymal gland. 
 
 These twigs are not distributed entirely in the gland. Some, after 
 passing through it, come outwardly, where they are distributed, partly 
 in the external part of the orbicularis palpebrarum muscle, partly in 
 the integuments of the malar region, and anastomose with some fila- 
 ments from the posterior branches of the facial, the frontal, and the 
 subcutaneous malar nerves. 
 
 B. SECOND PRINCIPAL BRANCH. 
 
 § 1871. The second principal branch of the fifth pair, the middle 
 branch, the superior maxillary nerve (R. quinti paris secundus, s. 
 médius , s. JV*. maxillaris superior), (3) is between the other two in 
 its situation and volume. It arises from the anterior part of the gan- 
 gfionnary plexus ; it goes almost directly forward, or at least a little 
 oblique from below upward, gives off no branch within the skull, 
 although it sometimes anastomoses there with a filament of the gan- 
 glionnary nerve, (4) and emerges from this cavity outward and for- 
 ward through the great foramen rotundum of the sphenoid bone. It 
 is flat, but after emerging it becomes round. 
 
 Some distance from the place where it leaves the skull, the superior 
 maxillary nerve gives off a small branch, the subcutaneous malar 
 nerve (JV*. subcutaneus males), which reascends in the spheno-maxil- 
 lary fissure. This branch enters into the orbit below the rectus ex- 
 ternus oculi muscle, and anastomoses by one or more filaments with 
 
 (1) Bock, loe. cit., p. 19. 
 
 (2) Bock, loc. cit., p. 20. 
 
 (3) J. F. Meckel, De quinto pare nervorum; in Ludwig', Opp. min., Gottingen, 
 1817. — A. Scarpa, Annot. acad., 1. ii., Modene, 1779. cap. iv. v. vi. tab. i. ii. 
 
 (4) Laumonier, in Roux, Journ. de méd., vol. xciii. p. 259. 
 
66 
 
 DESCRIPTIVE ANATOMY. 
 
 the external twig of the lachrymal nerve. It sends off, farther for- 
 ward, one or more ramifications, which enter into the lachrymal gland ; 
 some of them remain in its tissue, while others, after passing through 
 it, emerge from the orbit and are distributed in the orbicularis palpe- 
 brarum muscle and the skin of the cheek, where they communicate 
 with some filaments of the facial nerve and of the third principal 
 branch of the fifth pair. Finally, the subcutaneous malar nerve 
 emerges from the orbit through the malar foramen, sometimes in one 
 trunk, and sometimes divided into several filaments. It is distributed on 
 the face to the lower part of the orbicularis palpebrarum muscle, and 
 also to the skin of the malar region, and communicates with the twigs 
 of the facial and infraorbitar nerves. 
 
 The superior maxillary nerve then divides into two much larger 
 and nearly equal branches, which proceed almost directly from above 
 downward. They are the pterygo-palatine and the infraorbitar 
 nerves. 
 
 The jjter'ygo-joalatine nerve ( JV. pterygo-palatinus ) sometimes forms 
 a single trunk, sometimes arises by two or three distinct filaments, 
 winch become the roots of a small rounded triangular or cordiform 
 ganglion, situated on the outside of the spheno-palatine foramen, and 
 termed from its discoverer, the ganglion of Meckel (G. .Meckelii),(l) 
 and also the spheno-palatine ganglion (G. spheno-palalinum). The 
 recurrent and palatine nerves come from this ganglion. 
 
 The branches coming from the pterygo-palatine ganglion, vary ac- 
 cording as the spheno-palatine ganglion does or does not exist. 
 
 If it exists, the upper anterior nasal nerves partially arise from the 
 trunk of the pterygo-palatine nerve, partly from the palatine nerve, 
 and the naso-palatine nerve comes from the pterygo-palatine. 
 
 Several small branches come from the trunk of the pterygo-palatine 
 nerve, and from the spheno-palatine ganglion when they exist. 
 
 First arises a filament which enters the sphenoidal sinus, or which, 
 when it is very much developed, passes through this cavity and goes 
 to the external motor nerve, with which it anastomoses ;(2) sometimes 
 it sends ramifications to the sphenoidal sinus, and also to the posterior 
 and most superior part of the septum of the nasal fossæ. 
 
 Next come four or five filaments which are a little larger; they pass 
 through the dura-mater, which is extended on the pterygo-palatine 
 foramen, are distributed in the mucous membrane which lines the pos- 
 terior part of the upper and middle turbinated bones of the nose, and 
 anastomose with the ramifications of the olfactory nerve. They are 
 the upper anterior nasal or the spheno-palatine nerves (N. nasales 
 superiores et anteriores). Farther on are the nerve of the septum , which 
 will be described more properly after the naso-palatine nerve, and the 
 
 (1) J. F. Meckel, Observation anatomique sur un nœud ou ganglion du second 
 rameau de la cinquième paire des nerfs du cerveau nouvellement découvert avec 
 l’examen physiologique du veritable usage des nœuds ou ganglions des nerfs ; in 
 Mém. de Berlin , 1749. p. 84, 103. tab. iii. 
 
 (2) Bock, toc. cit., p. 26. 
 
OF THE NERVOUS SYSTEM. 
 
 67 
 
 upper posterior nasal nerves, which, however, are more frequently 
 branches of the recurrent nerve. 
 
 The pterygo-palatine nerve then divides in the summit of the pterygo- 
 palatine fossa, into a recurrent and a descending branch. 
 
 The recurrent branch, the pterygoid or vidian nerve (JV. quinti re- 
 current ;, s. anastomoticus, s. pterygoideus , s. vidianus ), is so termed 
 from its direction ; for it goes backward, enters into the pterygoid fora- 
 men, and anastomoses by several filaments with the facial and great 
 sympathetic nerves. 
 
 This nerve gives off first inward and downward, two or three fila- 
 ments termed the posterior and superior nasal nerves (JV. nasales pos- 
 teriores superiores ), which sometimes unite in a small trunk, termed 
 by Bock, the pharyngœal nerve (R. pharyngœus). These nervesemerge 
 sometimes through the lower part of the spheno-palatine foramen, 
 sometimes pass through the inner wall of the pterygoid canal, penetrate 
 inward through the pterygoid process, and are distributed in the pos- 
 terior part of the mucous membrane of the nose, where they anas- 
 tomose with the ramifications of the olfactory nerves in the muscles of 
 the velum palati, the skin of the soft palate, and around the anterior 
 orifice of the Fallopean tube. * 
 
 The external part of the nerve which is remarkable for its softness 
 and reddish color, then divides, before leaving the pterygoid canal into 
 two branches, which sometimes remain distinct to the ganglion, and 
 by which it terminates. 
 
 These two branches are the anastomotic nerves. The smaller 
 superior or superficial nerve is the superficial petrous nerve (JV. 
 petrosus superficialis) . It proceeds generally single, seldom divided,, 
 through the fibro-cartilage, situated between the sphenoid bone and 
 the petrous process, goes backward, upward, and outward, under the 
 third principal branch of the fifth pair, in a groove on the upper face of 
 the petrous process, leaves this groove and enters the Fallopian canal, 
 anastomoses here with the facial nerve which passes through it, and 
 sometimes sends filaments to the branches of the ganglionnary nerve 
 which surround the upper part of the carotid artery like a plexus.(l) 
 
 The inferior or deep, the larger, proceeds in the same direction as 
 the recurrent nerve, emerges from the posterior extremity of the ptery- 
 goid canal through the fibro-cartilage, between the sphenoid bone and 
 the petrous process, goes outward and backward, passes through the 
 dura-mater, and goes into the carotid canal, where ii anastomoses with 
 the upper extremity of the ganglionnary nerve, conjointly with a fila- 
 ment of the sixth pair, thus forming a very constant and very evident 
 anastomosis between the fifth pair and the great sympathetic nerve. 
 
 The differences sometimes observed in this respect will be more in 
 place in the description of the great sympathetic nerve. In fact, it is 
 probably more correct to consider the deep branch of the recurrent 
 nerve as a ramification of this latter. 
 
 (1) Bock, loc. cit., p. 28, 
 
68 
 
 DESCRIPTIVE ANATOMY. 
 
 The descending branch or the palatine nerve ( N . palatinus ) is much 
 larger than the recurrent, and is distributed to the middle and lower 
 part of the mucous membrane of the nose, and also to the membrane 
 of the palate. It is then more properly termed the naso-palatine nerve 
 ( N . naso palatinus.) 
 
 From this, or from the spheno-palatine ganglion, or finally from the 
 trunk of the pterygo-palatine nerve, arises first the nerve of the septum 
 of the nose (iV. septi narium ), which Scarpa(l) less properly terms 
 the naso-palatine nerve (N.naso-palatinus).( 2) 
 
 This nerve enters the nose with the anterior and superior nasal 
 nerves, through the spheno-palatine foramen, proceeds from without 
 inward, passing before the sphenoidal sinus towards the septum on 
 which it descends from behind forward, between the periosteum and 
 the mucous membrane, to the anterior palatine foramina, farther for- 
 ward on the left than on the right side, and thus arrives at the mem- 
 brane of the palate. In passing through the palatine canal the nerves 
 of the two sides unite, sometimes form a small prominence termed the 
 naso-palatine ganglion ( G. naso-palatinum ), and expand on a promi- 
 nence situated below the anterior palatine foramen. 
 
 The palatine nerve then divides into a large anterior branch, the 
 continuation of the trunk, and two or three smaller and posterior, all of 
 which descend into the pterygo-palatine fossa. These branches are 
 the great and small palatine nerves ( N . palatini major et minores). 
 They sometimes arise directly from the ganglion, or even, as is true 
 particularly of the smallest, from the second principal branch. 
 
 From the anterior part of the great palatine nerve arise first the 
 middle and inferior posterior nasal nerves ( N . nasales posteriores medii 
 et inferiores). (3) 
 
 The posterior middle nasal nerve soon divides into two branches, 
 which are sometimes separate at their origins. The superior goes 
 directly forward in the mucous membrane of the middle turbinated 
 bone. The second goes to the upper part of that of the inferior turbi- 
 nated bone. 
 
 The posterior inferior nasal nerve arises much lower, opposite the 
 posterior extremity of the lower turbinated bone, towards which it pro- 
 ceeds directly, and sends its filaments into the mucous membrane which 
 lines the inner face of this bone anteriorly. 
 
 These two nerves anastomose with the ramifications of the olfactory 
 nerve. 
 
 The anterior branch of the great nasal nerve sends directly back, 
 ward a small twig, which passes through the pterygoid process in a 
 special canal, and is distributed to the glandular substance of the soft 
 palate. 
 
 (1) Loc. cit., cap. v. De nervo palatino. 
 
 (2) Scarpa, loc. cit., tab. i.— Hunter, Observations on different parts of the animal 
 economy, tab. xvii. 
 
 (3) Cloquet, loc. cit., vol. ii. p. 687. 
 
OF THE NERVOUS SYSTEM. 
 
 69 
 
 The branch, the fasciculi of which separate from each other, goes 
 forward and downward in the pterygo-palatine canal, and comes 
 through the posterior palatine foramen to the lower face of the bony 
 palate, where it immedia.tely divides into three or four considerable 
 branches which proceed between the mucous membrane and the 
 periosteum, along the inner face of the alveolar processes opposite the 
 teeth, and are distributed in the gum. 
 
 The two or three small palatine nerves descend behind the great 
 palatine nerve, first in the pterygo-palatine fossa, then lower in small 
 special canals of the petrous portion of the temporal bone, on 
 emerging from which, they enter into the amygdalæ, the palato- 
 staphylinus muscle, the muscular and glandular substance of the 
 soft parts of the palate and the uvula. 
 
 § 1872. The infraorbitar nerve ( N . infraorbitalis ), the second of the 
 two branches in winch the superior maxillary nerve divides, is di- 
 rected from behind forward, from within outward, and from above 
 downward, in the spheno-maxillary fissure, and goes to the infra-orbital 
 canal. 
 
 But before entering into this canal, it sends off a considerable 
 branch called the dentar or posterior superior alveolar nerve ( R. den- 
 talis, s. alveolaris posterior superior). This nerve divides sometimes 
 even at its origin, sometimes afterward, into two branches, an anterior 
 which is smaller, and a posterior which is larger. 
 
 The posterior descends on the posterior part of the external w 7 all of 
 the maxillary sinus, below the temporalis muscle, which enters into 
 this cavity through its posterior wall, is distributed in its mucous mem- 
 brane, ( 1) and there anastomoses with the anterior dentar nerve. It 
 terminates by some superficial ramifications which go to the buccinator 
 muscle, and by deeper twigs which enter into small canals grooved in 
 the posterior part of the body of the superior maxillary bone, and pene- 
 trates into the roots of the three large posterior molar teeth. Each root 
 receives one of them. We see one of them also between each two 
 molar teeth, which goes into the gum. 
 
 The anterior branch is distributed principally in the upper and pos- 
 terior part of the buccinator muscle. 
 
 After giving off the upper and posterior dentar nerve, the infra- 
 orbitar nerve enters into the infra-orbitar canal. 
 
 In passing through this canal it usually gives off, sometimes sooner 
 and sometimes later, several branches, but always one at least, which 
 is larger than the others even when they exist ; these are the anterior 
 dentar nerves ( N . dentales anteriores) which enter into the superior 
 maxillary bone, send some filaments into the nose at the anterior part 
 of the inferior turbinated bone, anastomose by several filaments with 
 the posterior dentar nerves, pass forward on the roots of the anterior 
 teeth, and terminate by ramifications which go to the incisors, the ca- 
 
 (1) Bock asserts that the nerve is not distributed to the membrane of the maxillary 
 sinus ; but we have several times clearly seen filaments arising from it, 
 
 Vol. III. 10 
 
70 
 
 DESCRIPTIVE ANATOMY. 
 
 nine, and the anterior molar teeth, and to the gum. Those which be- 
 long to theincisors and the canine teeth arise directly from the anterior 
 dentar nerve ; those of the anterior molar teeth from the union of this 
 nerve with the posterior dentar nerve. 
 
 The infra-orbitar nerve then emerges from the canal through the 
 infra-orbitar foramen, within which it divides into two principal 
 branches, an internal and an external, and sometimes even in all the 
 other subordinate branches. It thus comes on the face, where it 
 divides into a considerable number of ramifications, which terminate in 
 the skin and the muscles of the nose and upper lip, and anastomose 
 with those of the first principal branch of the fifth pair, and also with 
 some filaments of the facial nerve. 
 
 The two principal branches usually subdivide into six or seven 
 twigs, which may be distinguished into superior , anterior , and in- 
 ferior. 
 
 1st. Superior branch. There is usually only one superior twig, 
 the inferior palpebral nerve (N. palpebralis inferior). This nerve, 
 the first given off by the infraorbitar nerve, from which it is some- 
 times separated even within this canal, and which often emerges 
 through a special foramen situated more internally than the infra- 
 orbitar, immediately ascends from without inward towards the lower 
 part of the orbicularis palpebrarum muscle, and divides into an external 
 and an internal twig. 
 
 The external goes outward towards the external angle of the eye, 
 on the lower part of the orbicularis palpebrarum, and gives off fila- 
 ments to this muscle. It anastomoses with those of the internal twig, 
 and with the temporal branches from the facial nerve. 
 
 The internal goes to the inner angle of the eye, gives a twig to the 
 skin of the nose which descends to the end of this organ, where it 
 anastomoses with the nasal twig of the first principal branch of the 
 fifth pair. It afterwards anastomoses in the lower eyelid with the 
 external twig and with a filament of the infra-trochlear nerve, and ter- 
 minates in the orbicularis palpebrarum muscle, the integuments of the 
 lower eyelid, the caruncula lachrymalis, and the lachrymal sac. 
 
 2d. Anterior or nasal twigs. The twigs which go forward, and 
 also at the same time a little outward, are the superficial or cutaneous 
 nasal nerves ( N . nasales superficiales), which may be distinguished 
 into an internal superior , and an external inferior. 
 
 The internal superior , generally the smaller, is reflected upward 
 under the levator palpebræ superioris muscle, often gives origin to the 
 preceding, and then divides into two or three filaments which proceed 
 forward below this muscle along the centre of the nose, send their rami- 
 fications into the levator labii superioris alæque nasi, and the depressor 
 alæ nasi muscles, and the integuments of the middle and inferior parts 
 of the nose. They extend to the back and tip of this organ, and anas- 
 tomose in the latter place with the nasal twig of the first principal 
 branch of the fifth pair. 
 
OF THE NERVOUS SVSTEM. 
 
 71 
 
 The external and inferior descends under the levator labii superioris 
 muscle, often sends an ascending filament to the lower eyelid and to 
 the lower part of the orbicularis palpebrarum muscle, then continues 
 its course from above downward, often receives a filament from the 
 preceding, goes forward to the ala of the nose above the levator labii 
 superioris aloeque nasi muscle, sends ramifications to this muscle and 
 to the middle and upper parts of the orbicularis oris, and terminates at 
 the lower part of the septum and of the top of the nose, where it anas- 
 tomoses with the nasal twig of the first principal branch of the fifth 
 pair. 
 
 3d. Descending or labial tu-igs. The descending twigs are generally 
 three or four superior labial nerves (N. labiales superiores ), they suc- 
 ceed one another from before backward. They are distinguished into 
 internal , middle , and external. All descend from before backward, 
 covered by the levator labii superioris muscle, are distributed in this 
 muscle, the skin of the upper lip, the corresponding part of the orbicu- 
 laris oris, and the lower part of the zygomatici and the buccinator 
 muscles. They even penetrate through the orbicularis oris muscle, 
 and go to the buccal membrane and the glands of the upper lip. 
 
 3d. We frequently find also an external twig of the infraorbitar 
 nerve, the external palpebral nerve. This very small twig passes 
 through the levator labii superioris muscle, goes outward, where some 
 of its filaments are distributed in the orbicularis palpebrarum muscle, 
 and others anastomose with filaments of the facial nerve. 
 
 C. THIRD PRINCIPAL BRANCH. 
 
 § 1873. The third principal branch , the inferior or posterior branch 
 of the fifth pair, the inferior maxillary nerve (22. quinti paris tertius , s. 
 inferior , s. posterior, s. nervus infra-inaxillaris),( 1 ) which is by far the 
 largest, arises from the lower and posterior part of the ganglionnary 
 plexus, and is formed principally by the small anterior portion, whence 
 Palletta(2) considers it a distinct nerve. It is the shortest of the three 
 within the skull, and goes from above downward, and slightly also 
 forward and outward, and enters the round foramen of the sphenoid 
 bone, after anastomosing hi this course with some inconstant filaments, 
 with the cavernous ganglion of the sympathetic nerve. (3) 
 
 The inferior maxillary nerve is distributed to the muscles, the in- 
 teguments, and the teeth of the lower jaw, the lower lip, the lower 
 salivary glands, and the tongue. 
 
 It is covered where it emerges from the cranium, by the pterygoideus 
 externus muscle, and soon divides into two large branches, an upper 
 and anterior, and a lower and posterior. This bifurcation however is 
 
 (1) A. F. L. Fitzau, De tertio ramo paris quinti nervorum cerebri s. nervi maxil - 
 lari inferiori, Leipsic, 1811. 
 
 (2) De nervis crotaphitico et buccinator io, Milan, 1784. 
 
 (3) Laumonier, loc. cit. — Munniks, De origine nervi intercost, in Ohs. rar., Gro- 
 ningen, 1805. 
 
72 
 
 DESCRIPTIVE ANATOMY. 
 
 not constant, for sometimes the twig formed by the two branches 
 comes directly from the trunk*. 
 
 § 1S74. The upper anterior branch is much smaller than the other, 
 divides soon after and even before emerging from the skull, into live 
 twigs, which separate from each other like rays. They are the mas- 
 seteric. , the internal and external deep temporal, the buccal and the 
 pterygoid nerves. 
 
 The masseteric nerve {N. massetericus ), the most external, which 
 generally arises the highest, pursues a transverse direction from within 
 outward, directly before the articular surface of the temporal bone, on 
 the outside of the pterygoideus externus muscle, where it sends fila- 
 ments to the ligaments of the temporo-maxillary articulation, and to 
 the lower part of the temporalis muscle, then descends from within 
 outward between this muscle and the pterygoideus externus muscle, 
 goes to the sigmoid fissure of the lower maxillary bone, and passing 
 behind the tendon of the temporalis muscle, glides between the two 
 layers of the masseter, in which it is almost entirely distributed. 
 
 The second twig, the external deep temporal nerve (N. temporalis 
 profundus externus ), arises farther forward and inward, often comes 
 from the preceding or from the buccal nerve, and sometimes from a 
 common trunk with the following. It goes outward under the ptery- 
 goideus externus on the temporalis muscles, commonly anastomoses 
 with the following and by an intermediate filament, and goes imme- 
 diately upward and inward to enter the temporalis muscle. 
 
 The third twig, the deep internal temporal (N. temporalis profundus 
 internus), is generally larger than the preceding, and follows the same 
 course. It is distributed also in the temporalis muscle, but also sends 
 some anastomotic filaments to the buccal nerves. It also gives off 
 others farther forward which go to anastomose with the cutaneous 
 malar and with the lachrymal nerve on the outside of, and sometimes 
 even within, the orbit : the existence however of these last two anas- 
 tomoses has been doubted, since the researches of Bock, who regards 
 the filaments generally considered as such, as ramifications of the 
 arteries.(l) 
 
 The fourth twig, the buccinator or buccal nerve ( N . buccinatorius ), 
 is usually the largest of the five, and sometimes the trunk of the three 
 preceding. It goes forward between the two pterygoidei muscles and 
 through the external, sends filaments to these two muscles, particu- 
 larly the externa], arrives at the lower part of the temporalis muscle, 
 then descends between this latter and the pterygoideus externus, comes 
 on the external face of the buccinator, is distributed mostly to this 
 muscle, passes through it to send some filaments to the membrane 
 and to the buccal glands, anastomoses with the anterior branches of 
 the facial nerve, and terminates in the levator and depressor anguli 
 oris muscles. 
 
 (I) Rock, toe. cil., p. 4-1. 
 
OF THE NERVOUS SYSTEM, 
 
 73 
 
 The fifth twig, the pterygoid nerve (N. pterygoidens), is the 
 smallest. It arises from the inner part of the superior branch, passes 
 between the pterygoideus extemus and peristaphylinus muscles and 
 arrives at the upper part of the pterygoideus internus, to which it is 
 entirely distributed. 
 
 § 1875, The posterior and inferior branch is much larger than the 
 preceding and the proper continuation of the trunk, divides soon after 
 arising into three twigs, the superficial temporal , the inferior dentar, 
 and the lingual nerve. 
 
 The superficial temporal nerve (JV. temporalis superficialis ) most 
 generally arises by two more rarely by three roots, and still more rarely 
 by one. Of these two roots, the inferior, the smaller, comes from the 
 inferior dentar nerve and reunites with the superior, so that the sphero- 
 spinous or middle cerebral artery passes between them. 
 
 The trunk goes from within outward on the inside of the temporo- 
 maxillary articulation between the condyle of the jaw and the lateral 
 ligament, and here divides in five or six branches. Two or three of 
 these branches penetrate from without inward and from behind for- 
 ward in the parotid gland, and anastomose with this trunk and with 
 some ramifications of the facial nerve. One or two of the others, 
 which may be termed the nerves of the external auditory passage (N, 
 meatus auditorii externi inferior , s. superior ), go backward, pass 
 through the anterior wall of the osseous portion of the auditory pas- 
 sage, and pass between this and the cartilaginous portion; Their rami- 
 fications are distributed some in the integuments of the inner part of 
 the external ear, and others in those of the auditory passage. We 
 see also one of them which goes to the membrane of the tympa- 
 num, glides between its two layers, and anastomoses by one or two 
 filaments with the cord of the tympanum.(l) 
 
 The last and largest branch of the superficial temporal nerve passes 
 through the parotid gland to the external ear, and terminates in the 
 integuments of the central part of the cranium by anastomosing with 
 some filaments of the great occipital and the frontal nerve of the first 
 principal branch of the fifth pair. It also communicates with some 
 filaments of the external lachrymal twig and of the cutaneous malar 
 nerve which go outward. 
 
 The other two nerves given off by the posterior and inferior branch 
 of the infra-maxillary nerve at first form only 'a single but very short 
 trunk. 
 
 The inferior dentar nerve ( N . alveolaris maxillœ inferioris, N. 
 maxillaris inferior ), which is situated between the other two twigs of 
 the posterior branch which is generally the largest ramification given 
 off by the trunk of the inframaxillary nerve, sometimes arises by two 
 roots which embrace the internal maxillary artery. It descends from 
 within outward and from behind forward, first between the two ptery- 
 
 (1) Bock, loc. cit., p. 49. 
 
74 
 
 DESCRIPTIVE ANATOMY. 
 
 goidei muscles, then between the external and the condyle of the jaw. 
 Near its origin it gives off a small and very constant branch, the mylo- 
 hyoid nerve (N. mylo-liyoideus ), which descends from behind forward 
 in a channel grooved in the inner face of the branch of the jaw, sends 
 a twig to the submaxillary gland, goes towards the lower face of the 
 mylo-liyoideus muscle, proceeds from behind forward between this 
 muscle and the anterior belly of the digastricus, gives some filaments 
 to both of them but particularly to the mylo-hyoideus muscle, and after 
 being reflected from below upward on the lower edge of the lower 
 jaw, is distributed in the muscles of the chin. 
 
 The trunk of the inferior dentar nerve proceeds from behind forward 
 in the inferior dentar canal. But it generally divides on entering into 
 two branches, a superior which is smaller, the dentar nerve ( N . den- 
 talis ), and an inferior and larger, the mental nerve {11. mentalis ) ; these 
 proceed at the side of each other, and communicate by numerous anas- 
 tomosing filaments. 
 
 The dentar branch is situated below the teeth, and sends a filament 
 to each of them and to each root of the molar teeth. All these fila- 
 ments arise farther back than the teeth to which they proceed : be- 
 tween each two teeth it sends a filament to the gum. 
 
 The mental branch emerges through the mental foramen. It soon 
 divides under the levator anguli oris muscle into two twigs, the infe- 
 rior labial nerves (N. labiales inferiores ), the internal of which is larger 
 in a greater or less degree than the. external: 
 
 The direction of the external is upward ; it sends some filaments to 
 the levator anguli oris muscle, but principally to the lower part of the 
 orbicularis oris, the glands of the lower lip and the buccal membrane, 
 and anastomoses with some filaments from the inferior branches of the 
 facial nerve. 
 
 The internal , covered by the depressor labii inferioris muscle, goes 
 forward and upward, sends filaments to this muscle, to the levator 
 menti, the central part of the orbicularis oris, the skin of the chin, the 
 glands of the lower lip, and the buccal membrane, and anastomoses 
 with the marginal branch of the facial nerve. 
 
 The lingual nerve ( N . lingualis , s. gustatorius ), the most anterior of 
 the three twigs of the lower and posterior branch of the inframaxillary 
 nerve is between the other two in respect to size. It arises farther 
 inward than they, and is frequently united to a considerable extent in a 
 common trunk with the preceding. It descends with it from behind 
 forward, usually on the inside of the internal maxillary artery, sepa- 
 rates from the inferior dentar nerve and goes inward, receives before 
 the palatostaphylinus and pterygostaphylinus muscles, and behind the 
 pterjrgoideus externus, the cord of the tympanum, which unites with it 
 at a very acute angle, then passes before the inferior dentar nerve, some- 
 times sends to the pterygoideus internus muscle a filament which is 
 often detached above the anastomosis with the cord of the tympanum, 
 enters between the pterygoideus internus and the ascending branch of 
 the jaw, and passing above the submaxillary gland, gives to it as high 
 
OF THE NERVOUS SYSTEM. 
 
 75 
 
 as the angle of the jaw several considerable filaments, which come 
 sometimes directly from its trunk, sometimes from a small ganglion 
 which it forms on it, and which is called the maxillary ganglion ( gan- 
 glion inaxillare.) 
 
 These filaments are distributed principally in the gland. Generally 
 however one of them emerges from it, descends on the hyoglossus 
 muscle, anastomoses with a branch of the lingual nerve, and termi- 
 nates in the genio-glossus muscle. 
 
 The trunk of the lingual nerve then goes forward between the hyo- 
 glossus and mylo-hyoideus muscles, passes between the sublingual 
 gland and the hyoglossus muscle having before it the excretory duct 
 of the submaxillary gland, anastomoses by several considerable fila- 
 ments which come from its inner side with the hypoglossal nerve, sends 
 some which are very minute to the buccal membrane and larger ones 
 to the sublingual gland, and divides into seven or eight branches which 
 proceed from behind forward and from below upward between the 
 styloglossus and genio-hyoideus muscles. These branches separate 
 like the sticks of a fan, and go principally to the edges and tip of the 
 tongue and are there distributed by minute filaments in the skin 
 of this organ. 
 
 IX. INTERNAL MOTOR NERVE. 
 
 § 1876. The superior or internal motor nerve, the pathetic , the 
 fourth pair, the internal oculo-muscular nerve (N. oculo-muscularis su- 
 perior, s. minimus, s. musculi oculi obliqui superioris, s. par cerebrale 
 quartum, s. N. patheticus) ,{l) the smallest cerebral nerve, generally 
 arises by an anterior and a posterior root, each composed of one fila- 
 ment about the same size. They are frequently half an inch apart, 
 but united by cellular tissue. They arise directly behind the external 
 half of the posterior part of the tubercula quadrigemina from the an- 
 terior and external part of the upper face of the cerebral valve, so that 
 the anterior arises from some transverse medullary fibres which cover 
 the valve in this place, and which unite them on the median line with 
 those of the opposite side. This nerve seldom has three roots and still 
 more rarely one only. 
 
 After arising, it goes downward and a little forward, first on the 
 upper extremity of the anterior prolongations of the cerebellum, then 
 about two lines from the anterior edge of the occipital protuberance, 
 first on the lateral and then on the lower face of the cerebral peduncle. 
 After proceeding much farther within the skull than any other ence- 
 phalic nerve, it comes to the posterior clinoid process. There it enters 
 into a special canal of the dura-mater, the internal wall of which is 
 very thin and separates it from the cavernous sinus, usually anasto- 
 moses there with the first branch of the trifacial nerve by a small fila- 
 
 (1) Zinn, loc. cit. — Scemmerringr, in Demours, loc. cit., vol. iv. p. 31, pi. vi., fig 1 . 1. 
 
76 
 
 DESCRIPTIVE ANATOMY. 
 
 ment, and is situated first below the common motor and the ophthal- 
 mic nerves. At the sphenoidal fissure it is situated above the first of 
 these two nerves, enters into the orbit through the upper and internal 
 part of this fissure, and its direction there is from behind forward and 
 from without inward directly under the periosteum, attended by the 
 frontal twig of the ophthalmic branch of the fifth pair, and enlarges 
 much in this course. Finally it enters the obliquus oculi superior 
 muscle at about its centre. 
 
 X. COMMON MOTOR NERVE. 
 
 § 1877. The common motor nerve, the common motor of the eye, the 
 third pair, the common oculo-muscular nerve (N. oculo-muscularis in- 
 ferior, s. médius, s. oculo-motorius communis, s. par tertium),{\ ) a con- 
 siderable trunk generally the fourth in size and rarely the third among 
 the encephalic nerves, arises about two lines before the anterior edge 
 of the annular protuberance on the inner face of the cerebral peduncle 
 about two lines above its lower edge, at the place where the gray 
 cribriform plate which covers the inner face of the peduncle com- 
 mences. It even arises in great part from this layer. Some smaller 
 filaments coming from near the internal edge of the lower face of 
 the cerebral peduncle usually join this root, which is single and very 
 large. 
 
 It is however easy to follow the origin of the nerve farther upward 
 and backward, for beyond the point where it leaves the annular pro- 
 tuberance it is covered anteriorly only by a very thin layer of gray 
 substance of which we perceive no trace posteriorly. When this sub- 
 stance is removed, when the annular protuberance is divided, turned 
 from above downward, and carefully cut longitudinally on the median 
 line, we observe that a medullary layer commences at the place where 
 the nerve emerges, continues with its fibres, and terminates like a fan 
 upward and a little forward, forms a fasciculus which is rounded pos- 
 teriorly although straight at first, and curves from below upward. 
 
 The anterior and flat part of this layer extends to the bottom of the 
 groove existing between the two cerebral peduncles. Its posterior 
 parts are arranged in fasciculi, converge from before backward, and 
 are blended at their posterior part. The anterior part, is loose, but in 
 order to see the posterior we must separate the anterior half of the 
 annular protuberance and turn over the two folds. The posterior part 
 of this medullary layer then rises directly below the floor of the aque- 
 duct of Sylvius. 
 
 The two nerves are at first attached to each other by their inner 
 faces, so that they slightly resemble the arrangement of the optic 
 nerves. After leaving this point, where they are detached from the 
 encephalon, they proceed from within outward and from before back- 
 
 (1) Zinn, loc. cit. — Scemmerring, in Dcmours, loc. cit., vol. iv. p. 34, pi. vi. fig. 2. 
 
OF THE NERVOUS SYSTEM. 
 
 77 
 
 ward, arrive at the external wall of the cavernous sinus, are situated 
 within and above the first branch of the trifacial and the superior motor 
 nerves ; then changing this direction below and on the outside of these 
 nerves they pass through the dura- mater which closes the sphenoidal 
 fissure, and enter the orbit with the external motor and the nasal branch 
 of the trifacial nerve. 
 
 Before passing through the dura-mater, the common motor nerve is 
 divided into a superior and an inferior branch. 
 
 The superior , the smaller, goes inward and forward, passes on the 
 optic nerve and the nasal twig of the ophthalmic branch, anastomoses 
 with this latter, sends its twigs into the rectus oculi superior muscle, 
 and passes through it to be distributed in the levator palpebræ superi- 
 oris muscle. 
 
 The inferior is much larger than the preceding, and passes below 
 and on the outside of the optic nerve, between it and the rectus oculi 
 inferior muscle. It usually divides into three twigs, an internal , which 
 is larger, which goes to the rectus internus muscle ; a middle , which 
 is shorter, for the rectus inferior muscle, and an external inferior 
 branch, which is the longest and thinnest, and which goes to the ob- 
 liquus inferior muscle, and the lenticular ganglion. 
 
 This latter gives off near its origin a short filament, which, situated 
 on the outside of the optic nerve, goes to the posterior extremity of the 
 lenticular ganglion, and forms its short root. This filament is always 
 composed of several threads, arises more rarely from the lower branch, 
 but sometimes also it comes at the same time from the external twig, 
 from the middle, and eveir from the trunk of the lower branch.(l) 
 
 Sometimes, but very rarely, the long root of the lenticular ganglion 
 also arises from the common motor nerve.(2) 
 
 XI. OPTIC NERVE. 
 
 § 1878. The optic or ocular nerve, the second pair (N. opticus , s. 
 visorius , s. par secundum ), the largest of the encephalic nerves arises 
 by a broad and flat portion from the posterior part of the external face, 
 and also from the upper face of the optic bed and the tubercula quad- 
 rigemina. Its anterior part, which is the broadest, leaves the upper 
 face of the optic bed, from the substance of which it is easily dis- 
 tinguished on account of the transverse direction of its medullary 
 fibres, to pass on its anterior and external tubercle. The posterior 
 passes below the posterior and external tubercle, and is attached in 
 this place to the tubercula quadrigemina, particularly the posterior, by 
 a medullary band, which goes forward from these latter, passing below 
 the posterior and external tubercle of the optic bed. Thence the optic 
 nerve proceeds from behind forward and from without inward, and de- 
 scends on the lower face of the cerebral peduncle, with which it is so 
 
 43. 
 
 (1) Bock, loc. cit., p. 12. 
 
 (2) Morgagni, Ep. anat ., xvi. § 59- — Meckel, De quinto pare , § 
 
 VOL, III. 11 
 
78 
 
 DESCRIPTIVE ANATOMY . 
 
 closely connected that we must admit that it partly arises from this 
 prolongation, although separated from it in almost all its extent by the 
 pia-mater. It gradually becomes narrower, but thicker and more 
 rounded, and unites at an obtuse angle with that of the opposite side 
 on the median line, on the lower face of the cerebrum, below the floor 
 of the third ventricle. The union is so intimate that the two nerves 
 form only one medullary mass. This mass itself has the form of an 
 elongated square, which differs in different subjects, as is indicated 
 in Morgagni(l) and Wenzel, (2) nor has it always the same volume. (3) 
 It receives above some medullary fibres from the floor of the third ven- 
 tricle, so that we are authorized to think that the optic nerve partially 
 arises from this point. 
 
 After this union the two optic nerves separate and go forward and 
 outward. Hence, when we view their place of union and their an- 
 terior and posterior parts, they represent the form of an X or of a cross. 
 Thus, their decussation has been termed the intercrossing (chiasma). 
 It is very rare, and perhaps never the case, that the two nerves do not 
 unite, (4) or that by an arrangement, perhaps the opposite of the pre- 
 ceding, a small pointed protuberance comes from the anterior edge of 
 the decussation.(ö) 
 
 Opinions vary in regard to the manner in which the optic nerves 
 unite. Some assert that they are only fitted to each other,(6) others 
 that they entirely intercross, and that of the right eye, for instance, 
 passes to the left side of the body behind the decussation.(7) Finally, 
 some think that there is only a partial decussation, an intercrossing of 
 most of the fibres, (8) that the external fibres of each nerve are situated 
 on the same side of the body before as behind the decussation, while 
 the internal intercross with the corresponding fibres of the opposite 
 side, and pass to the other side of the body. (9) 
 
 Those who maintain the first hypothesis, assert, 
 
 1st. That on examining the decussation in the recent state, the 
 fibres of the nerve are seen to pass through its external edge, but do 
 
 (1) Ep. anat., xvi. § 13. 
 
 (2) Depenit, struct, cerebri, p. 110. 
 
 (3) Ibid. 
 
 (4) Vesalius, De corp. hum. fab. 1. iv. c. iv. 
 
 (5) Scemmerring, in Nœthig, De decussatione nervorum opticorum, Mayence, 
 1780. 
 
 (6) Gallen, De util, part., lib. x. c. xii. — Also a great number of his successors, 
 mentioned in Nœthig.— Zinn, Desc. oc. hum., Gottingen, 1765, p. 190. — Vicq-d’Azyr, 
 in the Mém. de Paris, 1781, p. 554. — Meckel, in Haller, Grundriss, p. 386. 
 
 (7) This opinion was supported before Galen, as he refutes it ( loc . cit.) ; those who 
 have defended it since, are cited by Morgagni (Ep. anat.) and by Scemmerring, in 
 Nœthig, loc. cit., and Denksder Münchner Akad.. 1808, p. 60. 
 
 (8) Michælis, TJeber die Durchkreuzung der Sehnerven ; in Grosse, Magazin zur 
 Naturgeschichte des Menschen, vol. ii. part i. p. 149. 
 
 (9) Ackermann, in the Med. bibl. of lilumenbach. — Wenzel, Locus unionis ner- 
 vorum opticorum ; in De pen. sir. cereb., cap. xi. p. 109. 
 
OF THE NERVOUS SYSTEM. 
 
 79 
 
 -sot leave their side, while the middle part is absolutely homogeneous, 
 and presents no trace of fibrous structure^ 1) 
 
 2d. That the two optic nerves have been found entirely distinct from 
 each other, and the sight was unimpaired. (2) 
 
 3d. That where the optic nerve wasted after the loss of an eye, the 
 change in the texture was seen only in the nerve of the same side, be- 
 hind the decussation, (3) and that it is very easy to distinguish in this 
 latter the two nerves from each other, by their color and other proper- 
 ties. (4) 
 
 The partisans of the second opinion state, 
 
 1st. The normal appearance. (5) 
 
 2d. Those cases where the origin of one optic nerve, or the part of 
 the two nerves behind the decussation has been found unusually large 
 or small, and the nerve of the opposite side presented the same charac- 
 ter before the decussation, (6) while the sight was unaffected. 
 
 3d. The cases in which the disease of the nerve before the decussa- 
 tion extended behind it only to the .nervous cord of the opposite side, 
 and affected even the corresponding cerebral portions of this side.(7) 
 4th. The analogous cases where the origin of one of the two nerves 
 was affected, and the functions of the eye of the opposite side were 
 deranged.(8) Sometimes only this origin was diseased, and not the 
 portion of the nerve on the other side of the decussation. (9) 
 
 5th. The analogy with several animals, particularly with most 
 fishes, the nerves of which evidently intercross and enter each other. 
 The third hypothesis is supported, 
 
 1st. By the anatomical examination of the parts in the normal 
 state. (10) 
 
 (1) Vicq-d’Azyr, loc. cit. — Wenzel, p. Ill, 115. This anatomist admits that a 
 small portion of the inner part proceeds to the opposite side before they unite ; but 
 as he expressly remarks that he has been unable to discover any fibre in this in- 
 ternal part, the preceding' sentence does not favor the decussation, since the direc- 
 tion he allows to the fibres is only that of the whole nerve. — Caldani (Mem. delle 
 soc. ital., vol. xii. part ii. p. 28) has found the optic nerves united behind the decus- 
 sation by a transverse medullary band. 
 
 (2) Vesalius, loc. cit. — Nicolas de Janua, in Caldani, Opusc. anat ., Padua, 1803, 
 p. 40. 
 
 (3) Vesalius, loc. cit. — Cesalpino, in Riolan, Anlhopogr ., 1. iv. — Cheselden, in the 
 Phil, trans. — Santorini, Obs. anat., c. iii. p. 63, 64. — Meckel, in Haller, Grundriss , 
 p.386. — Caldani, Opusc. anat., p. 33 and 35: two cases. — Id., ' in Mem. delle soc ital., 
 vol. xii. plate ii. p. 27.— Burns, Anatomy of the head and neck, Edinburgh, 1811, 
 p. 359. 
 
 (4) Santorini, loc. cit. 
 
 (5) Petit, in the Mém de Paris, 1736, p. 7. — Sœmmerfing, loc. cit. 
 
 (6) Sœmmerring, loc. cit. Several cases. 
 
 (7) Michælis, loc. cit., p. 145. — Caldani, loc. cit., p. 35. — Wenzel. 
 
 (8) Valsalva, in Morgagni, Ep. anat., xiii. p. 115. obs. iii. 
 
 (9) Wenzel, loc. cit., p. 125. 
 
 (10) Caldani, Opusc. anat., p. 37. tab. ii. fig. 4. The simple maceration in water, 
 or immersion in sulphuric acid and vinegar, gave no result ; but this is not the 
 case with nitric acid after the neurilemma was removed. Caldani has observed, 
 eight times in this manner, that the external nervous fibres went directly to the eye 
 of the same side, and the internal to that of the opposite side, that consequently these 
 latter intercrossed, and that even the fasciculi visibly divided into several branches. 
 
so 
 
 DESCRIPTIVE ANATOMY. 
 
 2d. By those pathological cases where one eye being destroyed and 
 its nerve affected, the external fibres of the diseased nerve and of the 
 healthy nerve, remained each on their side before and behind the de- 
 cussation, while the internal fibres of the healthy eye passed through it 
 to go to the opposite side, where they formed the internal fibres of the 
 nerve of this side, and the internal fibres of the diseased nerve also 
 passed to the healthy side, although less evidently, at least in some 
 cases.(l) 
 
 3d. By the cases, where after the disease of an eye and of its optic 
 nerve, the decussation and the nerve of the same side behind it, were 
 wasted. (2) 
 
 4th. By the cases of the loss of an ej'e with the affection of only 
 one optic nerve before the decussation and of the opposite nerve, or of 
 both, behind this point. (3) This fact really seems to favor the hypo- 
 thesis of a partial decussation, since different physiologists think it 
 cannot be explained otherwise, and more so, because in many cases 
 where the two nerves were wasted behind the decussation, that of the 
 healthy eye was found unusually large. (4) 
 
 When all these pathological facts are duly considered, we must 
 admit that they do not prove positively either of the three opinions, in- 
 asmuch as the dissection of the healthy parts has not demonstrated 
 the fact of the decussation. In fact., they may be explained satisfac- 
 torily by saying that the substance of the two nerves is so blended in 
 the decussation, that these nervesdonot partially or wholly cross, and still 
 less are they placed one against the other, but they properly arise from 
 this common substance formed by the union of the two optic bands 
 ( tracius optici ), which opinion differs much from that of a partial de- 
 cussation. The differences of the pathological phenomena, authorize 
 the adoption of this hypothesis, as this alone explains them very well. 
 We may then consider as accidental, that where the optic nerve is 
 diseased to the decussation, the alteration is observed on the other side 
 of this union, on the cord of the same side, on that of the opposite side, 
 or on both at once. This intimate union of the two portions of the 
 optic nerves between their origin and decussation, is rendered very 
 probable by what we have remarked, and which had been seen before 
 us by Morgagni, (5) Michaelis, (6) Bichat, (7) and Wenzel, (8) that 
 when the optic nerve had wasted and had been gray for a long time 
 
 Wenzel has once found in a subject whose sight was not affected, some gray sub- 
 stance in the centre of the decussation ; the interna) fibres of the two nerves evi- 
 dently passed through this substance to intercross (toc. cit, p. 118). 
 
 (1) Wenzel, 113, 217. 
 
 (2) Walter, Uebcr die Einsavgung und die Durchkreuzung der Sehnerven, 
 Berlin, 1794, p. 97. 
 
 (3) Ackermann, loc. cit. — This has been seen in most cases. 
 
 (4) Morgagni, Epist. anat., xviii. 40. — Michælis, loc. cit., p. 145. — Wenzel, p. 125. 
 
 (5) Epist. anat., xviii. 40. 
 
 (6) Loc. cit., p. 146. 
 
 (7) Anat. descript., vol. iii. p. 153. 
 
 (8) Loc. cit. p. 1 12. 
 
OF THE NERVOUS SYSTEM. 
 
 SI 
 
 either before or behind the decussation, the decussation itself and the 
 portion of the nerve before or behind it, was not in the least abnormal, 
 and when the contrary occurred, the portion separated by the decus- 
 sation from that first affected by the disease, was always altered much 
 less than this latter. This phenomenon certainly indicates a great 
 difference and a marked distinction between the posterior part of the 
 nerve, including the decussation and the anterior portion, and the more, 
 as when the portion situated before or behind the decussation is dis- 
 eased, it usually presents the same kind of alteration in all its extent. 
 
 The differences between the pathological phenomena, mentioned by 
 us above, depend perhaps on primitive differences of structure. This 
 conjecture seems much more probable, as the structure of the nervous 
 system, notwithstanding its great regularity, nevertheless frequently 
 presents, when attentively considered, very great anomalies. It is 
 then possible, that as in other organs situated on the median line, the 
 union is sometimes more, sometimes less intimate, sometimes there 
 is merely a juxta-posidon, and that there are a series of successive 
 states, the first link of which is the case described by Sœmmerring, in 
 Noethig, and the last, that mentioned by Vesalius, although Haller 
 rejects this hypothesis.(l) 
 
 Finally, the texture of the optic nerve before or behind the decussa- 
 tion, according as the origin of the nerve or the eye are primitively 
 affected, proves nothing in favor of either of these three opinions, since 
 in some cases where the sense of vision was lost in both eyes at the 
 same time, one of the nerves was much thinner than the other behind 
 the decussation.(2) 
 
 Finally, according to our own observations, this partial decus- 
 sation is very probable; some at least of the differences in the patholo- 
 gical phenomena may then be easily explained, since, when the inner 
 part of the optic nerve is affected, that of the opposite side, and when 
 the outer part is diseased, that portion of the same nerve behind the 
 decussation presents marks of disease. 
 
 § 1879. The two optic nerves separate on leaving the decussation, 
 and pass through the optic foramina into the cavity of the orbits. Here 
 they are situated between the recti muscles of the eye, curve and be- 
 come convex outward. When near the eye they contract very much, 
 pass through the sclerotica and also the choroid membrane, and termi- 
 nate in the organ, expanding in the retina. 
 
 They are first covered with neurilemma before the decussation. 
 This membrane has there more firmness than in the other nerves, and 
 penetrates within them, forming distinct sheaths. The optic nerves 
 differ from all others, not only because they reunite, but also because 
 they are intimately enveloped in all their course by a fibrous sheath, 
 which is continuous posteriorly with the periosteum of the orbit and 
 dura-mater, anteriorly with the sclerotica. 
 
 (1) El. phys. book xvi. vol. v. p. 752. 
 
 (2) Wenzel, p. 115. obs. ii. 
 
S2 
 
 DESCRIPTIVE ANATOMY. 
 
 XII. OLFACTORY NERVE. 
 
 § 1S80. The olfactory nerve, the first pair, the ethmoidal nerve (N. 
 olfactorius, s. par primum, the caruncula of the ancients, who con- 
 sidered the optic nerves as the first cerebral pair), is situated on the 
 lower face of the hemispheres of the cerebrum, in a groove which is 
 there seen, but a few lines from their inner edge. It goes a little ob- 
 liquely from without inward, so that the cords of the two sides are 
 separated anteriorly only by the crista galli process. In this course it 
 advances, on the body of the sphenoid bone and the cribriform plate of 
 the ethmoid bone, covered by the pia-mater, which extends like a 
 bridge from one edge of the groove in which it is situated, to the other. 
 This groove, however, is much deeper than the thickness of the nerve, 
 and like all the other anfractuosities of the cerebrum, the pia-mater 
 exactly covers its surface in all parts. 
 
 The olfactory nerve arises by three medullary bands or roots, from 
 the posterior and inner part of the anterior lobe of the cerebrum, where 
 this latter unites to the posterior lobe. The external band is the nar- 
 rowest and strongest. Convex posteriorly, concave anteriorly, its 
 direction is from behind forward, from without inward, and from above 
 downward in the fissure of Sylvius, at the union of the anterior lobe 
 with the posterior, proceeds at first almost transversely, then descends 
 nearly perpendicularly, and reunites with the internal root some dis- 
 tance from the posterior extremity of the lower face of the anterior 
 lobe. 
 
 The middle root, the shortest, and which it is generally more correct 
 to consider only as the internal portion of the external root, arises from 
 the centre of the anterior perforated plate or even directly from this 
 plate by some fibres of which the internal are concave inward and the 
 external are straight. After proceeding from one to two lines, it unites 
 to the external root and gives rise to a common trunk a line and a half 
 large and very broad, the direction of which is oblique from behind for- 
 ward and from without inward. 
 
 The internal root is from one to four lines long. It comes from the 
 internal posterior extremity of the lower face of the anterior lobe, pro- 
 ceeds obliquely from above downward, from behind forward, and 
 from within outward, and anastomoses with the common trunk of the 
 others. 
 
 All these roots are so imbedded in the gray substance that we per- 
 ceive only their internal faces, and we cannot demonstrate them in 
 every part without separating them by art. 
 
 Very probably all the gray substance in which they are imbedded 
 should be regarded as a portion of the cerebrum which is connected 
 Avith the origin of the olfactory nerve. This portion is oblong. It is 
 continuous outward with the union of the anterior and posterior lobes, 
 backAvard Avith the anterior perforated or cribriform plate, forward at 
 its outside and inside with two circumvolutions Avliich bound the fis- 
 
OF THE NERVOUS SYSTEM. 
 
 83 
 
 sure of the olfactory nerve. It is loose at its centre and forms the pos- 
 terior wall of this fissure within which it projects. 
 
 The nerve enlarges much from behind forward, so that its anterior 
 extremity is two or three times thicker than its origin. 
 
 It is prismatic, the base looks downward, the two lateral faces are 
 turned inward and outward, and the upper angle is the most acute. 
 
 In its whole extent it is very evidently formed of gray and of white 
 substance disposed in longitudinal fibres which proceed at the side of 
 each other and interlace together. Its anterior and enlarged extre- 
 mity called the bulb of the olfactory nerve (bulb us n. olfactorii), is that 
 part where, proportionally speaking, we find the most of gray sub- 
 stance. 
 
 In all the rest of the course of the nerve this substance is particu- 
 larly abundant in the inner side. On the outside it is seen near the 
 lower face. 
 
 The lower face of the bulb is the only part of the olfactory nerve 
 whence filaments arise. These filaments, each of which is surrounded 
 by a small prolongation of the dura-mater, pass through the openings 
 of the cribriform plate of the ethmoid bone, thus enter in the nasal 
 fossa, and are mostly distributed in the mucous membrane which lines 
 the septum and the turbinated bones. They are distinguished into 
 internal , middle, and external. We shall mention the manner in which 
 they are distributed when describing the organ of smell.(l) 
 
 CHAPTER III. 
 
 GANCLIONNARY NERVE. 
 
 § 1881. The ganglionnary nerve, the nervous system of the gan- 
 glions, the great sympathetic nerve, the intercostal , the trisplanchnir. 
 nerve (N, gangliosus, s. N. sympatheticus magnus , s. intercostalis 
 maximus, s. vertebralis, Lieutaud, s. trisplanchnicns , s. sysiema vitce 
 antomaticœ vegetatives, Bichat, Gall),(l) differs so remarkably from all 
 
 (1) The olfactory nerve has been considered as the conductor of the sensations 
 
 produced by odors. Magendie, however, refers this function to the fifth pair, which 
 sends so many different twigs into the nose. He rests his opinion on the fact, that 
 the destruction of the olfactory nerves, and even of the anterior cerebral nerves, is 
 not attended with the loss of smell, which, however, is always the case when the 
 two nerves of the fifth pair are divided (Le nerf olfactif est-il l’organe de l’odorat ? 
 in the Journ. de phys. expérim., vol. iv. p. 69). If this opinion be confirmed, the 
 ethmoid nerve does not differ in this respect from the hypoglossal. P. T. 
 
 (2) Consult. 1st. On this nerve in general : C. Bergen, De nerro intercostali, 
 Erfort, 1731. — A. F. Walter, Programma quo paris intercostalis et ragi corporis 
 humani nervorum et ab ulroque latere ejus obviorum analomen exhibet, Leipsic, 1733, 
 1735. — J. F. Huber, De nerro intercostali , de nervo octavi et noni paris deque acces- 
 sorio, Cassel, 1744. — C. C. Schmidel, De nervo intercostali, Erlangen, 1754. — M. 
 Girardi, De nerro intercostali, Florence, 1791. — A. Portal, Description du nerf inter- 
 costal dans l’homme; in the Mém. de l’Institut, vol. iv. Paris, au. xi. p. 151, 209, 
 
81 
 
 EF.SCKIPTIVE ANATOMY. 
 
 the other nerves and is so opposed to the rest of the nervous system in 
 several respects that it would be more proper not to place it in the 
 same class with the encephalon, the spinal marrow and their nerves, 
 but to consider it as a different but subordinate system. 
 
 § 1882. This system is formed of numerous ganglions, varying in 
 number and size not only in both sides of the same subject but also in 
 different individuals, and of nervous twigs, some of which unite these 
 ganglions in several different ways, while others are given off to enter 
 the organs. It exists uninterruptedly on the two sides and the ante- 
 rior face of the vertebral column, along the neck, chest, and abdomen, 
 so that its two halves frequently anastomose on the median line 
 it extends from the base of the skull to the lower extremity of the 
 trunk, and is distributed in the organs of vegetative life. 
 
 The ganglions of this nervous system divide in respect to their situa- 
 tion and mode of distribution into two classes which comprise, the first 
 the internal or central ganglions , the second the limiting ganglions. 
 
 The central ganglions are principally situated in the abdomen, around 
 and above the trunks of the large vessels near the principal organs, 
 those which appear most independent in their functions. Several adja- 
 cent ganglions are united to each other by larger or shorter filaments, 
 and thus form a plexus whence arise some nerves which go 
 to the organs, also some filaments which anastomose with other 
 similar plexuses. The limiting ganglions are situated on the two 
 sides of the vertebral column in succession. They are fewer in the 
 neck than in the chest and abdomen, and are generally found in the 
 two latter sections of the trunk between each two vertebrae. They 
 are situated behind the serous membranes of the thoracic and abdomi- 
 nal cavities, and anastomose by some longitudinal cords with each 
 other and with the central ganglions by some oblong or transverse 
 fibres, and with most of the nerves of the centre of the nervous system 
 
 in the Anat. med., vol. iv. — Bock, Ueber das Gangliensystem ; in Abhandlung über 
 das fünfte Nervenpaar , Meissen, 1817. — E. H. Weber, Anatomia comparata nervi 
 sympathetici, Leipsic, 1817. — J. F. Lobstein, De nervi sympathetici liumani fabrica, 
 usu et morbis, Paris, 1823. — 2d. On its origin : D. Iwanhoff, De origine nervorum, 
 intercostal ium, Strasburg, 1780.- — J. Munniks, Observatio qua 'ad illustrandam 
 artem medicam, ostenüitur origo nervi intercostalis , ejusque commercium cum aliis 
 nervis, ab ejus origine usque ad exitum e calvaria , cum autopsia , tum observatis 
 medicis confirmata; in his Observ. var., Groningen, 1805, no. ii. — 3d. On some of its 
 parts : C. T. 1 .udwig, De ple.vibus nervorum abdominalium atque nervo intercostali 
 duplici observationes nonnullœ, Leipsic, 1772. — H. A. Wrisberg, Obs. anat. de nervis 
 viscerum abdominalium partie. I ; de ganglio plexuque semilunari , Gottingen, 1780. 
 G. Walter, Tabulae nervorum thoracis et abdominis , Berlin, 1783. — H. A. Wrisberg, 
 De nervis vise, abdom., part ii., de nervis systematis cœliaci. Sectio 1 ; de nervis gas- 
 tricis, quee est observationum de ganglio plexuque semilunari continuatio ; in the 
 Syllogc comment., 1800, p. 551, 570. — H. A. Wrisberg, Obs. anat. neurolog. de nervis 
 viscer. abdom., part iii., de nervis systematis cœliaci II ; de nervis hepaticis et sple- 
 nicis, quœ est observationum de ganglio plexuque semilunari continuatio II, Got- 
 tingen, 1808. — 4th. On its functions. Broussais, Réflexions sur les fonctions du sys- 
 tème nerveux en general, sur celles du grand sympathique en particulier, et sur 
 quelques autres points de physiologie ; in the Journ. unir, des $c. mêd., vol. xii. 
 
OF THE NERVOUS SYSTEM. 
 
 85 
 
 particularly with the anterior and posterior branches of all the spinal 
 nerves by intermediate filaments. 
 
 Such is the most general view of the ganglionnary nerve which can 
 be presented. The chain of the limiting ganglions and of the nervous 
 cords which unite them have been generally and until lately consi- 
 dered as its trunk and its upper extremity as its origin, admitting that 
 prolongations proceed outward from these two points to the nervous 
 system of animal life, inward to the thoracic and abdominal viscera. 
 But now it is admitted to be more proper to describe first its most 
 internal part, and to conclude with the history of the ganglions 
 which connect it with the nervous system of animal life, and the fila- 
 ments which establish this communication. 
 
 I. CENTRAL PORTION. 
 
 § 1883. The centre of the ganglionnary nerve is formed of several 
 ganglionnary plexuses situated in the cavity of the abdomen, and of 
 the nerves which proceed from them to the organs, and the limiting 
 ganglions. These plexuses considered from above downward are as 
 follow : 
 
 § 1884. The solar plexus, the semilunar ganglion , the suprarenal 
 ganglion and median plexus ( P . Solaris , Willis, s. G., s. P. semi-lu- 
 naris, abdominalis, transversus, communis, cerebrum abdominale ) de- 
 serves to be first studied, since from its size, the constancy of its gan- 
 glions whence all the abdominal plexuses emanate, and its direct 
 connection with several of the limiting ganglions, it is the real centre 
 of the nerve. 
 
 It is situated before the abdominal aorta behind the peritoneum be- 
 tween the two renal capsules, and it surrounds the trunk of the cceliac 
 artery. 
 
 The ganglions which unite to form it vary in number and size. 
 We however always find at least two ganglions, a right and a left, 
 which when many exist are always the largest. They are almost 
 semicircular, generally more than an inch long, about half an inch 
 broad in several parts particularly in the centre, and several lines thick 
 from before backward. Their convex edge is turned outward, their 
 concave edge inward. 
 
 The right is generally much larger than the left, broader in propor- 
 tion to its length, angular and rhomboidal. It is situated between 
 the ascending vena-cava and the right pillar of the diaphhragm, and 
 the right renal artery and the upper extremity of the right renal cap- 
 sule. 
 
 The left., smaller, is proportionally larger and more semicircular ; it 
 is situated between the left pillar of the diaphragm, the pancreas, the 
 splenic artery, and the left renal capsule. 
 
 Both are united by numerous nervous filaments which proceed trans- 
 versely from the internal edge and the two extremities of one to the 
 
 Vol. III. “ 12 
 
86 
 
 DESCRIPTIVE ANATOMY 
 
 corresponding points of the other. All or most of these filaments ra- 
 mify more or less in their course and frequently anastomose. 
 
 We usually observe between the two principal ganglions, particu- 
 larly between their lower extremities in the space between the cœliac 
 and superior mesenteric arteries, two or three which are smaller : these 
 anastomose with each other and with the two larger ones by interme- 
 diate filaments, and apparently belong sometimes to the right and 
 sometimes to the left ganglion. 
 
 Sometimes the principal ganglions instead of being thicker and 
 broader at their centre as is usual, are very narrow there, while they 
 enlarge at their extremities. This arrangement is the first step to- 
 wards a rare anomaly, where they divide from above downward in a 
 variable number of enlargements which communicate by nervous fila- 
 ments. The middle enlargements thus formed are generally the 
 largest ; but sometimes although more rarely they are smaller than 
 the superior and inferior, which renders the arrangement of the nerve 
 still more abnormal. 
 
 The ganglions in the first case are nearer each other than in this 
 latter ; in the latter case they are sometimes united in several nervous 
 filaments interwoven like a plexus. Sometimes from three to eleven 
 small subordinate ganglions form on the outside above and below one 
 or both of the principal ganglions ; from these arise filaments which 
 go to the adjacent plexuses, and also those which assist to form the 
 great splanchnic nerve. The principal ganglion of the same side is 
 more or less enlarged, so that this formation leads still more directly 
 to that where it is entirely divided into a considerable number of 
 smaller ganglions which are nearly equal in size. 
 
 Of all these forms those where the central portion is most concen- 
 trated is evidently superior to the others : they present a very remark- 
 able repetition of the development of the centre of the nervous system 
 of animal life both in the fetus and in the whole series of animals. 
 
 The whole solar plexus is considerably large and extends longitu- 
 dinally from the upper edge of the cceliac artery to below the renal 
 arteries, and it is from one to two inches broad. 
 
 It generally divides like the cœliac artery into three principal parts. 
 
 Some nervous filaments proceed directly from its middle and upper 
 part ; they unite to other filaments of the left pneumo-gastric nerve, 
 give rise to the superior coronary plexus of the stomach, stomo-gas- 
 trique , Ch. (P. coronarius , s. ventriculi superior , s. minor), which 
 accompanies the superior coronary artery along the small curve of the 
 stomach, extends to the left orifice of this viscus and anastomoses par- 
 ticularly on the posterior face of the stomach with the inferior coronary 
 and the left hepatic plexus, with which it communicates by twigs. 
 
 The second and largest of these plexuses is termed the hepatic 
 plexus (P. hepaticus). It descends from left to right. One portion, 
 attends the right inferior coronary artery along the great curve of the 
 stomach, where it is distributed and is termed the inferior coronary 
 plexus ( P. coronarius stomachicus inferior) ; the other is larger and. 
 
OF THE NERVOUS SYSTEM, 
 
 S7 
 
 joins the hepatic vessels with which it goes to the liver. It first at- 
 tends the hepatic artery, but near the sinus of the vena- porta it divides 
 into a right and a left hepatic plexus. The first is larger than the 
 other, and is formed of from six to eight filaments. It enters into the 
 right lobe of the liver and the left goes to its left lobe. Both anasto- 
 mose with some filaments of the right pneumo-gastric nerve and also 
 form at intervals small prominences in the substance of the liver. Be- 
 fore entering this gland they send some filaments to the pylorus, and 
 also to theduodenal and pancreatic arteries. 
 
 Independent of these plexuses a smaller one is sometimes detached 
 from the right semilunar ganglion, the filaments of which proceed 
 from behind forward and from below upward in the small lobe of the 
 liver. 
 
 The splenic plexus (P. splenicus ) arises from the right lower part of 
 the solar plexus and the left semilunar ganglion, the branches of which 
 accompanying those of the splenic artery which they surround pass 
 on the pancreas, send some filaments to this gland, and also to the 
 large cul-de-sac of the stomach, where they form the small inferior 
 plexus of the stomach ( P . ventriculi inferior et minor), and then enter 
 into the substance of the spleen with the branches of the splenic ar- 
 tery. 
 
 Some branches arise from the lower part of the semilunar ganglions 
 of the solar, the hepatic and splenic plexuses, and unite to form the su- 
 perior mesenteric plexus (P. mesentericus superior ). This plexus ac- 
 companies the trunk and branches of the superior mesenteric artery : 
 its filaments are distributed principally to the small and large intestine, 
 and some enter the pancreas. 
 
 The upper part of the semilunar ganglions sends off on each side 
 four or five considerable branches which are enlarged by some filaments 
 from the superior mesenteric plexus, descend towards the renal arte- 
 ries, and interlacing by five or six subordinate ganglions form the renal 
 plexus (P. renalis ) on each side, which give numerous ramifications to 
 the renal capsules and to the kidneys. 
 
 This plexus communicates upward and outward with the inferior 
 thoracic and the superior lumbar ganglions by twigs, of which the 
 upper unite in larger branches which go separately to the limiting 
 ganglions and the nervous cords by which these latter are united. 
 
 The same plexus is continuous below with the spermatic plexus (P. 
 spermaticus), which descends along the spermatic vessels, anastomoses 
 with the superior and inferior mesenteric plexuses, gives some fila- 
 ments to the ureter, and extends in man to the testicle, in the female 
 to the ovary. 
 
 Some branches arise below from the superior mesenteric plexus, 
 descend before the abdominal aorta, and enter the inferior mesenteric, 
 the left colic plexus (P. mesentericus, s. mesaraicus inferior , s. médius, 
 Vieussens) . This latter, which is smaller than the upper, embraces 
 the inferior mesenteric artery. It contains but a few small ganglions 
 near this artery. 
 
88 
 
 DESCRIPTIVE ANATOMY. 
 
 On entering the pelvis it divides into two pairs, one the 'proper infer- 
 rior mesenteric plexus attends the branches and twigs of the inferior 
 mesenteric artery, and anastomoses with the lumbar ganglion and 
 sometimes also with the anterior branches of some lumbar nerves. 
 
 The other has a direction outward and downward, is termed the 
 hypogastric plexus (P. hypogastricus, s. mesentericus inferior, s. ter- 
 tins, s. posterior ), anastomoses with the lumbar and sacral portions of 
 the terminal cord of the ganglionnary nerve like the sacral nerves, and 
 attending the hypogastric vessels is distributed to the rectum and the 
 bladder, and in the male to the prostate gland and vesiculæ séminales, 
 in the female to the uterus and vagina. It also emerges from the 
 pelvis with the external branches of the hypogastric artery. 
 
 II. LIMITING CORD AND ITS BRANCHES. 
 
 § 1885. We have already mentioned generally the arrangement of 
 the limiting cord which is situated on the two sides of the vertebral 
 column and the skull. We describe it from above downward, and 
 .commence by the superior cervical ganglion which exists constantly. 
 
 A. SUPERIOR CERVICAL GANGLION. 
 
 § 1886. The superior cervical, the olivary or fusiform ganglion (G r 
 cemicale supreinum, s. olivare, s. fusiforme), one of the largest of those 
 of the ganglionnary nerve, is situated above and behind the angle of 
 the lower jaw, behind the internal carotid artery before the transverse 
 processes of the second and third cervical vertebræ and the rectus ca- 
 pitis major anticus muscle, on the inside of the pneumo-gastric and 
 hypoglossal nerves. It is surrounded by a cellular sheath which em 
 velops also the trunk of the pneumo-gastric nerve. 
 
 Its form and size vary much. It is almost always oblong, thinner 
 below than above, terminates however also in a point at its upper and 
 fusiform extremity. Sometimes it tends to divide into several gan- 
 glions situated successively from above downward. The first degree 
 of this anomaly is a contraction in its centre. Next comes the 
 formation of an upper or lower appendage ; we then observe contrac- 
 tions in two or three points.(l) It does not constantly extend en- 
 tirely to the carotid canal. Below it usually descends to the third, 
 sometimes however to the sixth cervical vertebra. Generally it is an 
 inch and a half long and its greatest breadth is three lines ; its length 
 however varies from some lines to four inches, but its breadth and 
 thickness are always inversely as its length. 
 
 It sends off numerous branches upward, outward, inward, forward, 
 and downward. 
 
 (1) Lobstein ha3 figured (tab. v. fig. 3) a superior cervical ganglion which he has 
 found double. 
 
OP THE NERVOUS SYSTEM. 
 
 89 
 
 I. UPPER BRANCHES. 
 
 1 . The superior branch is sometimes although very rarely double, 
 leaves the upper extremity of the ganglion, enters into the carotid 
 canal, and establishes a communication between the ganglionnary 
 nerve and the portion of the nervous system of animal life contained in 
 the skull. It is situated behind the internal carotid artery towards the 
 lower curve of which it usually divides into two nearly equal branches 
 which separate at an acute angle and ascend in the canal before the 
 carotid artery, one being more external than the other. 
 
 Opinions vary both in regard to their mode of anastomosis and the 
 number of the portions of the nervous system contained within the 
 skull, with which the ganglionnary nerve communicates by these 
 filaments ; these differences in opinion depend partly on the difficulty 
 of dissecting such delicate parts, partly on the varieties in their ar- 
 rangement. 
 
 The most ancient opinion was that the ganglionnary nerve anasto- 
 mosed only with the fifth pair.(l) 
 
 At a later period it was asserted to anastomose only with the ex- 
 ternal motor nerve. (2) 
 
 "Then it was admitted to be connected with both. (3) 
 
 Anatomists vary also as to the point where the ganglionnary nerve 
 -communicates with the two encephalic nerves ; the differences in 
 opinions are but slight and trivial in regard to the external motor nerve ; 
 but they are great in regard to the fifth pair, for it anastomoses ac- 
 cording to some with the trunk of this nerve, (4) according to others 
 with one(5) or more(6) or even with all of its branches. Some think 
 ■they communicate directly, (7) others indirectly and by ganglions :(8) 
 the descriptions also of the anastomosis with the sixth pair vary in this 
 last respect. 
 
 § 1887. The ganglionnary nerve always anastomoses with the sixth 
 pair in the carotid canal by a considerable branch coming from the 
 superior cervical ganglion, which ascends along the internal carotid 
 artery first on the outside and then on its anterior face. 
 
 (4) Galen, De nervorum origine ; in Op. omn., Venice, Vot. ii. p. 54. — The Ara- 
 bians and the first Italian anatomists have adopted his opinion. Rau and Valsalva 
 assert that they have sometimes observed this arrang-ement since. (Morgagni, 
 Ep. an. xvi. p. 330.) 
 
 (2) Eustachius, tab. xviii. fig. 2. — Morgagni, Adv. anal ., vol. vi.p. 30. — Santorini. 
 Obs. anat., c. iii., p. 67. 
 
 (3) Meckel. 
 
 (4) Schmidel, Munniks, Bock. 
 
 (5) Most authors. 
 
 (6) Laumonier. 
 
 (7) Most authors who have written on this subject, and on neurology in general. 
 (3) Petit, loc. cit. — Schmidel, loe. cit. — Laumonier, in Bacher, Journ. de méd., vol. 
 
 xciii., March, 1793, p. 259. — Munniks, Obs. nor.— Cloquet, TV. d’anat., vol. ii., p. 
 
90 
 
 DESCRIPTIVE ANATOMY. 
 
 This branch generally unites to the external motor nerve by a single 
 twig which meets it and is detached at an acute angle from the ex- 
 ternal and inferior part of the sixth pair during its passage through the 
 cavernous sinus. 
 
 This twig is not unfrequently double and sometimes the recurrent 
 filament of the external motor nerve bifurcates soon after arising. 
 
 Sometimes also the anastomosing branch of the ganglionnary nerve 
 within the sixth pair is double, in which case one proceeds on the out- 
 side the other on the inside of the internal carotid artery. 
 
 We frequently and even perhaps always find at the upper part of the 
 carotid canal or in the cavernous sinus, instead of a direct anastomosis, 
 a ganglion situated on the outside of the internal carotid artery called 
 the cavernous ganglion (G. caver no sum). Three or more filaments 
 proceed from the summit of this ganglion to the nerve of the sixth 
 pair . ( 1 ) 
 
 The anastomosis with the trifacial nerve is always by a filament 
 which goes to the recurrent twig of the second branch of the fifth pair 
 or the vidian nerve. This filament is distributed partly in the carotid 
 artery, partly also emerges from the carotid canal, passes through the 
 dura-mater and enters the pterygoid canal where it unites with the 
 recurrent twig. 
 
 Thus the branch from the upper extremity of the upper cervical 
 ganglion usually divides into these two filaments, one of which goes 
 to the external motor, the other to the trifacial nerve. 
 
 This bifurcation generally takes place within the carotid canal, sel- 
 dom below and never above it. 
 
 Sometimes but rarely also the upper extremity of the superior cer- 
 vical ganglion gives origin to two superior branches, which go one to 
 the external motor the other to the vidian nerve. 
 
 When this arrangement exists the two anastomotic filaments and 
 the vidian nerve communicate with the external motor nerve. Some- 
 times also this triple anastomosis does not exist. 
 
 An analogous case is where either the anastomosing filament which 
 goes to the external motor nerve or that which proceeds to the trifacial 
 or both divide into several filaments, all of which unite in a common 
 trunk to go to the superior cervical ganglion. 
 
 § 1888. This is the only anastomosis admitted by most authors 
 between the ganglionnary and the trifacial nerves. In fact it is often 
 the only one which can be demonstrated. But the great sympathetic 
 nerve also unites by its upper extremity in another manner, at least 
 sometimes, with the trifacial nerve. 
 
 Many anatomists, and Portal among others, positively reject this 
 other anastomosis ; but many observations favor its existence. 
 
 In fact according to Schmidel and Munniks, several filaments come 
 from the ganglionnary plexus of the fifth pair and go to the carotid 
 
 (1) Laumonier, loc. cit. — Munniks, loc. cit. 
 
OF THE NERVOUS SYSTEM. 
 
 91 
 
 canal, where they unite with other filaments of the external motor 
 nerve and form a ganglion. 
 
 Others however whose opinions are like the preceding, assert that 
 beside those filaments mentioned, or even if they do not exist, we find 
 a smaller twig coming from the first branch of the fifth pair ; and this 
 unites sooner or later either with the anastomosing filament of the 
 sixth pair, as Petit, (1) Schmidel,(2) and Coopmanns(3) assert, or with 
 the cavernous ganglion. (4) 
 
 Laumonier, on the contrary, has found coming from the cavernous 
 ganglion, the two filaments which anastomose with the sixth pair and 
 the vidian nerve, and also a third which went to the second branch of 
 the fifth pair, and a fourth to the fourth branch of this same pair.(5) 
 Bock(6) asserts that ten filaments go to the anterior extremity of the 
 trunk of the fifth pair, particularly towards the portion which corres- 
 ponds to the first branch. 
 
 All these assertions, however agree, in this, that besides the fila- 
 ment which anastomoses with the vidian nerve, one or more anasto- 
 moses exist nearer the origin of the fifth pair with one or several of its 
 three principal branches, or with its trunk : these anastomoses take 
 place by a ganglion, and from this arises the filament of communica- 
 tion with the superior cervical ganglion. (7) 
 
 We also sometimes find a more indirect anastomosis between the 
 upper extremity of the ganglionnary nerve and the third pair of cere- 
 bral nerves, the latter anastomosing with the sixth and fifth in the 
 place where they give filaments, which communicate with the great 
 sympathetic nerve. (8) 
 
 According to Fontana(9) and Ribes,(10) whose correctness we have 
 partially attested, the ganglionnary nerve penetrates still farther up- 
 ward and forward, for it sends some filaments from the carotid canal to 
 the pituitary gland,(ll) or to theinfundibulum,(12) and also a fasciculus 
 which accompanies the ophthalmic artery, forms a plexus around the 
 different branches of this vessel, not excepting the central artery of the 
 retina, and anastomoses by a filament with the lenticular ganglion, 
 
 (1) Loc. cit., p. 4. 
 
 (2) Loc. cit., p. 16, 21. 
 
 (3) Loc. cit., p. 219. 
 
 (4) Cloquet, loc. cit., p. 687. 
 
 (5) Loc. cit., p. 259. 
 
 (6) Vom fiinften Nerven, p. 3. 
 
 (7) Lobstein does not admit all these anastomoses ; he has seen some transparent 
 
 and gelatinous filaments which united the ramifications of the great sympathetic 
 nerve with the common motor and other nerves; but by examining them with the 
 microscope, he has not found in them the characters of nervous organs. He regards 
 them as cellular tissue extended in filaments. F. T. 
 
 (8) Munniks, loc. cit., p. 25. 
 
 (9) In Girardi, loc. cit., p. 25. As Carus ( Anatomie und Physiologie des Nerven- 
 systems, p. 185) has also observed in several reptiles. 
 
 (10) Ribes, Rech. anat. etphys. sur quelques parties de l'œil ; in the Mém. de la sec. 
 mêd. d'émul., vol. vii. p. 97. 
 
 (11) Fontana, loc. cit., p. 56, 57. 
 
 (12) Cloquet, loc. cit. 
 
92 
 
 DESCRIPTIVE ANATOMY. 
 
 consequently with the first principal branch of the fifth, and with the 
 third pair.(l). And likewise as there exists also between the lenti- 
 cular ganglion, the cavernous sinus, and all the ganglionnary system, 
 a constant relation, (2) similar to that between the two ganglions, we 
 consider this small filament with the ciliary nerves which come from it, 
 as making part of the great sympathetic nerve, which supposition 
 seems to us very probable. 
 
 II. EXTERNAL BRANCHES. 
 
 The external branches are from one to four in number, pass above' 
 the rectus capitis major anticus muscle, to go and meet the first and 
 second cervical nerve. When there is only one, it is larger, and soon 
 divides into as many branches as generally exist, comes sometimes 
 from the upper, and sometimes from the centre of the superior cervical 
 ganglion. The upper two arise from the upper extremity of this same 
 ganglion, directly at the side of each other, and anastomose with the 
 anastomotic plexus of the first and second cervical nerves. The third 
 communicates with that of the third and fourth cervical pairs. The 
 fourth which arises more frequently from the twig of communication 
 between the first and second cervical ganglions, anastomoses on one 
 side by several filaments with the anastomotic plexus of the third and 
 fourth cervical nerves, and is distributed in the rectus capitis major 
 anticus and the scalenus anticus muscle. 
 
 III. INTERNAL BRANCHES. 
 
 The internal branches are much smaller and less constant in respect 
 to number, and are distributed to the longus colli, the rectus capitis 
 major anticus muscle, the pharynx and the larynx. 
 
 IV. ANTERIOR BRANCHES. 
 
 The anterior branches are the largest and most numerous. They 
 are distinguished by their reddish tint and their softness, and hence 
 are termed soft nerves ( N . molles ). The superior are shorter than the 
 others, proceed from below upward, and anastomose with the hypo- 
 glossal, the pneumo- gastric, and the facial nerves, just after they 
 emerge from the skull. The middle and inferior are larger, go forward' 
 and downward, envelop the primitive carotid arteries to their origin, 
 anastomose in this course with some branches of the pneumo-gastric 
 nerve, and surround also, together with the facial and pneumo-gastrie 
 nerves, the branches of the external and internal carotid arteries, to 
 the carotid canal. The latter not unfrequently come from a distinct 
 small ganglion. 
 
 (1) Ribcs.— Cloquet.— Bock. 
 
 (2) Ribes.— Cloquet.— Bock. 
 
OF THE NERVOUS SYSTEM. 
 
 93 
 
 The largest anterior branch is the superior or superficial cardiac 
 nerve (JV. cardiacus superior , s. superficialis ), which arises by from 
 four to six filaments from the internal anterior part of the cervical gan- 
 glion, sometimes also partially or wholly from the upper extremity 
 of the cord which joins this ganglion to the following. The minute 
 nerve formed by the union of these filaments, descends on the outside 
 of the primitive carotid artery, covered by the cord of communication 
 of the great sympathetic nerve, gives off at about its centre some fila- 
 ments which surround the inferior thyroid artery, anastomoses with 
 one or two twigs of the pneumo-gastric nerve, communicates also with 
 the descending branch of the hypoglossal nerve, gives ramifications to 
 the pharynx, the esophagus, the sterno-hyoideus and sterno-thyroideus 
 muscles, and usually terminates partly by anastomosing with some 
 ramuscules of the recurrent branch of the pneumo-gastric nerve, and 
 partly sends retrograde filaments to the thyroid gland. It more rarely 
 descends to the arch of the aorta, where it unites to the middle car- 
 diac nerve ; but it never extends to the heart., so that it does not de- 
 serve the term applied to it. 
 
 That of the left side commonly extends farther than that of the 
 right. 
 
 V. INFERIOR BRANCH. 
 
 The inferior branch establishes the communication between the su- 
 perior and the middle, or the inferior cervical ganglion, and is generally 
 considered as the continuation of the trunk. It varies in size and firm- 
 ness. It is generally thinnest in its centre, and is always larger than the 
 superior cardiac nerve which is situated before and on the inside of it. 
 It constantly arises from the lower extremity of the superior cervical 
 ganglion, with which it is less directly continuous, the larger it is and 
 the smaller the ganglion. Its length depends on that of the superior 
 ganglion, and on the presence or absence of the middle one. It 
 always exists. It is situated before the rectus capitis major anticus 
 and the longus colli muscles, near the inner edge of this latter, first be- 
 hind the internal carotid artery, then behind the primitive carotid, 
 between the internal jugular vein and the pneumo-gastric nerve. 
 
 It is most generally single. Very rarely it is divided at its lower 
 part into two twigs, which embrace the inferior thyroid artery, and 
 which usually enter, one the middle cervical ganglion, the other the 
 inferior cervical ganglion. 
 
 This branch anastomoses by some external filaments with the ac- 
 cessory and several cervical nerves, more frequently with the superior 
 than the inferior, sometimes even with the eighth. These differences 
 and those in the length of the cord, depend on those in the size of the 
 superior cervical ganglion, and also on the presence or absence of the 
 middle ganglion. The anastomosing branches generally unite in 
 some larger branches before coming to the trunk of the ganglionnary 
 nerve. 
 
 VOL. III. 
 
 13 
 
94 
 
 DESCRIPTIVE ANATOMY. 
 
 F rom this branch arise some filaments which contribute to form the 
 superficial cardiac nerves. It gives some also which unite to others 
 coming from the superior cervical ganglion, sometimes arise only from 
 the superficial cardiac nerves, and go almost transversely inward, and 
 are distributed, the superior particularly, in the constrictor muscles of 
 the pharynx, the inferior in the thyroid gland, the muscles, and the 
 mucous membrane of the larynx. These filaments frequently anas- 
 tomose with each other or with some ramifications of the pneumo- 
 gastric and glosso-pharyngeal nerve. 
 
 B. MIDDLE CERVICAL GANGLION. 
 
 1839. The middle cervical or thyroid ganglion (G. cervicale me- 
 dium, s. thyroideum ) is situated at the origin of the inferior thyroid 
 artery, between the fifth and sixth, or between the sixth and seventh 
 cervical vertebrae, directly before the longus colli muscle, behind the 
 primitive carotid artery and the pneumo-gastric nerve. It is not so 
 constant as the superior; it however exists more frequently than it is 
 absent, and in the proportion of 3 : 1, judging from our dissections ; it is 
 sometimes extremely small, and sometimes deficient. It is never ob- 
 long, but always broad and slightly flat. When deficient, we some- 
 times, but not always, find in its place two inferior cervical ganglions, 
 in which case consequently, it is only situated lower than usual. 
 Sometimes, but much more rarely, it is double, that is, it is divided into 
 two small ganglions, a superior and an inferior, the former of which is 
 then situated higher than the common single ganglion. 
 
 Its branches go upward, outward, inward, forward, and down- 
 ward. 
 
 The superior unites it to the superior cervical ganglion, which we 
 have already described. 
 
 The external are sometimes reduced in number to one, anastomose 
 with one or more of the inferior cervical pairs, especially from the fourth 
 to the sixth. 
 
 The internal accompany the inferior thyroid artery, on which they 
 give rise to the thyroid plexus (PI. thyroideus ), extend to the thyroid 
 gland, and go to join and enlarge the recurrent laryngceal nerve. 
 
 The anterior form the middle or deep cardiac nerve, the great car- 
 diac nerve (N. cardiacus médius, s. magnus, s. profundus ), which is 
 the largest. Five or six filaments unite near the ganglion, first into 
 two or three fasciculi, then in a trunk which descends obliquely from 
 without inward, first along the primitive carotid artery, then before the 
 subclavian, anastomoses in its course by several filaments with the 
 trunk of the pneumo-gastric nerve, and with its recurrent branch, and 
 unites with the inferior cardiac nerve to form the cardiac plexus. 
 
 The middle cardiac nerve differs on the right and left sides. 
 
 That of the right side, after passing before the subclavian artery, 
 descends along the trunk of the innominata, unites at its bifurcation by 
 a small ganglion with one or two twigs of the pneumo-gastric nerve, 
 
OF THE NERVOUS SYSTEM. 
 
 95 
 
 and then passes between the arch of the aorta and the bifurcation of 
 the trachea. 
 
 That of the left side arises by several filaments from the middle cervi- 
 cal ganglion, andfromthe inferior ganglion by one or two filaments which 
 are larger than the preceding. The two ganglions then unite in this 
 place, while on the right side they remain separate. The two roots 
 unite some distance from the origin of the subclavian artery. The 
 trunk passes behind the arch of the aorta, there unites to some fila- 
 ments of the pneumo-gastric nerve, and anastomoses with that of the 
 right side, and likewise with the two inferior cardiac nerves, to form 
 the cardiac plexus. 
 
 The inferior branches are very minute, shorter than the rest, and 
 five or six in number. They descend on the right side before and 
 behind the subclavian artery, on the left side before and behind the 
 trunk of the aorta, and anastomose with the superior ascending 
 branches of the inferior cervical ganglion. 
 
 Sometimes the anterior of these branches are deficient, and the pos- 
 terior also are united in a short common trunk, which establishes a 
 direct connection between the two cervical ganglions. 
 
 C. INFERIOR CERVICAL GANGLION. 
 
 § 1890. The inferior cervical ganglion (G. cervicale inferius) is 
 much more constant than the central, and is generally flat, rarely 
 rounded and oblong, often very irregular, and sometimes double. It 
 is situated before the transverse process of the seventh cervical vertebra 
 and the neck of the first rib, but sometimes descends to the second 
 rib. 
 
 Its superior branches anastomose with the inferior of the middle 
 ganglion. One which is rather large, enters the vertebral canal, 
 where it entwines around the vertebral artery, sends some filaments to 
 the intertransversarii muscles, and terminates at the third or second 
 cervical vertebra. 
 
 Sometimes this branch arises only from the filaments which anasto- 
 mose with the brachial plexus. 
 
 The external are smaller, but numerous, surround the subclavian 
 artery, and give ramifications to the muscles of the neck, and anas- 
 tomose with the two or three inferior cervical nerves, and also with 
 the first dorsal, sometimes even but more rarely with the second tho- 
 racic pair, when the inferior cervical ganglion is much developed. 
 
 The internal terminate principally in the longus colli muscle and 
 the pulmonary plexus. 
 
 The anterior form the inferior cardiac nerve (N. car diacus inferior. 
 s. tertius , s. parvus ), which generally exists only on the right side, while 
 on the left it is only indicated by the inferior root of the great cardiac 
 nerve. These branches frequently interlace before uniting in a single 
 trunk. The latter descends first behind the subclavian artery, then 
 before the innominata and the arch of the aorta, anastomoses often 
 
96 
 
 DESCRIPTIVE ANATOMY. 
 
 with the pneumogastric nerve, gives some filaments to the vessels 
 situated near its course, and goes to the left between the aorta and the 
 pulmonary artery, and terminates in the anterior cardiac plexus. 
 
 CARDIAC PLEXUS. 
 
 § 1891. The cardiac plexus (PI. cardiacus ) is formed principally by 
 the middle cardiac nerves. It is situated between the arch of the 
 aoi ta and the bifurcation of the trachea. It extends from the division 
 of the pulmonary artery to the origin of the innommata. 
 
 Its anterior filaments go principally to the anterior wall of the aorta, 
 and the posterior to the pulmonary plexus. The inferior are more 
 numerous, and go almost exclusively to the heart, where they form 
 the two coronary plexuses (PI. coronarii ), in which also terminate 
 some filaments of the inferior, and more generally of the superior 
 cardiac nerve. 
 
 The posterior coronary plexus is much larger than the anterior ; it 
 goes to the base of the heart, descending on the left pulmonary artery. 
 It is distributed to the lower and posterior part of the left ventricle, 
 along the posterior coronary artery and its branches. 
 
 The anterior follows the course of the left inferior cardiac nerve, in 
 its whole extent, passes between the aorta and the pulmonary artery, 
 and after anastomosing at its upper part with the posterior, attends 
 the anterior coronary artery and its ramifications, on the upper face of 
 the heart and the right auricle, where it frequently anastomoses with 
 the posterior, along the posterior edge of the organ. Some smaller 
 twigs of this plexus proceed on the left pulmonary artery, and go to 
 the pulmonary plexus of the left side. 
 
 The two plexuses frequently anastomose with some branches of the 
 pneumo-gastric nerve. 
 
 They are, however, mostly formed by the ganglionnary nerve. 
 
 After leaving the lower part of the neck, the ganglions of the great 
 sympathetic nerve are more numerous. 
 
 D. THORACIC GANGLIONS. 
 
 § 1892. We find in the chest between the transverse processes of 
 each two vertebrae, and on each side, a ganglion called the thoracic 
 (Gl. thoracicum). These ganglions are generally slightly rounded, 
 elongated, triangular, and fusiform. They are situated more on the 
 outside than the cervical. The first counting from above downward 
 (G. thoracicum supremum) is the largest of all the limiting ganglions 
 except the superior- cervical. Sometimes it is blended with the second ; 
 this, however, is rare, and even when it appears, generally exists on 
 the outside. The middle ganglions are often a little smaller than the 
 superior and the inferior. 
 
OF THE NERVOUS SYSTEM. 
 
 97 
 
 All these ganglions are united to each other by one very strong 
 filament, rarely by two. 
 
 The superior is almost constantly attached to the inferior cervical 
 nerve by two filaments, the anterior, of which not unfrequently divides 
 in turn into two smaller filaments. Each thoracic ganglion anastomoses 
 on the outside by two filaments, with its corresponding thoracic nerve. 
 Internally, the superior gives off branches, some of which go to the 
 lower part of the longus colli muscle, others to the cardiac plexus, 
 several to the pulmonary plexus, which, however, is principally formed 
 by the pneumo-gastric nerve ; finally, some .proceed to the aorta. 
 
 I. SPLANCHNIC NERVE. 
 
 § 1893. From the inferior thoracic ganglions, and from their fila- 
 ments of union, generally from the sixth or the seventh to the eleventh, 
 arise cords, the upper of which are usually the largest ; they vary in 
 number from three to seven, and are very rarely the same on both 
 sides of the body ; they unite at an acute angle near the diaphragm, 
 to form the splanchnic nerve, grand surrénal , Ch. (JV*. splanchnicus). 
 This nerve descends behind the pleura, and generally goes from the 
 chest into the abdomen, between the inner and middle prolongations 
 of the pillar of the diaphragm, sometimes also through the aortic open- 
 ing. It anastomoses in the abdomen principally with the semilunar 
 ganglion of its side, sometimes directly, sometimes indirectly, by some 
 small ganglions. It then forms the principle mode of union between 
 the central portion of the ganglionnary nerve and the limiting gan- 
 glions. Not unfrequently some of the roots by which it arises, parti- 
 cularly the inferior, go separately to the semilunar ganglion, and some 
 of them often anastomose, not with this ganglion, but with some fila- 
 ments of the solar, the hepatic, the splenic, and the two renal plexuses, 
 
 II. SMALL SPLANCHNIC NERVE. 
 
 § 1894. Two or three inferior branches, which, however, remain 
 distinct, sometimes unite on the right side more frequently than on the 
 left, in a small special trunk, called the small splanchnic nerve, petit 
 surrénal , Ch. (N. splanchnicus minor.) This trunk passes through 
 the pillar of the diaphragm below the preceding. It is enlarged by 
 some filaments from the superior lumbar ganglions, and goes princi- 
 pally into the renal plexus, which is often in great part formed by it. 
 
 E. ABDOMINAL GANGLIONS. 
 
 § 1895. The cord by which the limiting ganglions unite is always 
 very small below the origin of the splanchnic nerve. Sometimes it is 
 entirely deficient in some points, so that the trunk of the great sympa- 
 
98 
 
 DESCRIPTIVE ANATOMY. 
 
 thetic nerve is there interrupted 1 ) and the limiting ganglions form one 
 and the same series with the abdominal ganglions and plexuses only 
 by intermediate connections. When this series comes on the lumbar 
 vertebrae it goes forward. We there see ganglions which are much 
 smaller, more remote from each other, and less constant in their situa- 
 tion than those hitherto examined. The upper is always larger than 
 the others, which gradually diminish from above downward and often 
 do not exist, or at least are almost invisible. 
 
 The upper pelvic ganglions of the limiting cord are a little larger 
 than the inferior lumbar, and form a series which converges from above 
 downward. There are usually four or five, the lowest of which is 
 situated forward between the sacrum and the coccyx, and anastomoses 
 with the corresponding ganglion of the opposite side by a shortened 
 thin filament which is convex downward. 
 
 The lumbar and pelvic ganglions are united by some filaments 
 which differ from those existing between the others in their length and 
 also in their number and size ; for there are usually three or four be- 
 tween each two ganglions, which are much smaller than those be- 
 tween the superior ganglions. 
 
 Their external branches proceed to meet the lumbar and sacral 
 nerves, and anastomose with their anterior branches near the inter- 
 vertebral and sacral foramina. 
 
 Those of the superior lumbar ganglions have a direction oblique 
 from below upward. 
 
 The middle are transverse, and the superior oblique from above 
 downward. The latter are very long, the first very short. Some 
 which are smaller go upward to the psoas muscle, downward to the 
 pyramidalis and to the levator ani muscles. 
 
 The lumbar ganglions give off some internal branches which go to 
 the anterior face of the aorta, and contribute to form the aortic plexus 
 which comes from the superior mesenteric plexus. Some of the sacral 
 ganglions anastomose together before the sacrum ; others terminate 
 in the hypogastric plexus. 
 
 The series of limiting ganglions terminates below in some filaments 
 which radiate from the last of them, and which are distributed in the 
 lower and posterior part of the rectum. 
 
 § 1896. Our mode of describing the ganglionnary nerve differs from 
 that hitherto adopted even by those anatomists who consider it as 
 ■directly opposed to the rest of the system, for they generally commence 
 by that part which descends along the vertebral column, by the ex- 
 ternal ganglionnary cord, and terminate with the central portion. 
 
 (1) This has been seen twice by Haller (Elem. phys., vol. iv. p. 261). Bichat has 
 ■also made this remark (Reck. phys. sur la vie et la mort , p. 82), and uses this as the 
 principal argument in favor of his opinion, that the sympathetic nerve does not form 
 a continuous trunk from the head to the pelvis. Wrisberg ( Obs. anat. de ganglia 
 plexuque semilunari, § 19, in the Comm. Geetting, 1779, vol. ii. p. 102) has admitted 
 this arrangement to be an anomaly, and Weber (Anat. comp, nervi sympathy p. 122 
 regards this observation as doubtful. 
 
OF THE NERVOUS SYSTEM. 
 
 99 
 
 Our course will at first view be more surprising, because we have 
 several times mentioned that there is no manifest contrariety between 
 the two nervous systems. 
 
 In fact the ganglionnary nerve is only the highest development of a 
 form which has passed through several gradations. We may consider 
 the diaphragmatic nerve as the first of these : this arises from several 
 cervical pairs, and passes some distance to go to a voluntary muscle, 
 the diaphragm, the principal agent in respiration. This formation is 
 still more developed in the four posterior cerebral nerves, particularly 
 in the pneumo-gastric, which forms plexiform anastomoses with the 
 superior cervical nerves, descends along the neck, is distributed to the 
 organs of respiration, and descends to the stomach in the abdominal 
 cavity. The whole course of this nerve favors our analogies still more, 
 inasmuch as it forms numerous plexuses whence branches proceed to 
 the organs. 
 
 The ganglionnary nerve, if we except some filaments which arise 
 perhaps from the pituitary gland, does not commence directly at the cen- 
 tre of the nervous system, but from several of the cerebral and from all 
 the spinal nerves. It descends lower than the pneumo-gastric nerves, 
 gives some filaments to all those organs of vegetative life which re- 
 ceive none from this latter, and frequently anastomoses with the two 
 preceding. The plexiform and ganglionnary structure is more evident 
 in it than in any other nerve, so that even the inner part of its expan- 
 sion exceeds the outer ; and hence from its form, situation, and con- 
 nections with the encephalon and spinal marrow, it may be regarded 
 as the trunk of the nerve, as is generally admitted, and thus the inner 
 part is considered the central portion. 
 
 These are our reasons for departing from the common course, al- 
 though the anatomical and the physiological relations of the gangli- 
 onnary nerve prove that it is dependent on the centre of the nervous 
 system, being connected with it by its outer part. 
 
 CHAPTER IV. 
 
 DIFFERENCES PRESENTED BY THE NERVES DURING THEIR 
 DEVELOPMENT. 
 
 § 1897. The differences presented by the nerves during their deve- 
 lopment have been but slightly studied, and we have but few observa- 
 tions which refer to them. Not having had sufficient opportunities of 
 obtaining well preserved human fetuses, we cannot add as many re- 
 marks as are desirable to those already existing. 
 
 We may state on this subject the following corollaries : 
 
 1st. All the nerves are not developed with equal rapidity in respect 
 to color, texture, and consistence. The spinal generally increase 
 
100 
 
 DESCRIPTIVE ANATOMY. 
 
 faster than the cerebral nerves. We have found them perfectly white 
 and evidently fibrous in the fetus of six months, while the cerebral 
 nerves were gray. The fibrous texture and color are developed latest 
 in the optic nerves. At six months it is much larger than the other 
 encephalic nerves, and even at the ninth month of pregnancy it is still 
 as gray as the rest of the cortical substance, is very soft, and presents 
 no appearance of fibres. We have not yet been ablctD determine if it 
 whitens before birth ; it however experiences this change early, for in 
 two children one month old we have found it perfectly white in all its 
 course, except most of the portion between the decussation and the 
 eye ; the latter was entirely white before the decussation, gray on the 
 outside and white on the inside in the centre ; finally totally gray for- 
 ward. 
 
 We may conclude from these facts that the nerves complete their 
 development from within outward and from behind forward. This 
 proposition applies both to the different nerves and to the same nerves 
 in different parts of the body. It is then very curious that the olfac- 
 tory nerve which is the most anterior remains almost entirely gray 
 during life, and constantly preserves this tint in its whole anterior part. 
 This law seems to be general, for we have since met with it in fetuses 
 of the hog and cat. 
 
 We have also found the great root of the trifacial nerve entirely gray 
 in the fetus of eight months. 
 
 2d. The following remarks are applicable to the other differences 
 presented by the nerves : 
 
 Among the spinal nerves we have found in a great many fetuses 
 the crurai nerve divided on emerging from the pelvis into its tibial and 
 peroneal branches, which were the more distinct the younger the fetys. 
 
 Before the end of the fifth month of pregnancy they were not united 
 so intimately as they are at an advanced age ; hence this arrangement, 
 which is abnormal in the adult, is normal during the early periods of 
 existence.(l) We have not been able as yet to observe any difference 
 in the other spinal nerves 
 
 The trifacial nerve differs from what it is in the adult : 
 
 1. In the number of its cords, which are at first fewer. In the fetus 
 of eight months there are only eighteen in the large root, while there 
 are from twenty-eight to thirty in a child when bom. (2) 
 
 2. The texture of its ganglionnary plexus is less fibrous. We have 
 found structure of this plexus was homogeneous at the sixth month 
 of pregnancy. 
 
 These two peculiarities may be referred to the same principle, the 
 imperfect development of the nervous tissue. 
 
 (1) We have' already said that this arrangement is curions as analogous with the 
 mammalia, but did not intend to assert that it is common to all these animals. 
 
 (2) Vesting, Obs. anal., no. viii. — Sœmmerring, De basi cncephali, § 60. — Nie- 
 meyer, in Keil, Archiv, f ür die Physiologie , vol. xi., p. 54. 
 
OF THE NERVOUS SYSTEM. 
 
 101 
 
 The olfactory nerve is at first proportionally much larger ; at the 
 same time it is rounded, thicker, and shorter. 
 
 Until the sixth month there is within it a cavity which communi- 
 cates with the lateral ventricles of the cerebrum. 
 
 These are two remarkable analogies with the mammalia. 
 
 In the full grown fetus its external root is evidently medullary. We 
 perceive also some medullary striæ on the lower face of the nerve, but 
 there is no trace of the medullary band which represents its internal 
 root. 
 
 In the early periods of fetal existence the great sympathetic nerve is 
 more developed in proportion to the body than almost any other part of 
 the nervous system. It is very remarkable that the large limiting gan- 
 glions are so near each other, particularly in the chest, that they form 
 an uninterrupted series. The splanchnic nerve is also proportionally 
 much thicker than in the adult. 
 
 At about the middle of fetal existence this nerve has diminished 
 much, and then presents very nearly the proportions which continue 
 during life.(l) 
 
 CHAPTER V. 
 
 PARALLEL BETWEEN THE DIFFERENT NERVES. 
 
 1 . BETWEEN THE SPINAL AND THE ENCEPHALIC NERVES. 
 
 § 1898. The spinal and encephalic nerves are generally strictly 
 opposed to each other, and are distinguished by characters mentioned 
 previously (§ 170) ; but the differences between them are not so dis- 
 tinct as is asserted. First those which truly exist do not prevent us 
 from considering the encephalic nerves in the condition of spinal nerves, 
 and from demonstrating that they are only modifications of the latter, 
 and from investigating the cause of these modifications. 
 
 All the encephalic nerves are portions of spinal nerves which are 
 not united in a single trunk like the latter, but are developed as so 
 many separate nerves. Tins modification of the primitive type de- 
 pends on the development of the centre of the nervous system within 
 the skull and on that of the skull itself, which mechanically separates 
 the different groups of the roots of the nerves at their origin and in 
 their course. 
 
 It also depends on special organs, those of the senses, which are de- 
 veloped in the skull, the roots of which are formed by the nerves that 
 go to them, and which are perfect in the direct ratio of the development 
 of their special nerves. Comparative anatomy demonstrates, at least 
 
 (1) Lobstein has given a history of the evolution of the ganglionnary nerve in the 
 fetus, and the modifications it experiences as age advances (Joe. cit., p. 47-56.) 
 
 Vol. III. 14 
 
102 
 
 DESCRIPTIVE ANATOMY. 
 
 in regard to several organs of the senses, that new nerves are not 
 formed for them,(l) hut only that single branches arising from a spe- 
 cial part of the encephalon become trunks. In fact we see several 
 nerves, especially among those of tire organs of the senses, which form 
 separate trunks in superior animals,- are only subordinate branches in 
 the inferior animals. This is the case particularly with the trifacial 
 nerve ; and this is much more evident the more inferior the animal. 
 
 This development of portions of nerves which raises them to the 
 rank of distinct nerves is gradually increased from the posterior to the 
 anterior extremity of the cerebrum. It is manifested in the posterior 
 pairs only by the want of union between the anterior and posterior 
 roots ; but the anterior roots seem to be formed from the fact that single 
 fasciculi appear to be the proper nerves. 
 
 The nervous system then follows precisely the same type as the 
 other systems, particularly the osseous ; for the bones of the skull are 
 more similar to the vertebrae the more posteriorly they are situated, and 
 the dissimilarity between them and the vertebrae which gradually in- 
 creases from behind forward, depends principally upon the fact that 
 simple portions of the vertebrae have become sufficiently developed to 
 be considered distinct pieces of bone. 
 
 In this view of the subject, we should consider the last four cerebral 
 pairs, the accessory, the pneumo-gastric, the glosso-pharyngeal, and 
 the hypoglossal nerves, as so many sections of one and the same nerve, 
 the posterior of which is formed by the first three nerves, and the an- 
 terior by the fourth. In fact, the accessory, the pneumo-gastric, and 
 the glosso-pharyngeal nerves, arise by an uninterrupted series from the 
 posterior cord of the spinal marrow, and emerge from the skull through 
 the same opening. They thus form in the skull, trunks, the external 
 parts of which are separate from each other, and generally pass 
 through the dura-mater in different points. But this is far from being 
 the case with the accessory nerve, and even when it is, the accessory 
 is adapted to the pneumo-gastric nerve so intimately, that they form 
 a single trunk. Beside, after the two nerves separate, the inner 
 branch of the ' accessory nerve again unites with the eighth pair, and 
 continues with it. The glosso-pharyngeal nerve also anastomoses by 
 one filament even within the cranium, with the pneumo-gastric nerve, 
 and after leaving the skull, they communicate by several other fila- 
 ments. It is curious that the accessory and pneumo-gastric nerves 
 on one side, the glosso-pharyngeal nerve on the other, and just before 
 where it unites with the two preceeding, form ganglions near the 
 place where they emerge from the skull, exactly as do the posterior 
 
 (1) See on this subject the important memoir of Treviranus, in which he proves 
 that the nerves of the fifth pair take the place of those of very important sense* in 
 some animals, and that there is in these animals some org-ans of sense very different 
 from those of man, the nerves of which are the branches of the fifth pair (Sur les 
 nerfs de la cinquième paire, considérés comme organes ou /conducteurs, de sensations ; 
 in the Journ. oomplém. dessc. méd., vol. xv. p. 207). Ilis observations have been 
 confirmed since by Magendie. F. T. 
 
OF THE NERVOUS SYSTEM. 
 
 103 
 
 roots of the spinal nerves ; nor ought we to omit mentioning that the 
 posterior root of the superior cervical nerve often joins the accessory, 
 which then assumes the character of the posterior root, which cha- 
 racter is also expressed very distinctly by its situation behind the liga- 
 mentum denticulatum. 
 
 The glosso-pharyngeal nerve, the anterior root of this pair of nerves, 
 arises from the anterior cord of the medulla oblongata, like the other 
 anterior roots of the spinal nerves, and as its origin is situated more 
 inward and forward, it also emerges from the skull through an open- 
 ing situated more inward and forward. In fact, it leaves the skull 
 through a special opening in the occipital bone, rather distant from 
 that through which the other three pass. But this difference from 
 the spinal nerves depend on the two causes mentioned above, and we 
 see in it only a greater development of the arrangement of the anterior 
 and posterior roots of the spinal nerves which pass through distinct 
 openings in the dura-mater before uniting ; finally, the glosso-pharyn- 
 geal nerve just after leaving the skull, is adapted directly to the trunk of 
 the pneumo-gastric nerve, anastomoses with it by some filaments, par- 
 ticularly below its ganglion, and goes forward, while the eighth pair, 
 united with the other two, is distributed principally below and back- 
 ward. We ought not to forget that this nerve never forms the gan- 
 glion alone, and rarely or never communicates with the ganglion of 
 the three posterior nerves. 
 
 The fasciculi of this nerve, like those of the first three, frequently 
 emerge from the dura-mater, and sometimes from the skull, through 
 distinct openings, but this difference is 'not essential, for if the fasciculi 
 of each of the roots of the spinal nerves unite in man before that each 
 root passes through the dura-mater, in the mammalia, they perforate 
 this membrane in three or four points, and before uniting, as is also 
 true of the nerves of which we speak. Comparative anatomy fur- 
 nishes several other facts which prove the parallel stated by us. In 
 fishes, the anterior and posterior roots of the spinal nerves emerge 
 separately from the spinal column through special openings, so that 
 they are still more similar to the cerebral nerves in this class of the 
 animal kingdom. On the other hand, in most of the mammalia the 
 first cervical nerve, and even the second in some, particularly the hog 
 and the ox, frequently arise entirely from the anterior cord of the 
 spinal marrow, and form only the anterior root of a spinal nerve, which 
 does not emerge through a groove, but through an opening in the 
 first and second cervical vertebræ. In almost all the mammalia the 
 posterior root of the first cervical nerve enlarges into a ganglion long 
 before it unites with the anterior, and’ before the nerve passes through 
 the first cervical vertebra. The ganglion sometimes divides, as we have 
 often observed in the hog for instance, into two enlargements, an an- 
 terior and a posterior, or at least we not unfrequently observe a deep 
 strangulation at its centre and the portion of the posterior root between 
 it and the part of the nerve where it emerges from the vertebral 
 column, forms two in the hog, an anterior and a posterior ; f his shows 
 
104 
 
 DESCRIPTIVE ANATOMY. 
 
 that in this animal, except in the first cervical nerve, the posterior root 
 tends to separate from the anterior, and to become a distinct and 
 special nerve. 
 
 From all these remarks it is not difficult to reduce the last four cere- 
 bral pairs. 
 
 Scemmerring had already remarked that the glosso-pharyngeal nerve 
 appeared at its origin like each of the spinal nerves ; hence, it ought 
 not to be separated from them and be considered an encephalic 
 nerve. (1) The same anatomist compared the origin of the pneumo- 
 gastric to that of the spinal nerves. (2) Finally, others had considered 
 the accessory as a spinal nerve, or as making the transition from the 
 spinal to the encephalic nerves. But each admits that these compari- 
 sons, founded on peculiarities which escape the eye, have no connec- 
 tion with the proposition we establish, viz. that the last four cerebral 
 pairs form in fact only one encephalic nerve, the posterior root of which 
 emerges through the intervertebral foramen, situated between the 
 last and the last but one of the vertebrae of the skull (the occipital 
 and the temporal bones), while the second emerges from it only 
 through the last cephalic vertebra. 
 
 The reduction of the other eight pairs is more difficult. Some, 
 however, the common and the external motor, evidently have the 
 characters of anterior roots, or at least of portions of anterior roots ~ 
 others, as the auditory and the superior motor nerve, present no less 
 manifestly those of the posterior roots. It is more difficult to determine 
 in regard to the rest. We may, nevertheless, compare the facial with 
 the auditory nerve, and consequently with tho posterior roots, on 
 account of its course and the nearness of its origin, even as the origin 
 and the course of the trifacial nerve authorize us to arrange it along 
 the anterior roots. As to the two anterior pairs, the second may be 
 compared to a posterior root, because it arises from the tubercula 
 quadrigemina and the optic beds, and the first may be compared to an 
 anterior root. We may then consider four pairs as anterior roots, and 
 four as posterior roots, or as portions of these roots. It is now easy to 
 to refer the auditory, the facial, the trifacial, and the motor nerve, to a 
 single trunk. When we follow the origin of the facial, trifacial, and 
 auditory nerves within the cerebrum and backward, we see that they 
 singularly approach each other. In regard to the facial and the audi- 
 tory nerve, we must mention beside the nearness of their origins, the 
 remark of Santorini, that we can trace below the transverse fibres of 
 the annular protuberance, to the origin of the auditory nerve, some 
 fibres which from their progress and direction, are evidently the com- 
 mencement of the facial nerve. (3) The trifacial nerve which partly 
 arises from the olivary bodies, blends here with the sixth pair. The 
 common motor nerve goes from before backward to meet all these 
 
 (1) He hast encephali ; in Ludwiw, lor. cit., p. 103. 
 
 (2) Loc. cit., p. 101. 
 
 (3) Septcmdec. tab. p. 23. 
 
OF THE NERVOUS SYSTEM, 
 
 105 
 
 nerves in the annular protuberance. The superior motor nerve and 
 the optic nerve, are also very intimately united with them by the band 
 which extends from the medulla oblongata to the tubercula quadri- 
 gemina. 
 
 The demonstration is most difficult with regard to the two anterior 
 nerves ; still the short distance between the origins of the external 
 motor and optic nerves, indicate that the latter depends on the others, 
 and the anterior commissure imites the olfactory and the optic nerves. 
 
 IL PARALLEL BETWEEN THE NERVES OF THE UPPER AND LOWER EX- 
 TREMITIES. 
 
 § 1899. The nerves of the upper and lower extremities, like the 
 bones, the muscles, and the vessels, are formed essentially after the 
 same type, and differ only by slight modifications of this type, which 
 is subject to the same laws as those of the other three systems. 
 
 At first view the number of the pairs of nerves which unite to form 
 the nerves of the two extremities, seem to differ considerably, as there 
 are but five pahs of nerves of the upper extremities, while those of the 
 lower are formed by ten. This difference, however, vanishes on strict 
 examination. In fact, all the cervical nerves are evidently arranged 
 among those which concur to form the brachial plexus, since they are 
 all united and changed into a real plexus like all the lumbar and 
 sacral nerves, by large anastomoses between their anterior branches. 
 Further, the difference in number between the nerves of the two ex- 
 tremities is only one pair. But we may also explain this apparent 
 anomaly by considering the last four encephalic nerves, the glosso- 
 pharyngeal, the accessory, the pneumo-gastric, and the hypoglossal 
 nerves as one pair, which corresponds to the branches of the inferior 
 sacral nerves. This comparison is authorized by the discussion in re- 
 gard to the origin of these four nerves which we have mentioned, and 
 by considering the manner in which they are distributed. In fact, 
 they give off branches to the tongue and -upper part of the intestinal 
 -canal, even as the inferior sacral nerves send them to the organs of 
 generation and to the lower part of the intestinal canal. 
 
 All these analogies admitted, the number of pairs of nerves in the 
 two extremities is equal : we must not, however, attach much im- 
 portance to this uniformity of number, nor consume time in endeavor- 
 ing to establish it, for it is unimportant, but presents itself so naturally, 
 that it would be wrong to neglect it. 
 
 We may also proceed in an opposite manner, and decompose the su- 
 perior and inferior plexuses, considering separately the deep cervical 
 and brachial plexuses above, and the lombo-abdominal and sacral 
 plexuses below, and oppose them to each other. This is Bichat’s 
 method. But it is inferior to the other, because it obliges us to 
 separate parts which are united. 
 
 The principal common relations between the nerves of the two ex- 
 tremities in their distribution, are as follow : 
 
106 
 
 DESCRIPTIVE ANATOMY. 
 
 The superior cervical nerves are distributed to the muscles and in- 
 teguments of the neck, the same as the superior lumbar nerves are to 
 the muscles and skin of the loins. The first sends some branches to 
 the skin of the shoulder, the suprascapular nerves, while the second 
 furnish some to the skin of the haunch and the arms. 
 
 The thoracic nerves correspond to the obturator nerve by their high 
 origin, their course .below the bones of the same part, and their distri- 
 bution to muscles which correspond. 
 
 The scapular nerve is the superior gluteal. 
 
 The axillary nerve is the inferior gluteal. 
 
 The nerves which are distributed lower in the two extremities' differ 
 much more, since two twigs and even large branches, which corres- 
 pond in their mode of distribution, arise from different trunks. The 
 branches, however, are the same, and we can easily explain their dif- 
 ferences in respect to origin. 
 
 The nerves yet to be compared are in the upper extremity, the internal 
 and the external cutaneous nerve, the radial, the median, and the 
 ulnar nerve ; in the lower extremity, the crural and the sciatic nerve. 
 
 The external cutaneous radial nerves correspond to the crural : the 
 internal cutaneous, the median, and the ulnar nerve, to the sciatic. 
 
 The external cutaneous nerve and the long cutaneous branch of the ra- 
 dial nerve, are evidently thesuperior and inferior internal saphena nerves 
 of the lower extremity, since they descend along the side of the thumb 
 and of the large toe, which is the internal the the upper limb is in a 
 moderate degree of pronation, and is always so in the lower extremi.y 
 when it is at rest. 
 
 The muscular branches of the crural nerve are the upper branches 
 of the radial nerve. They are distributed in the extensor muscles of 
 the leg, as the latter are in those of the fore-arm. 
 
 The analogy, however, between the radial and crural nerves, ceases 
 there. The lower branches given off by the latter are represented in 
 the leg, but come there from the sciatic nerve. 
 
 The superior and posterior cutaneous nerves of this latter, very evi- 
 dently correspond to the upper branches of the internal cutaneous 
 nerve of the arm, since they descend on the outer or fibular side of 
 the little toe, as these latter do on the ulnar side of the little finger. 
 
 The tibial nerve corresponds principally to the median and a part of 
 the ulnar nerve. The peroneal represents the lower part of the ulnar 
 nerve, and still more that of the radial. We may compare the posterior 
 cutaneous branch of the tibial nerve, which so frequently arises from 
 the peroneal nerve, to some ramifications of the internal cutaneous 
 brachial nerve. 
 
 The muscular branches given by this nerve to the leg correspond to 
 those sent by the median nerve to the muscles of the fore-arm. 
 
 The superficial plantar nerve is represented by the superficial palmar 
 branch of the median nerve. 
 
 The internal plantar nerve corresponds exactly to the palmar branch 
 of the median nerve. 
 
OF THE NERVOUS SYSTEM. 
 
 107 
 
 The external plantar nerve is represented by the palmar branch of 
 the ulnar nerve. 
 
 The muscular branch of the peroneal nerve corresponds to the mus- 
 cular branches of the radial and ulnar nerves of the fore-arm. 
 
 The cutaneous branch which is distributed in the back of the foot 
 corresponds by its external- twig to the dorsal branch of the ulnar 
 nerve, and by the internal to that of the radial nerve. 
 
 § 1900. The differences here remarked may be easily explained : 
 
 1st. Some nerves which arise as distinct trunks in the upper extre- 
 mity are one nerve in the lower. 
 
 2d. Some branches arise from different trunks. 
 
 These two anomalies depend on the general difference in the form 
 of the two extremities. 
 
 1st. As the fibula, from its smallness and its want of articulation with 
 the tibia, seems reduced in man to a simple constituent part of the 
 tibia ; as several muscles of the leg are attached in a common ten- 
 don, while others situated hi the fore-arm in the upper extremity are 
 found in the sole of the foot ; as the external cutaneous vein of the 
 pelvic limb unites with the internal at the knee, while these two veins 
 remain distinct to the axilla in the upper extremity ; finally as the arte- 
 ries often divide very high in the upper extremity, while this anomaly 
 is very rare in the lower, so likewise the nervous trunks which sepa- 
 rate very early in the arm, long remain united in the leg. 
 
 Farther, the tibial and peroneal nerves are not only sometimes dis- 
 tinct in the pelvis as those of the upper extremity sometimes are in the 
 axilla : but also the cutaneous nerves of the arm are frequently simple 
 branches of the three larger nerves. The difference mentioned above 
 in the crural nerve during its development, also establishes a greater 
 analogy between the two limbs in the early periods of life than at a 
 more advanced age. 
 
 2d. The difference in origin depends partly on the preceding fact, 
 partly also on the difference in the direction and situation of the two 
 extremities. If the arm is in the state of pronation, and thus possesses 
 a direction similar to that of the lower extremity, these differences are 
 explained with facility. 
 
 The radial nerve is then drawn up as high as the elbow, so that we 
 may imagine it to terminate here, and that its lower part unites with 
 the ulnar nerve. 
 
 The antibrachial parts of the median and ulnar nerves are also ap- 
 proximated, and they blend in a single trunk which divides into two- 
 branches at the palm of the hand. 
 

 
 I • ' . , 1 N 
 
BOOK VI. 
 
 SPLANCHNOLOGY. 
 
 § 1901. Splanchnology, or the branch of anatomy which treats of 
 the apparatus for the functions, includes the description of the most 
 complex parts of the organism, those formed by the union of a greater 
 or less number of simple organs or systems. We cannot consider these 
 as belonging to the class of those already mentioned, as they differ too 
 much from these latter or from each other. We must however re- 
 mark that they may .finally be referred in respect to their essential 
 characters to the cutaneous and glandular systems. 
 
 In regard to their functions they may be divided into two classes, 
 one of which establishes an immaterial, the other a material connection 
 between the organism and the external world. The first are the 
 organs of sense, the others are properly termed the viscera. 
 
 The organs of the se7ises perceive actively the impressions of quali- 
 ties belonging to the body which they contribute to form, or to external 
 objects. They transmit them to the brain by means of their nerves, 
 and cause in this viscus the formation of ideas , that is, they there 
 produce modifications of the principle of the mind, of which it is the im- 
 mediate organ. 
 
 Some of the viscera receive foreign external substances, others re- 
 move all that the vital powers have rendered useless, or separate parts 
 proper to form similar new bodies, that is, they remove from the organ- 
 ism all that is useless and which cannot serve to preserve the species. 
 Some of these organs, as the intestinal canal and the lungs, perform 
 both of these functions at the same time ; others, as the kidneys and 
 genital organs, serve only for the excretory function ; they all have 
 this in common, that they form new substances, and that they thus pre- 
 serve the individual in the normal state. The substance formed by the 
 genital organs serves also and in a special manner to preserve the 
 species. 
 
 However different the results and the mode of action of the organs 
 of sense and the apparatus of formation may be, the first are in regard 
 to mind exactly the same as are the second in relation to the body. 
 Farther the inferior senses, those of smell, taste, and touch, which are 
 the bases of all, insensibly establish the transition from the superior 
 senses, those of sight and hearing, to the proper viscera, both in respect 
 to their form and situation, and to their mode of action. We may also 
 Vol. III. 15 
 
110 
 
 DESCRIPTIVE ANATOMV. 
 
 admit that the organs of sense and the viscera have several characters 
 in common ; these are : 
 
 1st. They are developments of the cutaneous system. 
 
 2d. They are mostly or entirely situated ir; more or less perfect bony 
 cavities. 
 
 3d. They are prolonged outward by valvular folds of the skin, which 
 are provided with simple glands and hairs. 
 
 4th. There is only one or at most but two : in the former case they 
 are situated so that the median line divides them into two equal parts j 
 in the second there is only one on each side, a right and a left. 
 
 As the direct organ of the spiritual principle is that which we consi- 
 dered last, it is most convenient to examine first the organ of the most 
 intellectual sense, that of hearing, and next to treat of that of sight, 
 that of smell, and lastly the organ of taste, which forms a part of the 
 digestive apparatus. After describing this apparatus we shall pass to 
 the organs of respiration and of voice, then to those of the urinary se- 
 cretion, and lastly to those of generation and the history of the fetus. 
 
 SECTION I. 
 
 OF THE ORGANS OF SENSE. 
 
 § 1902. All the organs of the senses( 1) are similar in the following 
 characters : 
 
 1st. They are situated in the head. The organ of hearing is placed 
 the farthest backward and belongs entirely to the skull ; it is also 
 situated the most on the side, and its two lateral portions are entirely 
 distinct from each other. The cavity occupied by the eye is partly 
 formed by the bones of the skull and mostly by those of the face. 
 That of the olfactory organ belongs still more to the face, in fact al- 
 most exclusively to it, since the ethmoid bones form less of the skull 
 than of the face. The cavity of the mouth is formed only by the bones 
 of the face. The right and left portions also gradually approach each 
 other from the organ of hearing to that of taste, so that they finally 
 blend in the tongue. 
 
 2d. They are all connected by short and large nerves with the ence- 
 phalon. The auditory is proportionally the shortest and largest nerve. 
 It arises from the calamus scrip torius as from a distinct cavity, so that 
 
 (1) A. Molinetti, Dissertaliones anatomicœ et pathologicæ de sensibus et eorum or- 
 ganisa Padua, 1669. — Casserio, Pantæsthesejon , hoc est de quinque sensibus liber, 
 organorum fabrieam, usum et actionem conlinens , Venice, 1699. — Haller, De sensibus 
 in gcncre, Gottingen, 1742.— Lecat, Traité des sens, Amsterdam, 1744. — Sœmmer- 
 ring-, Abbildungen dec menschlichen Sinnorgane, Francfort, 1809. 
 
OF THE EAR, 
 
 111 
 
 ïïo other nerve of the organs of sense is connected so intimately with 
 the mass of the encephalon. 
 
 3d. Ml receive their nerves from at least two pairs. The larger 
 nerve is termed the nerve of sense , and the smaller the accessory nerve. 
 In the organs of hearing, smell, and taste, the nerve of sense forms as 
 many distinct pairs, the auditory, optic, and olfactory nerves, while in 
 that of taste it is only a branch of the trifacial nerve, which is also the 
 common trunk of the accessory nerves ; but this includes also the 
 hypoglossal, the glosso-pharyngœal and the facial, the three motor 
 and the ganglionnary nerves. The names of several of these nerves 
 prove that the accessory nerves serve principally to excite the motions 
 of the organs of sense. The olfactory nerve is the only one which is 
 to a certain extent an exception to the rule, since its proper accessory 
 nerves, like its nerve of sense, are distributed in the mucous membrane 
 of the nose. The nerves of sense and the accessory nerves are not 
 necessarily connected ; these connections do not exist in the organs of 
 sight and hearing. They are slight and probably inconstant in the 
 organ of smell, and are well developed only in the tongue, which is 
 the most similar to the general organ of touch. 
 
 4th. The proper nerves of sense expand more or less evidently as a 
 thin membrane , which is covered directly by a fluid above which is a 
 tissue similar to the epidermis. 
 
 5th. They all communicate by ducts more or less broad, the prolon- 
 gations of the internal cutaneous membrane which make part of them, 
 and which perform a part as much more important in their organiza- 
 tion the less they are developed. The more similarity there is between 
 them, as between the organs of taste and smell, the more loose and ex- 
 tensive the communication, so that so they really form but one in the 
 early periods of life, at which time the roof of the palate which will 
 separate the last two from each other is not yet formed. The com- 
 munication between these two organs of sense and the others is more 
 marked the nearer the fetus is to its period of formation. 
 
 In fact the cutaneous system is more or less evidently the prototype 
 of all the organs of sense, and the external integuments are the seat of 
 sensation, as the hand is that of the special modification of the general 
 sensation termed the touch. 
 
 CHAPTER I. 
 
 OF THE ORGAN OF HEARING. 
 
 § 1903. The organ of hearing, (l) or the ear, is situated at the 
 centre of the side and the base of the skull within and on the surface 
 
 (1) Fallopius, in his Obs. anat., Venice, 1561 ; Opp. omn., vol. i., tr. ii.— Eustachius, 
 De auditus organo ; in the Opusc. anat., Venice, 1564. — Fabricius d’Aquapendente, 
 
112 
 
 DESCRIPTIVE ANATOMY. 
 
 of t lie temporal bone. This organ, the most noble and the most intel- 
 lectual of the senses, belongs entirely to the skull. It is connected 
 with the encephalon more directly, and is protected better against ex- 
 ternal injuries than any other of the senses. 
 
 It is formed of a considerable number of parts differing very much in 
 their form and texture, and which may be divided generally into two 
 sections, comprehending the external and the internal ear. 
 
 ARTICLE FIRST. 
 
 EXTERNAL EAR, 
 
 § 1904. The external ear, oriente , Ch. (auris externa), (l) is formed 
 by the cartilage of the ear, the cartilaginous portion of the external 
 auditory passage, and several muscles which are attached to the dif- 
 ferent regions of the auricular cartilage. All these parts are covered 
 by the common integuments. 
 
 A. CARTILAGE OF THE EAR. 
 
 § 1905. The cartilage of the ear ( cartilago auris), (2) considered 
 generally, is formed like a short tunnel with a broad oval opening 
 larger from above downward than from before backward. This sur- 
 face is very uneven from several prominences and depressions which 
 circumscribe this opening. 
 
 De visione, voce et auditu, Venice, 1688.— J. Mery, Description exacte de l'oreille, 
 l’aria, 1681. — Duverney, Traité de l’organe de l’ouïe, contenant la structure, les 
 usages et les maladies de toutes les parties de L’oreille, Paris, 1683. — C. G. Schel- 
 hammer, De auditu liber anus , Leyden, 1684. A. M. Vasalva, Tradatus de aure 
 humanâ, Bologna, 1704. — R. Vieussens, Traité delà structure de l’oreille, Toulouse, 
 1714. — J. F. Casscbohm, Tradatus quatuor de aure humanâ, Halle, 1734; Trac- 
 tatus quintus et sextus , Halle, 1735. — Morgagni, Ep. anat., ep. iv., v., vii., xii., xiii. 
 —Geoffroy, Dissertations sur l’organe de l'ouïe de l’homme, des reptiles et des 
 poissons, Amsterdam, 1788. — C. P. C. Wildberg, Versuch einer anatomisch physiolo- 
 gischpathologischen Abhandlung über die Gehörwerkzeuge des Menschen, Jena, 
 1795. — Soemmerring, Abbindungen der menschlichen Gehörorgane, Francfort, 1806. 
 — J. S. Schroeter, Das menschliche Ohr, nach den Abbildungen Soemmerrings ver- 
 grössert dargestellt, Weimar, 1811. — J. Cunningham. — Saunders, The anatomy of 
 the human ear, illustrated by a series of engravings of the natural size, with a trea- 
 tise on the diseases ofthat organ, the causes of deafness, and their proper treatment, 
 1817. — C. S. Pohl, Exposili) generalis anatomica organis auditus per classes ani- 
 malium, Vienna, 1818. — T. H. Weber, De aure et auditu hominis el animalium, 
 Leipsic, 1830. — J. Van der Hœven, Diss. de organo auditus in homine, Utrecht, 
 1822. * y 
 
 (1) D. Santorini, De aure ‘ inteymfo^m the Observât, anatom., Venice, 1724, ch. 
 
 ii. 
 
 (2) 11. S. Albinus, De cartilagine auriculœ ; in the Annot. academ., lib. vi., cap. 
 vii., tab. iv. 
 
OF THE EAR. 
 
 113 
 
 1st. The most external eminence which mostly surrounds all the 
 others is called the helix. 
 
 It begins at the centre of the anterior edge of the external ear, goes 
 first from below upward to the upper extremity of the auricular car- 
 tilage, then curves backward, and finally descends to the posterior part 
 of the circumference of the ear and terminates imperceptibly at its 
 lower extremity. 
 
 2d. A second eminence surrounded by the preceding, and termed 
 the anthelix. It begins below and behind near the lower extremity of 
 the helix, goes upward and forward, separates a little from this latter 
 and divides at its upper and anterior extremity into a superior and an 
 inferior branch, which extend to near the ascending portion of the 
 helix where they gradually terminate. 
 
 3d. Opposite the commencement of the helix is a third square emi- 
 nence which forms the anterior and inferior part of the cartilage of the 
 ear. It is termed the tragus. 
 
 4th. Opposite the tragus we observe posteriorly a similar promi- 
 nence termed the antitragus , separated by a groove from the prece- 
 ding. The helix and the anthelix terminate here. 
 
 § 1906. The depressions between these different prominences are : 
 
 1st. The scaphoid or navicular fossa ( fossa scaphoidea), a slight 
 depression which is concave forward, convex backward, and which 
 extends between the posterior part of the helix and anthelix. 
 
 2d. The anonymous triangular or oval fossa ( fossa anonyma, s. 
 triangularis , s. ovalis ), which extends between the two branches of 
 the anthelix. 
 
 3d. The concha ( concha auris ), a deep cavity which serves as the 
 entrance to the cartilaginous portion of the auditory passage. It is 
 situated between the helix, the tragus, and the antitragus. 
 
 4th. The groove of the ear ( incisura aims), situated between the 
 helix and the tragus. 
 
 § 1907. The lower part of the external ear or the lobule ( auriculas , 
 s. lobulus aurus ), has no cartilaginous frame. It is only a simple pro- 
 longation of the skin filled with fat and mucous tissue. 
 
 The cartilage of the ear extends at its lower part into a semicanal, 
 which is open above and is termed the auditory passage, the auricular 
 or oricular channel ( meatus auditorius cartilaginous). This canal com- 
 mences at the anterior part of the external ear, where it is more or less 
 covered by the tragus like a valve. Its direction is at first transverse 
 from without inward, or even a little from below upward : it then be- 
 comes in most of its course oblique from below upward and from before 
 backward. It is terminated above by the long posterior root of the 
 zygomatic process of the temporal bone, and below this root by some 
 fibrous tissue. 
 
 The cartilage of the auditory passage, which is only a prolonga- 
 tion of that of the ear, is generally interrupted in some portions of its 
 extent. 
 
114 
 
 DESCRIPTIVE ANATOMY. 
 
 The principal space is in part where the direction of the passage is 
 changed in the manner mentioned. There in fact the internal and 
 external portions of its cartilage are not united above and below except 
 by a narrow band. 
 
 The cartilage also presents at its external part a second smaller 
 band, which descends from its upper edge and extends along its an- 
 terior wall. 
 
 The cartilaginous auditory passage is much shorter from before 
 backward, than from above downward. It is about an inch long, four 
 lines high, and three broad. Its inferior part extends inward and down- 
 ward some lines farther than the upper. 
 
 It is attached to the adjacent parts of the temporal bone by a firm, 
 short cellular tissue. Its internal orifice particularly unites to the as- 
 perities of the external orifice of the bony portion of the auditory pas- 
 sage, of which this cartilaginous portion is the continuation. 
 
 § 1908. The cartilage of the external ear is entirely covered on its 
 external and its internal face by the skin which intimately adheres to 
 its inequalities. It gradually becomes thinner from without inward, 
 moister and more analogous to a mucous membrane. The entrance 
 of the auditory passage is generally furnished with short thin hairs 
 which are arranged very compactly. The skin which lines it usu- 
 ally presents on its inner face a considerable number of broad rounded 
 openings. These openings lead to a glandular and reddish layer, 
 which surrounds them and secretes the wax {cerumen annum), a thick 
 yellowish, viscous, very inflammable fluid, in which chemical analysis 
 demonstrates a fatty oil, a peculiar albuminous and a coloring sub- 
 stance.^) 
 
 B. MUSCLES OF THE EXTERNAL EAR. 
 
 § 1909. The cartilage of the external ear is provided with several 
 muscles(2) which are generally thin and small, and may be referred 
 to two classes ; one includes those which move the whole external ear, 
 and thus contribute to change its situation and direction ; the other 
 is composed of those which move only some of its parts, and modify 
 more or less evidently its general form. 
 
 I. MUSCLES WHICH MOVE ALL THE EXTERNAL EAR. 
 
 § 1910. These muscles are the attollens auricula , the retrahentes 
 auricula , and the attrahens auricula. 
 
 (1) Berzelius observes ( Djurkmei , vol. ii. p. 230) that the cerumen ought also to 
 
 contain water, and it is not well proved that the albuminous substance is truly of 
 this nature. Rudolphi considers the bitter principle of the cerumen to be the same as 
 that of the bile. F. T. 
 
 (2) D. Santorini, Obs. anat., cap. i. tab. 1 ; ejusdem Tab. posth., vol. i. — A. F. 
 Walter, Anatome tenuiorum musculorum corporis humani repetita, with the table of 
 Santorini. 
 
OP THE EAR. 
 
 135 
 
 a. Attollens auriculæ. 
 
 § 1911. The attollens auriculae muscle, the superior auricular 
 muscle, temporo oriculaire, Ch., the largest muscle of the ear, is thin 
 and triangular. It arises from the centre of the aponeurotic envelop of 
 the skull and the aponeurosis of the temporalis muscle, contracts from 
 before backward, and is attached to the eminence of the auricular 
 cartilage, which corresponds to the triangular depression between the 
 two branches of the anthelix. 
 
 It elevates the ear, particularly during the action of the occipito- 
 frontalis muscle, as it arises from the median tendon of this muscle. 
 
 b. Retrahentes auriculæ. 
 
 § 1912% There are generally three retrahentes auriculæ or posterior 
 auricular muscles, mastoido-oriculaires , Ch. Sometimes there are 
 but two, more rarely four, the inferior of which is very thin. These 
 muscles are always situated successively from above downward, are 
 very small, thin, and elongated. They arise from the mastoid process, 
 and are attached by short tendinous fibres to the centre of the external 
 face of the ear, on the eminence which corresponds to the entrance of 
 the auditory organ. 
 
 Their inferior extremity is often blended with the occipitalis, or with 
 the complexus or the sterno-cleido-mastoideus muscles. 
 
 These muscles draw the ear backward, and slightly dilate the 
 concha. 
 
 c. Attrahens auriculæ. 
 
 § 1913. The attrahens auriculæ muscle, the anterior auricular 
 muscle, zygomato-oriculaire, Ch., is also very small, but always a 
 little larger than the preceding. It arises on the zygomatic process, 
 goes backward and downward, gradually contracts, and is attached by 
 a short tendon to the inferior and anterior transverse portion of the 
 helix, which forms the commencement of this eminence. 
 
 It carries the ear forward and upward. 
 
 II. MUSCLES WHICH MOVE CERTAIN PARTS OF THE EXTERNAL EAR. 
 
 § 1914. The muscles which move certain parts of the external ear 
 are extremely small and weak, particularly in civilized nations. Being 
 used but slightly or not at all, they cannot modify the form of the ex- 
 ternal ear, and may be considered as rudiments of those which are 
 much more developed in animals. All are thin, and are attached by 
 all their internal face to the part of the ear which they move. 
 
 They are the tragicus, the antitragicus , the helicis major , the helicis 
 minor, and the transversus auriculæ muscles. 
 
116 
 
 DESCRIPTIVE ANATOMY. 
 
 a. Tragicus muscle. 
 
 § 1915. The Iragicus muscle, tragien , Ch. is oblong. It arises 
 from the inferior and anterior part of the concha, directly below the 
 tragus, which it covers outwardly. Its superior edge is situated below 
 the lower extremity of this eminence. It rarely goes farther, and ex- 
 tends to the lower extremity of the anterior edge of the helix, in which 
 case it is even blended with the helicis major muscle. 
 
 It carries the tragus outward, and thus shows the orifice of the 
 
 concha. 
 
 b. Anti-tragicus muscle. 
 
 § 1916. The anti-tragicus muscle, antilragien, Ch. arises from the 
 upper extremity of the external face of the antitragus, and is attached 
 to the lower extremity of the anthelix. 
 
 It approximates these two eminences, and carries the anti-tragus a 
 little backward and outward. 
 
 c. Helici3 major muscle. 
 
 § 1917. The helieis major muscle, grand helicien, Ch.,is elongated. 
 It arises from the inferior extremity of the helix, and ascends on the 
 external and anterior face of this eminence, to which it is attached di- 
 rectly above the point where the ear separates from the head. 
 
 It draws the anterior part of the concha a little backward and 
 downward. 
 
 d. Helicis minor muscle. 
 
 § 1918. The helicis minor muscle, petit helicien, Ch., is the smallest 
 muscle of the external ear. It is situated like the preceding, on the 
 external face of the helix ; it arises much lower and more posteriorly 
 than it, in the place where this eminence leaves the external ear, and 
 is attached sometimes higher to its ascending portion near the pos- 
 terior edge. 
 
 It slightly depresses the anterior part of the helix. 
 
 e. Transversus auricula: muscle. 
 
 § 1919. The transversus auriculae muscle, transverse de l'oricule, 
 Ch., is situated on the internal face of the external ear, viz. that which 
 looks towards the head. It is larger than the preceding, but is formed 
 of fasciculi which are less coherent, and generally also less evidently 
 fleshy. Its direction is transverse in almost all its course, and it ex- 
 tends from the anthelix to the scaphoid fossa. 
 
 It draws the scaphoid fossa and the helix outward, and thus en- 
 larges the opening of the ear. 
 
OF THE EAR. 
 
 117 
 
 ARTICLE SECOND. 
 
 INTERNAL EAR. 
 
 § 1920. The internal ear ( auris interna)( 1) comprehends : 
 
 1st. A considerable portion of the temporal bone, especially the 
 petrous and mastoid processes. 
 
 2d. The small bones of the ear, which moveably articulate with the 
 temporal bone. 
 
 3d. The muscles which move these little bones. 
 
 4th. A cartilaginous channel by which the ear communicates with 
 the cavity of the mouth. 
 
 5th. A fibro-cartilaginous expansion contained within the bony por- 
 tion of the ear. 
 
 6th. The auditory nerve which is distributed to this expansion. 
 
 A. EXTERNAL PORTION. 
 
 I. OSSEOUS PORTION OP THE AUDITORY PASSAGE. 
 
 § 1921. The osseous portion of the auditory passage , conduit 
 auriculaire , s. oriculaire , Ch. ( meatus auditorius osseus), when per- 
 fectly developed, forms the posterior and external part of the lower face 
 of the petrous process of the temporal bone. It is an elliptical canal, 
 the direction of which is from above downward, from behind forward, 
 and from without inward, which gradually contracts in the same di- 
 rection. This canal is about half an inch long. Its height exceeds its 
 breadth. 
 
 Its external orifice which presents grooves and asperities on its 
 edge, is called the external auditory foramen ( porus acusticus externus, 
 aditus admeatum auditorium osseum). It is turned from within out- 
 ward, and is intimately united to the cartilaginous portion of the audi- 
 tory passage. 
 
 Its posterior wall is a little shorter than the anterior. It is lined in 
 its whole extent by a prolongation of the skin which covers ■ the ear, 
 and which gradually becomes thinner from without inward. 
 
 Its internal orifice presents a considerable depression, a groove in 
 which the membrane of the tympanum is situated. This groove ex- 
 tends all around it, except its upper portion. 
 
 (1) C, Folius, Nova auris internee delineatio, Venice, 1645. — B. S. Albinus, De 
 aure liumanâ anteriore ; in the Annot. acad., book iv., cap. ii. — A. Comparetti, 06- 
 servationes anatomicce de aure interna comparatâ, Padua, 1789. — A. Monro, On the 
 brain, the eye and the ear, Edinburgh, 1797. — Ribes, Mémoire sur quelques parties 
 de V oreille interne; in the Bulletin de la soc. mêd. d’émul., 1823, November, p. 650 
 December, p. 707. 
 
 Vol. III. 
 
 16 
 
118 
 
 DESCRIPTIVE ANATOMY. 
 
 II. MEMBRANE OP THE TYMPANUM. 
 
 § 1922. The membrane of the tympanum (mem. tympani),(l) which 
 is inclosed in the internal orifice of the auditory passage, separates the 
 canal from that part of the internal ear which is next to it, that is from 
 the cavity of the tympanum. 
 
 It is a thin, elliptical membrane, the direction of which is a little 
 oblique from above downward, from without inward, and from behind 
 forward. There is positively no opening in it in the normal state, 
 although the contrary opinion has been maintained in several different 
 forms.(2) It consequently completely separates the cavity of the tym- 
 panum and the labyrinth from the osseous portion of the auditory 
 passage and from the external ear. As it extends a little farther than 
 the opening which receives it, its form changes in regard to its degree 
 of tension and relaxa tion,(3) which is produced principally by the ac- 
 tion of the muscles of the little bones of the ear. It fits exactly into 
 the groove at the internal extremity of the auditory passage. 
 
 Anatomists differ in opinion in regard to the formation of the mem- 
 brane of the tympanum. The most correct consider it formed of a 
 special membrane situated in the centre, of a second which is external, 
 situated next to that of the bony portion of the auditory passage. 
 In this view of the subject the external layers would be culs-de-sac of 
 the internal and the external cutaneous system, while the middle 
 layer forms a distinct and special membrane arising from the bony 
 portion of the auditory passage. 
 
 This special membrane presents very distinct fibres which radiate 
 from its centre to its circumference, and are very manifest in its internal 
 face. Judging from analogy, that is from what occurs in the large 
 animals particularly the elephant, these fibres are probably muscu- 
 lar. (4) The most careful injections demonstrate also numerous blood- 
 vessels which come principally from two circular trunks, an external 
 and an internal, and which anastomose together frequently. 
 
 (1) A. F. Walther, De membrana tympani, Leipsic, 1725. — Brugnone, Observa- 
 tions anatomiques sur la structure de la membrane du tympan et de celle de la caisse ; 
 in the Mém. de Turin, an. xii., p. 1,(2. — E. Home, in the Phil, trans., 1804. 
 
 (2) Very recently even Vest, judging from his own observations and those of 
 Wittmann, has maintained the normal existence of an opening' in the membrane of 
 the tympanum, admitted some time since by Rivinus, and long neglected. He 
 asserts that this opening is oblique, and thus forms a kind of valve. But he admits 
 it is frequently deficient ( Uuber die Wittmann ’ sehe Trommclfellklappe ; in the 
 Medicinische Jahrbücher des Oesterrenchischen Staates, vol. v., Vienna, 1819, p. 
 123-133). To conclude from a few cases, which were probably morbid, that the 
 opening is formed primitively, is evidently to make the exception a rule. F. T. 
 
 (3) F. Savart, Recherches sur les usages de la membrane du tympan et de l'oreille 
 externe ; in the Journal de physiol, experiment., vol. iv., p. 183. 
 
 (4) Sir E. Home asserts he has found some muscular fibres in the membrane of the 
 
 tympanum in the elephant. Their existence is at least doubtfnl. Rudolphi has 
 observed nothing similar in the whale or horse. F. T. 
 
OF THE EAR. 
 
 119 
 
 Of the two superficial layers the external is easily insulated : but it 
 is more difficult to separate the internal from the middle, both on ac- 
 count of its fineness and because it adheres to this latter more inti- 
 mately. 
 
 B. MIDDLE PART. 
 
 X. TYMPANUM. 
 
 § 1923. The tympanum or the drum ( tympanum , s. cavitas tym- 
 pani){ 1) is a narrow, rounded cavity, which is generally convex inter- 
 nally and which is continuous outwardly with the osseous portion of 
 the auditory passage by a broad opening before which the membrane 
 of the tympanum is expanded, and forward with the Eustachian tube 
 through another narrower opening. This cavity forms the central 
 part of the internal ear ; hence some anatomists term it the middle ear, 
 in opposition to the labyrinth and all the parts on the outside of it. It 
 occupies the external and posterior part of the petrous portion and 
 communicates anteriorly with the cavity of the mouth, posteriorly with 
 the mastoid cellules. 
 
 Its internal and very irregular face presents numerous elevations 
 and depressions which are connected with the labyrinth. It incloses 
 the little bones of the ear and the cord of the tympanum. 
 
 When we consider only the bones, we perceive that it is open for- 
 ward, backward, and downward. A mucous membrane which is 
 continuous with that of the throat lines its whole extent. 
 
 § 1924. On the inner face of the cavity of the tympanum, forward 
 and downward, at about its centre is a considerable eminence, termed 
 the promontory ( promontorium ), formed by the commencement of the 
 cochlea, and always covered by osseous substance. 
 
 At its lower and posterior partis an oblong, triangular opening, more 
 high than broad, which is directed backward and outward ; this is the 
 fenestra rotunda, the cochlear opening of the tympanum.{ 2) This 
 opening communicates with the cochlea, but it is closed by the mu- 
 cous membrane which lines the whole cavity of the tympanum. (3) 
 
 Above the promontary and a little above the centre of the tympa- 
 num is a second and much larger opening, called the fenestra ovalis, 
 the vestibular opening of the tympanum {fenestra ovalis, s. semi-ovalis). 
 The length of this opening, the greatest diameter of which is directed 
 from above downward and from before backward, exceeds its breadth. 
 
 (1) Santorini, Opp. posth., tab. v. 
 
 (2) A. Scarpa De structurâ fenestras, rotnndœ auris, et de tympana secundaria 
 anatomicce observations, Modena, 1772. — Ribes, loc. cit., p. 652. 
 
 (3) Ribes asserts that the membrane of the fenestra rotunda is composed of a 
 
 special layer, of a second given off by that of the cavity, and of a third coming from 
 that which lines the internal scala of the cochlea. Its structure then resembles that 
 of the membrane of the tympanum. F. T. 
 
120 
 
 DESCRIPTIVE ANATOMY. 
 
 Its posterior edge is convex, the anterior is straight. It is surrounded 
 outward by a small groove. 
 
 On the posterior wall of the cavity of the tympanum opposite the 
 lower extremity of the fenestra ovalis, farther backward and much 
 more outward, we remark the pyramid (emmentia pyramidalis), a small 
 triangular eminence which terminates forward by an opening which is 
 grooved in it, and which communicates with the Fallopian canal : 
 from the anterior extremity of this a small bridge of bone is frequently 
 detached, which goes to the upper extremity of the promontory, below 
 the fenestra ovalis. 
 
 Below and more posteriorly is another opening ( apertara chordœ) 
 through which the cord of the tympanum passes from the Fallopian 
 canal to the tympanum. 
 
 The space between the pyramid, the promontory, and the fenestra 
 ovalis forms a considerable depression termed the sinus of the tympa- 
 num ( sinus tympani). 
 
 Above and in the centre the cavity of the tympanum is grooved to 
 receive the upper part of the two largest bones of the ear. 
 
 Upward and backward it communicates by one or more considera- 
 ble openings with the cavity of the mastoid process, which must con- 
 sequently be considered as a prolongation of it. This cavity is divided 
 by numerous septa into cellules, which enlarge much from the centre 
 to the circumference, and which are lined by the mucous membrane 
 which covers the inner face of the tympanum. 
 
 The internal wall of the tympanum presents at its anterior part a 
 groove which leads into an osseous prolongation ; this extends forward, 
 and is the bony portion of the Eustachian tube ( tuba Eustachii ossea). 
 Above this groove we observe a second, which sometimes is not sepa- 
 rated from the other in its whole extent, and which lodges the tensor 
 tympani muscle. 
 
 Under the posterior extremity of the second groove is a small open- 
 ing which leads above to the superficial petrous groove, below to a 
 groove which descends on the promontory. This groove becomes 
 at its lower part a canal which opens outward on the lower face of 
 the pyramid, between the carotid canal and the fissure of the jugular 
 vein. 
 
 Through this canal passes a filament of anastomosis between the 
 second branch of the trifacial, the glosso-pharyngceal, and the gan- 
 glionnary nerve ; this minute filament arises from the superficial 
 petrous nerve, enters the cavity of the tympanum with another fila- 
 ment of the great sympathetic nerve, and communicates below this 
 cavity with the ganglion of the glosso-pharyngceal nerve.(l) 
 
 (1) Jacobson, Supplcmenla ad otoiatriam ; in Act. IlaJ'n., vol. v., 1818, p. 292. 
 
OP THE EAR, 
 
 121 
 
 II. EUSTACHIAN TUBE. 
 
 § 1925. The Eustach an tube , conduit guttural de V oreille, Ch, 
 ( tuba Eustachii ), is a canal the posterior part of which is formed of 
 bone, but is fibrous and fibro-cartilaginous at its anterior portion, and 
 extends from the tympanum to the upper part of the pharynx. The 
 direction of this canal is oblique from above downward, from without 
 inward, and from behind forward. It is nearly two inches long. 
 
 The osseous portion is the shortest, and is situated above the carotid 
 canal. It becomes narrow from behind forward. 
 
 The cartilaginous portion proceeds directly below the base of the 
 skull, but on the contrary gradually enlarges in the same direction. 
 It is compressed from within outward in its wholq extent. Its form is 
 elliptical and it is fibro-cartilaginous in the inner portion and sometimes 
 also in the upper portion of its external wall. In other parts it is com- 
 posed of a fibrous tissue which arises from the periosteum of the infe- 
 rior pterygoid process. 
 
 The Fallopian tube is entirely lined internally by a very fine mucous 
 membrane which is continuous with that of the oral cavity and of the 
 tympanum. Around the buccal orifice of this tube this membrane 
 becomes much thicker, partly from a great development of the muci- 
 parous glands. Thence a prominence is formed which changes this 
 opening into a narrow longitudinal fissure and forms a kind of valve. 
 
 III. BONES OF THE EAR. 
 
 § 1926. The bones of the ear ( ossicida auditus),{ 1) situated at the 
 upper part of the cavity of the tympanum, are the smallest bones in 
 the body. They form a chain composed of pieces movably articu- 
 lated with each other, which extends from the membrane of the tym- 
 panum to the fenestra ovalis, consequently to the labyrinth, and which 
 conveys to the deepest parts of the internal ear the changes which 
 supervene in the membrane of the tympanum. 
 
 There are three bones, the hammer {malleus), the anvil {incus), and 
 the stirrup {stapes) ; and in the early periods of life a fourth, the lenti- 
 cular bone. 
 
 (1) J. A. Schmid, De periostoo ossiculorum audilus ejusque vaseculis, Leyden, 1719. 
 — H. F. Teichmeycr, Diss. medica solemnis sistens vindicias quorundam inventorum 
 anatomicorum, Leipsic, 1727.— Magendie, Sur tes organes qui tendent ou relâchent 
 la membrane du tympan et la chaîne des osselets de l'ouïe dans l’homme et dans les 
 animaux mammifères ; in the Jour, de phys. expèrim.., vol. i., p. 341-347, tab. iv. 
 
122 
 
 DESCRIPTIVE ANATOMY- 
 
 a. Malleus. 
 
 § 1927. The hammer ( malleus ) forms the anterior and external part 
 of the chain, and is divided into a head , a neck, a handle , and pro- 
 cesses. 
 
 The head, the upper part, is rounded, oblong, convex and smooth 
 forward, concave and slightly uneven backward. Its posterior face is 
 oblong and surrounded by a slightly prominent edge. A transverse 
 eminence divides it into an upper and a lower face. 
 
 The head is situated above the inferior edge of the membrane of the 
 tympanum in the anterior part of the upper prolongation of the cavity 
 of the tympanum. 
 
 The neck is short, compressed in all parts, but particularly slightly 
 flattened from without inward. 
 
 Its lower extremity is divided into three sections, the handle and the 
 two processes. 
 
 The handle ( manubrium ), or the inferior section, descends a little 
 from without inward and from behind forward. It is terminated at its 
 lower extremity by a small prominence, and is situated between the 
 layers of the membrane of the tympanum. 
 
 The external or the short process {processus externus , s. obtusus , s. 
 brevis) projects more or less at the upper extremity of the handle, and 
 forms with it. a right angle. It is directed outward, and is separated 
 by a deep groove from the head, into which the upper side of the in- 
 ternal extremity, of the auditory passage enters. 
 
 The anterior long or spinous process ( processus anterior, s. longus, 
 s. spinosus ) is thinner but much longer than the preceding, and is con- 
 vex above and concave below. It is received by a broad and super- 
 ficial groove hollowed on the inner face of the upper extremity of the 
 ring of the tympanum. 
 
 The malleus is connected with the membrane of the tympanum and 
 with the incus. 
 
 b. Incüs. 
 
 § 1928. The anvil (incus) has nearly the form of a bicuspid molar 
 tooth ; it is composed of two branches and of a centre which may be 
 termed the body. , 
 
 The body is almost square, flat, and presents forward a concave sur- 
 face by which the bone articulates with the head of the malleus 
 (§ 1926). It is situated above the membrane of the tympanum. 
 
 The upper or posterior and shorter branch is flattened from within 
 outward, terminated by a blunt summit also situated above the mem- 
 brane of the tympanum, and is directed horizontally from before back- 
 ward where its loose extremity terminates. . 
 
OF THE EAR. 
 
 123 
 
 The anterior or inferior branch varies in length and is almost 
 straight ; its direction is from above downward and from behind for- 
 ward, and it is situated more internally than the preceding. It termi- 
 nates in a small button-like prominence ; it is situated behind the 
 handle of the malleus, a little on the outside of it. 
 
 The body of the incus articulates above and forward with the head 
 of the malleus, by its long branch below with the stapes. It is not di- 
 rectly connected with the membrane of the tympanum. 
 
 c. Lenticular bone. 
 
 § 1929. The lenticular bone - (os lenticulare , s. Sylvii) is an ex- 
 tremely small, flat, and rounded bone, situated on the inner face of the 
 lower extremity of the long branch of the incus. It generally fuses 
 with the incus very early, even during the latter months of pregnancy, 
 and then forms an eminence which projects on its inner face. 
 
 d. Stapes. 
 
 § 1930. The stirrup ( stapes ) is situated more internally than the 
 other two bones of the ear, and is not perpendicular like them but hori- 
 zontal. It is composed of a head, two branches , and the transverse 
 face or the base. 
 
 The head is rounded, oblong, and flattened from above downward. 
 Its upper extremity looks outward and presents a slight depression for 
 the lenticular bone : the two branches are sometimes separated by a 
 contracted neck. 
 
 The anterior branch is always shorter and also straighter than the 
 posterior branch. Both are grooved on their internal faces, which look 
 towards a groove in which a membrane, ! a prolongation of that of 
 the tympanum, extends between them. 
 
 The base has exactly the same form as the fenestra ovalis, with 
 which it is movably united by the membrane of the tympanum. It 
 is always a little narrower, so that it can enter and leave the vestibule 
 through this opening. 
 
 Its inner face, which corresponds to the fenestra, is straight. The 
 external is concave and circumscribed by prominent edges. 
 
 IV. MUSCLES OF THE BONES OF THE EAR. 
 
 § 1931. The small bones of the ear are moved by four muscles, 
 which, like the bones to which they are attached, are the smallest in 
 the body. Three of these are inserted in the malleus and one in the 
 stapes. Two muscles. of the malleus are situated before the cavity of 
 the tympanum, the third above this cavity. That of the stapes is 
 situated behind it. The incus has no special muscle : it forms only a 
 connecting link between the malleus and the stapes. 
 
124 
 
 DESCRIPTIVE ANATOM V. 
 
 a. Muscles of the malleus. 
 
 § 1932. The three muscles of the malleus from their connections of 
 the bone with the membrane of the tympanum vary the degree of 
 tension of this membrane. They are distinguished into an internal and 
 an external. 
 
 1. Tensor tympani muscle. 
 
 § 1933. The tensor tympani muscle, the internal muscle of the malleus 
 {m. tensor tympani , s. mallei interims) is elongated. It arises from the 
 upper part of the cartilaginous portion of the Eustachian tube near the 
 sphenoid bone, and generally comes from its large wing. Its direction is 
 from before backward in the canal from which the petrous process is 
 grooved to allow it to pass to the osseous portion of the tube. In the 
 cavity of the tympanum the direction of its tendon changes, leaves the 
 internal wall of this cavity, goes outward and is attached to the upper 
 extremity of the inner face of the malleus directly below its long 
 process. 
 
 This muscle draws the malleus inward, tenses the membrane of the 
 tympanum which the bone draws with it, and brings the chain of bones 
 inward so as to -sink the stapes into the fenestra ovalis. 
 
 2. Laxator tympani major muscle. 
 
 § 1934. The laxator tympani major muscle, the great external 
 muscle of the malleus (JVf. laxator tympani major , s. mallei externus 
 major), arises from the grooved prolongation of the great wing of the 
 sphenoid bone, and is directed from without inward and from before 
 backward. Its tendon enters the fissure of Glaser and is attached to 
 the long process of the malleus. 
 
 It draws the malleus forward and outward, and thus relaxes the 
 membrane of the tympanum. 
 
 3. Laxator tympani minor muscle. 
 
 § 1935. The laxator tympani minor muscle, the small external mus- 
 cle of the malleus {JVL. laxator tympani minor , s. mallei externus minor) , 
 is much smaller than the two preceding and arises from the upper edge 
 of the osseous portion of the auditory passage, passes between the 
 layers of the membrane of the tympanum, goes forward and outward, 
 and is attached sometimes higher and sometimes lower to the handle 
 and the external process of the malleus. 
 
 It draws the malleus upward, backward, and outward. It conse- 
 quently relaxes the membrane of the tympanum. 
 
OF THE EAR. 
 
 123 
 
 b. Stapedius muscle. 
 
 § 1936. The stapedius muscie (M. stapedius) is oblong and trian- 
 gular. It arises at the base of the pyramid and goes forward and 
 upward. Its tendon comes through the anterior opening in the top of 
 the pyramid, and is attached to the posterior part of the head of the 
 stapes. 
 
 It draws the stapes backward so as to bring the posterior portion 
 of its base into the fenestra ovalis. It also draws the chain of the 
 bones inward, and thus tenses the membrane of the tympanum. 
 
 We have every reason to think that it acts at the same time as the 
 tensor tympani muscle. 
 
 C. INTERNAL PORTION OR LABYRINTH. 
 
 § 1937. The labyrinth (labyrinthus),{ 1) the most internal part of 
 the organ of hearing, comes next inside to the tympanum. It is a 
 double cavity situated in the petrous portion of the temporal bone, di- 
 rectly surrounded by the very firm substance of this portion, and is 
 formed of several compartments of very complex figures. We distin- 
 guish in it a central part the vestibule , a posterior part the semicircu- 
 lar canals , an anterior portion the cochlea s and the lateral parts the 
 aqueducts. 
 
 One of the two cavities which form it completely surrounds the 
 other and is moulded upon it. 
 
 The first is the osseous labyrinth , the second the membranous laby- 
 rinth. 
 
 I. OF THE OSSEOUS LABYRINTH. 
 
 § 1938. The osseous labyrinth in the adult is not distinct from the 
 compact substance of the petrous process of the temporal bone, of 
 which it forms the most internal, the firmest and the hardest part, 
 which closely envelops and covers the membranous labyrinth. But 
 in the early periods of life it is formed by a solid, hard, and brittle sub- 
 stance, separated from the external layer of the petrous process by a 
 less compact osseous tissue. Its internal face is moistened with limpid 
 serum which exactly fills all the space between it and the membranous 
 labyrinth. (2) 
 
 During the early periods of life we find between the two labyrinths 
 a membrane which is not the periosteum of the osseous portion, al- 
 though generally considered as such, but which belongs to the class 
 
 (1) A. Scarpa, Disquis. anatomicæ de auditu et olfactu, Pavia, 1789. — A. Monro, 
 lee. cit. — Brugrone, Observations anatomico-physiologiques sur le labyrinthe de 
 l’oreille ; in the Mémoires de Turin , 1805-1808, p. 167-177. 
 
 (2) Cotugno, Diss. cit., § xxix.— P. F. T. Meckel, De labyrinthi auris cov.tev.tis, 
 Strasburg, 1777. 
 
 Vol. III. 
 
 17 
 
126 
 
 DESCRIPTIVE ANATOMY. 
 
 of sero-mucous membranes. This is demonstrated by the numerous 
 vessels it receives and by its abundant secretion and its connections 
 with the membrane of the tympanum. 
 
 a. Vestibule. 
 
 § 1939. The vestibule ( vestibulum),(\ ) the middle of the bony laby- 
 rinth, is situated farther inward and more posteriorly than the tym- 
 panum. It is of a rounded and oblong cavity at about the centre of 
 which we perceive the internal orifice of the fenestra ovalis. We there 
 remark principally two small depressions or superficial grooves, one 
 superior , posterior and external , more extensive than the other and of 
 an oval form (fovea, s. cavitas ovalis, s. elliptica, s. semi- elliptic a) ; the 
 other inferior and anterior, smaller and semicircular ( fovea hemi- 
 sphœrica, s. orbicularis). The first is situated on the posterior and 
 inferior wall, the second on the superior and external. They are 
 separated by a sharp crest which extends from above downward. 
 
 The oval fossa k is continuous below with another which is smaller, 
 the sulciform groove (fovea sulciformis) . 
 
 § 1940. In the circumference of the vestibule are six large foramina 
 and one which is rounded and very small. 
 
 Of these six large foramina, one which occupies the anterior and 
 inferior part of the vestibule leads to the superior scala of the 
 cochlea ; the other five situated at the posterior part are the orifices of 
 the posterior part of the labyrinth or the semicircular canals. 
 
 The small opening at the posterior and inner part of the vestibule in 
 the sulciform groove leads to the aqueduct of the vestibule. 
 
 b. Semicircular canals. 
 
 §1941. 'The semicircular canals (canales semi- circular es) form the 
 posterior and largest part of the labyrinth. 
 
 There are three of them which occupy a square space : the superior 
 or anterior, the posterior , internal or inferior, and the external. The 
 first two are perpendicular, the third is horizontal. 
 
 When united they form more than half a semicircle. They are 
 much more prominent at one of their extremities than at the other and 
 in the rest of their course, so that they represent in this place a rounded 
 vesicle (ampulla). They are not perfectly round externally nor intef- 
 nally, but are slightly flattened and elliptical. 
 
 The diameter of their cavity is about half a line. 
 
 Their orifices are a little broader than the rest of their course. 
 
 The superior is oblique from without inward and from before back- 
 ward. It forms the highest part of the labyrinth, and its two branches 
 are separated the farthest. Its anterior and external opening, which 
 
 (1) Ribes, loc. cit., p. 651. 
 
OF THE EAR. 
 
 127 
 
 is situated above the fenestra ovalis, forms a considerable vesicle of 
 which we see another trace at its posterior extremity, through which 
 it blends with the superior opening of the internal canal. 
 
 The inferior is also perpendicular, but its convexity looks backward 
 and its concavity forward. It commences above by a short canal 
 which it has in common with the internal extremity of the superior, 
 and terminates by a vesicular enlargement below and inward in the 
 vestibule. 
 
 It is the longest and its branches are nearest each other. 
 
 The external or horizontal arises by a slightly marked vesicular 
 prominence below the external orifice of the superior. Its internal 
 orifice in the vestibule is situated on the outside and below the com- 
 mon opening of the superior and the inferior. 
 
 It is the shortest and also the broadest of the three semicircular 
 canals. 
 
 The reunion which occurs between the superior and inferior canal 
 diminishes the number of the openings of the semicircular canals to 
 five instead of six. 
 
 c. Cochlea. 
 
 § 1942. The cochlea(l) forms the anterior and most complex part 
 of the labyrinth. It presents to a certain extent the repetition of the 
 semicircular canals, and its figure perfectly resembles that of the shell- 
 fish whose name it bears. 
 
 It is a grooved canal which gradually diminishes from its origin to 
 its extremity, and thus it finally becomes very narrow. It turns 
 around a central and perpendicular portion termed the axis (modiolus), 
 which gradually becomes thinner. It thus describes two turns and a 
 half. 
 
 The first turn is much larger than the rest, which it envelops ; the 
 others however project much beyond it. 
 
 § 1943. A horizontal plate of bone, which arises from the inner part 
 of the cochlea and which is termed the spiral septum ( lamina spiralis ), 
 divides it into two canals situated one above the other and termed the 
 scalæ. 
 
 The lower face of the spiral septum presents grooves which look 
 towards the axis. Its upper face is the smoothest. 
 
 It is formed of two laminæ, a superior and an inferior. 
 
 (1) G. Brendel, De auditu in apice cochleae, Program. I. II, Gottingen, 1747. — J. 
 G. Zinn, Observationes de vasis subtilioribus oculi et cochlea auris internee, Got- 
 tingen, 1753. — J. G. llg, Einige anatomische Bemerkungen, enthaltend eine Be- 
 richtigung der zeitigen Lehre vom Bau der Schnecke des menschlichen Gehöror- 
 gans, nebst einer anatomischen Beschreibung und Abbildung eines durch ausseror- 
 dentliche knochenwucherung sehr merkwürdigen menschlichen Schädels, Prague, 
 
}28 
 
 DESCRIPTIVE ANATOMY. 
 
 The inferior lamina is much broader than the superior, and termi- 
 nates backward and outward in the fenestra rotunda in the tympanum. 
 This has been termed the scala of the tympanum ( scala tympani). 
 It is separated from the cavity of the tympanum by a membrane which 
 presents a depression on the side of this cavity which is termed the 
 secondary tympanum ( tympanum secundarium) . 
 
 The superior scala is much narrower than the inferior. It terminates 
 at the anterior opening of the vestibule. Thence it is termed the scala 
 of the veslibide ( scala vestibuli). 
 
 The cochlea however does not continue separated the entire length 
 of this cavity, and the spiral septum terminates near the middle of the 
 second turn in a pointed hook termed the hook of the cochlea ( hamulus 
 cochleae). 
 
 By uniting in this manner, the two canals of the cochlea give rise to 
 a tunnel-like cavity, the infundibulum ( scyplms ), the base of which is 
 turned upward and the summit downward towards the cupola of the 
 cochlea. 
 
 This conical cavity forms the most prominent part of the cochlea. 
 
 The axis(l) which turns on itself is hollow like the scalæ. A larger 
 canal passes longitudinally through it from its base to its summit. It 
 also presents numerous small openings, the diameter of which gradually 
 diminishes from its base to its summit. These openings lead to s>nal} 
 canals which terminate on the spinal lamina. (2) 
 
 (1) Rosenthal, Sur la structure de l'axe du limaçon dans l'oreille de l'homme ; iji 
 the Journal complém. du Diet, des sc. méd ,, vol. xvi., p. 180. 
 
 (2) Anatomists have hitherto considered the axis of the cochlea as a small column 
 formed by a very thin osseous lamina, through which a canal passes from the base 
 to the summit, which is perforated by numerous small foramina. It is asserted that 
 it terminates at the second turn of the cochlea, at the top of which it appears on 
 leaving this place as a tunnel-form layer of bone, the summit of which is the termi- 
 nation of the axis, and the upper extremity of which looks towards the summit of 
 the cochlea and is covered by a plate of bone. Hence are distinguished the cavity of 
 the axis and that of the infundibulum. There is also admitted in the latter a thin 
 column around which the spiral septum turns from the second curve, and which 
 terminates in a small osseous plate curved like a hook. Ilg describes the structure 
 of this axis differently. He states that the spiral channels of the cochlea do not turn 
 around a special nucleus of hone; hence he does not admit an axis, but asserts that 
 it is the inner and concave wall of the spiral canal which forms the species of column 
 around which this canal turns, and that we perceive in it the form of a cylinder on 
 ppening the first and second turn of the cochlea. The column is very thick in the 
 first turn where it is a line and a half in diameter, but very thin in the'second where 
 its diameter does not exceed half a line. As the internal wall of the spiral canal 
 forms what is termed the a?is in the first two curves, so likewise if produces some- 
 thing similar in the third. But. this pillar of the third turn has not the form of a 
 cylinder ; it is composed only of a very thin and twisted osseous plate, which arises 
 from the summit of the cylindrical column and extends to the cupola of the cochlea, 
 ■where it is attached. The loose edge of this plate, which exists all the length of the 
 imaginary axis of the cochlea, from the termination of the cylindrical column to the 
 top of this cavity, is smooth, rounded, and generally a little concave in the direction 
 of its length. Sometimes also it represents a small column which goes directly to 
 the summit of the cochlea. The axis of the column is perforated by a small canal, 
 and this column is filled to the second turn by an osseous cellular mass, the cellules 
 of which communicate with numerous small foramina grooved along the parietes of 
 the column, and into which open some small canals which proceed between the two 
 Jayerg of the septum or spiral lamina. Rosenthal has since modified and rectified the 
 
OF THE EAR, 
 
 129 
 
 d. Aqueducts. 
 
 § 1944. The aqueducts ( aquceductus , diverticula, )(1) of the laby- 
 rinth are short, narrow canals, which are directed from above down- 
 ward through the substance of the petrous process of the temporal 
 bone, and which enlarge a little in their course. There are two, the 
 aqueduct of the vestibule , and the aqueduct of the cochlea. 
 
 The aqueduct of the vestibule ( aquceductus vestibuli) begins by a very 
 small opening in the inner wall of the vestibule before the common 
 opening of the two perpendicular semicircular canals in the sulciform 
 groove of the vestibule, which is in fact their internal orifice. It first 
 goes a short distance from without inward and a little from below up- 
 ward in the centre of the petrous process, then from above downward, 
 insensibly enlarges on leaving this curve, and after proceeding about 
 four lines terminates a little behind the centre of the inner face of the 
 petrous process of the temporal bone near the fossa intended for the 
 gulf of the internal jugular vein, with which it always communicates 
 by a slight groove. 
 
 The aqueduct of the cochlea ( aquceductus cochlea ) commences by a 
 wider opening in the tympanitic scala of the cochlea directly before 
 the fenestra rotunda, descends from before backward, enlarges in this 
 course, and terminates by a triangular opening at about the centre of 
 the inferior edge of the petrous process of the temporal bone. 
 
 By these two aqueducts the membranous labyrinth communicates 
 externally, (2) and forms culs-de-sac between the bone and the dura- 
 mater. 
 
 description of Ilg. It follows from his researches, that from the summit of the pillar 
 of the first two turns a layçr proceeds in a semicircle to the external wall, and ter- 
 minates by a loose and semilunar edge, which ascends to the infundibulum. The 
 last turn is open on the side of this edge, by which the lamina turned opposite the 
 pillar terminates, and the unciform extremity of the spiral lamina which is reflected 
 around tire same edge projects in the turn in question ; the two laminpe terminate in 
 this place, or rather blend in this small rounded cavity. The crook turning around 
 the edge of the lamina of the axis in the place where this lamina separates from the 
 centre of the pillar, is like the extremity of the latter, separated from the infundi- 
 bulum. The edges of the spiral lamina and of that of the pillar are fitted to each 
 other, cross so that their faces are turned from the side of the external wall of the 
 cochlea, and as the latter inclines a little towards the centre of the pillar, they form 
 in some measure a broad tunnel-like edge for the canal grooved in the first two 
 turns of tfie column to emerge. It follows then from Rosent hal’s description: 1st, 
 that, as Scarpa and some other anatomists have asserted, the base of the infundi- 
 bulum is situated on the summit of the cochlea and its summit in that of the pillar, 
 but it does not extend so deeply as they assert, for it terminates below the last semi- 
 turn and is loose below the cupola of the cochlea, and there is no extended lamina 
 of the column which unites with its covering ; 2d, that Ilg is mistaken in saying 
 that the axis extends to the centre of the cochlea, to its roof, and that it does not 
 form a tunnel-like edge, and is attached to the summit of the cochlea by a rounded 
 point closed at its extremity, P. T. 
 
 (1) D. Cotugno, De aquæductibus auris humance internee anatomica dissertatio, 
 Naples, 1761. — P. F. Meckel, De labyrintJii auris contentis, Strasburg, 1777.— -Ribes, 
 loc. cit, p. 713. 
 
 (2) The opinion that the aqueducts establish the communication between the la- 
 byrinth and the exterior was admitted by Cotugno, who, thinking 1 that the internal 
 
130 
 
 DESCRIPTIVE ANATOMY. 
 
 They also serve for the passage of the arteries which enter the laby- 
 rinth and the veins which come from it and the lymphatics, the ab- 
 sorbent action of which prevents the abnormal accumulation of serum 
 in this cavity. The veins, and perhaps some of the lymphatics also, 
 empty into the internal jugular vein. This explains why mercury 
 and other fluids pass from the labyrinth into this vein through the 
 aqueducts, after distending the sacs of the membranous labyrinth. 
 
 ear is always exactly filled with scrum, had been obliged to explain how this liquid 
 can be moved by the compression exercised upon it by the base of the stapes to sup- 
 pose the existence of derivative canals, which allow it to escape in part, and to leave 
 a certain space between it and the parietes of the ventricle. The observations of 
 Brugnone and of Ribes, which we shall mention hereafter, overturn all this theory. 
 These anatomists consider the pretended aqueducts only as passages for the arteries 
 and veins. In regard to that of the vestibule, Ribes has discovered that at about the 
 centre of the posterior face of the petrous portion of the temporal bone, where it 
 begins as an uneven and undulating layer, it goes forward, upward, and outward, 
 proceeds first on the inside of the posterior semicircular canal, next between the 
 posterior wall of the vestibule and the superior semicircular canal, curves and pene- 
 trates into the concavity formed by this canal, thence goes backward and outward, 
 and is distributed in the spungy tissue of the posterior part of the labyrinth. This 
 duct is at first very broad, and it contracts much in its course upward. It generally 
 gives off in its course other smaller duets, at each of which it becomes smaller, and 
 among which Ribes has found some which opened into the inner part of the vesti- 
 bule, others into the posterior semicircular canal, but only in three pieces, for in all 
 others there was no duct from the aqueduct proceeding either within the vestibule 
 or to any other point within the labyrinth. Besides this aqueduct does not exist in 
 the full grown fetus nor even some time after birth. It is designed to contain the 
 blood-vessels which ramify in all the spongy tissue surrounding the labyrinth, and 
 sometimes enter into the vestibule. Ribes asserts that the aqueduct of the cochlea 
 arises at the base of a small depression situated about the centre of the lower edge 
 of the petrous portion of the temporal bone, ascends obliquely to the lower part of 
 the internal auditory passage, passes under the labyrinth, goes horizontally back- 
 ward and outward, and terminates not in the internal scala of the cochlea, as is 
 stated, but in the canal of the fenestra rotunda below the membrane which closes 
 its opening. As this passage proceeds towards the tympanum it gives rise to nu- 
 merous branches. It lodges the vessels which are distributed under the labyrinth 
 in the spungy tissue of tne petrous portion of the temporal bone and within the 
 tympanum. Thus the two pretended aqueducts belong to the class of vascular 
 canals described in a note on the osseous system. But there are others beside them 
 observed in the petrous process. Ribes mentions three others-: 1st, one which arises 
 at about the centre of the posterior base of the petrous process near its upper edge 
 and two lines from the internal auditory passage, goes backward and outward, 
 passes under the anterior semicircular canal, opens directly under the curve of the 
 superior semicircular canal, where it receives the pretended aqueduct of the vesti- 
 bule, with which it then goes into the spungy substance of the posterior part of the 
 petrous process and in the mastoid cellules, lined by a prolongation of the dura- 
 mater : 2d, another which arises near the centre of the anterior face near the upper 
 edge of the petrous portion, and goes behind the superior semicircular canal: 3d, 
 another which arises at the bottom of the longitudinal fissure which indicates the 
 union of the petrous process with the squamous portion of the temporal bone, and 
 through which pass some vessels which are distributed in the mastoid cells and the 
 membrane of the tympanum. These details may seem minute, but they are of the 
 highest importance, since they contribute to destroy an anatomical error on which 
 rests a part of the theory by which physiologists still explain the philosophy of hear- 
 ing. F - T. 
 
OF THE EAR. 
 
 131 
 
 II. MEMBRANOUS LABYRINTH. 
 
 § 1945. The membranous labyrinth(l) is inclosed in the osseous 
 labyrinth, and corresponds perfectly to its form, although it is much 
 smaller. 
 
 It is formed of a thin and whitish membrane, differing entirely from 
 that which covers the inner face of the osseous labyrinth in the early 
 periods of fetal existence. Its external face adheres to the inner face 
 of the bony labyrinth by a loose cellular tissue. It contains in its cavity 
 a fluid called the serum of the membranous labyrinth or the lymph of 
 Cotugno , ( aquula labyrinthi membranacei) .(2) Numerous vessels are 
 distributed in its external face. 
 
 The upper and posterior part of the osseous vestibule is occupied by 
 a rounded and oblong membranous sac in which the membranous 
 semicircular canals open, which enlarge also in the parts which cor- 
 respond to the enlargements of the osseous canals. Before this sac 
 we find one which is rounded, perfectly closed, and consequently en- 
 tirely separate from the membranous labyrinth, which is smaller, si- 
 tuated partly in the semicircular fossa, and also filled with a serous 
 fluid. These two sacs are attached to the osseous labyiinth by their 
 posterior wall. The anterior, which looks toward the anterior wall of 
 this latter and the fenestra ovalis, is loose and surrounded by the serum 
 of the osseous labyrinth. The semicircular canals are arranged pre- 
 cisely like the osseous semicircular canals. 
 
 The membranous cochlea is formed by a fibro-cartilaginous layer, 
 the membranous spiral lamina, which is adapted to the external and 
 loose edge of the osseous spiral lamina, and which becoming softer 
 and thinner on the outside is attached by its external edge to the outer 
 side of the osseous cochlea. This lamina is longer than the osseous, 
 for it extends to the summit of the cochlea.. In this part of its course 
 it is loose on its inner edge, while the external is attached as in every 
 otljer part. It terminates in a prominence. 
 
 (1) Scarpa, loc. cit. — Brugnone, Observations anatomico-physiologiques sur le la- 
 byrinthe de l’oreille ; in the Mémoires de Turin, 1805-1808, p. 167-176. 
 
 (2) Ribes {loc. cit., p. 207) remarks that there are many adults in whom this hu- 
 
 mor fills the labyrinth, but there are many in whom it is partially empty, and who 
 nevertheless always hear perfectly. He concludes, from these remarks, that the 
 labyrinth is not constantly filled by serum, and that then there is in fact a space 
 doubtless occupied by an äeriform fluid ; but this space, he adds, does not always 
 exist equally in all the cavities of the labyrinth. Sometimes, in fact, we find little of 
 this humor in the semicircular canals, and much in the vestibule and the cochlea ; 
 and sometimes the semicircular canals are full, while the other cavities contain but 
 little. Finally he thinks that these changes depend only on the situation in which 
 the cadaver is held. These observations fully confirm those of Brugnone ( Mém . 
 de Turin, vol. xvi., p. 167), who also thinks that there is almost always serum in all 
 the cavities of the labyrinth, but that this liquid does not exactly fill them in the 
 natural state, because spaces exist in ice removed from them, although liquids ac- 
 quire more volume by congelation. F. T. 
 
132 
 
 DESCRIPTIVE ANATOMY. 
 
 III. AVDITOBY NEBVE. 
 
 § 1946. We have already mentioned the origin of the auditory 
 nerve and its course to the internal auditory passage, accompanied by 
 the facial nerve. On entering this canal the auditory nerve divides 
 into several branches, -which enter the labyrinth, and the progress of 
 which is indicated by the arrangement of the bones. 
 
 In fact the internal auditory passage(l) presents at the base of its 
 cavity forward, in the place where the internal and perforated plate of 
 the axis of the cochlea is situated, a crest, the direction of which is from 
 before backward ; it is at first slightly sensible, but is very marked in 
 the adult, which divides it into two halves, a superior and an inferior, 
 which is larger. The first belongs entirely to the facial nerve, while 
 the other belongs to it only in a small portion of its anterior part, so 
 that we may say that the superior groove receives the facial nerve, and 
 the inferior the auditory nerve. The first is divided by a longitudinal 
 prominence into two halves, an anterior, the commencement of the 
 Fallopian canal, and a posterior, in which the superior branch of the 
 auditory nerve is situated. 
 
 § 1947. The auditory nerve is distributed to the membranous laby- 
 rinth. (2) Its first branches go to the semicircular canals and the ves-^ 
 tibule. The first, the largest, passes through the depression behind 
 the origin of the Fallopian canal, and arrives at the sac of the superior 
 semicircular canal ; the second goes to the oval depression of the ves- 
 tibule ; the third, still smaller, arrives at the sac of the posterior semi- 
 circular canal. 
 
 When the first branch has arrived thus far it divides into two twigs, 
 which separate like a fan ; one of them goes to the larger or common 
 sac of the semicircular canals, while the other belongs to those of the 
 superior and the external canal. 
 
 All these twigs are evidently fibrous and interlace on the outer face 
 of the sacs, but when examined on their inner face they appear to be 
 a formless mucus. They do not extend over the whole vestibule and 
 the semicircular canals, but remain very distinct upon the surface of 
 the sacs. 
 
 The nerve then goes forward in the axis of the cochlea, follows 
 exactly the curves of the cavity, and gives off numerous filaments 
 which go inward through the openings in its axis. 
 
 The first filaments given off are the largest ; the others gradually 
 diminish, and are nearer together. 
 
 Finally the nerve terminates at the summit of the axis by a consi- 
 derable filament much larger than the others, and which enters the 
 openings in the axis. 
 
 (1) Ribes, loc. cit., p. 660. 
 
 (2) Ribes, ibid. p. 665. 
 
OF THE EAR. 
 
 133 
 
 The most internal of these filaments pass through the openings in 
 the curves of the pillar, enter into the canals which terminate there, 
 arrive on the spiral lamina, form an extremely minute plexus along its 
 two faces, and terminate on the membranous spiral lamina, where they 
 are entirely exposed. 
 
 Scarpa(l) asserts that they proceed only between the two plates of 
 the spiral lamina ; but they in fact cover also the outside of the supe- 
 rior and inferior faces of this Jayer,(2) and those seen in this place, par- 
 ticularly those on the lower face, are even the largest. Some fewer 
 and much smaller filaments pass through the foramina in the spires of 
 the cochlea near the pillar, and go not into the spiral lamina, but to 
 that portion of the membranous cochlea which forms its external wall. 
 All anastomose together on the outside of the cochlea. 
 
 The nervous filaments which enter the cochlea are, like the prece- 
 ding, white, opaque, and evidently fibrous near their origin ; but their 
 latter expansions are semitransparent, more gray, and similar to 
 mucus. 
 
 § 1948. The changes which are communicated to the cerebrum by 
 the auditory nerve and excite there the sensation of sounds, take place 
 in the expansions of this nerve in the membranous labyrinth. These 
 changes are doubtless caused by the compression which the serum in 
 the labyrinth exercises on the ramifications of the nerves, and this 
 pressure is necessarily the consequence of a change in the state of the 
 parts on the outside of the labyrinth, especially in the little bones of 
 the ear and their muscles. In fact, according as the base of the 
 stapes is more or less deeply, and partially or wholly imbedded in 
 the fenestra ovalis, it compresses the serum within it in different 
 degrees, and presses upon different parts of the labyrinth. The 
 external ear and the membrane of the tympanum principally serve to 
 receive the undulations of sound and to strengthen them, which is 
 effected by the tympanum and the mastoid cells. In regard to the 
 little bones of the ear, independent of the use assigned them, the malleus 
 certainly modifies the degree of tension of the membrane of the tym- 
 panum, serving to diminish it in loud and to increase it in weak sounds. 
 The Eustachian tubes serve to evacuate the fluids secreted In the 
 tympanum and to admit the air, to balance that acting on the out- 
 side of the membrane of the tympanum. They concur also directly to 
 healing, for they also lead into the tympanum the undulations of sound, 
 which, reflected by the w'alls of this cavity, fall principally on the 
 membrane of the fenestra rotunda, called for this reason the accessory 
 tympanum. (3) 
 
 (1) De org, aud. et olf , p. 55-56, § xi. 
 
 (21 Monro, On the ear, p. 197-199, vol. iii-iv. 
 
 (3) Savart has concluded from his important researches on the mechanism of 
 hearing : 1st, that the communication of the vibrations by tire air seems to take 
 place, at least for small distances, according to the same laws as those for solid bo- 
 dies; 2d, that it is not necessary lo suppose a special mechanism to cause the mem- 
 brane of the tympanum to vibrate continually in unison with the bodies which act 
 
 Vol. Ill, 18 
 
134 
 
 DESCRIPTIVE ANA TOW V 
 
 ARTICLE THIRD. 
 
 DIFFERENCES IN THE EAR DEPENDENT ON DEVELOPMENT. 
 
 I. EXTERNAL EAR. 
 
 § 1949. The external part of the organ of hearing does not begin 
 to appear till towards the end of the second month of pregnancy. It 
 first resembles a slightly perceptible eminence formed like an elongated 
 triangle, the base of which looks upward, the summit downward, and 
 which is directly continuous with the lower part of the side of the 
 head, and in the middle of which is a triangular longitudinal fissure 
 which becomes narrower and deeper from above downward. The 
 prominence which surrounds the median depression soon rises to its 
 posterior part, and becomes thinner in this place. It projects above the 
 surface of the side of the head, and slightly shows the median fossa. 
 At the same time, or soon after, the anterior part of the prominence is 
 divided by a transverse fissure which arises from its posterior part into 
 two halves, of which the inferior is the antitragus and the superior the 
 commencement of the helix. At the same time this anterior part of 
 the external ear also rises and the posterior enlarges, but is not re- 
 
 upon it, and that it is always in the conditions fit to be influenced by any number 
 of vibrations ; 3d, that its tension probably does not vary, except to increase or 
 diminish the extent of these variations, as Bichat had asserted, but always supposing', 
 as Meckel still admits, the contrary of what residts from these experiments, that is, 
 by imagining that the membrane is loose in loud and tense in feeble sounds ; 4tli, 
 that the vibrations of the membrane extend to the labyrinth unchanged by means 
 of the little bones ; 5th, that the little bones also serve to modify the extent 
 of the vibrations of the parts in the labyrinth ; Cth, finally that the tympanum pro- 
 bably serves to contain an air the physical properties of which are constant. Itard 
 asserts that the membrane of the tympanum does not perform any motion which 
 is visible or denoted by a bristle situated in the centre ; but the more delicate 
 experiments of Savart do not allow us to doubt these motions. When we saw the 
 temporal bone on the level of the external face of the membrane, and cover this with 
 sand, we can perceive that the grains move slightly when we bring a disque which 
 is vibrating, parallel to the membrane and near the surface, although its slight extent 
 and especially its form do not allow us to establish there any nodal line. Itard 
 states that the function of the little bones, are to allow us to hear low tones. J. F. St. 
 Hilaire thinks that they arc of but little use, and are only indications of the respira- 
 tory apparatus, the operculum, developed in fishes. The justice of this second pro- 
 position, which we shall not examine here, would not necessarily involve that of the 
 first, although not contradicted by experience. The direct participation of the 
 Eustachian tube in hearing, which was asserted in the commencement of the last 
 century, and afterwards brought forward by Brcssa, is evidently erroneous. It has 
 been perfectly refuted by Cotugno and Itard. If it was correct, we ought, as Ru- 
 dolphi asserts, hear our own voice when speaking loudly after stopping the ears : 
 hut this is not true. Itard has very ingeniously compared the Eustachian tube to a 
 hole without which the air in a military drum would not vibrate ; but he is mistaken 
 in saying that it seems only to renew the air in the tympanum. This is undoubtedly 
 its principal function, but it also serves to excrete the 1 mucus and the condensed 
 perspirat ion constantly secreted by the mucous membrane of this cavity. F. T, 
 
OF THE EAR 
 
 135 
 
 moved farther from the side of the head. The anthelix and the tragus 
 are developed also very early at the third month. The anthelix is at 
 first more prominent than it is subsequently, because the posterior 
 edge of the ear rises but slightly or not at all. The lobule appears 
 last. 
 
 The external ear is much smaller in proportion to the head, the 
 younger the fetus is. 
 
 Its cartilage begins to appear at the third month ; but it is deve- 
 loped slowly, for towards the end of pregnancy it is not as yet so 
 extensive under the skin as in full grown individuals. 
 
 The cartilaginous portion of the auditory passage, like the external 
 ear, is at first proportionally much smaller than subsequently. 
 
 The long portion of this passage begins to form some time after birth 
 by the enlargement of the cavity of the tympanum. Its ossification is 
 singular in this respect, that it generally begins much sooner in the 
 external part of the canal, where it unites to the cartilaginous portion, 
 than in the middle region of its lower part. 
 
 The prolongation of the external cutaneous system, around which 
 this passage is situated, already exists very early in the fetus, and 
 it is' not then even proportionally much shorter than in the adult, 
 but it has another form and another direction. As the direction of the 
 tympanum is then much more oblique from without inward than it 
 is afterward, the upper part of its circumference at first does not 
 exist ; the inferior alone is developed, and forms on the outside and at 
 the bottom of the tympanum, a large sac, which is much more ample 
 in proportion to its length than it is afterward, descends also more per- 
 pendicularly, and is situated below the membrane of the tympanum, 
 so as really to form its upper wall. 
 
 The skin of the bony portion of the auditory passage is softer and 
 thicker in the fetus than in the adult. 
 
 § 1950. 1st. The tympanum in the early periods of life is proportion- 
 ally shorter and narrower than at a later season, particularly, because 
 the mastoid process is very small, and its cells are not yet formed. It is 
 filled in the fetus with a thick gelatinous fluid, and it communicates 
 with the mouth more directly the younger the fetus is, since the 
 Eustachian tube is shorter and broader in the same proportion. The 
 cartilaginous portion of this tube, until the middle of pregnancy, is 
 simply membranous, and even in the full grown fetus the bony portion 
 is at most separated within the canal by a layer of bone, which forma- 
 tion continues most generally through life, so that the septum rarely 
 extends also to the outer side. 
 
 The tympanum, and with it the membrane, are much larger in pro- 
 portion either to the external ear or to the whole head and body, the 
 younger the fetus is, and even until the fifth month of pregnancy, both 
 
 II. INTERNAL EAR, 
 
130 
 
 DESCRIPTIVE ANATOMY. 
 
 arc larger than the external ear. Besides, as the osseous portion of 
 the auditory passage is not yet developed, the membrane of the tym- 
 panum is much nearer the surface in the early periods of existence 
 than subsequently, so that the upper part directly touches the entrance 
 of the cartilaginous portion of the auditory passage, and consequently 
 is almost exposed in this point, a very curious circumstance from its ana- 
 logy with reptiles. Both also differ at first in direction, which is more 
 horizontal, because at this period the membrane of the tympanum is 
 more oblique from above downward and from without inward. 
 
 2d. The small bones of the ear differ from all other bones of the body 
 by their uncommonly early appearance and development. 
 
 They are visible and even uncommonly large in proportion, at the 
 commencement of the third month of pregnancy, although at this 
 period they are still entirely cartilaginous, and we cannot well dis- 
 tinguish the stapes from the incus. Thus, for instance, the malleus is 
 about three lines high in the fetus of four months, so that the body 
 being then four inches from the vertex to the coccyx, its length 
 is to that of the whole body as 1 : 16, while in the adult, where is to 
 four lines long, and where the distance between the vertex and the 
 coccyx is two feet and a half, the proportion is only as 1 : 90. The 
 small bones of the ear are as large in the full grown fetus as in the 
 adult. 
 
 They begin to ossify also very early, even before the end of the third 
 month. Cassebohm asserts(l) that the stapes and incus ossify sooner 
 than the malleus, that the osseous nucleus of the incus is seen first in 
 its anterior branch, and that of the stapes in the head, whence it ex- 
 tends along the two branches to the base, which, with the lower region 
 of the anterior branch, ossifies the last. In the malleus, ossification 
 commences in the head and anterior process. Our observations do not 
 exactly agree with those of Cassebohm. It is true that the anterior 
 branch of the incus ossifies before the posterior : we have always found 
 it perfectly ossified, while the latter was entirely cartilaginous, but the 
 ossification of the malleus commences at the same time as that of the 
 incus, and the stapes is still entirely cartilaginous, when it has ad- 
 vanced considerably in the other two bones. The place where it be- 
 gins in the stapes is not well determined : it is sometimes in the lower 
 part of the posterior branch, and sometimes in the base, but never, ac- 
 cording to our observations, in the head. 
 
 These bones differ very much in their forms. The incus changes 
 the least. The branches of the stapes seem at first not to be separated 
 from each other, which deserves to be noticed on account of the ana- 
 logy resulting from it with the formation of this bone in the cetaceous 
 animals, and with that of the inner part of the single bone of the ear 
 in birds and reptiles. It is certain that even where these two branches 
 are detached from each other, the opening between them and the base 
 is proportionally much smaller than at subsequent periods, although, 
 
 (1) Loc. ci t., p. 56. 
 
OF THE EAR. 
 
 137 
 
 however, its form is then less oblong. This narrowness of the fora- 
 men, which is evidently an approximation to its entire deficiency, and 
 the union of all the parts of the stapes in one, depend principally on 
 the greater thickness of its branches. 
 
 But of all the bones of the ear, the malleus changes the most during 
 its development. Perhaps no other bone can be compared with it in 
 this respect. 
 
 The most remarkable difference is the existence of a right cartila- 
 ginous process, formed like a very elongated cone, which is also very 
 long and very thick in proportion to the rest of the bone. This pro- 
 cess arises from the anterior side of its head, leaves the tympanum 
 between the petrous process of the temporal bone and the ring of the 
 tympanum, is fitted directly to the inner face of the lower jaw, and 
 extends to the anterior extremity of this bone, where it sometimes, 
 perhaps even always, unites with that of the opposite side. This 
 cartilage never ossifies, although in the commencement it forms most 
 of the mass of the bone ; it disappears at the eighth month. The an- 
 terior process of the malleus corresponds with it, it is true, to a certain 
 extent, in respect to its position : but we also perceive that in the fetus, 
 where the two parts are distinct from each other, the cartilage is situ- 
 ated above the anterior process. We may then at most admit that this 
 latter makes part of it, and that they are separated very early. This 
 cartilage is very curious, because fishes, reptiles, and birds, present a 
 similar one, which extends from the posterior to the anterior portion of 
 the lower jaw. In these animals it rests on a small bone placed on 
 the inner face of the posterior part of the lower maxillary bone, and we 
 may consider it as a rudiment of the malleus, which does not exist in 
 them. 
 
 3d. The membranous labyrinth exists long before the osseous 
 labyrinth. We have found it at three months perfectly developed in 
 the cartilaginous mass, which afterwards ossifies. Even in the early 
 periods of life it is more distinct, and formed of firmer and more solid 
 membranes than at subsequent periods. It is composed at first of two 
 very distinct membranes, an external and an internal, which are 
 simply inclosed in each other, but there is no continuity between 
 them. 
 
 The internal is white, transparent, thinner, but firmer and more 
 elastic than the external. The latter does not adhere to the cartilage, 
 as afterward it is not attached to the bone which is developed at the 
 expense of this latter. 
 
 The inner face of the external membrane is smooth, and the external 
 is corrugated. It gradually disappears, so that at seven months we 
 cannot trace it. Before entirely disappearing it gradually becomes 
 thinner. The internal becomes proportionally narrower but firmer : it 
 seems to be attached more intimately to the inner face of the cartilage 
 which surrounds it, in the early periods of existence than subse- 
 quently. 
 
138 
 
 DESCRIPTIVE ANATOMY. 
 
 As yet we have been unable to ascertain if there is not a period 
 when the membranous labyrinth is uncovered in the skull, at least in 
 part, and where its structure is more simple than it is afterward. At 
 three months it is entirely surrounded by a mass of cartilage, and is as 
 complex in its structure as at a more advanced period of life. We only 
 remark, that like the cartilage which envelops it, it is at first more 
 compressed from without inward, and proportionally higher, which un- 
 doubtedly depends, at least in part, on the greater development of the 
 encephalon. 
 
 At four months we find the membranous cochlea as complex as it is 
 in the adult, while afterward its circumference seems to be formed only 
 by the membranous labyrinth; it is then constituted by a very thick 
 membrane, which makes a part of this latter. We have as yet been 
 unable to obtain any sufficient data in regard to its form before the 
 fourth month of pregnancy. 
 
 The secondary tympanum and the finestra rotunda are at first 
 situated more externally and parallel to the membrane of the tympa- 
 num. They afterwards go backward, which depends principally on 
 the development of bone in their circumference. 
 
 4th. When we study the development of the osseous labyrinth, we 
 must distinguish the formation of the osseous substance of the petrous 
 process of the temporal bone from that of its own. The first commen- 
 ces before the second, and follows the usual mode of ossification, 
 that is, it takes place by the development of a loose, soft, and plexi- 
 form tissue, in the homogeneous mass of cartilage previously existing, 
 which gradually extends from before backward. The circumference of 
 the fenestra rotunda ossifies first towards the end of the third month, 
 which is curious as an analogy between this opening and the tympa- 
 num. Ossification begins at the upper part, then extends to the lower, 
 and when it has thus formed a ring, it goes forward. At the same 
 time there is developed a special osseous nucleus, which is entirely 
 distinct from the preceding, at the outer extremity of the superior per- 
 pendicular semicanal : next there appears a third small scale at about 
 the centre of the internal perpendicular semicanal. At the same time 
 ossification proceeds rapidly backward and downward from the point 
 first formed, and gives rise to the floor of the labyrinth. The second 
 nucleus enlarges more quickly perhaps than the first, so that the su- 
 perior perpendicular semicanal is soon entirely ossified, excepting only 
 its lower and concave face. At the same time, ossification, commencing 
 at its internal extremity, advances on the internal face of the petrous' 
 process, circumscribes the internal auditory foramen, enters within it, 
 and forms the floor of the cochlea. 
 
 The horizontal semicircular canal begins to ossify at the fifth month. 
 At this time the piece of bone which forms the superior perpendicular 
 canal extends backward, downward, and outward, around the mem- 
 branous horizontal canal. At least we have been unable to discover 
 a special nucleus for this canal, which seems to ossify by the extension 
 of the first two nuclei, the edges of which finally unite. 
 
OF THE EAR. 
 
 139 
 
 The formation of the interior of the cochlea belongs almost wholly 
 to the osseous labyrinth. The cartilage and then the osseous sub- 
 stance of the petrous process, do not participate in it except by a nar- 
 row prolongation sent by this latter into the cavity containing the 
 membranous and then the osseous labyrinth, the spires of winch it 
 slightly separates. 
 
 The loose edge of this projecting lamina is turned outward. It ex- 
 tends from the upper part of the fenestra rotunda and the outside of the 
 cochlea, to the summit of this latter, across its cavities, and thus divides 
 it anteriorly, but very imperfectly, into an external and an internal 
 cavity. This lamina is broader at first than it is subsequently. Be- 
 sides, the internal face of the cochlea is entirely smooth, and this part 
 of the internal ear presents at this period the greatest analogy with the 
 cochlea of birds : at a later period, after the third month, as the cochlea 
 enlarges from without inward, the lamina in question becomes nar- 
 rower, and at the same time slight prominences are developed, which 
 separate externally the two and half turn's of the cochlea from each 
 other, and make part of it. 
 
 The osseous labyrinth is at first entirely separated from the osseous 
 mass of the petrous process which surrounds it, and which is developed 
 before it. It is, however, always applied to it. Its surface then is en- 
 tirely smooth. The inner face of the osseous mass of the petrous pro- 
 cess is also smooth to a certain extent, although more corrugated than 
 that of the labyrinth. The two surfaces soon blend together, but they 
 can be entirely separated in children, and the smooth polished surface 
 of the labyrinth can be demonstrated ; but they afterward become in- 
 separable. The line of demarkation is very evident in every part, 
 particularly in the cochlea, where it is perceived that the prolongations 
 described above are perfectly distinct from the canal formed by the 
 membranous and osseous labyrinths. 
 
 Thus the osseous labyrinth is developed independent of the osseous 
 substance of the petrous portion. As the external membrane of the 
 membranous labyrinth disappears at the period of its formation, it is 
 not improbable that it changes into osseous substance, or at least that 
 this substance transudes through its external face. In fact, this 
 membrane does not exist for some time with the osseous labyrinth, and 
 may always be easily separated from it : but we are satisfied, from nu- 
 merous observations, that as the osseous labyrinth is developed around 
 it, it becomes denser, firmer, dryer, and in a measure horny : hence we 
 have been induced to believe that the two modes of formation coexist, 
 that is, that the membrane secretes first the labyrinth, then that an 
 analogous substance being deposited with it, it unites with the layer it 
 had first formed, and becomes its internal layer. The formation of the 
 osseous labyrinth would thus resemble that of the teeth.(l) 
 
 (1) Ribes has asserted that in the fetus the serum of the labyrinth is reddish, 
 bloody, and exactly fills it. As the infant grows older, it becomes clear, limpid, and 
 less in quantity, and the ear becomes more sensible to sounds. F. T. 
 
140 
 
 DESCRIPTIVE ANAl'OlVtY. 
 
 ARTICLE FOURTH. 
 
 ORGAN OF HEARING IN THE' ABNORMAL STATE. 
 
 § 1951. As the organ of hearing is very complex, it presents very 
 numerous and very different anomalies(l) in respect to their essence ; 
 by these the ear is unusually hard or soft, or is entirely deficient. 
 
 § 1952. The deviations of formation are here, as in every other part, 
 the most interesting in a physiological point of view. 
 
 As in all other parts of the body, they are more or less characterized 
 by a retarded development, (2) and are also more or less repetitions of 
 what is observed in animals inferior to man. 
 
 Sometimes the development of the whole car is arrested. (3) 
 
 I. EXTERNAL EAR. 
 
 § 1953. 1st. Deviations of form in regard to quantity. The entire 
 absence of the external ear, of which we possess some instances, de- 
 pends on the permanence of a state which marks the early periods 
 of fetal existence. 
 
 The anomaly varies a little less from perfect development when the 
 ear is closed, which can exist in different degrees; these lead imper- 
 ceptibly to the normal formation by the shortness and narrowness of 
 the external auditory passage. 
 
 The absence of the lobule, or its adhesion with the skin of the head, 
 is the least deviation from the normal state. This state also exists 
 regularly at a certain period of the formation of the fetus. 
 
 We may consider the frequent enormous enlargement of the ears as 
 an anomaly of an entirely different character. 
 
 2d. Deviations of formation in regard to quality. These are the 
 turning of the ear on the orifice of the external auditory passage, 
 which more or less closes this canal. (4) 
 
 II. INTERNAL EAR. 
 
 A. TYMPANUM. 
 
 § 1954. 1st. Deviations of formation in respect to quantity. Some- 
 times the tympanum is not- sufficiently large, and is even closed on the 
 
 (1 ) Besides the works of Duvernoy, Wildberg - , and Saunders, already mentioned, 
 which treat also of the diseases of the ear, consult, J. A Rivinus, De auditvs ritiis , 
 Leipsic, 1717.— J. M. G. Itard, Traite des maladies de l’oreille et de l'audition, 
 Paris, 1821. — C. F'. A. Escbke, Diss. de avditusvitiis, Berlin, 1819. 
 
 (2) See on this subject our Handbuch der jiathologischcn Anatomie, vol. i. p. 
 400-406. 
 
 (3) Rœderer, Descripl. fœtus parasiU; in Comm. soc. Gostl., vol. iv. 
 
 (4) Walter, PeUhaulgeschwüLslc , Land shut, 1814. p. 33. 
 
OF THE EAR. 
 
 141 
 
 outside as in fishes. Sometimes one or more of the little bones of the 
 ear are deficient, or they are too small. (1) Sometimes they are un- 
 usually large, thus preserving the distinctive characters of the fetus. 
 They are rarely more numerous than usual. When supernumerary 
 bones exist, they are always very small. They occur particularly be- 
 tween the malleus and incus, and also in the neck of the stapes. 
 
 2d. Deviations of formation in regard to quality. The bones of the 
 ear are sometimes formed after a different type, and then are more or 
 less similar to those of certain animals. 
 
 Thus Comparetti(2) observed in a man, that not only the two 
 stapedes were very small, but also formed by a single branch, with a 
 small base closing the fenestra ovalis, which was very narrow. (3) 
 
 B. LABYRINTH. 
 
 When the labyrinth is very imperfectly developed, there is only a 
 single cavity closed externally, which is not divided into the vestibule, 
 cochlea, and semicircular canals, and which does not communicate 
 with the tympanum. (4) This form resembles that of the organ of 
 hearing in the Crustacea and the cephalopoda. Perhaps it is normal 
 also in the early periods of the existence of the human fetus. 
 
 When the development is more advanced, the cochlea describes 
 fewer turns than usual, (5) even as in reptiles and birds, it appears as 
 a sac-like prolongation, which is not curved on itself. From our pre- 
 ceding remarks, this anomaly should be considered as a continuance 
 in the fetal state. 
 
 The labyrinth is sometimes ossified imperfectly, whence a portion of 
 the membranous labyrinth is exposed.(6) 
 
 (1) Bernard, Sur un vice d'organisation de l’oreille externe; in the Journ. de 
 physiol, expér., vol. iv. p. 167. 
 
 (2) Loc. cit., p. 24. 
 
 (3) Wefind the malleus sometimes larger, sometimes shorter, sometimes with an 
 
 enlarged head or process. The incus has been observed sometimes narrower, some- 
 times broader, and sometimes with its long branch more or less arched. Rudolphi 
 has described and figured (Diss. sis. observationes osleologicas, Berlin, 1812, tab. i. 
 fig. 15.) a stapes, of which the branch alone communicated with the base, the other 
 being loose, and forming with the preceding an obtuse angle. Lœsecke seems to 
 have observed a similar case ( Obs . anat. Chirurg., Berlin, 1754, p. 15.) Tiedemann 
 has described a stapes found in a newly born infant, which presented neither 
 branches nor opening. It resembled a small pyramid, the base of which represented 
 the plane surface, and from whence a piece of bone arose, slightly depressed, which 
 was articulated with the long- branch of the incus by a rounded process. He has also 
 seen in an adult the two branches of the stapes completely united by a layer of bone, 
 so that there is a slight depression, but no opening between them ( Sur quelques 
 variations dans la forme de l’etricr chez l’homme ; in the Journ. complém. des sc. 
 méd., vol. viii. p. 83. F. T. 
 
 (4) Roderer, loc. cit.— Meckel, Handbuch der pathologischen Anatomie , vol. i. p. 
 
 (5) Mondini, Anat. surdinati; in the Comm. Bonon., vol. viii.— Meckel, loc. cit. 
 
 vol. i. p. 403. ’ ’ 
 
 (6) Mondini, loc. cit. 
 
 Vol. III. 
 
 19 
 
142 
 
 DESCRIPTIVE ANATOMY. 
 
 C. AUDITORY NERVE. 
 
 Sometimes in deaf and dumb people the auditory nerve is smaller(l) 
 by half than it is generally. (2) 
 
 § 1955. The accidental or consecutive deviations of formation result 
 from an external lesion, which is purely mechanical, or an alteration in 
 texture. Sometimes in hydrocephalus the two external bones of the 
 ear are pushed outward and detached from the stapes, and sometimes 
 even this is unconnected with the fenestra ovalis.(3) 
 
 § 1956. The alterations of texture in the organ of hearing are prin- 
 cipally inflammation and its consequences, among which we must first 
 mention adhesion and suppuration, which frequently affect the ex- 
 ternal and the internal ear. The buccal orifice of the Eustachian 
 tube is frequently obliterated after scarlatina, or the tympanum 
 and the bones are destroyed by ulceration. The entire or partial de- 
 struction of the membrane of the tympanum and very probably also 
 the anomalies in the tumors of the labyrinth, which are thickened, (4) 
 solidified, and changed into a hard body (5) after long affections of the 
 internal ear, (6) belong to this class. 
 
 The new formations developed in the organ of hearing are : 
 
 1st. Accidental ossification , by which the bones of the ear adhere to 
 each other, and obstruct the fenestra rotunda, (7) in which case we also 
 find the bones, particularly the stapes, twice as large as they are gene- 
 rally : the stapes also is fused with the fenestra ovalis,(8) and forms 
 osseous concretions(9) in the membrane of the tympanum. (10) 
 
 (1) Haighton, Mem. of the med. society, x ol. iii. p. 1. 
 
 (2) This fact has been observed several times, among 1 2 3 4 * 6 7 8 9 10 others by Sylvius, Hoffman, 
 and Arenda. Itard also has seen it: but he thinks that the wasting of the auditory 
 nerve is more frequently the effect than the cause of deafness (toc. cit., vol. i. p. 392.) 
 
 F. T. 
 
 (3) Blumenbach, Geschichte der Knochen, p. 140. 
 
 (4) Haighton, toc. cit. — Cline, in Saunders, toc. cit., p. 88. 
 
 (5 ) Seeon this subject an important memoir on the physiological relations, by G. 
 F. St. Hilaire, Sur la nature, la formation et les usages des pierres qu'on trouve 
 dans les cellules auditives des poissons ; in the Mém. du Muséum, 1824. 
 
 (6) Itard has seen one case ( loc . cit., vol. i, p. 395) where the fluid of the labyrinth 
 was deficient. 
 
 (7) Cotugno, loc. cit., § 72, p. 61. 
 
 (8) Valsalva, De mire humanâ , cap. ii. § x. 
 
 (9) Cassebohm, vol. iii., p. 33. — Loesecke, Ohs. anal., p. 25. — Koehler, Beschrei- 
 bung der Loderischen Präparate, p. 148. 
 
 (10) Kibes (loc. cit., p. 654) has found the membrane of the fenestra rotunda ossified 
 in a man completely deaf, and destroyed in several subjects, some of whom had not 
 completely lost the power of hearing. This latter circumstance deserves to be re- 
 marked, since complete deafness does not result from injuries of the membrane of 
 the tympanum, which is so analogous to that of the fenestra rotunda. According 
 to Pinel’s observations, it would seem that deafness depends on an alteration in the 
 texture of the mucous membrane of the internal ear rather than on any other cause, 
 although he seems to attribute it to the diminution of the fluid in the labyrinth, 
 which in this case is only a consequence of inflammation. (Recherches sur tes 
 causes de la surdité chez les viellards ; in the Archiv, gén. de méd., vol. vi., p. 247.) 
 
OF THE EYE. 
 
 143 
 
 2d. The formation of accidental cartilages and fibro-cartilages some- 
 times observed under the form of tumors which adhere to the auditory 
 nerve.(l) 
 
 Among the entirely abnormal formations we must arrange the 
 fungous tumors and the polypi , which are developed principally in the 
 mucous membrane of the auditory passage. 
 
 CHAPTER II. 
 
 ORGAN OP SIGHT. 
 
 § 1957. The organ of sight ( oculus)(2 ) occupies the upper part of 
 the front of the face, and is situated on the right and left, on the sides 
 and above the root of the nose in the orbit and circumference of this 
 cavity. We distinguish the eye or the globeof the eye ( bulhus oculi) 
 with the muscles which move it and the parts which protect it. 
 
 ARTICLE FIRST. 
 
 PARTS WHICH PROTECT THE EYE. 
 
 § 1958. The parts which protect the eye(3) comprise two folds of 
 skin, called the eyelids , very thick hairs, called the eyebroivs , and the 
 lachrymal passages. 
 
 (1) Sandifort, Obs. anat. pathol., book i. c. 9. 
 
 (2) Fabricius d’Aquapendente, De visione, voce et auditu , Venice, 1606. — V. F. 
 Plemp, Ophthalmographia , s. tractatio de oculo, Louvain, 1648. — G. Briggs, Oph- 
 thalmographia, seu oculi ejusque partium descriptio anatomica, London, 1685. — J. 
 Taylor, Nouveau traité d’anatomie du globe de l'œil , avec l’usage de ses différentes 
 parties , et de celles qui lui sont contiguës , Paris, 1738. — A. Bertrandi, Diss. II. de 
 hepate et oculo , Turin, 1748'. — J. G. Zinn, Descriptio anatomica oculi liumani , Got- 
 tingen, 1753. — G. Porterfield, Treatise on the eyes , the manner and phenomena of 
 vision , F.dinburgb, 1759. — M. Horrebow, De oculo humano ejusque morbis , Copen- 
 hagen, 1792. — A. Monro, Miscellaneous observations on the structure and the func- 
 tion of the eyes ; in his Treatise on the brain, the eye , and the ear, Edinburgh, 1797. 
 — S. T. Sœmmerring, in Demours, Traité des maladies des yeux, vol. iv. — J. G. 
 G. Voit, Oculi humani anaiomia et pathologia, Nuremberg, 1810. — C. H. T. Schre- 
 ger, Versuch einer vergleichenden Anatomie des Auges, Leipsic, 1818. — D. G. Sœm- 
 merring, De oculorum humani animaliumque sectione horizontali, Gottingen, 1818. 
 — J. A. Hegar, Diss. de oculi partibus quibusdam, Gottingen, 1818. — C. F. Simon- 
 son, Anatomico-physiologicus tractatus de oculo, Copenhagen, 1820. 
 
 (3) Rosenmuller, Organorum lacrymalium partiumque oculi externarum descriptio, 
 Leipsic, 1797. 
 
144 
 
 DESCRIPTIVE ANATOMY. 
 
 I. EYELIDS. 
 
 § 1959 The eyelids (palpebrœ) are perpendicular folds situated 
 before the anterior orifice of the orbit, which they close more or less 
 perfectly. They are distinguished into upper and lower. They blend 
 together in the great or internal angle, and the small or external angle 
 of the eye ( cantlii oculi , intermis et cxiernus ), and are separated from 
 each other their entire breadth by a transverse fissure ( fissura palpe- 
 brarum). 
 
 The superior is much greater than the inferior ; a flat ligament 
 formed of transverse fibres several lines long, leaves the great angle of 
 the eye and goes inward between the fibres of the internal portion of 
 the orbicularis palpebrarum muscle ; its internal extremity is broader 
 than the external, and is attached to the upper part of the nasal pro- 
 cess of the superior maxillary bone. This is the palpebral ligament 
 ( lig . palpebrarum). 
 
 The eyelids are composed of two layers of skin, one external and the 
 other internal, of cartilage and muscular fibres. They rarely or never 
 contain fat. 
 
 The exterior layer of skin makes a part of the external cutaneous 
 system. It differs from the rest of the skin only in being very thin and 
 destitute of hair. 
 
 It is continuous on the edge of the eyelids, which is nearly a line 
 broad, with the internal layer which belongs to the internal cutaneous 
 system, that is, to the mucous membranes. This layer is also thin, 
 reddish, and moist. 
 
 It is termed the conjunctiva. It lines the whole extent of the inner 
 face of the eyelids, is reflected on itself in the parts where these movable 
 folds are attached to the rest of the skin, and is called the tunica ad- 
 nata, is fitted to the anterior part of the sclerotica , from which it may 
 always be easily separated, and which it covers to the circumference 
 of the transparent cornea. At least it is not possible strictly to demon- 
 strate that it extends also on the anterior face of this last membrane, 
 for if in certain morbid affections a layer rises on the anterior face of 
 of the cornea, this circumstance authorizes us to think, but does not 
 prove, that this layer in question is a prolongation of the conjunctiva. 
 Admitting that this passes really on the cornea, and that it blends with 
 the external pellicle of this membrane without any marks of separa- 
 tion, it does not follow that it possesses in this place the characters of a 
 serous membrane,(l) for the anterior face of the transparent cornea 
 belongs rather to the class of the mucous membranes. (2) Walther has 
 already demonstrated(3) that it is wrong to exclude the conjunctiva 
 
 (1) P. P. Walther, Abhandlungen aus dem Gebiete der pralclischcn Med., Land- 
 shut, 1810, p. 413. 
 
 (2) Wardrop, Morbid anatomy of the eye, Edinburgh, 1818, p 14. 
 
 (3) Loc. cit., p. 414. 
 
OF THE EYE. 
 
 145 
 
 entirely from among the last membranes. The adhesions(l) between 
 its two opposite faces which have been brought forward to sepa- 
 rate it from the other mucous membranes, and which have been used 
 to a certain extent to class it among the serous membranes, are rare 
 and accidental, and supervene probably after suppuration, in which 
 case even the mucous membranes contract adhesions. 
 
 A. EYELASHES. 
 
 § 1960. The anterior part of the edges of the eyelids presents three 
 or four irregular ranges of short, straight and arched hairs, which gra- 
 dually become larger from the two angles of the eye to the centre, and 
 which are termed the eyelashes (cilia). (2) Those of the upper lid are 
 more numerous and stronger than those of the lower. The former 
 are arched from above downward, the latter from below upward. 
 When the lids close they intercross and form from their curve a broad 
 ridge. 
 
 B. MEIBOMIAN GLANDS. 
 
 & 
 
 § 1961. Farther back and nearer the posterior limit of the edge of 
 the eyelids, at about its centre, is a series of openings regularly arranged, 
 which are also larger in the upper than in the lower eyelid, and 
 which do not occupy the entire breadth of these movable lids. These 
 openings lead to the glands of JMeibomius, or the sebaceous glands of 
 the eyelids (Gl. JWeibomiance , s. 'palpebrarum sebaceœ), small, very 
 elongated, narrow, tortuous bursæ, which terminate in sacs generally 
 single, but sometimes divided at their base into several compartments, 
 which are situated perpendicularly below the conjunctiva, between it 
 and the tarsaL cartilages. These glands are filled with a thick, yel- 
 lowish -viscous substance, called lema, which accumulates around the 
 eyelashes during sleep, and which is easily distinguished by its color 
 from the red conjunctiva. 
 
 C. PALPEBRAL CARTILAGES. 
 
 § 1962. Each eyelid contains between the two layers of skin and 
 near its loose edge an oblong cartilage, called the tarsus , which de- 
 termines its form. These cartilages extend much farther from without 
 inward than from above downward, and they are very thin from before 
 backward. They are much thicker at their loose and straight edge 
 than on their convex portion, which looks to the base of the eyelids ; 
 
 (1) A. Schmidt, in the Ophthalmologische Bibliothek., vol. iii., part 1, p. 18. 
 
 (2) H. Meibom, De vasis palpebrarum novis Epist., Helmstadt, 1666. 
 
146 
 
 DESCRIPTIVE ANATOMY. 
 
 they extend on the inside only to the lachrymal puncta, and terminate 
 on the outside also a little before the commissure of the two eyelids. 
 Their convex edge and their internal and external extremity becomes 
 at the two angles of the eye a very dense cellular tissue, which is 
 called the tarsal ligament ( lig . tarsi , internum et externum ) ; this unites 
 them to the external and internal edge of the anterior opening of the 
 orbit. 
 
 D. MUSCLES OP THE EYELIDS. 
 
 § 1963. The eyelids have two muscles which act in opposite di- 
 rections, the orbicularis 'palpebrarum and the levator palpebrce supe- 
 riors muscles. The first is common to the two ; the second be- 
 longs to the upper eyelid only. The lower eyelid has no special 
 muscle. 
 
 A. ORBICULARIS PALPEBRARUM MUSCLE. 
 
 § 1964. The orbicularis palpebrarum muscle, naso-palpébral , Ch. 
 (JVT. sphincter palpebrarum, s. nculi ), is thin, membranous and circular, 
 although a little elongated. It occupies the upper and anterior part 
 of the face and the lower and anterior part of the skull. Consequently 
 it is not by any means confined solely in the eyelids. 
 
 Its internal part is the slightest but the thickest. After leaving this 
 point it extends considerably upward, downward and outward. 
 
 It is attached above and below to the palpebral ligament, so that it 
 may be said to leave the inner angle of the eye and to return to it. 
 
 Besides this origin, several other fasciculi pass before and behind 
 the palpebral ligament, whence it follows that a portion of this muscle 
 is formed by uninterrupted circular fibres. 
 
 The orbicularis muscle arises above by short tendinous fibres from 
 the upper extremity of the nasal process of the superior maxillary 
 bone, from the os unguis, and the lower and anterior part of the nasal 
 and orbitar portions of the frontal bone. 
 
 It arises below by similar fibres from the lower part of the inner 
 edge, and from the inner part of the lower edge of the orbit, which are 
 formed by the ascending process and by the body of the superior max- 
 illary bone. 
 
 Its fibres separate especially in its lower part, and fasciculi are de- 
 tached from its outer part, some of which go the cellular substance 
 and others enter the zygomaticus minor and the levator labii superioris 
 muscles. 
 
 The internal part of this muscle which is contained in the eyelids, 
 where it is situated directly below the external cutaneous layer, is 
 much less extensive than the external. Its fibres are straighter, 
 thinner and paler than those of the latter, with which it is always un- 
 
OF THE EVE. 
 
 147 
 
 interruptedly continuous, although it has been considered a special 
 muscle, called the ciliaris muscle. 
 
 B. LEVATOR PALPEBRJE SUPERIORIS MUSCLE. 
 
 § 1965. The levator palpebrcz superioris muscle, orbito-palpébral , 
 Ch., is very long, thin and triangular. It arises by a short tendon at 
 the base of the orbit from the periosteum which lines the upper part 
 of the optic foramen, and blends in this place with the tendons of the 
 rectus internus and rectus superior muscles. It gradually becomes 
 broader and thinner, advances directly under the orbitar plate, covering 
 first the inner and then the whole of the rectus superior muscle. It 
 finally becomes a very thin tendinous expansion, often scarcety per- 
 ceptible, part of which is attached to the upper edge of the superior 
 palpebral cartilage, while the other passes between the orbicularis 
 palpebrarum muscle and this cartilage, and extends to its lower edge 
 where it is inserted. 
 
 It raises the upper eyelid. 
 
 E. THIRD EYELID AND CARUNCULA LACHRYMAL IS. 
 
 § 1966. Beside the upper and lower eyelids there is also in the 
 great angle of the eye a third which is much smaller and imperfect. 
 
 The two palpebral commissures differ in form. The external is 
 more pointed than the internal. The latter resembles a small and 
 narrow prolongation of the palpebral fissure towards the nose, the 
 separation of which with the rest of the fissure is marked very evi- 
 dently by the lachrymal puncta, and which terminates inward in a 
 rounded edge. 
 
 The third eyelid is found in this space. 
 
 It has the form of a triangle, the summit of which looks inward and 
 the loose edge outward ; this last is semicircular. It is formed by a 
 fold of the conjunctiva by a small palpebral cartilage situated near its 
 loose edge, and by a considerable number of sebaceous glands united 
 in a rounded or slightly triangular mass, between which are small, 
 straight and very fine hairs analogous to the eyelashes. 
 
 The sebaceous glands are situated entirely inward, and project par- 
 ticularly on its anterior face. 
 
 They are called the caruncula lachrymalis. The external and loose 
 part of the third eyelid which passes much farther forward than the 
 caruncula, has been termed the semilunar fold ( plica semi-lunaris) . 
 
 This part then really possesses all the constituent parts of an eyelid. 
 It differs from the other eyelids by its smallness and in the deficiency 
 of an external layer of skin and of muscular fibres. It is in fact a 
 rudiment of the third eyelid which exists in most vertebrated animals. 
 In fact the perpendicular eyelid of these last differs from it only by its 
 
148 
 
 DESCRIPTIVE ANATOMY. 
 
 greater size. When wc descend in the animal scale we see that its 
 development is always in an inverse ratio with that of the horizontal 
 eyelids, and that finally it entirely replaces them. 
 
 II. EYEBROWS. 
 
 § 1967. The eyebrows ( supercilia ) are short, strong, compact hairs, 
 which gradually increase in size from within outward, and which are 
 arranged in several superimposed striæ. These hairs form a little 
 above the upper eyelid an arch, the convexity of which looks upward. 
 The two arches they describe blend more or less at their inner part. 
 
 We may consider this part of the face as the commencement of the 
 upper eyelid. 
 
 The eyebrows are moved each by a special muscle, the corrugator 
 supcrcilii. 
 
 The corrugator supercilii muscle ( fronto sourcilier , Ch.) is thick 
 and large. It covers the inner part of the upper edge of the orbit. It 
 is covered at its origin by the upper internal part of the orbicularis pal- 
 pebrarum muscle, and by the internal and inferior part of the frontalis 
 muscle ; it arises by very short tendinous fibres from the frontal bone, 
 below the inner part of the supraciliary ridge. Its fibres are oblique. 
 Its direction is outward, and it gradually becomes thinner. It is so 
 blended, particularly in its external part, with the upper portion of the 
 orbicularis palpebrarum muscle, which entirely covers it, and which 
 may be considered as a deeper layer of this latter muscle. 
 
 It wrinkles the eyebrows, and the skin of the forehead perpendicu- 
 larly. 
 
 III. LACHRYMAL PASSAGES. 
 
 § 1968. The lachrymal organs or passages ( organa lachrymalia , s. 
 vice lachrymales), form a special apparatus, the function of which is to 
 secrete and excrete a transparent liquid termed the tears (lachrymce).(l) 
 
 This apparatus includes the lachrymal gland and its excretory ducts, 
 the lachrymal puncta, and the lachrymal passages , the lachrymal sac , 
 and the nasal canal. We may annex to a certain extent the con- 
 junctiva, as it is uninterruptedly continuous with the excretory pas- 
 sages, the gland, and the lachrymal puncta, and as, strictly speak- 
 ing, it is only a considerable dilatation of the excretory portion of the 
 lachrymal organ. 
 
 A. LACHRYMAL GLAND. 
 
 § 1969. Only one lachrymal gland is commonly admitted :(2) there 
 are, however, two, generally arranged so that one is superior, the other 
 
 (1) Berzelius, Djurkcmi, vol. ii. p. 219-221. 
 
 (2) N. Stcnon, De glandulis ocutorum novisque corum vasis observalwncs ana- 
 tomicœquibus ver ilacry mur um juntes detegunlur ; in the Obs. anat., Leyden, 1Ü62. — 
 
OF THE EYE. 
 
 149 
 
 inferior. Both belong to the list of conglomerate glands. They are 
 situated behind the upper eyelid, directly below the orbitar plate. 
 
 The superior lachrymal gland ( Gl . lachrymalis superior , s. innomi- 
 nata Galeni), is much larger than the other. It occupies the lachry- 
 mal depression of the frontal bone. It is triangular, and flattened from 
 above downward. The inferior (Gl. congregalœ JWonroi) ( 1 ) touches 
 at its posterior extremity, the anterior part of the preceding, and 
 extends to the external part of the upper edge of the cartilage of the 
 upper eyelid: Its lobules are smaller and more remote from each other, 
 than those of the upper. 
 
 Six or seven very small canals arise from these two glands, and go 
 from behind forward, from without inward, and from above downward, 
 and open at the side of each other from without inward, on the inner 
 face of the upper eyelid, near the external angle of the eye. 
 
 B. LACHRYMAL PUNCTA AND LACHRYMAL PASSAGES. 
 
 § 1970. The upper and the lower eyelids present each, at the part 
 where the inner angle commences, and where the orifices of the 
 Meibomian glands terminate, an opening, the direction of which is 
 rather more backward, and which may easily be distinguished from 
 those of the palpebral glands and the lids, as its diameter is much 
 larger, and as it is supported by a conical prominence. These two 
 openings are termed the lachrymal puncta (P. 1 . superius et inferius). 
 The direction of the upper is downward, and that of the lower is up- 
 ward. The latter is most generally larger than the other. 
 
 These puncta are the orifices of the lachnjmal passages ( canaliculi 
 lachrymales, s. cornua limacum ), which extend to the lachrymal sac. 
 
 The lachrymal passages proceed directly on the edges of the eyelids, 
 covered posteriorly by the internal cutaneous laj-er of these lids, and 
 anteriorly by the orbicularis muscle, with which they are so intimately 
 connected, that they are detached from its fibres with great difficulty. 
 
 The superior first ascends a little outward, in which direction also 
 the inferior descends. In this part of their course they are very narrow. 
 Then after slightly projecting, the superior goes inward and downward, 
 and the inferior upward, and both converge very much. Arrived at 
 the inner angle of the eye, they pass under the palpebral ligament, 
 and open into the anterior and external part of the lachrymal sac, one 
 directly above the other, but by two distinct orifices. They form within 
 this cavity a small rounded prominence. 
 
 A whitish and smooth mucous membrane forms their parietes. 
 
 A. Monro, Gntlie lachrymal glands and duels; iii the Anatomical and physiological 
 observations , Edinburgh, 173S, p. 770. tab. ii. — J. J. Beaux, Physiologic de la glande 
 lachrymale , Paris, 1321. 
 
 (1) Loc. cil., p. 77. 
 
 VOL. III. 
 
 20 
 
150 
 
 DESCRIPTIVE ANATOMY. 
 
 C. LACHRYMAL SAC. 
 
 § 1971. The lachrymal sac (saccus lachrymalis) differs much in its 
 breadth, direction, and structure, from the lachrymal passages. 
 
 It is infinitely broader than they, but it contracts a little from above 
 downward. 
 
 It is covered anteriorly by the inner part of the orbicularis palpe- 
 brarum muscle, and is situated above in the lachrymal groove, along 
 which it extends upward into the lachrymal passages by a small cul-de- 
 sac, and downward into the nasal canal. It descends first from within 
 outward and from behind forward, then, on arriving at the nasal canal 
 its direction is from before backward. In its course its diameter gradu- 
 ally diminishes. It opens into the anterior part of the lower meatus of 
 the nasal fossæ, by an opening which is oblique from above downward 
 and from within outward, and which is provided with a small valve. 
 
 It is formed of three superimposed membranes. 
 
 The external is whitish, and is evidently fibrous, and also serves as 
 a periosteum to the bones which receive the lachrymal sac; but it is 
 also very apparent on the anterior side of the upper part of the sac 
 which lodges the lachrymal groove. 
 
 The middle is thin and cellular : it corresponds to the cellular tunic 
 of the mucous membranes. The internal is thick, rough, spungy, 
 verrucous, and of a deep red. It always secretes an abundant mucus, 
 which oozes through the rounded and oblong orifices of small glands 
 arranged very compactly. 
 
 This internal membrane is evidently the continuation of that of the 
 nasal fossæ, while that which forms the lachrymal passages is con- 
 tinuous with the conjunctiva, so that it establishes the limit between 
 the eye and the nose.(l) 
 
 (l) Horner has discovered a new muscle of the eye, the following - description of it 
 is extracted from his Treatise on General and Special Anatomy , vol. ii. p. 408. 
 
 “The tensor tarsi is a small muscle on the orbital face of the lachrymal sac. It arises 
 from the posterior superior part of the os unguis, just in advance of the vertical 
 suture between the os planum and the' os unguis. Having advanced three lines, it 
 bifurcates ; one bifurcation is inserted along the upper lachrymal duct, and termi- 
 nates at its punctum, or near it ; and the lower bifurcation has the same relation to 
 the lower lachrymal duct. The base of the caruncula lachrymalis is placed in the 
 angle of the bifurcation. The superior and the inferior margins of the muscle touch 
 the corresponding fibres of the orbicularis palpebrarum, where the latter is con- 
 nected with the margin of the internal canthus of the eye, but may be readily dis- 
 tinguished by their horizontal course. The nasal face of this muscle adheres very 
 closely to that portion of the sac which it covers, and also to the lachrymal ducts. 
 The lachrymal sac rises about a line above its superior margin, and extends in the 
 orbit four lines below its inferior margin. The orbital face of the muscle is covered 
 by a lamina of cellular membrane, and between this lamina and the ball of the eye 
 are placed the valvula semilunaris, and a considerable quantity of adipose matter. 
 
 As the bifurcated extremities of the muscle follow the course of the ducts, they 
 are covered by the tunica conjunctiva. When this muscle is examined from be- 
 hind, the eyelids being in situ, it becomes obvious that it is concave on its orbital 
 surface, and consequently convex on the nasal ; that the muscle is an oblong body, 
 half an inch in length, and about three lines wide, bifurcated at one end ; and that it 
 
Of THE EYE 
 
 151 
 
 ARTICLE SECOND. 
 
 GLOBE OF THE EYE. 
 
 § 1972. The globe of Ike eye ( bulbus oculi),( 1) often termed simply 
 the eye, is formed like an almost regular globe. In the adult its 
 diameter is about an inch : its length, however, exceeds its breadth and 
 its height. It occupies the anterior part of the cavity of the orbit, but 
 passes a little before it. It is surrounded in every part by an abundance 
 of fat, and also by the muscles which move it, and which contribute 
 with the optic nerve, and numerous blood-vessels, to retain it in place. 
 
 It is formed by several superimposed membranes and the humors 
 contained by them. In respect to the form and the texture of the 
 membranes, and that of the nature of the humors, we may divide it 
 into two parts, a posterior and an anterior, the first of which is more 
 extensive than the other. 
 
 arises much deeper from the orbit than any acknowledged origin of the orbicularis. 
 The superior fork, however, has a few of its fibres blended with the ciliaris. 
 
 In regard to the use of this muscle. Its attachment to the posterior face of the sac 
 is such, that it draws the orbital parietes of the sac away from the nasal, and dilates 
 the sac, from the nasal face of the latter being fixed to the hones. As this muscle 
 has a cylindrical concavity on its orbital side, it is evident that when it contracts the 
 fibres become straight, or nearly so, like the fibres of the diaphragm, and the cavity 
 of the sac is enlarged after the same manner as the cavity of the thorax. A tendency 
 to a vacuum being thus produced by it, the valves or folds of the internal membrane 
 of the sac, permit the vacuum to be filled more readily through the puncta than 
 from the nose; and the puncta being continually bathed in the tears of the lacus 
 lachrymalis, both in the waking and in the sleeping state, the tears are constantly 
 propelled through them by atmospheric pressure. The evacuation of the sac is no 
 doubt accomplished by its own elasticity, and by the contraction of the orbicularis ; 
 probably in a chief degree by the latter, because in persons who have epiphora, or a 
 tendency to obstruction in the nasal duct, the accumulation of tears and matter 
 principally take place at night, when the action of the orbicularis is suspended by 
 sleep. For these reasons we should argue, that this little muscle is active all the 
 time, both night and day. To Dr. Physick I am indebted for suggesting another 
 use for this muscle ; that of keeping the lids in contact with the ball of the eye. Some 
 persons possess unusual voluntary power of this muscle, of which I have seen two 
 examples ; one in a lady ; another in a gentleman, a student of medicine. In each 
 instance the individual could shorten so much the internal angle of the eyelids, as 
 to conceal it, along with the puncta, in the internal canthus of the orbit.” 
 
 Trasmondi, on the contrary, thinks that it acts on the lachrymal sac and passages, 
 that it compresses the caruncula lachrymalis so as to favor the excretion of the 
 humor formed by its crypts, and that it relaxes or also tenses the membrane, so as to 
 increase or diminish the base of the lachrymal sac, and to force the tears into the 
 nasal canal. ( Notice sur l a découverte de deux nerfs de l’œil humain ; in the Mé- 
 langes de chirurgie étrangère , Geneva, 1824, p. 415). Gery {Ibid. p. 453) does not 
 agree with his fellow-countryman, and thinks with Horner, that this muscle serves 
 to adapt the lids to the globe of the eye, and to direct the tears into the lachrymal 
 sac. F. T. 
 
 (1) C. A. Rudolpbi, Diss. de oculi quibusdam partibus, Gripswald, 1801.— -Id. 
 lieber einige Theile des Auges in his Anatomisch-physiologische Untersuchungen , 
 vol. i. p. 1-30. — Dœllingcr, Illustratif ichnographica oculi humani, VVurtzburg, 
 1817. — Edwards, Sur la structure de l'œil: in the Bulletin de la soc. philom., 1814, 
 p. 21. — E. Home and F. Bauer, Observations microscopiques sur la structure de V oeil ; 
 in Phil, trans ., 1822, p. 76, and in Archiv, génér. de méd., vol. ii. p. 151. 
 
152 
 
 DESCRIPTIVE ANATOMY. 
 
 The most external membrane is the cornea , the posterior part of 
 which is the opaque cornea or the sclerotica , and the anterior, the 
 transparent cornea. Next comes the middle membrane, the choroid , 
 the anterior part of which is termed the iris, and below this is a 
 third, the retina, which is a prolongation or expansion of the optic 
 nerve. 
 
 I. MEMBRANES OF THE EYE. 
 
 A. EXTERNAL MEMBRANES OF THE EYE. 
 
 § 1973. The external membranes of the globe of the eye are much 
 firmer and thicker than the others. Its form is determined principally 
 by them. 
 
 A. SCLEROTICA. 
 
 § 1974. The sclerotica, the opaque cornea, or the albugineous mem- 
 brane of the eye ( tunica sclerotica, s. albuginea, s. cornea opaca), covers 
 the posterior part of the eye, and occupies about five sixths of its cir- 
 cumference. It presents posteriorly, a little nearer its inner side than 
 its centre, a round foramen, or at least it is much thinner there than in 
 its other parts, and there presents numerous small cribriform openings, 
 through which the fasciculi of the optic nerve communicate with the 
 retina. It is terminated anteriorly by a broad rounded opening which 
 recieves the transparent cornea. 
 
 As it belongs to the class of fibrous membranes it is white, brilliant, 
 fibrous, very elastic and solid. We may forcibly divide it into several 
 layers : but these are united by intermediate filaments. 
 
 The two faces are smooth. Numerous blood-vessels, the trunks of 
 the twigs distributed to the inner part of the eye, intimately adhere to 
 the external ; some of these vessels perforate it posteriorly, others more 
 anteriorly at about its centre. They all proceed within its substance 
 a greater or less distance, which is proportional to their own volume. 
 
 Smaller openings in its posterior part give passage to the ciliary 
 nerves, which penetrate from without inward between it and the 
 choroid membrane. 
 
 The sclerotica is not equally thick in every part. It generally 
 diminishes much from behind forward. Posteriorly it is about a line 
 thick, and about one half of a line at the edge of the transparent 
 cornea. 
 
 The membrane is thinner in the points which correspond to the 
 attachment of the tendons of the recti muscles of the eye, than between 
 these insertions. 
 
 In the place where the optic nerve communicates with the globe of 
 the eye, it unites very intimately with the envelop given to this nerve 
 by the dura-mater. Although it is eight or ten times thicker, and also 
 
or THE EVE 
 
 153 
 
 firmer than this envelop, we may however consider them as identical, 
 since they do not differ essentially in regard to texture, 
 
 § 1975. Among the superimposed layers of the sclerotica, one may 
 be detached more or less easily from the others, and with greater 
 facility in the early periods of life, than in the adult. This very thin 
 layer is a prolongation, not of the pia-mater as has been supposed 
 since Zinn’s time,( 1 ) but of the envelop sent by the arachnoid mem- 
 brane to the optic nerve, and with which it is evidently continuous. It 
 forms a small bursa projecting inward, around the cribriform plate, 
 through which the optic nerve enters the eye, and is reflected from the 
 circumference of this layer on the inner face of the sclerotica, with 
 which it unites intimately, proceeding with it to its anterior edge. 
 
 There is then between this layer and the sclerotica, exactly the 
 same relation as between the dura-mater and the arachnoid membrane 
 within the skull and the vertebral column, or, emplojring a more gene- 
 ral comparison, as between the hard substances, as the cartilages and 
 the fibrous organs, covered with serous membranes and these mem- 
 branes. 
 
 The inner face of this internal layer of the sclerotica, is rather inti- 
 mately united to the choroid membrane by a loose cellular tissue, and 
 also by the nerves and vessels which pass through the external cap- 
 sule of the eye. We may, however, especially some days after death, 
 separate and remove the sclerotica, without injuring the choroid mem- 
 brane. ' 
 
 B . TRANSPARENT CORNEA. 
 
 § 1976, The transparent cornea ( tunica cornea , s. cornea pellu- 
 cida)( 2) which surrounds the anterior part of the eye, differs from the 
 sclerotica in its texture so much, that it is impossible to apply the same 
 term to these two membranes. 
 
 It represents a segment of a sphere which is a little smaller than 
 that of which the sclerotica is the figure, so that it is more convex and 
 projects slightly on the surface of the latter. 
 
 It is always a little thicker than the sclerotica, and its thickness is 
 generally uniform, except at its circumference, where it gradually be- 
 comes much thinner, but only in a slight extent. Sometimes, how- 
 ever, it is a little thicker in the centre than on the edge. Its posterior- 
 face always describes a concavity which corresponds exactly to the 
 convexity of its anterior face. 
 
 The conjunctiva extends towards the upper edge and the lower edge 
 of its external face for about half a line, so that this external face is 
 not perfectly round, but slightly elliptical, The upper face, on the 
 
 (1) Zinn, loc. cit., p. 11 
 
 (2) B. D. Manchart, Corneæ oculi tunicæ examen analoviico-physiologicum , Tu- 
 bingen, 1743. — Hoffbauer, Diss. de cornea ejusque morbis, Berlin, 1820. — M. J. 
 Chelius, l’eber die durchsichtige Hornhaut des Auges t Carlaruhe, 1818. 
 
154 
 
 DESCRIPTIVE ANATOMY. 
 
 contrary, is entirely round. It terminates by a circular depression or 
 groove which receives a prominent edge, situated on the limit between 
 the ciliary ligament and the iris. 
 
 It always becomes much thinner and is serrated at its point of union 
 with the sclerotica. 
 
 The two membranes are united in three different ways. 
 
 Sometimes the anterior face gradually diminishes, so that the trans- 
 parent cornea is partly covered by the sclerotica. 
 
 Sometimes the two faces gradually become thinner, and the cornea 
 is inserted in a channel grooved on the anterior edge of the sclerotica. 
 
 Finally sometimes the internal face insensibly disappears, and the 
 cornea rests a little on the anterior edge of the sclerotica. 
 
 The first is the most common and the last the rarest arrangement. 
 
 § 1977. The transparent cornea is formed of several layers having 
 between them a limpid fluid which are separated more easily than 
 those of the sclerotica, and which are united by a loose cellular tissue. 
 
 This fluid transudes after death. Its evaporation causes in part the 
 opacity and collapse of the cornea, which then occur. 
 
 The posterior face of the cornea is covered by a thin, pellucid, homo- 
 geneous and slightly extensible membrane, which tears evenly when 
 forcibly extended and is easily detached from it by a slight maceration 
 or by boiling.(l) This membrane is attached to the edge of the cornea, 
 and does not proceed at least sensibly on the iris. It has been termed 
 the membrane of the aqueous humor (mem. humoris aquei ) I his term 
 is inappropriate, as it docs not seem to secrete the aqueous humor.* (2) 
 
 B. CHOROID MEMBRANE AND IRIS. 
 
 § 1978. Directly below the external tunic of the globe of the eye is 
 another membrane of about the same extent and also composed of two 
 halves differing in their organization. The posterior is termed the 
 choroid membrane, and. the anterior, which is much smaller, the iris. 
 
 (1) B. Duddell, Treatise on the diseases of the horny coat in the eye , London, 1729. 
 — J. Descemet, An sola lens crystallina cataractœ sedes , Paris, 1758. — Id. in the 
 Mem. des sav. étrangers , book i. — Demours, Lettre à M. Petit , Paris, 1767. — The 
 details of the quarrel between Descemet and Demours, in regard to the discovery of 
 this membrane, are given in the Journ. de med ., 1769, 1770, 1771. 
 
 * Professor Schlemm of Berlin, asserts that the cornea is well supplied with 
 nerves : “ They arise from the ciliary nerves which divide behind the ciliary liga- 
 ment into a superficial and a deep-seated order of filaments. The latter are larger 
 and more numerous, and are distributed to the iris ; the superficial however enter 
 the sclerotica on a level with the ciliary ligament, from whence they extend forward 
 to enter the groove of the edge of the cornea which is united with the corresponding 
 border of the sclerotica, and traverse the posterior part of the cornea until they 
 become lost by their extreme tensity upon that membrane.” (Am. Journ. of the 
 Med. Sciences, Nov., 1830, p. 211.) 
 
 (2) S. Sawrey in 1807 claimed the discovery of this membrane, which had been 
 
 vaguely imagined by Duddell, and which in fact had been discovered by Demours 
 or Descemet. (An account of a newly discovered membrane in (he human eye, Lon- 
 don, 1807.) F. T. 
 
OF THE EYE, 
 
 155 
 
 A. CHOROID MEMBRANE. 
 
 § 1979. The choroid membrane (tunica vasculosa, s. choroidea)( 1) 
 corresponds to the sclerotica. It extends from the anterior edge of this 
 membrane to the entrance of the optic nerve for which it presents a 
 rounded opening and to which it is directly united, particularly along 
 the course of the nerves and vessels, in its whole extent by rather a 
 loose cellular tissue. The union between the two membranes is only 
 interrupted here and there by the ciliary nerves and the long ciliary 
 arteries, which proceed between them from behiird forward. 
 
 The inner face of the choroid membrane is not attached to the re- 
 tina, although they are in direct contact. 
 
 § 1980. Near the anterior extremity of the choroid membrane the 
 mucous tissue becomes much thicker in the outer face of the mem- 
 brane, and forms a whitish ring about one line broad, called the ciliary 
 ligament, the commissure of the choroid membrane , Ch. (L. ciliare, or- 
 biculus ciliaris, circulas ciliaris, plexus ciliaris). This ring attaches 
 the choroid membrane to the sclerotica more firmly than hi the rest of 
 its extent ; but it is united to the sclerotica much less intimately than 
 to the choroid membrane, which is thinner in the part corresponding to 
 it, so that the latter can be easily detached from the opaque cornea, 
 while this is not the case with the ciliary ligament, which may conse- 
 quently be considered as forming part of it. 
 
 The internal circumference of the ciliary ligament is bounded by 
 a narrow but very evident white projection, which fils exactly into 
 a groove on the circumference of the inner face of the transparent 
 cornea. 
 
 Before this ring is the iris, which is intimately united with it. 
 
 B. CILIARY BODY. 
 
 § 1981. The inner face of the choroid membrane is singularly 
 changed in this place, where it forms the ciliary body ( corona ciliaris, 
 s. orbiculus ciliaris, corpus ciliare, tunica ciliaris). (2 ) In fact on 
 leaving the external edge of the ciliary ligament it forms, inward and 
 for the breadth of about a line and a half, numerous small folds, whence 
 come a great number of slightly prominent rays which go from with- 
 out inward. Another smaller and more internal circle then succeeds, 
 formed by more distinct folds, the inner edge of which is convex and 
 
 (1) Ruysch, Ep. an at. xiii. — L. Heister, Diss.de tunica choroidcâ , in the Ease, 
 diss. med., Leyden, 1745. — B. S. Albinus, Dc tunica Ruyschianâ et choroidcâ oculi ; 
 in the Ann. acad., 1. vii., cap. iv. 
 
 (2) J. G. Zinn, De ligament is ciliaribus progrefifnma, Gottingen, ] 753. — Doellinger, 
 tlur les procès ciliares dans l’œil dc l’homme; in the J\ov. actanat. cut., voL ix., 
 p. 274. 
 
156 
 
 DESCRIPTIVE ANATOMY. 
 
 which become more prominent from without inward, and terminate in 
 a rounded edge. These folds, which are termed ciliary processes 
 (processus ciliaris), are fewer in number although very numerous, as 
 there are about seventy. They are however much more remote from 
 each other than the external. Their anterior extremity is loose. They 
 arc attached to the large circumference of the crystaline capsule by 
 the anterior part of their adherent edge. The posterior part of all this 
 region of the choroid membrane adheres very intimately to the ex- 
 ternal face of the ciliary ligament, for its folds are received into the 
 depressions of this latter, the form of which corresponds exactly to 
 theirs, so that in this part the inner face of the choroid membrane is 
 firmly united to the subjacent parts, and when we attempt to detach 
 it in the recent state the ciliary ligament is generally torn. 
 
 § 1982. The choroid membrane is soft and thin, but its tissue is 
 firm and solid. On removing the coat of the pigment it appears 
 whitish and slightly transparent. It is almost entirely formed by 
 blood-vessels which are very distinct on its two faces, especially on 
 the external. 
 
 Some of these vessels are arteries and others veins,(l) but the latter 
 are much more numerous. 
 
 § 1983. The arteries of the choroid membrane, termed the ciliary 
 arteries (A. ciliares), are principally of two kinds. 
 
 The long ciliary arteries (A. ciliares longa) are longer and more 
 superficial than the others ; there are generally but two, an external 
 and superior and an internal and inferior. These two arteries are 
 situated more or less nearly opposite each other. After passing 
 through the sclerotica at its posterior part they are situated on the 
 anterior part of the choroid membrane, proceed directly from behind 
 forward without sending off any very large branch, and are distri- 
 buted in the iris. Hence they do not really belong to the choroid 
 membrane. 
 
 The short or posterior ciliary arteries, uvéales , Ch. (A. ciliares breves , 
 s. postenores), are much smaller but more numerous than the long. 
 There are usually twenty or more of them of different sizes. They 
 perforate the sclerotica more posteriorly and internally than the pre- 
 ceding, nearer the optic nerve, and soon enter the choroid membrane. 
 They there divide into twigs which are given off at acute angles, 
 frequently anastomose together, especially in the anterior part of the 
 choroid membrane, and form forward, behind the external edge of the 
 ciliary body, a circle composed of a very complex network. 
 
 The twigs they produce in dividing are parallel, and proceed very 
 closely from behind forward. At the posterior part of the choroid 
 membrane they are situated on its outer face, but towards the centre 
 of the globe of the eye they pass through it and go to its internal face, 
 
 (1) J. E. Hebenstreit, De rosis sanguiferis oculi, Leipsic, 1742. — J. G. Zinn, Di 
 casts subtilioribus oculi et coehlcce auris internee , Gottingen, 1753. 
 
OF THE EVE, 
 
 157 
 
 where consequently they are more distinctly perceptible than in the 
 external. 
 
 § 1984. The veins of the choroid membrane are easily distinguished 
 from the arteries by their course and their larger size. 
 
 Their branches are very compact, radiate from before backward and 
 from without inward, form large arches, and divide into twelve or four- 
 teen small twigs which pass through the sclerotica at about the centre 
 of the globe of the eye, proceed a few lines from before backward in 
 this membrane, and reunite in four or five larger trunks which pass 
 out of the eye at its posterior part and enter the ophthalmic veins. 
 Four of these trunks are much larger than the rest, some of which 
 proceeding also from before backward, receive the twigs coming from 
 the iris. 
 
 These veins have been termed from their numerous curves the vasa 
 vorticosa. They are more superficial than the arteries, and are also 
 more external at the anterior part of the choroid membrane and form 
 its external layer. 
 
 Besides these veins there are others, the long or anterior ciliary 
 veins (r. ciliares longœ, s. anteriores ), which accompany the long 
 ciliary arteries, return from the iris, and receive no considerable rami- 
 fications from the choroid membrane.(l) 
 
 § 1985. The blood-vessels and the mucous tissue which supports 
 them are the only organic elements visible in the choroid membrane. 
 Those fibres which are directed from before backward, and are ad- 
 mitted by several anatomists to exist, have never been seen by us, and 
 even the ciliary body seems only a very complex tissue of vessels. 
 
 § 1986. The internal face of the choroid membrane does notap- 
 pears perfectly smooth to the naked eye, but presents, particularly if 
 the eye be injected, numerous small floating flocculæ which give it a 
 downy appearance ; this is much more evident if we use the micro- 
 scope. These flocculæ are very well developed in the ciliary body. 
 They are mostly formed by a very compact tissue of vessels, particu- 
 larly in the posterior region of the choroid membrane, the inner face of 
 which is almost entirely covered by them, while they leave it much 
 looser anteriorly. 
 
 § 1 987. The internal face of the choroid membrane cannot be con- 
 sidered as a special membrane in man, as we cannot divide it into two 
 layers. Ruysch first asserted this opinion, while his son termed this 
 coat the tunica Ruyschiana. It is also incorrect to admit as the villo- 
 glandular tunic {2) or the supra-choroid membrane ( membruna supra- 
 choroidca){3), another membrane situated on the outside of the choroid, 
 which would be the second middle tunic of the eye, or even the third, 
 
 (1) See the plate of the vessels of the choroid membrane, in S corn inerring, lieber 
 das feinste Gefassnelz der Aderhaut im Augäpfel, -1818. 
 
 (2) B. A. Stier, De tunicâ quadam oculi novissime delectà , Halte, 1759. 
 
 (3) Montain, in the Journal de mcd., vol. lvii. — Bull, de la soc. mid. d’Emul. , 
 1807, p. 330. 
 
 Vol 111 
 
 21 
 
156 
 
 DESCRIPTIVE ANATOMY. 
 
 by admitting the tunica Ruyschiana, and which has been regarded as 
 belonging to the class of serous membranes.(l) 
 
 Finally it is still more incorrect to represent the choroid coat as 
 formed by live superimposed layers, (2) of which the second, third, and 
 fourth form the proper choroid membrane, and the other two the two 
 membranes mentioned 
 
 C, IRIS. 
 
 § 1988. The im( 3) is a circular membrane perforated in its centre 
 with a rounded and nearly concentric opening, termed the pupil. 
 This opening is a little narrower on its inner side, which looks towards 
 the nose, than in the rest of its course, (4) and its external edge is at- 
 tached to the anterior edge of the choroid membrane, viz. to the ciliary 
 ligament. Finally, it is entirely loose in the chamber of the eye, where 
 it forms a transverse septum extended from above downward and from 
 light to left, which divides this chamber into two compartments, an 
 anterior and a posterior , communicating by the opening of the pupil. 
 
 The iris forms the posterior wall of the anterior chamber of the eye, 
 and the transparent cornea forms its anterior wall. It constitutes, on 
 the contrary, the anterior wall of the posterior chamber, the posterior 
 wall of which is formed by the anterior face of the cryslaline lens, 
 and the anterior edge of the ciliary body. 
 
 The posterior wall of the iris is also termed the uvea. 
 
 In man it is straight and not convex anteriorly, as has been as- 
 serted.^) It is nearer the anterior face of the crystaline membrane 
 than the posterior face of the transparent cornea.(6) The space on 
 its external face where it is greatest, between it and the cryslaline 
 membrane, is not even half a line, but in the centre it is only a quarter 
 of a line. Its centre is about a line distant from the transparent cornea, 
 but its outer edge is much nearer this membrane. 
 
 Its extent from without inward varies extremely It is not only often 
 morbidly dilated to such an extent that the pupil almost entirely dis- 
 appears, and sometimes contracts so much as to be invisible or nearly 
 so, but also in the normal state it dilates and contracts rapidly under 
 the influence of certain external and internal causes. (7) By carefully 
 
 (1) Docllingcr, loc. cit., p. G. 
 
 (21 Hovius, De circular l humorum motu, Leyden, 17 LG, p. 29. 
 
 (3) Maunoir, Mémoire sur l'organisation de l’iris , et V opération de la pupille arti- 
 ficielle, Paris, 1812. 
 
 (4) Winslow, Observations sur la mécanique des muscles obliques de l’œil , sur 
 l'iris, &c. ; in the Mém. de Paris, 1721, p. 4G3. — Littleton, Sur les causes d’où 
 dépend la largeur de la pupille ; in Bradley, Med. and phvs. Journal, vol. xxxvi., 
 
 p. 89. 
 
 (5) Petit, Mém. sur les yeux gelés, dans lequel on détermine la grandeur des 
 chambres qui renferment l’humeur aquesc ; in the Mém. do Paris, 1725, p. 54. 
 
 (G) Ibid., 1728, p. 295 and 408. 
 
 (7) J. G. Zinn, De motu uvcœ ; in tue Cumin. GolL, vol. i. — F. Fontana, Dei molt 
 dcll'iride , Lucca, 1765, — J F Blumenbach, De oculis leucaethiopum cl molli 
 
or THE EYE 
 
 1 59 
 
 examining all the circumstances which belong to these two pheno- 
 mena we conclude that the active state of the iris js that of dilatation, 
 the passive that of contraction 
 
 § 19S9. This membrane is much thicker in its larger and external 
 than in its internal part, where it seems to be divided obliquely from 
 without inward and from before backward, and terminates there in a 
 thin edge. The most internal part excepted, the iris is three or four 
 times thicker than the choroid membrane. 
 
 Its external and internal edges are more deeply colored than the 
 intermediate parts. The darkest part of the membrane is a small 
 portion of the inner surface situated a little on the outer side of the 
 inner edge. This dark place and the portion of the iris between it and 
 the pupil is called the small or the internal circle ( annulus minor , s. 
 internus) . The rest of the membrane is termed the great or the. ex- 
 ternal circle ( annulus major, s. externus). 
 
 The whole of the anterior face of the iris is entirely colored. The 
 posterior is colored only in the portion corresponding to the small 
 circle : all the rest is whitish, but covered with a dark mucus (§ 1997), 
 The anterior face is the seat of the peculiar color of the eyes. It is 
 every where covered by very minute and differently colored flocculæ, 
 which with the streaks of pigment abovementioned on the posterior 
 face are the grounds of the different color of the eyes, 
 
 § 1990. We observe both on the anterior and the posterior face of 
 the iris circular fibres which are slightly undulatory, and longitudinal 
 fibres which radiate from without inward. The first are particularly 
 evident near the outer and inner edge. The others are more distinct 
 on the anterior face ; they are larger and more perceptible in the great 
 than in the small circle 
 
 Some of these fibres are whitish and alternate with others less ma- 
 nifestly gray. The first divide frequently at acute angles into a con- 
 sidererable number of small branches, which anastomose on the outer 
 circumference of the small circle, giving rise to arches which are convex 
 forward, and thus form a complex crown from which smaller and closer 
 longitudinal striæ emanate ; these radiate in the internal circle to the 
 edge of the pupil, 
 
 § 1991, The iris is soft and spungy. 
 
 It i3 mostly composed of nerves and vessels united by mucous tissue, 
 and very probably also of fibres, the seat of the contraction and dilata- 
 tion mentioned above (§ 1988). 
 
 iridis, Gottingen, 1785. — F. llildcbrandt, De motu iridis, Brunswick, 1786. — Doem- 
 ting, Ueber die Ursache der Bewegung der Regenbogenhaut ; in Reil, Archiv. Jur 
 Physiologie , vol, v. — Oaldani, Intorno di movimenti dcWiride ; in the Mem. della 
 soc. ital., vol. xiv., pt. 2, p. 101-114. — C. A. F. Kluge, Diss. de iridis motu, Erford, 
 1S06.— S. S. Guttentag-, De iridis motu, Breslau, 181 5. — Littleton, On the couses 
 which influence the sise oj the pupil ; in the Land. mcd. and phys. journal, vol. Ivi , 
 1816 p. 89, 265, — E H Weber Traci ulus dr motu iridis, Lcipsp • 1821, 
 
160 
 
 DESCRIPTIVE ANATOMY. 
 
 § 1992. The nerves of the iris (JV', ciliares)( 1) arise from the first 
 branch of the fifth pair, from the sixth pair and the great sympathetic 
 nerve, are about twenty in number, and perforate the sclerotica a little 
 behind the centre of the great diameter of the eye, pass some lines even 
 in the substance of this membrane, are then situated between it and 
 the outer face of the choroid membrane, adhere but slightly to these two 
 coats, proceed from behind forward without giving off any branch, and 
 arrive at the external edge of the ciliary ligament., directly behind which 
 they generally divide at an acute angle into two branches. These 
 branches go forward on the anterior face of the chorokTmembrane un- 
 der the ciliary ligament and arrive at the anterior face of the iris, 
 where they form the whitish and radiating filaments there observed ; 
 in the course of . these are rounded filaments which are perhaps gan- 
 glions. 
 
 The ciliary nerves are unusually large in proportion to the iris, and 
 hence this membrane is one of the parts of the body, if not the very 
 part, which possesses the most nerves. 
 
 § 1993. The vessels of the iris arise principally from the long or 
 anterior ciliary vessels. 
 
 E-ach of the two long ciliary arteries divides below the ciliary liga- 
 ment into two branches, which go to meet the two corresponding 
 branches of the other arterial trunk, and which by anastomosing with 
 them form on the external edge of the iris a crown slightly convex 
 forward, from which numerous twigs arise ; the latter radiate towards 
 the inner edge of the membrane and still bifurcate, communicating here 
 and there by transverse ramuscules. They anastomose together on 
 the outer edge, of the internal ring so as to form at the opening of the 
 pupil a more or less concentric circle ; from this, new radiating twigs 
 arise and go to the small circumference, but several of them however 
 come directly from the rays of the great external arterial circle. 
 
 Besides the arterial twigs, the iris also contains many little veins 
 which enter some into the long ciliary veins and others into the vasa 
 vorticosa. As they cannot be filled except by injecting them through 
 the arteries, or as when injected through the venous trunks, they are 
 filled less perfectly than the arteries, the veins seem fewer and form 
 but small arches. (2) 
 
 These vessels are most apparent on the anterior face of the iris, to 
 which they seem but loosely attached. 
 
 They certainly carry red blood, since the membrane [bleeds when 
 wounded, and their reddish color is very evident in the eyes of albinos, 
 where the pigment continues colorless from a primitive deviation of 
 formation. (3) 
 
 § 1994. Even in the most perfect injections, the iris still seems to be 
 formed of more or less evident yellowish white fibres, which as we 
 
 (1) Tiedemann, Diss. dc ganglio ophihalmico el nenis ciliaribus animalium,' Land- 
 shut, 1815. 
 
 (2) Zinn, loe. cit., p. <J4. 
 
 (3) Monro, Ucber den Bau der Fische, Lcipsic, 1787, r>- 74, 
 
OF THE EYE 
 
 161 
 
 have already stated; seem to be the seat of the motions executed by 
 this membrane. 
 
 Several anatomists, as Drelincourt,(l) Ruysch,(2) and Monro, (3) 
 formally adopt this opinion, or are, like Zinn, (4) very much inclined 
 to it. 
 
 They assert that some of the fibres are radiated and others circular : 
 the first extend from the external to the internal circle, where Ruysch 
 thinks that they are even attached by small tendons : the circular form 
 most of the internal circle of the iris. (5) In contracting, the longitu- 
 dinal fibres dilate the pupil, while the circular contract it. 
 
 Beside the circular fibres which are admitted by Monro and Ruysch, 
 we have sometimes observed on the anterior face of the iris, towards 
 its outer edge, some very evident circular fasciculi, corresponding to 
 those discovered in the same place in the eye of the ox by Monro ;(6) 
 but neither the anatomy, nor the observation of the vital phenomena of 
 the iris, seem to us to justify the admission of radiating longitudinal 
 fibres. 
 
 § 1996. The iris in man can be divided, but not naturally, into two 
 layers, an anterior or the proper iris, and a posterior or the uvea, and 
 these cannot be separated except in small portions. It is also uncer- 
 tain whether its anterior face be lined by a prolongation of the mem- 
 brane of Demours ; at least it is here also much thinner than on the 
 posterior face of the transparent cornea, and its nature is different. 
 
 § 1 997. Opinions vary in regard to the manner in which the iris 
 and choroid membrane are united. Some assert that the iris is a pro- 
 longation of the latter ; others think that it should be regarded as a 
 distinct membrane. 
 
 The arguments in favor of the second opinion are : 
 
 1st. The greater thickness of the iris. 
 
 2d. Its numerous nerves, while the choroid membrane has none. 
 
 3d. The fewer vessels which carry blood to it, which differ in their 
 origin and arrangement from those of the choroid membrane. 
 
 4th. The difference between the two membranes in respect to their 
 vital phenomena, since the iris is highly contractile, while the choroid 
 membrane possesses no contractility. 
 
 We may also add that the great edge of the iris is easily detached 
 after a maceration, which does not continue long enough to destroy 
 the continuity of the tissue either of this or of the choroid membrane 
 
 (1) Prœlud. anat. Opp. omit., p. 195. 
 
 (2) Respons. ad epist. anat. xiii-, Thcs. anat, ii,, p. 13-15. 
 
 (3) Loc. at., p. 110-115. 
 
 (4) Loc. cit., p. 91,|95. 
 
 (5) Monro (loc. cit., tab, 3). 
 
 (6) Loc. cit., tab. 2. 
 
162 
 
 OESCRirTIVE ANATOMY 
 
 D. PIGMENT, 
 
 § 1997. The two faces of the choroid membrane and the posterior 
 face of the iris or the uvea, in the normal state, are covered with a 
 brownish colored substance, termed the pigment ( pigmentum ni- 
 grum ).(]) In some parts’, particularly on the posterior face of the 
 iris, this pigment can be detached in a greater or less extent as a fine 
 and coherent membrane. In some places, particularly on the inner 
 face of the ciliary body, especially between the processes, and the pos- 
 terior face of the iris, and generally in the internal regions, it is more 
 abundant, deeper in color, and more attached to the adjacent parts. 
 There is less on the external than on the internal face of the choroid 
 membrane, although that which exists there does not differ essentially 
 from that found in other parts. There is none on the posterior part of 
 the inner face of the choroid membrane around the opening which 
 gives passage to the optic nerve, so that the choroid coat is white in 
 this place. 
 
 The pigment is composed of a peculiar mucous substance and of 
 another coloring substance, the first of which connects all the mole- 
 cules together, so that they have the form of a membrane. In regard 
 to mechanical structure, this coloring substance is composed of glo- 
 bules. These globules are not perfectly black, but only present occa- 
 sionally small points of a deeper tint. Their form is irregularly round 
 They arc smaller in the ciliary processes, but are arranged in several 
 superimposed layers more uniformly black. In regard to their che- 
 mical composition, they contain a considerable quantity of iron and also 
 of carbon, which forms almost half of them, so that of all parts of the 
 body they contain the most of this elementary substance. (2) The 
 iron is the cause of their heaviness but not the source of their color, 
 since the quantity of this metal in the reto mucosum of the skin 
 of the negro is small, and even leas than in that of the Caucasian 
 race.(3) 
 
 The pigment is essentially so similar to the retc mucosum, that we 
 may admit they arc the same, whence it follows that the pigment is 
 not a secreted fluid but a solid tissue, an organic element possessing a 
 special form. 
 
 (1) Morulini, De oculi pigmenta ; in the Comm. Donon., vol. vii., p. 29. — Elsaesser, 
 De pigmento oculi nigra, Tubingen, 1800. — L. Gmelin, IJiss, sistens indagalionem 
 chimicam pigmenti nigri oculorvm taurinorum cl vilulinurum , adnexis quibusdam 
 in id animadversionibus physiologicis, Gottingen, 1812.— F, Monclini, Sul nero pig- 
 mento dell' occhio ; in the Opuscoli scicntijiclii di Bologna , 1818, l'asc, vii-, p 15-27. 
 — Berzelius, Djurlcemi, ii., n 201 
 
 (2) Berzelius, in the Mea. chir. trano., vol. iii., p. 255. — Coli, in Mondini jun., loc. 
 cit., p. 17. 
 
 (3) Coli, loc. cit., p. 26. 
 
or THE EYE 
 
 163 
 
 C. KETINa. 
 
 § 1998. The third distinct membrane of the eye is the retina. { 1) 
 It is the expansion of the optic nerve, the anterior extremity of which 
 contracts much in passing through the sclerotica, but more gradually 
 and more insensibly at its inner than at its outer part, so that the nerve 
 describes an arch much larger outward than inward. 
 
 Before the anterior extremity of the optic nerve the sclerotica pre- 
 sents a surface with numerous foramina, through which the fasciculi 
 of the nerves pass. Beyond this cribiform plate the extremity of the 
 nerve forms a small mammillary prominence, from which the expan- 
 sion of thç retina arises ; this terminates forward at the posterior ex- 
 tremity of\he ciliary body by a straight edge more or less evidently 
 enlarged, which is unconnected with the crystalline capsule. (2) 
 
 § 1999. The retina is white, thin, homogeneous, and destitute of 
 fibres, equally thick in every part, excepting one small point of its 
 extent posteriorly. It is composed, in a measure, of two layers, an 
 external, which is medullary, and an internal, formed by cellular tissue 
 and vessels. The latter separates the medullary layer from the vit- 
 reous body. We cannot however insulate the two layers from each 
 other so as to obtain one alone in the form of a connected and coherent 
 whole, although the internal appears in this form when putrefaction 
 has destroyed the medullary layer. Hence we cannot consider the 
 retina except as formed by the union of two special and distinct mem- 
 branes ; but We really find on its external face a very thin mem- 
 brane^) very analogous to the serous membranes, which seems to us 
 
 (1) J. H. Moeller, De tunica nerved el nervo optico , Halle, 1749.-— B. S. Albums, 
 De tunica quam vacant rctinam ; in the Annot. acad., book iii., cap. xvi., Ann. 1756. 
 
 (2) Several old anatomists, particularly Winslow, Cassebohm, Ferrein, Lieutaud, 
 and Haller, whose arguments have been collected by Zinn ( loc . cit., p. 114), and 
 Monro among the moderns (toc. cit., p. 96), have asserted that the retina passes 
 below the ciliary body, and that it extends io the great edge of the crystaline cap- 
 sule, to which it is attached. But careful dissections have led us to embrace the 
 contrary opinion, which has been supported by Morgagni, Zinn, and some of their 
 predecessors. Monro says that we can prove that the retina extends to the crys- 
 taline humor : 1st, by resting the eye on the transparent cornea, and there making 
 a transverse section which includes all the membranes with the vitreous body ; 2d, 
 by raising the ciliary body and carefully removing the pigment with a pair of 
 forceps. But in following these two processes we have always recognized that the 
 retina terminates evidently at the posterior extremity of the ciliary body, arid we 
 have even found that the layer still partially covered by the pigment, which extends 
 from the hyaloid membrane to the crystaline capsule, was more transparent than 
 the retina. The eyes of the fetus are better than those of the adult to demonstrate 
 that Monro’s opinion is false, because in them the retina is more opaque, and the 
 external wall of the canal of Petit is thinner. 
 
 (3) Jacob, Newly discovered membrane in the eye; in Thomson, Annals of philo- 
 sophy, July, 1818, p. 74; Phil, trans., 1819, p. 30Ö; Juurn. compl. des sc. méd., vol. 
 xi., p. 187. — Jacobson, Mémoire sur une humeur peu connue de l’œil, et sur les ma- 
 ladies auxquelles donnent quelquefois lieu les changemens survenus dans sa sécré- 
 tion ; in the Act. soc. reg. med. Hafn., vol. vi. ; and Bull, de la soc. méd. d’ Emu/., 
 September, 1822. — G. Mirault, Sur une hydrophile puiiiculiirc au globe de l’œil ; 
 in the Archvo. gén. de méd., vol. jj., p. 46. 
 
164 
 
 DESCmi’TIVJi ANATOMY. 
 
 to be the seat of the ossifications sometimes occurring between the 
 choroid membrane and the retina. 
 
 § 2000. The retina is extended on the vitreous body, and forms 
 there no fold, except in a small extent of its posterior part, at some dis- 
 tance from the entrance of the optic nerve, and on its outer side. 
 
 There in fact the membrane presents, a fold which is directed 
 inward, a yellow spot , and a round place, where it is extremely 
 thin.(l) 
 
 The direction of this fold is transverse from within outward. It 
 commences at some distance from, or directly at the side of the entrance 
 of the optic nerve by a small point, and is terminated by a blunt extre- 
 mity. It is generally from a line and a half to two lines long. It is 
 commonly single, but sometimes also it is double. In some subjects it 
 is deficient.(2) Home asserts even that it is never natural, and that 
 its formation depends on the more intimate union in this place between 
 the retina and the hyaloid membrane. But the error of the English 
 anatomist is proved by the facts that the fold is observed even when 
 the connections between the two membranes are unaltered, and that 
 it is much more evident in youth than subsequently. 
 
 The retina presents at the same place a yellowish spot of the same 
 size, which is darker in the centre than on the edges. It is generally 
 one line high, and from one and a half to two lines broad. But it 
 has not the same extent and degree of color in every part, although 
 these two peculiarities are not necessarily connected with the sense of 
 vision. 
 
 The retina is much thinner in this place than in the rest of its extent, 
 particularly in the centre of the yellow spot, where some admit the 
 existence of a foramen, while others, and according to our dissections 
 more correctly, think that there is a place entirely destitute of medul 
 lary substance, of an oval form and surrounded with smooth and dis- 
 tinct edges. 
 
 This thin place becomes very apparent only when the vitreous hu- 
 mor is compressed to push the fold outward and to efface it. 
 
 (1) Ruzzi, in the Opusc. suite scienze e sullc aril, Milan, vol. v., 1784, and vol. vii. 
 — Scemmcrring', Dc foraminc centrait limbo luleo cincto retinœ humancc ; in the 
 Comm. soc. Gott., vol. xiii., 1795 -1798. — P. Michaelis, Buber einen gelben Fleck und 
 ein Loch in der Ncrvenhaul des menschlichen Auges ; in the Journal der Erfin- 
 dungen , part xv., p. 1-17, 1796, and cah. xvii., p. 133. — J. C. Reil, Die Falle , der 
 gelbe Fleck und die durchsichtge Stelle in der Retzhaut des Auges ; in Ihc Archiv. 
 Für die Physiologie, vol. ii., p. 468-797.- — E. Horne, An account of the orifice in the 
 retina of the human eye ; in the Phil. Irans., 1798, p. ii. — Exposé des résultats de 
 plusieurs recherches sur la lache jaune, le pli cl le Irou central de la rétine, d’après 
 deux mémoires communiqués par Marc et Léveille ; in the Mémoires de la soc. méd. 
 d’Em., vol. i., 1802, p. 364-397. — J. M. Wantzel, Heber die Home’schcn Entdeckun- 
 gen, das Loch, die Falte und den gelben Fleck im Mittelpunkt der Retzhaut 
 betreffende ; in Rosenmuller and Isenllamin, Beiträgen Jur die Zergliederung- 
 sfeunst, Leipsic, 1800, vol. i., partii-, p. 204. 
 
 (2) Reil, loc. cit., p. 470. 
 
OF THE EYE. 
 
 165 
 
 n humors or the eye. 
 
 a- VITREOUS IIUMOR. 
 
 § 2001 The posterior part of the eye is occupied by the vitreous 
 humor or body ( humor vitreus , s, corpus vilreurn), which corresponds 
 in its situation to the choroid membrane and the retina.(l) 
 
 This humor is perfectly transparent, thin, and formed almost entirely 
 of water, which contains a small quantity of the hydrochlorates and 
 the lactates, with still less of albumen and soda. (2) It is contained in 
 a special, very thin, delicate, transparent membrane, which every 
 where surrounds it, and which is termed the hyaloid membrane ( tunica 
 hyaloidea). This membrane sends internally numerous prolongations 
 in the spaces of which the liquid is contained as in so many cellules. 
 The union of the membrane and of the liquid which forms it, is pro- 
 perly speaking, the vitreous body. 
 
 This body presents on its anterior face a slight cavity which is con- 
 nected with the crystaline capsule, the posterior part of which is 
 situated there, and adheres to it so intimately in the normal state that 
 it cannot be detached from it, at least when the eye is perfectly fresh, 
 without tearing the hyaloid membrane. 
 
 2002. Eetween the great edge of the crystaline capsule and the 
 anterior part of the hyaloid membrane, a little behind the anterior edge 
 of this latter, is a thin layer, termed the ciliary layer ( lamina ciliaris. 
 zonula Zinnii), which is extended like a bridge on the most anterior 
 part of the vitreous body, in connection with which it circumscribes a 
 triangular space, the base of which is formed by the posterior part 
 of the circumference of the crystaline capsule, while the two branches 
 are constituted, one by the layer, and the other, by the most anterior 
 pait of the vitreous body. 
 
 This empty space surrounds ihe crystaline pmd the vitreous body 
 It is termed the canal of Petit ( canalis , s. circulas Petiti) It is easily- 
 demonstrated by inflating it with air. 
 
 (1) P. IVlartegiam (Nota obs.de oculo humano , Naples, 1814, p. 19) admits be- 
 
 tween the vitreous body and the retina an empty space, in the centre of which is the 
 central artery of the retina, termed by him the area Martcgiani, in honor of his 
 father. J. Cloquet seems to admit the existence of this deviation, for he says (De la 
 squelettopée , Paris, 1S19, p. 72,) that the hyaloid membrane is reflected on itself on 
 a level with the enhance of the optic nerve into the eye, to form a canal which passes 
 from behind forward directly through the vitreous body. He proposes to call this 
 passage the hyaloid canal, and asserts that it always exists in man. P. T. 
 
 (2) According to Berzelius (Animal fiuids ; in the Med. chir. Irans., vol. iii., p. 
 253), one hundred parts of the vitreous humor contains 98,40 of water, 0,16 of albu- 
 men, 1,42 of the hydrochlorates and lactates, 0,02 of soda and an animal matter 
 completely soluble in water. 
 
 VOL. III. 
 
 22 
 
166 
 
 DESCRIPTIVE ANATOMY. 
 
 The ciliary layer presents numerous fissures, the direction of which 
 is from before backward and «from within outward, because it corres- 
 ponds exactly to the inner face of the ciliary body, which is intimately 
 united with it, and the folds of which are situated in its depressions. 
 Its external face seems blackish after the ciliary body is removed, be- 
 cause the pigment remains attached to it there. When the canal of 
 Petit is inflated, it is raised, its grooves become more superficial, and its 
 external face seems formed of rounded or triangular eminences which 
 project but slightly and are near each other. 
 
 This layer is thicker than the hyaloid membrane ; still as it is united 
 with this latter, and as the posterior edge of the layer is continuous 
 with it, we have reason to say that the hyaloid membrane is divided 
 at its anterior part into two layers, of which the external gives rise to 
 the ciliary layer, while the internal is adapted to the posterior face of 
 the crystaline capsule. 
 
 Ribes(l) asserts that canals exist between the ciliary layer and the 
 ciliary body, which canals conduct the aqueous humor in the cham- 
 bers of the eye, and take it up again from these two cavities. He 
 supports his opinion by the dilatation of these pretended canals in an 
 eye affected with hydrophthalmia, and the escape of the vitreous hu- 
 mor, when the eye is suspended by the optic nerve, after removing the 
 transparent cornea. But these facts do not demonstrate it sufficiently. 
 The first phenomenon depends probably on the general accumulation 
 of serum in the eye, as there is also a considerable collection of 
 serum between the crystaline lens and the vitreous body. We have 
 every reason to think that the second depended on the pressure of the 
 vitreous body on a part which ought to yield more easily after cutting 
 the transparent cornea. 
 
 III. CRYSTALINE LENS. 
 
 § 2003. The crystaline lens ( lens crislallina)(2) is a soft, rounded 
 body, perfectly transparent in the normal state, the breadth and height 
 of which are almost double its thickness, and the posterior face of 
 which is much more convex than the anterior ; at least an inverse 
 relation between its two faces rarely exists, and they are more fre- 
 quently similar. The posterior face is generally a segment of a sphere 
 about from six to nine lines in diameter, while the anterior is a segment 
 of a sphere about five lines in diameter. 
 
 (1) Mém. de la soc. mtd. d’émul., vol. viii., p. 622-624. 
 
 (21 A. F. Walter, De lente cristallina oculi humani, Leipsic, 1712. — Petit, Mémoire 
 sur le cristallin de l'œil de l'homme , des animaux à quatre pieds , des oiseaux et des 
 poissons ; in the Mém. de Paris , 1730, p. 4-33. — S. G. Sättig, De lentis crystallines 
 structura fibrosâ, Halle, 1794. — B. F. Bacrcns, Diss. sistens lentis crystallina : mono- 
 graphiam, 1819.— Leiblcin, Bemerkungen über das System der Krystallinsc bey 
 Saughthieren und Vögeln, Wurzburg. 1821. 
 
OF THE EYE 
 
 167 
 
 The thickness and the convexity of the crystaline lens are not al- 
 ways in the same proportion, as there is no constant relation between 
 these two qualities and the breadth and height of the lens. 
 
 The crystaline lenses of the two eyes in the same man sometimes 
 differ very much in form 
 
 This body is situated before the vitreous body, the concave anterior 
 face of which receives its posterior face, below the ciliary body, the in- 
 ternal face of which is partly attached to its great edge, It is situated 
 behind the iris, with which it is not connected. 
 
 It however is not loose. A thin but solid membrane which is trans- 
 parent and much thicker than that of the vitreous body exactly en- 
 velops it in every pavt.(l) This membrane, termed the crystaline 
 capsule ( capsula cristallina), is the medium of connection between the 
 crystaline lens and the adjacent parts. 
 
 The crystaline lens is loose in its capsule. It is at most attached 
 only by extremely minute vessels, which are detached from this mem- 
 brane and enter its substance. 
 
 Between it and the capsular membrane is a transparent and very 
 thin fluid, termed the humor of Morgagni (liquor Morgagnii) .(2) 
 
 § 2004. The crystaline lens is formed of two substances, one ex- 
 ternal and soft, the other internal and harder. These two substances 
 blend together imperceptibly. The first is termed the cortical layer , 
 and the second the nucleus. The cortical substance can be easily 
 separated from the nucleus by crushing it between the fingers. 
 
 A special process is necessary to demonstrate this texture : but 
 when the most complex means are emploj'ed, the crystaline lens is 
 proved to be much more complicated than it seems at first view, and 
 it may constantly be reduced into a certain number of parts. (3) 
 
 In fact by maceration and by the action of acids this body is divided 
 in its whole extent from before backward into several triangular seg- 
 ments, the summits of which are turned inward and the bases outward, 
 and which unite in the centre of the lens. Besides each segment also 
 divides into numerous small laminæ, which are situated one above an- 
 other from without inward, and which cover each other like the coats 
 of an onion. 
 
 These layers are reflected from before backward on the outer edge 
 of the crystaline lens, in the centre of which they accordingly termi- 
 nate by two points, an anterior and a posterior. 
 
 (1) Petit, De la capsule du cristallin ; in the Mém. de Paris , 1730, p. 622-643. 
 
 (2) Graefe, Ueber die Bestimmung der Morgagnischen Feuchtigkeit der Lin- 
 senkapsel und des Faltenkranzes ; in Reil, Archiv, für die Physiologie, vol. ix., p, 
 225-236, and in Abhandlungen der Erlanger Soc., vol. i., p. 309-396. 
 
 (3) A. Leeuwenhoek, De formatione humoris crystalline in variis animalibus, de 
 substantia fibrosa quæ in oculo apparct, &c. ; in the Arc. nat. detect., Delft, 1695, p. 
 70. — Morgagni, in the Epist. anat., A. 30, 31, 32, 33.— Sättig-, De lentis crystallina: 
 structura fibrosa, Halle, 1793. — Young, in the Phil. Irans., 1793. — Monro, On the 
 structure of the body of the crystaline lens, and whether the fibres which enter into 
 its composition are muscular ; loc. cit., p. 85. 
 
168 
 
 DESCRIPTIVE ANATOMY. 
 
 Their anterior half is often detached from i he posterior, and the 
 whole crystalinc lens seems more or less evidently divided into an 
 anterior and a posterior half by a fissure which extends from the cir- 
 cumference to the centre. 
 
 The layers which compose the crystalinc lens are united by fibres 
 which extend from one to another. They are likewise composed of 
 fibres, the direction of which is parallel to their proper longitudinal 
 diameter. These fibres consequently commence at the centre of the 
 crystaline lens. Thus the tissue of the crystalinc lens is lamellar and 
 fibrous.(l) 
 
 Between these layers is a diaphanous humor, more abundant on the 
 outside than on the inside, which seems like that existing between the 
 lens and its capsule. 
 
 The segments of the crystaline lens in respect to their thickness 
 and their lamellar texture, are more distinct on its outer than on its 
 inner side. The fibrous texture is more evident in the inner part. 
 
 § 2005. The crystalinc lens almost entirely dissolves in water, ex 
 cepting a small quantity of a transparent and insoluble membranous 
 substance. Berzelius has found in it of one hundred parts: of water, 
 58.0 ; of a peculiar substance, 35.9 ; of hydrochlorates, lactates, and 
 animal matter, all soluble in alcohol, 2.4 ; of animal matter, soluble 
 only in water, with some phosphates, 1.3; of insoluble membranous 
 residue, 2.4. (2) 
 
 It is particularly worthy of notice that, excepting the color, the pe- 
 culiar substance which is coagulated by heat is perfectly similar in 
 chemical composition to the coloring matter of the blood. It contains 
 a little iron, while there is much carbon and iron in the pigment. The 
 blood then seems to be decomposed, as the aqueous and vitreous hu- 
 mors contain only the water which contributed to form it. Hence why 
 these two humors do not coagulate. 
 
 § 2006. The crystaline ccupsulc receives blood from the central artery 
 of the retina and the -vessels of the ciliary body. (3) 
 
 The central artery of the retina is distributed in great part by its 
 anterior branches on the posterior face of the capsule, for its last rami- 
 fications on arriving at the anterior edge of the vitreous body are re- 
 flected from without inward, and converge towards the centre of this 
 face ; but there are also several small ones which pass on the ex- 
 ternal edge of the capsule and go on its anterior face. 
 
 The arteries which arise from the anterior edge of the ciliary body 
 go exclusively on the anterior face of the crystaline capsule, and anas 
 
 (1) Berzelius supposes, but wrongly, that it also includes a membrane divided into 
 
 several compartments by internal septa, like those of the vitreous body ( Djurkemi , 
 vol. ii., p. 212). Finally, he observes, and justly, that this body cannot be referred 
 to the class of fibrous organs, as has been done to a certain extent by Mayer ( lieber 
 Histologie, p. 13), and by Heusingcr unrestrictedly {Histologie, part i, ; p, 42), since it 
 is entirely soluble in water. F. T. 
 
 (2) Loc. cil., p. 254. 
 
 (3) J. G Walter, De venir oçxtfi cl artériel centraii rclince, Berlin, 1T78. 
 
OF THE EVE 
 
 1G9 
 
 tomose there with the ramifications of the central artery of the retina. 
 In the fetus they send off from behind forward numerous ramuscules, 
 which are distributed on the posterior face of the pupillary membrane. 
 
 The vessels of the crystaline capsule and those of the pupillary 
 membrane always correspond remarkably in regard to their arrange- 
 ment and developmental ) 
 
 Finally the arteries of the capsule, especially those which arise from 
 the central artery of the retina, send several very minute twigs to the 
 lens which are distributed between its laminæ, so that the latter are 
 not nourished, at least entirely, by absorbing the liquid which sur- 
 rounds them. 
 
 Veins have not yet been strictly demonstrated in the crystaline cap- 
 sule, although they are known to proceed on its posterior face. The 
 latter empty into the veins of the choroid membrane, with which they 
 open on the external face of the ciliary lamina. (2) 
 
 Farther, in the normal state there is no red blood in the crystaline 
 lens or in the vitreous body. 
 
 We have not as yet discovered nerves in the crystaline lens nor in 
 its capsule, 
 
 B. AQUEOUS HUMOR. 
 
 § 2007. The aqueous humor of the eye ( humor aqueus) is a per- 
 fectly clear and transparent fluid which fills the two chambers. It is 
 composed almost entirely of water, (3) and is formed very rapidly. 
 
 ARTICLE THIRD 
 
 MUSCLES OF THE EVE. 
 
 § 2008. The eye is moved by six muscles. (4) Five of them arise 
 
 from the floor of the orbit ; the sixth comes from the lower part of its 
 anterior circumference. They surround the sclerotica, to which they 
 are attached and blend with it. (5) 
 
 (1) Hunter, in the Med. commentaries , London, 1762, p. 63, note. 
 
 (2) Walter, loc. cit., p. 28, 29. 
 
 (3) Berzelius ( Djurkemi, vol. ii., p, 208) has found, in one hundred parte, 98.10 of 
 water; some marks of albumen; 1.16 of hydrochlorates and lactates; and 0.75 oi 
 animal substance, soluble only in water. 
 
 (4) C. Bell, Recherches sur les mouvemens de l’œil et sur les usages des muscles 
 et des nerfs renfermes dans l’orbite ; in the Archiv, sén, de méd., vol vi , n 250 
 and 445. 
 
 (5) The aponeuroses which terminate them have been considered, but wrongly, as 
 a special membrane between the conjunctiva and sclerotica. (É. Home and P 
 Smith, Philos ; irons., 1795, no, i., p. 1Î, and no. xii., p, 262.) 
 
170 
 
 DESCRIPTIVE ANATOMY 
 
 They are divided according to their direction into straight and 
 oblique. The first are four in number There are two oblique mus- 
 cles. 
 
 I STRAIGHT MUSCLES. 
 
 § 2009. The straight muscles of the eye (M. recti Irnlbi oculi ) are 
 the superior , the internal, the external, and the inferior ; but beside 
 these names, founded on the changes they cause in the situation of the 
 globe of the eye when they contract, they have received others also, 
 drawn from the expression they give to the countenance, and from 
 the state of the mind which their action designates. 
 
 Their common character, is that they all arise from the floor of the 
 orbit by a short and thin tendon, and are attached to the anterior part 
 of the circumference of the sclerotica by another thin but broad tendon. 
 
 I. RECTUS SUPERIOR. 
 
 § 2010. The recites superior muscle (M. rectus oculi superior, s, 
 attollens, s. superbus), arises from the periosteum of the orbit, between 
 the optic foramen and the upper sphenoidal fissure, between the upper 
 part of the optic foramen and the sheath of the optic nerve, directly 
 below the levator palpebræ superioris muscle. It goes forward, rest- 
 ing on the upper part of the globe of the eye, becomes broader and 
 thicker from behind forward, and is attached by a broad but thin 
 tendon, to the sclerotica alone, two lines above the transparent cornea. 
 
 It is the second in size among the straight muscles of the eye. It 
 is a little shorter but much thinner than the following muscle. 
 
 It raises the eye. 
 
 II. COMMON TENDON OF THE OTHER THREE STRAIGHT MUSCLES OF THE EVE. 
 
 § 201 1 . The other three straight muscles of the eye arise partly by a 
 common tendon, or from a ligament which extends from the inner ex- 
 tremity of the sphenoidal fissure, to two or three lines before this point 
 
 III. RECTUS EXTERNUS. 
 
 § 2012. The rectus externus muscle (M. oculi rectus externus, s. ab 
 duccns, s. indignatorius ) arises by two heads. The lower, the larger, 
 comes from the external face of the common tendon, where it adheres 
 very intimately to the tendon of the rectus inferior muscle. The up- 
 per is much smaller, and is blended with the tendon of the rectus 
 superior muscle, arises from the portion of the sphenoid bone comprised 
 between the optic foramen and the commencement of the sphenoidal 
 fissure. Hence, the muscle proceeds along the centre of the external 
 
OF THE EYE, 
 
 171 
 
 wall of the orbit, situated on the periosteum, and is attached by a thin 
 tendon to the outer part of the edge of the sclerotica, some lines from 
 the edge of the transparent cornea. It is broader at its centre than in 
 the rest of its course, and is much flatter and thinner from without in- 
 ward than from above downward. 
 
 It is the largest, and particularly the thickest of the straight muscles 
 of the eye : it is a little shorter, but infinitely thicker than the obliquus 
 superior muscle. 
 
 It carries the eye outward, and acts when looking to the outside. 
 
 IV. RECTUS INFERIOR. 
 
 2013. The rectus inferior or the depressor oculi muscle (J\I. rectus 
 oculi inferior , s. deprimens, s. Iiumilis), unites with the lower head of 
 the rectus externus and rectus internus muscles, arises from the com- 
 mon tendon, and never comes from the sheath of theoptic nerve. 
 It goes from before backward, and from above downward under the 
 optic nerve, and is attached to the sclerotica. 
 
 It is the third in size of the recti muscles of the eye, but it is thinner 
 and shorter than the rectus internus muscle. 
 
 It depresses the eye. 
 
 V. RECTUS INTERNUS. 
 
 § 2014. The rectus internus muscle (JMT. rectus oculi internus , s. ad- 
 ducens , s. amatorius , s. bibitorius) arises by two heads. The inferior 
 or external comes from the upper and internal part of the common 
 tendon. The superior or internal is the larger, and arises from the 
 inner part of the sheath of the optic nerve. This latter blends with 
 the origins of the rectus superior and the levator palpebræ superioris 
 muscles. Thence the muscle goes inward and forward, along the 
 inner wall of the orbit, from which it is separated by a layer of fat. Its 
 short and thin tendon is attached to the inner part of the circumference 
 of the sclerotica. 
 
 It is the shortest of the four recti muscles, but it is thicker than the 
 superior and inferior. 
 
 It draws the eye inward. 
 
 II. OBLIQ.UE MUSCLES. 
 
 ' § 2015. The oblique muscles of the eye (JVf. obliqui bulbi oculi) are 
 
 distinguished into superior and inferior. They turn the globe of the 
 eye on its longitudinal axis in opposite directions. 
 
 I. OBLIQUUS SUPERIOR. 
 
 § 2016. The obliquus superior muscle, grand oblique , Ch. (JVf, 
 oculi obliquus superior , s, longus , s. irochharis , pafhetims), arises from 
 
172 
 
 DESCRIPTIVE ANATOMY. 
 
 the posterior part of ihc inner face of the internal wall of the orbit, 
 belorc the optic foramen, and also arises from the sheath of the optic 
 nerve by a thin and short tendon Thence it goes upward and forward 
 along the upper edge of the internal wall of the orbit, and becomes 
 near its anterior extremity, a long rounded tendon. 
 
 This tendon immediately enters into a small cartilaginous layei 
 about two lines long and broad, which is reflected on itself, and thus 
 represents a semicanal, open upward, forward, and backward, and forms 
 a pulley, the anterior edge of which becomes a pointed prominence, 
 while the upper edges arc attached by ligamentous fibres to the upper 
 part of the internal wall of the orbit. 
 
 The tendon is kept in this pully by a loose and movable cellular 
 tissue Its direction changes, so that on emerging it descends horn 
 before backward, and from within outward. It then becomes broader, 
 and is attached to the inner and upper part of the sclerotica, on the 
 inside of the tendon of the rectus superior muscle w flieh partially 
 covers it. 
 
 This muscle is the longest and thinnest muscle of the eye. 
 
 It draws the eye forward, inward, and upward 
 
 Sometimes, but rarely, it is more or less perfectly double. 
 
 II. OBLIQUUS INFEKÏOK. 
 
 2017 . The obliquus inferior muscle, petti oblique , Ch (M. oculi 
 obliquus inferior ), the shortest muscle of the eye, differs from the other 
 muscles in its origin and direction. It arises by a short tendon from 
 the inner extremity of the lower edge of the orbit, goes upward and 
 outward, then becomes a short and broad tendon, which ascends below 
 the anterior part of the rectus extemus muscle, and between the 
 muscle and the globe of the eye, and is attached to the sclerotica, some 
 distance behind the tendons of the recti muscles, between that of the 
 extemus and that of the superior. 
 
 It rotates the eye on its axis, first outward, then downward, and 
 finally inward. It also draws the eye a little forward. 
 
 A It T I V LE FOURT II. 
 
 FUNCTIONS OF THE EYE. 
 
 §2018. The eye represents ah optical instrumental) composed of 
 several transparent substances situated successively horn without in- 
 ti) G. G. Ploucqùct, Dits, sislens momenta quudam physiologica circa visum, 
 Tubingen, 1797. — J. Campbell, iu Thomson, Annals of philosophy, vol. x. p. 1 7—29.— 
 Dunglison, ibid., no. GO. p. 432.— T. Young, Of the mechanism of the eye; in the 
 Phil. Irans., 1801, p. 81. — E. Hall, iu the Journal of sciences and the arts , no. x. p. 
 249-257.— A. Horn, The scat of vision determined , London, 1815. — M. T. Muhlibach, 
 InmdsUio de visûs sensu, Vienna, 1816..— J. Purkinje, Beytrage sur Kenntniss des 
 lichens in siihjehtircr Hinsicht, Prague; 1810 Troxler, in Himly, Ophthal Bibi, 
 
ÖF THE EVE. 
 
 173 
 
 ward, which differ in density, although in all, this is greater than that 
 of the atmosphere. The rays of light which enter it gradually con- 
 verge on- passing through it, so as to form but one fasciculus, which 
 paints the image of the object at the bottom of the eye on the retina. 
 The impression upon this membrane extends to the brain along the 
 optic nerve, and there produces' the sensation of sight. 
 
 The transparency of the centres which form the eye, the sensibility 
 of the retina, and the conducting power in the optic nerve, are then 
 the principal conditions necessary to sight. The opacity of one or 
 several of the centres which concur to form the eye, the paralysis of 
 the retina and of the optic nerve, the alterations in the texture of all these 
 parts, the abnormal productions which are developed within or around 
 them, consequently alter or destroy the sense of vision. The globular 
 form of the eye favors the refraction of rays of light. Hence, why the 
 general form of the eye and of its different parts very much influence 
 the distance at which objects are seen clearly. When the eye is very 
 convex, the rays of light are forcibly refracted, and we cannot discern 
 objects which are near (myopia). When the eye is flattened the re- 
 fraction is. less, and only- distant objects are seen clearly ( presbytia , 
 presbyopia). Hence, why myopia belongs only to youth and infancy, 
 and presbytia to old age. The eye possesses also the power of modify- 
 ing its form, the relations of its constituent parts, its situation, and its 
 direction, either to obtain a distinct view of objects situated at different 
 distances, in a ray of a certain breadth, or to see without moving the 
 head or body, those which occupy the different points of a portion of a 
 surrounding sphere. This last effect is produced by the action of the 
 six muscles of the eye. The other depends on the contraction of the 
 muscles, partly on the modifications in the secretion and excretion of 
 the humors of the eye, partly on the action of tjie ciliary body, since 
 these three causes united change the curve of the transparent cornea 
 and the crystaline lens, as also the situation of this latter in regard to the 
 cornea and the base of the eye.(l) The dark color of the pigment 
 tempers the violence of the impression which the light would other- 
 wise cause on the retina, which is extremely sensible, (2) for this black 
 
 vol. i. p. 21—99. — Meyer, Das Auge, ein Hohlspiegel ; in Deutsches Archiv fur die 
 Physiologic, vol. v. p. 54. — M. G. Plagge, Neue physikalische Ansicht des Sehens: 
 ibid., vol. v. p. 97. — Id. Neuer Bcy trag zàr Lehre von Sehen: ibid., vol. vii. p. 213. — 
 E. E. Rœdenbeck, Quœdam ad Iheoriam visus pertinentia, Berlin, 1822. 
 
 (1) Simonoff has concluded from calculations, that it is not necessary to suppose 
 
 the crystaline lens displaced, and that the clearness of vision of objects situated lrom 
 two hundred and fifty millimetres to any distance, however great, depends only on 
 their apparent diameters, and on the transparency of the air between. ( Réfutation 
 de lapretendue nécessité mathématique du déplacement du cristallin pour conserver 
 constante la distance focale de l'œil: in the Journ. de physiol, experirn., vol. iv. p. 
 260.) F. T. 
 
 (2) The sensibility of the retina is extreme only in regard to light. Magendie has 
 
 determined that but a slight sensation is produced when this membrane is touched 
 by a needle, and that even on scraping it, the pain is but slight, and not to be com- 
 pared with that caused by pricking the surface of the eye. (De l'influence de La 
 cinquième paire sur la nutrition cl les fondions de l’œil: in the Journ. dephys. expér., 
 vol. iv. p. 176.) This physiologist lias also determined that the section of the two 
 nerves ot the fifth pair causes the loss of sight. F. T. 
 
 Vol. Ill 23 
 
174 
 
 DKSCRIPTJVE ANATOMS. 
 
 layer absorbs a part of toe rays of light. This is the real function of 
 the pigment, since vision is weak and imperfect when it has not its 
 usual color. The iris also serves to moderate the intensity of the light 
 which enters the eye, since this membrane dilates, and thus con- 
 tracts the pupil, when the light is very vivid, or when we look at an 
 object near, while it contracts and thus enlarges the pupil, when the 
 light is weak, or when we look at rather a distant object. 
 
 ARTICLE FIFTH. 
 
 DIFFERENCES IN THE EYE DEPENDING ON DEVELOPMENT. 
 
 § 2019. The eye differs considerably at different periods of life, (1) 
 in respect to the existence, proportional volume, and form of the 
 whole eye or of its parts. 
 
 The eye appears very early. It is visible at the fourth week of 
 pregnancy as a black spot. 
 
 But at this period the globe of the eye is still exposed, for the eye- 
 lids do not exist. They begin to appear during the tenth week, in 
 the form of narrow bursæ, which gradually enlarge. After about the 
 twelfth week their edges touch, and they remain closed as in sleep 
 until birth. 
 
 The lachrymal puncta, and generally all the lachrymal apparatus, 
 as also the Meibomian glands, are proportionally more developed 
 during the early periods of life than subsequently. 
 
 The eye is proportionally larger in the early periods of life than af- 
 terward. The two external membranes, the sclerotica, especially 
 its posterior part, and the transparent cornea, are proportionally 
 thicker. This character belongs especially to the cornea, which is twice 
 as thick as it is in the adult, from a considerable quantity of reddish se- 
 rum existing between its layers, in the full grown fetus, so that its an- 
 terior face is nearly plane, and the posterior touches the iris. It is also 
 less transparent than subsequently. In old age it becomes planer, 
 harder, denser, and more solid : we also see developed, in old men, a 
 nebulum, which extends from the edge to the centre ( geronlonoxon , s, 
 arcus senilis), which undoubtedly depends on the slowness with which 
 the substance is renewed, whence the fluids have more tendency to 
 coagulate ; this resembles those ossifications which supervene in old 
 age in other parts of the body. 
 
 The choroid membrane also is proportionally thicker, and the black 
 pigment which covers.it has a deeper tint. 
 
 The pigment begins to appear very early at- the fifth month of preg- 
 nancy. But before birth it is less colored than in the adult : it adheres 
 less to the choroid membrane and the iris : it does not exist on the outer 
 face of the first of these two membranes, so that the intensity of its 
 
 (1) J. G. Brendel, De fabric a oculiin f&bihus abortivis observala, Gottingen, 1752. 
 
OF THE EVE. 
 
 175 
 
 color and even its quantity seems to depend on the action of the light. 
 In subjects al an advanced age, its color changes like the hair, and it is 
 lighter, but the cornea and crystaline lens loose their transparency in 
 the same proportion. The deeper color of the pigment in youth, 
 depends partly on the fact, that the globules are nearer each other, 
 partly also on their being blacker at this period. They are also 
 softer in young people, and hence they lose their form, and are de- 
 tached from each other by drying. In the full grown fetus, the white 
 cellular tissue existing between the vessels of the choroid membrane, 
 contains no iron, while there is much in that , colored black found in the 
 same place in the adult. (1) 
 
 The iris is one of the parts of the ej'e which varies the most at 
 different periods ; the greatest change is the closing of the pupil by 
 the pupillary membrane ( membrana pvpillaris ), or the membrane of 
 Wachendorff, in honor of its discoverer. (2) 
 
 The external edge of this membrane arises from the inner edge of 
 the iris. It fills the whole pupil, so as to separate completely the pos- 
 terior from the anterior chamber. It is a very tense, rather solid, but 
 very delicate, thin, and transparent membrane, so that when its blood- 
 vessels are injected, they cannot be perceived until the eye is hardened 
 by immersion in alcohol. It is composed of two layers, the anterior of 
 which is a continuation of the serous membrane which lines the an- 
 terior face of the iris ; and the posterior is very vascular, and is con- 
 tinuous -with the posterior face of the his. We have never known it 
 to be covered posteriorly with a fibrous mucus, as Haller and Wachen- 
 dorff assert. 
 
 Some of its arteries arise : 
 
 1st. From those which form the inner circle of the iris : they radi- 
 ate from this circle towards the centre of the pupillary membrane, 
 where anastomosing with the adjacent vessels, and not with those op- 
 posite, they terminate and leave a small space in the centre of the 
 membrane. They also anastomose with each other frequently in their 
 course. 
 
 2d. Other branches arise directly from the long ciliary arteries, pass 
 on the iris, and go directly to the pupillary membrane, where they 
 anastomose with the preceding. 
 
 3d. Others still smaller arise from the vessels of the anterior face 
 and from the greater edge of the crystaline lens, and are distributed 
 principally on the posterior face of the pupillary membrane. 
 
 (1) Coli, in Mondini, loc. cit., p. 17. 
 
 (2) E. J. Wachendorff, in Comm. J\or., 1740. Hebd. 18. p. 137. — Haller, De nova 
 tunica pupillam fœtus clauder.ti ; in the Act. Upsdl., 1742, and Op. min., vol. i. p. 
 329.— J. G. Rœderer, Defœtu perfecta , Strasburg-, 1750, § xxvi.— B. S. Albinus, De 
 membrana pupillam Inf antis nuper natiprœcludente : in Anrot., acad. 1. i. cap. vii. 
 — Vicq-d’Azyr, Sur la membrane pupillaire du fœtus : in Hist, de la soc. roy. de méd., 
 ann. 1777 and 1778, p. 257. — J. F. Blumenbach, De oçulis leucœthiopum et motu 
 iridis, Gottingen, 1786. — H. A. Wrisberg, De membrana fœtus pupillari: in Non. 
 comm. Gott., vol. ii. and in Syllog. comm. I. — Edwards, Sur la structure de l'œil .- in the 
 Bull, delà soc. philomatique, 1814, p. 21. — J. Cloquet, Mémoire sur la membrane 
 pupillaire et sur la formation du petit cercle artériel de Viris, Paris, 1818.— Portai, 
 Sur la membrane pupillaire : in Mémoires du Museum, vol; iv. p. 457. 
 
176 
 
 DESCRIPTIVE ANATOMY. 
 
 Veins have not been demonstrated with certainty on the posterior 
 face of the pupillary membrane. 
 
 The pupillary membrane passes through several periods of develop- 
 ment. Its primitive form is not known, nor the manner in which it is 
 produced, nor the period of its first appearance. 
 
 According to Wrisberg it is not perceived distinctly before the third 
 month of pregnancy. It is gelatinous and destitute of vessels until the 
 fifth month, but at this period it becomes • firmer and vessels are de- 
 veloped in it. Perhaps, however, in the early periods of life it is 
 greater in proportion to the rest of the iris, for the development of the 
 latter membrane begins at its external edge. 
 
 It is most evident at the seventh month of pregnancy. It begins to 
 disappear at the eighth month from the centre to the edge, that is, from 
 the portion which has no vessels. In the full-grown fetus the only 
 vestiges of this membrane are some small loose flocculæ attached to 
 the edge of the pupil. 
 
 It generalty disappears much sooner in animals bom with the faculty 
 of seeing than in those born blind ; it continues in these latter also as 
 long as the eyelids remain closed.(l) The vessels are not destroyed 
 with it. They contract from the centre toward the circumference ; 
 their arches diminish, and they are finally adapted to the inner edge of 
 the ins, where they form the small arterial circle, which does not exist 
 so long as the pupillary membrane continues. (2) 
 
 Although this membrane perfectly separates the two chambers, each 
 cavity constantly incloses an aqueous humor, which does not exist in 
 the posterior alone as Edwards(3) and Ribes(4) assert. We have 
 demonstrated this perfectly, (5) and Cloquet after us. (6) 
 
 A very curious periodical difference of the iris is a want of continuity 
 of its circle, which is observed during the early periods of pregnancy, 
 and which is very sensible at its inner part until about the seventh week. 
 
 The retina is much thicker in the early periods of life than after- 
 ward. This thickness does not depend on the greater development of 
 its inner layer ; and so far from the medullary layer being propor- 
 tionally thinner at this period, so far from possessing at that time less 
 medullary matter, as has been assorted, (7) this substance on the con- 
 trary is more abundant, and hence the increase of thickness presented 
 
 (1) Meckel, lieber die Dauer der pupülar Membran ; in the Deutsches Archiv, 
 für die Physiologie , vol. i., p. 430 ; vol. ii.. p. 136. 
 
 (2) . In demonstrating- this fact J. Cloquet has verified a conjecture of Blumen- 
 bach : E jusque (memijranœ puvillaris) vasorum elliplici arcus scnsim scnsimquc 
 reirahuntur, tuneque, ni graviter fall.or, annulum iridis inlcriorcm cjjiciunt, cujus 
 ccrte ante eum terminum nullum in Jcetuum oculis vestigium reperire potui. (Inst, 
 physiol., 1787, p. 208.) 
 
 S Loc. cit. 
 
 Loc. cit. 
 
 (5) Loc. cit. 
 
 (6) Loc. cit. 
 
 (7) Brandis, Pathologic , Hamburgh, 1808, p. 241. 
 
OF THE ETE. 
 
 177 
 
 by the membrane. In old men the retina becomes extremely thin, but 
 also more firm and resisting. 
 
 We already perceive its fold in the sixth month of pregnancy, and 
 even in the full-grown fetus it is greater than in the adult. The thin 
 place is visible, but the yellow tint does not appear till some time after 
 birth. It gradually becomes more intense, but turns paler as age ad- 
 vances. It would seem that the fold diminished regularly and finally dis- 
 appeared entirely. The less marked development in this region in old 
 men is about in a direct ratio with the loss of transparency which gra- 
 dually takes place in the cornea. The aqueous humor is turbid in 
 the fetus. It becomes perfectly transparent during the first few weeks 
 after birth. 
 
 The crystaline lens also is much more convex in the fetus and in 
 infancy than in the adult. At first it projects through the pupil, and 
 thus pushes the iris before it, so that it is separated from the transpa- 
 rent cornea only by this membrane, being situated in its special groove. 
 In this respect and in the absence of the eyelids, the eye of the fetus 
 resembles that of fishes. 
 
 This arrangement, added to the great thickness of the transparent 
 cornea, causes the chambers to be smaller and the aqueous humor less 
 abundant than in the adult. All the humors, however, excepting the 
 aqueous, are more abundant in youth than subsequently, whence it 
 follows that the whole eye, and particularly the cornea, projects more, 
 while as age advances, the eye slightly collapses and the transparent 
 cornea particularly flattens. 
 
 As age advances the crystaline lens assumes more consistence, and 
 also becomes yellowish on tearing the centre, so that this tint is found 
 generally in persons in advanced life. The same is true of the humor 
 of Morgagni. At the same time this humor and that which fills the 
 two chambers are slightly turbid, which is sometimes the case also 
 with the vitreous humor. 
 
 ARTICLE SIXTH. 
 
 EYE IN THE ABNORMAL STATE. 
 
 § 2020. The situation of the eye exposing it to the action of all 
 external causes of injury, and its extreme sensibility rendering it liable 
 to be diseased from the influence of these causes, or to participate in 
 the affections of other parts of the body, and finally its very complex 
 structure, singularly multiply the number of the anomalies it may pre- 
 sent ; these anomalies are more easily perceived even during life than in 
 
178 
 
 DESORITTIVE ANATOMY. 
 
 most other organs, on account of its situation and the transparency of 
 its parts.(l) 
 
 I. DEVIATIONS OF FORMATION. 
 
 § 2021. Here, as in other organs of the body, the primitive devia- 
 tions of formation are the most remarkable in respect to the conse- 
 quences deduced from them in regard to the general theory of organi- 
 zation. 
 
 A. PRIMITIVE DEVIATIONS OF FORMATION. 
 
 § 2022. I. The primitive deviations of formation in respect to quan- 
 tity consist essentially in too slight an action of the formative power. 
 They are : 
 
 1st. Deviations in formation from defect in development. Here we 
 may mention : 
 
 a. The absence of the eye or of some of its parts. Here, as in the 
 other organs, the conditions are not always exactly the same. In one 
 case observed by Malacarne,(2) the optic beds and nerves, the common 
 and the superior motor nerves, the globe of the eye, its muscles, the 
 caruncula lachrymalis, and the optic foramina, were all deficient. The 
 globe of the eye was replaced by a hard mass. The lachrymal appa- 
 ratus and the eyelids were perfectly developed. 
 
 In another case(3) the globe of the eye and the optic nerve as far 
 as its bed and the optic foramen were deficient, but the accessory 
 nerves and the lachrymal gland were present. 
 
 b. Smallness of the organ. 
 
 (1) Beside the treatises on the diseases of the eyes, among' which we may mention 
 particularly those of Maître Jean, Taylor, Janin, Rowley, Beer, Scarpa, Schmidt, 
 and Himly, beside also the works already mentioned, because their authors have 
 examined it both in the state of health and that of disease, we shall mention, on the 
 pathological anatomy of this organ, the following: J. C. Sybel, Diss. de quibusdam 
 materiœ et formas oculi aberrationibus a statu normali , Halle, 1798. — J. Wardrop, 
 Essays on the morbid anatomy of the human eye , London, 1818. — Farre, A treatise 
 on some 'practical points relating to the diseases of the eye , by the late Conningham 
 Saunders, to which are added , &c., London, 1816. — Demours, Traité des maladies 
 des yeux, Paris, 1818. — Helling, Praktisches Handbuch der Augenkrankheiten, Ber- 
 lin, 1721. — Baratta, Osservazioni pratiche suite principali malatti e degli occhi , 
 Milan, 1821. — L. M. Mejra, Tratado tcorico y practico sobre las infermidades de los 
 ojos, Orea, 1820. — B. Travers, Synopsis of the diseases of the eye, London, 1820. — 
 J. Vetch, A practical treatise on the diseases of the eye, London, 1820. — Consult also, 
 on the pathological anatomy of the lachrymal organ, J. A. Schmidt, Ueber die 
 Krankheiten des Thranenorgans, Vienna, 1803. — C. H. Tode, Des maladies de la 
 glpnde lacrymale ; in the Mélanges de chirurgie étrangère, Geneva, 1824, p. 391. 
 
 (2) ’Isistemi, Padua, 1803. 
 
 (3) Weidele, in Himly, Ophthalmolog. Bibliothek., vol. iii., p. 2, p. 170. 
 
OF THE EYE, 
 
 179 
 
 c. The abnormal continuance of parts primarily existing, particu- 
 larly of the pupillary membrane.(l) 
 
 d. The adhesion of the two eyes. It is rather a general law in this 
 case that the eye formed by the fusion of the two in one is situated 
 directly on the median line, and is symmetrical in its structure. 
 
 2d. Deviations in formation or in regard to quantity in an opposite 
 sense when the body and head are normal, are very rare, and perhaps 
 have never been observed. 
 
 II. The deviations of formation in respect to quality are also rare. 
 They affect most frequently the form of the iris and that of the pupil, 
 which then is usually less round and most commonly perpendicular, 
 rarely horizontal. This anomaly, often peculiar to certain families, 
 and hereditary, is always curious as an analogy with animals. (2) 
 The iris is rarely enlarged so much outward that the pupil does not 
 correspond to the axis of the eye, being carried much more inward. (3) 
 
 The transparent cornea is sometimes conical ( staplujloma conoides ), 
 and at the same time it is more or less thin. This state is its greatest 
 degree of convexity, whence this includes also the greatest degree of 
 myopia. 
 
 Sometimes the cornea presents an opposite arrangement, being not 
 sufficiently convex or entirely plane. 
 
 B. ACCIDENTAL DEVIATIONS OF FORMATION. 
 
 § 2023. The accidental deviations of formation are more common 
 than the preceding and very various, but they depend most generally 
 on a previous alteration in the chemical composition, and the texture 
 of the parts is then more or less changed. The principal deviations of 
 this kind are : 
 
 1st. Absence. Here we may mention the loss of the eyelashes and 
 eyebrows, caused by the destruction of their bulbs, by inflammations 
 and ulcerations of the eyelids. 
 
 2d. Alterations in size. 
 
 a. Smallness. In blindness, the whole eye or at least some of its 
 parts, particularly the optic nerve and the retina, are often wasted. 
 
 We have found several times in subjects who have been blind for a 
 long time, that the retina was unusually thin and destitute of medul- 
 lary substance in séveral parts of its extent, this substance existing 
 at intervals. 
 
 When the power of vision is more or less diminished, the yellow spot 
 also returns to the degree of color it presented before the eye was 
 exposed to the light, for in this case its tint is more or less enfeebled. 
 
 (1) See our Randbuch der pathologischen Anatomie , vol. i., p. 396. 
 
 (2) See our Handbuch der pathologischen Anatomie , vol. ii., p. 158. 
 
 (3) Demours, tab. lxiv., fig. 1. , 
 
löO 
 
 DEâCltlPTIVE ANATOMT. 
 
 At tho samo time the fold is more ov less effaced.(l) Sometimes in 
 subjects affected with amaurosis the retina presents in this place black 
 spots ;(2) but only the diseased eye undergoes this change ; the fold 
 and the spot are on the contrary sometimes more sensible in that of 
 the -healthy side ;(3) the optic nerve is even sometimes larger than in 
 the normal state. (4) 
 
 The optic nerve is generally thinner and gray like horn. 
 
 The transparent cornea sometimes becomes much flatter after dis- 
 eases of long duration and excessive evacuations. 
 
 The crystaline lens, left in the eye after separating it from its cap- 
 sule partially or wholly, disappears very rapidly. At the end of a few 
 years there is hardly a piece as large as a pin-head.(5) 
 
 b. Enlargement. The eye sometimes enlarges so mttch from dropsy 
 ( hydrophtlialmus ), that it projects on the outside of the orbit. This 
 dropsy is situated primitively in the vitreous body ; but it extends to 
 every part, so that in some subjects we find considerable serum be- 
 tween the ciystaline lens and the vitreous body. (6) Scarpa states 
 that dropsy of the posterior part of the eye is usually attended with an 
 increased secretion out of the vitreous body, as we have found several 
 times on the inside of the choroid membrane and of the retina a great 
 quantity of limpid serum, in which is a cord directed from before back- 
 ward, formed by the morbid alteration of the vitreous body and re- 
 tina. (7) In this case probably the serum came from the serous mem- 
 brane discovered, by Jacob. 
 
 A partial enlargement of the eye, often met with, forms staphy- 
 loma,(8) a greater or less thickening of the transparent cornea, which 
 causes the falling of this membrane, attended with its opacity, and 
 depends on a previous inflammation situated in it. In this case the 
 cornea generally adheres to the iris. The increase with the thinness 
 of the sclerotica, which is much rarer and is also termed staphyloma , 
 appears under the form of bluish elevations, the color of which depends 
 on the varicose state of the vessels of the choroid membrane. It su- 
 pervenes principally on the circumference of the transparent cornea 
 after arthritic ophthalmia, but is observed more rarely at the posterior 
 part of the sclerotica.(9) 
 
 The lachrymal sac is more or less distended after inflammation of 
 the lachrymal passages. 
 
 3d. Solutions of continuity. 
 
 (1) Michaelis, loc. cit., p. 8. — Reil, loc. cit., p. 472. — Lcveillé, in Wenzel, De penit. 
 struct, cereb., p. 167. 
 
 (2) Wenzci, in Michaelis, loc. cit ., p. 9. 
 
 (3) Michaelis, loc. cit., p. 3. 
 
 (4) Wenzel, De pen. struct, ccrcb., no. xi. 
 
 (5) Scarpa, Malattic degli occhi, Pavia, 1801, p. 183. 
 
 (61 Ribes, loc. cit. 
 
 (7) Malattic degli occhi, p, 230. 
 
 (8) J- L. Friedrich, Diss. dc stdphylomate, lierlin, 1821. 
 
 (9) Loc. cit., tab. ii., fig. 10.— Poraours, loc. cit., tab. lxiv., fig. 3. 
 
OF THE EYE. 
 
 181 
 
 a. Abnormal union. This anomaly is rather common, and always 
 results from inflammation. 
 
 When the conjunctiva has been violently inflamed and neglected, 
 the eyelids join either to the anterior face of the eye ( symblepharon ), or 
 with each other ( ancyloblepharon ). Sometimes these two kinds of 
 adhesion take place simultaneously. The parts fused are sometimes 
 nearer each other, and are often united by a greater or less number 
 of accidental membranes which vary in length. Sometimes they 
 adhere at birth. 
 
 After inflammations of the iris, the pupil adheres ( synizesis ), or the 
 anterior face of the iris imites to the posterior face of the transparent 
 cornea, or finally the posterior to the anterior face of the crystaline 
 capsule (synechia), by an effusion of albumen which coagulates, and 
 which is sometimes distinct from the other parts in the form of a 
 membrane. 
 
 The obliteration of the ducts of the lachrymal gland is caused by 
 external lesions on the outside of the .eye. It depends on inflammation 
 and ulceration, like the contractions of the excretory channels of the 
 lachrymal humor. 
 
 The shrinking (myosis) and the immobility of the pupil, observed 
 after inflammations of the eye, very probably result from an effusion 
 of albumen into its substance. 
 
 b. Abnormal separation. The parts of the eye rarely present this 
 anomaly except from external injuries. We however must arrange 
 here the detachment of the crystaline lens observed after violent ce- 
 phalagia and the fall of this lens into the anterior chamber across the 
 pupil, which results from the percussion or commotion of the eye.(l) 
 
 Ulcers produce especially in the transparent cornea, sometimes also 
 in the iris, solutions of continuity, which, when situated in the first of 
 these two membranes, cause the effusion of the aqueous humor and 
 the falling of the iris. The iris is frequently detached in a greater or 
 less extent from the sclerotica by a powerful shock : two pupils might 
 then be said to exist. We must refer also to this head the abnormal 
 enlargement of the openings, for instance, the pupil (mydriasis). 
 
 Ruptures and other lesions of one or more excretory passages of the 
 lachrymal gland form the lachrymal tumor (dacryops), the accumula- 
 tion of tears between the conjunctiva and the globe of the eye, or a too 
 great effusion of this fluid. 
 
 Suppuration of the lachrymal' sac frequently destroys a portion of 
 it and its communication with the exterior, and thus produces fistula 
 lachrymalis. 
 
 4th. Deviations in situation. These anomalies extend to the whole 
 eye, or affect some of its constituent parts only. The globe of the 
 eye may be pushed out of the orbit by tumors in its cavity ( exoph- 
 thalmia' ), and may fall forward from the injury or the paralysis of its 
 
 (1) Fribault, Observai ion sur un cristallin qui a passé par le pupille dans la 
 chambre antérieure de l'œil ; in the Journ. de méd.. vol. lix , p. 72. 
 
 Vol 111 24 
 
182 
 
 DESCRIPTIVE ANATOMY 
 
 muscles ( ophthalmo ptosis ), which changes more or less the situation 
 of the eyelids, and causes them to turn over outward. 
 
 The direction of the eyelids alone is frequently changed, which may 
 take place in two different modes, according as they are turned out- 
 ward ( ectropium ) or inward ( entropium ). The latter effect is pro- 
 duced particularly by the destruction of the internal layer of the skin 
 of the lid and the cartilage, after inflammation of the eyelids, by a drop- 
 sical state of these parts, sometimes by the paralysis of the levator 
 palpebræ muscle. This paralysis however is never sufficient to cause 
 it alone, it producing only the fall of the upper eyelid ( blepharoplosis ). 
 The first state is caused principally by wounds in the skin with loss 
 of substance, sometimes also by the development of tumors and ex 
 crcscences on its inner face. 
 
 When the fid is turned inward, the eyelashes naturally ’touch the 
 globe of the eye. Hence it is called trichiasis , in which only some 
 lashes participate, which occurs after inflammations of the eyelids, and 
 arises from the inner part of the edge of the eyelids being destroyed by 
 ulcerations. 
 
 The prolapsus of the iris occurs in wounds of the transparent cornea, 
 and when this latter membrane presents several openings through 
 which the iiis protrudes, a kind of staphyloma occurs which is termed 
 the hunch of grapes. At first the protruded portion of the iris is ex- 
 posed, soft, thin, and very vascular ; it gradually becomes solid, the 
 circulation stops, and it is covered by a thin, grayish white membrane, 
 which Beer regards as the regenerated conjunctiva ;(1) but it is more 
 correct to consider it a new production formed by the exudation of the 
 lymph from the iris. 
 
 The protrusion of the membrane of the aqueous humor, admitted by 
 most writers, is a prolapsus of the vitreous body, as Scarpa has per- 
 fectly demonstrated. (2) 
 
 II. ALTERATIONS IN COMPOSITION AND TEXTURE. 
 
 § 2024. Almost all the alterations of composition and texture in the 
 eye, as in other parts of the body, depend on inflammation, to which 
 this organ is very much exposed. Several of them however are de- 
 veloped, and we cannot consider them as resulting exactly from pre- 
 vious inflammation. 
 
 Alterations in texture are very rarely congenital. We must, how- 
 ever, regard as such the anomalies in the color of the eye, which may 
 be referred ; 1st, to a want of color in the pigment ( léucœthiopia ) ; 2d, 
 to the different colors of the iris in the two eyes, or even in its different 
 
 (1) Augcnkrankheitcn, vol. ii. , p. 63. 
 
 (2) Lou. cit., p. 170, 
 
OF THE EYE. 
 
 183 
 
 parts in the same eye ; 3d, to a want of transparency. Farar also(l) 
 has observed, in three children of the -same family, that the cornea at 
 the moment of birth was clouded by a nebulosity, which afterwards 
 gradually disappeared from the outside towards the centre. 
 
 The new formations which must always, or at least in most cases, 
 be considered as consequences of inflammation, are principally the fol- 
 lowing : 
 
 1st. In the eyelids. 
 
 a. Grando , a rounded tumor, which varies in hardness and is de- 
 veloped on or a little below the lower edge. It is a purulent cyst, a 
 stye ( hordeolum ), not entirely destroyed by suppuration, and which is 
 filled with coagulated albumen. 
 
 b. Sarcoma of the eyelid, which is red and at first soft, afterwards 
 harder, and which is developed on the inner face of the eyelids, parti- 
 cularly in lymphatic subjects. 
 
 Here we may mention the encantliis , a tumor situated in the carun 
 cula lachrymahs and the third eyelid. 
 
 2d. In the conjunctiva. The film is a greater or less elevation which 
 is developed between the anterior face of the sclerotica and the con- 
 junctiva which covers it. The pterygium( 2) commonly arises in the 
 inner angle of the eye, where it extends outward to the anterior face 
 of the transparent cornea, and beyond the centre of this latter. We 
 rarely find a second or even a third in the external angle of the eye or 
 in another region. It is more or less vascular, and its base always 
 looks toward the circumference and its summit towards the centre of 
 the eye, undoubtedly because the connection of the conjunctiva with 
 the subjacent membrane is less intimate in the first place than in the 
 second, where in fact it blends with the transparent cornea. 
 
 The pannus differs from the pterygium as it is the substance of the 
 conjunctiva, and sometimes also that of the transparent cornea, which 
 thickens. The tumor termed pinguecula is generally developed in the 
 external angle of the eye, or at least on the outside of the cornea. It 
 is seldom larger than a bean, and it is formed by the conjunctiva and 
 the subjacent cellular tissue. 
 
 3d. In the transparent cornea( 3) the principal results of inflamma- 
 tion are maculae and nebulae, ( obscuratio , albugo, s. leucoma ), which 
 sometimes arise only from simple exsudations in the tissue of the 
 cornea, sometimes also are cicatrices of ulcers of this membrane, and 
 vary in their extent and their degree of opacity. In the first case, the 
 surface of the cornea does not differ at the spot where the point is, from 
 
 (1) Med. communie., vol. ii., p. 463. 
 
 (2) Beer ( loc . cit., vol. ii., p. 638) does not consider the pterygium as resulting' from 
 an inflammation. We may however mention in support of this not only his own 
 opinion that the tumor usually appears when caustics are applied (p. 640), but also 
 Larrey’s observations, who remarked that it frequently was a consequent of the 
 Egyptian ophthalmia. 
 
 (3) G. Mirault, Mémoire sur la kératite ou inflammation de la cornée transpa- 
 rente ; in the Arch. gén. de méd ., vol iii., p. 5. 
 
184 
 
 DESCRIPTIVE ANATOMY 
 
 other parts ; in the second it is deep. The cicatrix is always hard, 
 like the spot produced by an old exsudation. Farther we observe no 
 other alteration of texture in the place where it is situated.(l) 
 
 4th. In the iris the pupil is effaced ( atresia pupilloe) by an opaque 
 false membrane, which causes at the same time the adhesion of the 
 posterior face of the iris to the crystaline ( synechia ) capsule. Then 
 the production of pus or of a puriform fluid on the surface of the iris, 
 whence a puriform congestion is formed in the chamber of the eye, 
 which is termed hypopon. Scarpa thinks that it is real pus which 
 forms here, since we do not find in the iris an abscess the rupture of 
 which could produce this purulent humor. (2) The serous nature of 
 the two faces of the iris favors his opinion, but the authority of Beer(3) 
 at least authorizes us to doubt it as a general rule. 
 
 5th. In the crystaline lens and ils capsule , which are frequently the 
 seat of cataract ( calaracla , s. sußusio), which most generally renders 
 opaque, parts normally transparent. 
 
 Cataract varies in situation, consistence, and color. It usually arises 
 from opacity of the crystaline lens (C. crislallina, C. lenticularis), more 
 rarely of the crystaline capsule, especially of its posterior face ( C. cap- 
 sulaire, C. capsularis), still more rarely in the humor of Morgagni (C, 
 laiteuse, C. JVlorgagniana, s. lactea). These three kinds coexist in the 
 capsulo -cry si aline cataract (C. capsulo-lenticularis ) . 
 
 Opacity generally commences in the ccntre(4) and very deeply in 
 the crystaline cataract, and on the contrary in the margin in the cap- 
 sular cataract. Sometimes in the latter case only some parts are 
 opaque, forming the doited or mottled cataract (C. feneslrata). Most 
 generally, but not always in old men, the crystaline lens is unusually 
 hard, and in a measure ossified or petrified (C. dura). It is rarely 
 softer than in the normal state (C. mollis), or even fluid (C. fluida), 
 The capsule is more frequently hardened and thickened. Its anterior 
 face is also covered in some cases (C. trabiculata, pyramidala) by a 
 layer of substance, sometimes having the consistence of osseous tis- 
 sue, (5) which arises from an exsudation formed by the inflamed iris, 
 and which consequently can always be separated to a certain extent 
 from the capsule. (6) The color of the cataract is most generally 
 grayish white. 
 
 In the crystaline and the capsular cataract, the crystaline lens and 
 its capsule are not unfrequently detached from each other, or from the 
 adjacent parts, by a shock of the body. But they are sometimes con- 
 nected more intimately, and so extensively that the crystaline capsule 
 and the iris adhere. 
 
 (1) Wardrop, toe. cit., p. 93. 
 
 (2) Loc. cit., p. 149. 
 
 (3) Loc. cit., vol. i., p. 436. 
 
 (4) Rudolphi ( Grundriss der Physiologic, vol. ii., p. 184) mentions a family in 
 Berlin in which the central cataract [C. cenf rajas) is hereditary; this consists in a 
 eingle dark point in the centre of the crystaline lens, which remains stationary 
 
 (5) Beer, loc. cit., p. 303. 
 
 (6) Beer, loc. cit., p 297 
 
OF THE EYE, 
 
 185 
 
 In the pyramidal cataract the thick anterior wall of the capsule 
 sometimes projects through the pupil and advances to the transparent 
 cornea, to which it sometimes adheres. 
 
 6th. In the vitreous body, the loss of transparency ( glaucoma ) and 
 the complete dissolution of it ( synchysis ), which usually attend gutta 
 serena.(l) 
 
 § 2025. The new formations developed in the eye are probably- 
 caused by an action similar to inflammation ; we cannot, however, 
 always consider them as resulting positively from this cause. They 
 are divided as in every other part, into those which are abnormal only 
 from the place where they are developed, and those which are entirely 
 new. 
 
 1st. Among the tissues normally existing in other parts of the body 
 we distinguish : 
 
 a. The cellular tissue, which, assuming the form of false membranes, 
 unites parts which are primitively separate, and which we have al- 
 ready mentioned in this respect as produced by inflammation. 
 
 b. The vascular tissue, which arises in the same manner in the dif- 
 ferent new formations, especially in the preceding. 
 
 c. The serous tissue, which is developed in the eyelids, especially 
 the superior, in the form of cysts within the lachrymal gland in the 
 orbit, (2) more rarely between the choroid coat and the retina. (3) We 
 probably can arrange here the cysts formed on the surface of the iris 
 when this membrane projects through an opening in the transparent 
 cornea: 
 
 cl. The fibrous tissue, which occurs much more rarely. In one 
 case the retina was changed into a white, fibrous, and very solid mem- 
 brane, exactly similar to an aponeurosis, the external face of which 
 adhered very intimately to an osseous layer between it and the choroid 
 membrane. (4) 
 
 e. The osseous tissue, which generally appears in the form of more 
 or less irregular thin layers between the choroid coat and the retina, 
 probably from the change of the serous membrane which covers the 
 outer part of the choroid coat. It is seen more rarely in the transpa- 
 rent cornea, (5) and it is probably developed primitively in the mem- 
 brane of Descemet. 
 
 We must probably mention here the considerable and petrous hard- 
 ening of the opaque crystaline lens and the formation of stony concre- 
 tions in the place of the vitreous body ; for the latter concretions, even 
 when they become considerably thick, do not result from the change 
 of the vitreous body, but from between the choroid membrane and the 
 
 (1) Heister, in the Act. nat. cur., vol. i., p. 71, — Demours, loc. cit., vol. i., p, 390. 
 
 (2) Beer, loc. cit., vol. ii., p. 589, note. 
 
 (3) Portal, Anat. méd., vol. iv., p. 418. 
 
 (4) Magendie, in Demours, loc. cit., 73, vol. i. 
 
 (5) Walter, Amt. mus., vol, i., p. 139. — Wardrop, loc. cit., p. 72.— Anderson, ibid . 
 p. 73. 
 
1S6 
 
 DESCRTI'TIVF, ANATOMY. 
 
 retina, and only push this body outward, since it is crowded and 
 wasted in their centre.(l) 
 
 f Among 1 2 3 4 5 6 the constituent parts of the cutaneous tissue the hairs 
 are probably the only ones abnormally developed in the eye, uhless 
 we refer to it those cysts which form around hernias of the iris, and 
 which we have referred to the serous system. The conjunctiva seems 
 to be the only part of the eye where the hairs take root. They some- 
 times appear also as abnormal eyelashes ( distichiasis ) on the inner 
 edge of the upper eyelid after neglected ophthalmias, and differ from 
 the common lashes in their situation, thinness, smallness, and whitish 
 eolor.(2) They are rarely developed in the conjunctiva of the eye, 
 where they appear either in the conjunctiva itself, which is most 
 usual, (3) or on the transparent cornea. (4) In the cases observed by 
 Himly they were inserted in the centre of a fatty production, and in 
 all other cases, at least those detailed by Wardrop, and Demours, a 
 pterygium or film was the base of them, that is, they were preceded 
 by a morbid change. Himly and Wardrop have observed this forma- 
 tion in the external, and Demours in the internal angle of the eye. 
 This latter case consequently resembles the considerable increase of 
 one of the hairs of the caruncula lachrymalis, seen by Albinus.(5) It 
 is curious that in the few cases of this anomaly as yet published, there 
 is an evident connection between the period of puberty and the deve- 
 lopment of accidental hairs. In the cases described by Wardrop, the 
 hairs did not appear till the age of sixteen years with the beard, and 
 in that described by Himly the tumor appeared at the age of two 
 years, but did not become troublesome till the age of twenty, doubtless 
 because hairs were not developed upon its surface. 
 
 2d. The entirely new formations are : 
 
 a. Figlike excrescences which appear in the iris, from syphilitic 
 inflammation. 
 
 b. Fungus hematodes, which is developed sometimes in the eye 
 itself, and as it would seem on the posterior part of the choroid mem- 
 brane, whence it goes forward, destroying before it all parts of the 
 organ, and often extends to the outside of the eye in the fat of the 
 orbit. Perhaps we ought also to arrange here the excrescences which 
 are developed within the optic nerve. (6) 
 
 c. The entozoaries. To these may probably be referred, at least 
 sometimes, the loose hydatids which appear in the lachrymal gland, 
 and which are explained better in this manner than by attributing 
 
 (1) Scarpa, p. 269. 
 
 (2) Beer, loc. cit., p. 119. 
 
 (3) Himly, Ophthalm. Bibl., vol. ii., part i., p. 199 — Ware, On entropion , p. 7. — 
 Wardrop, p. 31.— Demours, tab. Ixiv., fig-. 1. 
 
 (4) Gazelles, in the Journ. de méd., vol. xxiv. 
 
 (5) Annot. acad., book iii., cap. viii. 
 
 (6) Gallereux, in Demours, vol, i., p. 75. 
 
OF THE NOSE. 
 
 187 
 
 them to a change of the cellular tissue.(l) The filaria Medmensis 
 sometimes occurs below tire conjunctiva. (2) 
 
 CHAPTER III. 
 
 ORGAN OF SMELL. 
 
 § 2026. The senses of hearing and sight, the organs of which have 
 been described, differ from the others in respect to their relations with 
 other organs, as they are more independent. Those of smell and taste, 
 on the contrary, are only portions of other organs, for they both belong 
 to the digestive system, and the first also to the respiratory system. 
 It would then be proper to consider the organs of smell, voice, and 
 respiration, of taste, and of digestion, as forming a single system. It 
 is impossible to separate the history of the tongue from that of the in- 
 testinal canal, since it is situated in a cavity, the commencement of the 
 digestive apparatus, and in which the food is remarkably changed, 
 since it is also situated behind the organs which cause these changes. 
 But we shall consider the organ of smell separately, since it is more 
 independent than that of taste, and after leaving the fishes it is entirely 
 separated from the respiratory system, which in the three upper classes 
 of animals communicates with the exterior, not only by the olfactory 
 organ, but also by the oral cavity. 
 
 ARTICLE FIRST. 
 
 ORGAN OF SMELL IN THE PERFECT STATE. 
 
 § 2027. The organ of smell, or the nose, (3) is composed : 
 
 1st. Of a bony cavity divided into several compartments, the upper 
 and posterior part of which is more extensive, and is formed by bones, 
 whence it is termed the bony nose ( nasus osseus ), and has already been 
 described in osteology. 
 
 2d. Of an anterior, smaller, triangular, elongated, and cartilaginous 
 portion, the cartilaginous portion ( nasus cartilagineus) . 
 
 3d. Of muscles which move this cartilaginous portion. 
 
 (1) Schmidt, Krankheiten des Thränenorgans, p. 75. 
 
 (2) Larrey, Mémoires et compagnes, vol. i., p. 223. 
 
 (3) Santorini, Obscrvationcs analomicœ, Venice, 1724, cap. v., De naso, p. 84. 
 
 Ziervogel (Aurivillius), De naribus internis, Upsal, 1760.— A. Scarpa, Anatomicæ 
 disquisilioncs de audita et olfactu, Milan, 1795.— T. C. Rosenthal, De organo ol- 
 t actus quor undem animalium, Gripswald, 1807. — S. T. Scemmerring“, Abbildungen 
 des menschlichen Organs des Geruchs, Frankfurt, 1809. 
 
188 
 
 DESCRIPTIVE ANATOMY. 
 
 4th. Of a mucous membrane which covers the osseous and the car- 
 tilaginous nose. 
 
 5th. Of nerves which are distributed in this membrane. 
 
 In considering the nose externally we distinguish an upper part or 
 the root, an anterior edge or the back, and a lower part or the tip. 
 
 I. CARTILAGINOUS NOSE. 
 
 § 2028. The cartilaginous nose, the anterior extremity of the bony 
 nose, is composed of a central and perpendicular portion, the cartilagi- 
 nous septum of the nose ( septum narium cartilagineum), of two alee. 
 ( pinnae , s. alee nasi), finally of two oblong openings termed nostrils 
 (jiares), by which the cavity of the nose opens externally, and which 
 are supplied, especially on their inside, with stiff hairs ( vibrissa : .) 
 
 It is composed of several thin cartilages united with each other and 
 with the bony portion of the nose, externally with the skin, internally 
 with a mucous membrane. There are generally eleven. 
 
 The largest, the cartilage of the septum , is perpendicular and square. 
 It completes the osseous septum anteriorly, where if is included be- 
 tween the perpendicular plate of the ethmoid bone, the vomer, and the 
 median suture of the two proper nasal bones. Its anterior edge de- 
 scends from before backward, is loose, and is attached to a long pro- 
 longation of the skin, the cutaneous septum of the nose. 
 
 The superior lateral cartilage is square and is attached to the lower 
 edge of the proper nasal bone, to the ascending process of the superior 
 maxillary bone, and to the upper edge of the preceding. It is generally 
 blended with this latter so intimately that they form but one body.(l) 
 Below this superior lateral cartilage, and at the side of the lower part 
 of the median line, is the inferior lateral cartilage, or the cartilage of 
 the ala ( C . pinna ;), which is very low. This cartilage is' narrow and 
 formed of two pieces, an internal and an external, which unite forward 
 at an acute angle, where they frequently present a foramen, and are 
 sometimes entirely separated from each other. The external piece is 
 longer and higher than the internal. Next come from before back- 
 ward and from without inward several square cartilages ; these are 
 much smaller, diminish in extent from before backward, circumscribe 
 the nostril backward and outward, and are often blended with each 
 other and with the preceding. From two to five other still smaller 
 sesamoid cartilages (C. sesamoideœ ) are situated forward on each side, 
 between that of the septum and the two lateral cartilages. 
 
 (1) Santorini, foc. cil ., p. 85. 
 
OF THE NOSE. 
 
 189 
 
 II. MUSCLES OF THE NOSE. 
 
 § 2029. The cartilaginous nose is moved by a great many mus- 
 cles, ( 1) two of which belong to it exclusively and two are common 
 with the adjacent parts. 
 
 A. LEVATOR ALS NASI LABIIQUE SUPERIORIS. 
 
 § 2030. The levator alee, nasi labiique svperioris or the pyramidal 
 muscle, grand sus-maxillo-labial, Ch., arises from the nasal process of 
 the upper maxillary bone, usually blends in this place with the frontalis 
 muscle, descends in the side of the nose, and divides into two fasciculi, 
 an anterior which is smaller, and is expanded in the lower lateral car- 
 tilage ; the other is much larger, and blends with the orbicularis oris 
 and the superior muscles of the upper lip. It raises the ala of the 
 nose and the upper lip, and opens the nostril. 
 
 B. COMPRESSOR NARIUM. 
 
 § 2031. The compressor narium muscle, sus-maxillo-nasal , Ch., is 
 triangular, thick, and narrow at the base, and broad above. It ascends 
 from the posterior part of the ala of the nose, where it is blended with 
 the preceding, which partly covers it, and goes from behind forward 
 toward the back of the nose, on which it unites with that of the op- 
 posite side without any intermediate tendon. It often gives off at the 
 upper part, a prolongation which blends with the frontalis muscle. 
 This is the procerus muscle of Santorini, the lower part of his Irans- 
 versus nasi muscle. 
 
 It contracts the nostrils when it acts from below upwarc^ or from 
 above downward, and never dilates them. 
 
 C. DEPRESSOR ALÆ NASI. 
 
 § 2032. The depressor alee nasi muscle, the proper muscle of the 
 ala ( JMT. pinnarum, s. narium lateralis , Santorini, s. dilator narium pro- 
 prius , s. inferior ), arises from the upper maxillary bone above the 
 c.anine tooth and the external incisor. It is formed of oblique fibres, 
 and extends almost the whole length of the outside of the cartilage of 
 the ala of the nose. Its principal effect is to dilate the nostril when 
 the nose is at rest. Being inserted in the upper maxillary bone, it 
 can depress the nose. Finally, as its external face is attached to the 
 integuments of the upper lip, it can also depress this latter; 
 
 (1) Santorini, Obs. anat., cap. i., de musculis faciei, p. 11. — Id., Tabulas XVII., 
 tab. i. — A. F. Walter, Tenor, muse. hum. corp. anat. repet., Leipsic, 17-31. — Isen- 
 flannn has described and figured them in his Praktische Anmerkungen über die 
 Muskeln, Erlangen, 1778, p. 345. 
 
 Vol. III. 
 
 25 
 
190 
 
 DESCRIPTIVE ANATOMY. 
 
 We sometimes find before it a proper, but much smaller muscle, to 
 dilate the nostril ; it is called the myrtiform muscle of Santorini , and 
 sometimes surrounds the nose like a sphincter. 
 
 D. DEPRESSOR NARIUM. 
 
 § 2033. The depressor narium muscle forms on each side a small fasci- 
 culus situated along the median line : it arises from the inner upper 
 part of the orbicularis oris muscle, and is attached backward and in- 
 ward to the inner branch of the cartilage of the ala of the nose. It 
 draws the cartilaginous nose downward and backward, and also con- 
 tracts the nostrils. 
 
 III. MUCOUS MEMBRANE, 
 
 § 2034. The mucous, olfactory, pituitary, or Schneiderian mem- 
 brane of the nose, has not the same nature in all parts. The proper 
 nasal portion is more than a line thick in some places ; it is thick, very 
 red, and intimately fitted to the bones which it covers in every part ; it 
 contains numerous depressions and mucous follicles, and also at the 
 lower and inner part of the nose, some small yellowish and distinct 
 glands, which are imbedded in its peculiar tissue. At the anterior and 
 inferior part of the nose it is thinner, harder, drier, and also provided 
 with mucous follicles. If we except this latter portion, the pituitary 
 membrane is covered in every part with very short villosities. At the 
 lower edge of the septum there is not unfrequently a narrow canal, 
 the direction of which is from behind forward, terminating posteriorly 
 in a cul-de-sac, and which opens at some distance behind the anterior 
 edge, evidently above the organ of Jacobson.(l) 
 
 The mucous membrane of the accessory cavities or of the sinuses, 
 is externally thin, smooth, and yellowish white. It adheres but slightly 
 to the surface of the bony cavities it covers, undoubtedly because nu- 
 merous vessels and nerves do not enter it, through the substance of 
 the bones. 
 
 IV. nerves. 
 
 § 2035. The nose receives its nerves from two sources, the olfactory 
 and the second branch of the trifacial nerve. (2) 
 
 The olfactory nerve is undoubtedly the proper nerve of the organ of 
 smell, (3) since when absent or compressed, the sense of smell is lost. 
 
 (1) Ruysch, Thesaur. anat. III. tab. v., fig. 5. — Jacobson, Ann. du mus., vol. 
 xviii. p. 412. 
 
 (2) J. Hunter, A description of the nerves which supply the organ of smelling ; in 
 Obs. on different parts of the animal economy, p. 239, tab. ix-xviii. — A. Scarpa, loc. 
 eit., cap. iii-vi. 
 
 (3) Magendie has doubted the proposition generally admitted in a memoir, en- 
 titled “ Le nerf olfactif est-il l’organe de l’odorat ? In the Journ. de phys. expér., 
 vol. iv. p. 169.” Mery already doubted that the olfactory nerve was the organ of 
 smell, and asserted that it was supplied by the fifth pair. (Brunet, Progrès de la 
 
OF THE NOSE. 
 
 191 
 
 From the lower face of the prominence which terminates it, two series 
 of filaments arise, an external and an internal, which correspond to the 
 two series of foramina in the cribriform plate of the ethmoid bone, 
 although two or three of them frequently emerge through the same 
 foramen. They vary much in number and size. There are from four 
 to twelve. The anterior go downward and forward, the middle di- 
 rectly downward, the posterior downward and backward. Shortly 
 after leaving the olfactory nerve they enter the sheaths of the dura- 
 mater, within which the posterior, particularly, pass a long distance 
 before entering the foramina of the cribriform plate. They are covered 
 first by the dura-mater, and flattened by the arachnoid membrane, 
 which is less compact, and does not attend them as far. Entirely on 
 the outside, each is surrounded by a tunnel-like prolongation of the 
 dura-mater, which extends very far, and makes them apparently larger 
 than they are on leaving the ganglion. They anastomose below the 
 cribriform plate, descend between the bones and the pituitary mem- 
 brane, soon ramify very much, and thus gradually approach the loose 
 surface of the membrane. 
 
 Part of the internal seiies belongs to the septum, the component 
 nerves of which pass entirely through it : the middle are the longest and 
 the posterior the shortest. 
 
 They descend side by side, forming a single layer. 
 
 The external series is distributed in the sides of the nose, particularly 
 in the two superior turbinated bones, forms considerable anastomoses, 
 but the filaments formed by these nerves are much less compact than 
 those of the external : they do not enter into the ethmoid cellules, and 
 do not go to the mucous membrane of the inferior turbinated bones, or 
 at least send forward but few and very minute minuscules. 
 
 The olfactory nerve sends no filaments to the pituitary membrane of 
 the sinuses. 
 
 médecine, 1697.) Having opened the skulls of three or four men, in whom the organ 
 of smell during life was unaltered, he found the pair of nerves callous near the cere- 
 brum. Loder, however, (Observatio tumoris scirrhosi in basi cranii reperti, Jena, 
 1779,) has seen the olfactory nerve destroyed in a man destitute of the power of per- 
 ception, and Oppcrt also has observed the same thing in a female, in whom the sense 
 of smelling was deficient (Diss. de vitiis nervorum organicis, Berlin, 1815, p. 16). 
 Cerutti ( Beschreibung der pathologischen Präparate des anatomischen 7 'heaters zu 
 Leipzig, 1819, p. 208) mentions the cerebrum of a • îan who never possessed the 
 faculty of smelling, in whom the olfactory nerve and its groove on the lower face of 
 the inferior lobe were deficient. Rosenmuller even has described this case (De de- 
 fcclu nervi olfac., Leipsic, 1817). But Rudolphi regrets, and with justice, that the 
 turbinated bones of the septum were not examined, since in many cases, when it has 
 been said to be deficient, it has been found, but very soft and diffluent. Farther, 
 the facts related by Magendie, seem to give some weight to the old opinion of Mery ; 
 at least they should draw the attention of physiologists to the sinuses of the nasal 
 fossæ, to which Malacarne, Weinhold, Blumenbach, and Treviranus, have attri- 
 buted very different uses, which are sometimes very trivial, as those mentioned by 
 Weinhold. It would be important to prove, whether, as Deschamps and Richerand 
 assert from experiments made on subjects affected with diseases of these cavities, 
 they are unconnected with the olfactory function; but of this we may doubt until we 
 have more information, especially since the fine researches of Treviranus on the 
 fifth pair of nerves. F, T. 
 
192 
 
 DESCRIPTIVE ANATOMY. 
 
 Among the nerves of the fifth pair or the accessory nerves of the 
 nose, the superior nasal nerves go backward, the middle and the in- 
 ferior nasal nerves, and the nerve of the septum which arise from the 
 pterygo-palatine nerve, and the ethmoid nerve which comes from the 
 nasal branch, go farthest forward, for they extend even before the ol- 
 factory nerve, and are distributed in the mucous membrane of the nose. 
 These nerves also surround the surface in which the olfactory nerve 
 is distributed, and anastomose with its posterior and external filaments. 
 Those from the second branch of the fifth pair communicate also with 
 the ethmoid nerve. Hence, the accessory nerves form a complete 
 circle around the expansion of the olfactory nerve, like that formed by 
 the ciliary nerves around the retina. Although they proceed much 
 farther, they however occupy much less space than the twigs of the 
 olfactory nerve. 
 
 § 2036. The impressions of the odors are received by the olfactory 
 nerve, and directly by the pituitary membrane. The portion of this 
 latter in which the olfactory nerve is distributed, seems to be the prin- 
 cipal seat of the faculty of perceiving them, although the membrane 
 which lines the sinuses, partially contributes. 
 
 ARTICLE SECOND. 
 
 DIFFERENCES IN THE NOSE DEPENDENT ON DEVELOPMENT. 
 
 § 2037. We have already mentioned in osteology, the principal 
 periodical differences in the bony nose. 
 
 The whole organ long continues very imperfect. There is no trace 
 of the external nose until the seventh or eighth week of pregnancy. 
 At this time the nostrils appear, separated by a proportionally very 
 broad septum, as two very small openings ; little later the nose begins 
 to project over the mouth ; but during pregnancy it is blunt, and pro- 
 portionally very small ; a large nose in an infant is very unpleasant, 
 because it is a character foreign to the early periods of life. 
 
 The cartilaginous structure of the external nose does not begin to 
 appear till towards the end of the third month. 
 
 Until the end of the second, the nasal cavity communicates with that 
 of the mouth. It is at first very narrow from above downward, and 
 from right to left, on account of the greater breadth of the septum. 
 
 The nasal canals are formed at the end of the second month, by the 
 still membranous prominences of the turbinated bones. 
 
OF THE NOSE. 
 
 193 
 
 ARTICLE THIRD. 
 
 ORGAN OP SMELL IN THE ABNORMAL STATE. 
 
 A, NOSE. 
 
 § 2038. The primitive deviations of formation in the nose(l) are : 
 
 1st. Its entire deficiency, which is very rare, is generally attended 
 with the fusion of the two eyes in one. 
 
 2d, The union of the two halves of the nose in a tube situated 
 below the single eye. 
 
 3d. Greater or less openings in the septum. 
 
 4th. Narrowness or closing of the nostrils. 
 
 5th. The abnormal communication of the cavity -of the nose with 
 that of the mouth, by the deficiency of a greater or less portion of the 
 palate. (2) 
 
 6th. The more or less evident want of symmetry arising from an 
 obliquity in the septum, which is sometimes so great that this latter 
 even touches the wall towards which it inclines. 
 
 Most of these primitive deviations of formation are developed also 
 consecutively during life, after the bony and musculo-membranous 
 parts of the nose and palate are destroyed by syphilis. 
 
 The most frequent abnormal formations are the polypi of the pitui- 
 tary membrane. Hydatids are infinitely more rare. They sometimes 
 become so large that they considerably contract the nasal cavity.(3) 
 
 B. SINUSES OF THE NASAL F0SSÆ. 
 
 § 2039. The accessory cavities or the sinuses of the nasal fossœ , pre- 
 sent numerous and frequent anomalies.(4) 
 
 Their deviations of formation consist in their absence and narrow- 
 ness, which are usually congenital. Sometimes these sinuses do not 
 communicate with the nasal fossæ : but this anomaly almost always 
 occurs, consecutively, after inflammation. (5) 
 
 Once, however, we found in the cadaver of an old woman the two 
 maxillary sinuses completely closed, without any pathological change 
 
 (1) Deschamps, Traité des maladies des fosses nasales et de leurs sinus, Paris, 
 1804, p. 8. 
 
 (2) Portai, Anat. méd ., vol. iv. p. 499. 
 
 (3) Idem, loc. cit. 
 
 (4) L. H. Runge, De morbis prœcipuis sinuum assis frontis et maxilice superior is, 
 Rinteln, 1750. — Bordenave, Sur les maladies du sinus maxillaire ; in the Mem. de 
 Vac. de chir., vol. iv. p. 329. — C. A. Weinhokl, TJ cher die krankhaften Metamorphosen 
 der Highmorshöhle, Leipsic, 1810. — F. D. Wagner, Diss. de po'lypis nariumet antri 
 maxillaris, Berlin, 1821. 
 
 (5) A. F. Rohowsky, Diss. de choanarum obliteratione, Berlin, 1815,— Otto, Patho- 
 logische Anatomie , p. 203, ann. 15. 
 
194 
 
 DESCRIPTIVE ANATOMV. 
 
 in the texture of the pituitary membrane, and their surface also was 
 moist as usual. 
 
 A greater or less quantity of liquid, however, often collects within 
 them, from the effect of certain causes ; this more or less forcibly dis- 
 tends them, their parietes' become thinner, and are finally destroyed 
 when the compression continues a long time, although this state does 
 not deserve the name of dropsy of the maxillary sinus, because the 
 effused liquid is not of the same nature as that exhaled by serous mem- 
 branes. ( 1) 
 
 Entirely new formations, as fibro-cartilages and polypi, either alone 
 or united, are not unfrequently developed in the accessory cavities of 
 the nose. These formations are particularly common in the maxillary 
 sinus, which is the most subject to morbid alterations, doubtless on ac- 
 count of the nearness of the teeth, and because the situation of its 
 opening renders the escape of its secreted fluids more difficult. We 
 may, however, blend them with the analogous tumors which are deve- 
 loped out of the antrum Highmorianum, in the zygomatic fossa. (2) 
 
 SECTION II. 
 
 OF THE VISCERA OR FORMATIVE ORGANS. 
 
 § 2040. The viscera, { 3) which may also be called the formative or- 
 gans, because their essential function is to form new substances, pre- 
 sent several general characters, the principal of which are as fol- 
 low : 
 
 1st. They are situated principally in the trunk, and occupy only a 
 small part, of the lower region of the face, and are generally placed in 
 cavities formed by bones, muscles, and serous membranes, which vary 
 much in capacity. An aqueous vapor is effused between them and the 
 parietes of these cavities. 
 
 2d. They are entirely, or at least in great part, and in their most 
 important portions, enveloped by serous membranes. Each system is 
 separated in this manner from the others, and each occupies a distinct 
 section of the trunk. 
 
 3d. They receive most of their nerves from the ganglionnary sys- 
 tem, and their nerves are always proportionally larger than those that 
 go to the organs of sense, excepting always certain parts, as the tongue 
 and the external organs of generation, which being abundantly sup- 
 plied with nerves, possess a very acute and special sensibility, and are 
 
 (1) Runge, loc. cit. — Fauchard, Chir. dentiste , vol. i. — Sauve, Cas d’hydropisie 
 du sinus maxillaire ; in the Bull, de la fac. de mcd., 1818, p. 9. 
 
 (2) Lesage, Sur une tumeur enkystée de la fosse zygomatique prise pour un polype 
 du sinus maxillaire ; in the Bull, de la fac. de mcd., 1816, vol. v. p. 268. 
 
 (3) R. C. de Garengeot, Splanehnologie, ou l’anatomie des viscères, Paris, 1742. — 
 Gavard, Traité de splanehnologie, Paris, 1809.— Boyer, Traité de splanehnologie, 
 Paris, 1815. 
 
OF THE VISCERA. 
 
 195 
 
 in fact, real organs of sense. Most of the viscera receive their nerves 
 from the ganglionnary system, and next from the pneumogastric nerve ; 
 but the hypoglossal, the glosso-pharyngeal, and the trifacial nerves, 
 are also distributed in their upper portion, and the inferior spinal nerves 
 in their lower portion. 
 
 The nerves usually pass some distance before arriving at the organs, 
 and generally each of the latter receives nerves from one pair only. 
 One pair of nerves is distributed in part to several organs. 
 
 4th. The course of the nerves in most of their extent is constant. 
 As this condition does not exist in regard to those organs which re- 
 ceive their nerves from the ganglionnary system, we must conclude 
 that it does not depend on the nature of this nerve. It is false that 
 the spiritual principle is not connected with them, and the changes 
 that take place in them are not perceived ; this perception is very mani- 
 fest in disease, and the sensations that result from them are not more 
 vague or obscure than those ascribed to all the organs except that of 
 sight. _ v 
 
 5th. All the viscera are not united, at least in the perfect state, by 
 mucous membranes. The respiratory and digestive systems commu- 
 nicate together in the neck, the urinary and genital systems in the 
 lower part of the trunk ; but the two latter are separated from the di- 
 gestive system, or at least are connected with it only by the skin. 
 
 6th. These organs are much less symmetrical as to form and situa- 
 tion, than those of the senses. 
 
 7th. Their most important part is more or less evidently glandular, 
 All are formed by several glands, the combined action of which is to 
 correct the fluids secreted by them. The necessity of the combined 
 action of several glands is very evident in the most complex system, 
 that of digestion. Next come in this respect the genital organs, espe- 
 cially those of the male. The concurrence of several glands to form a 
 new substance, seems least necessary in the urinary and respiratory 
 systems. 
 
 A second part is composed of a canal formed of several different 
 superimposed membranes, united by cellular tissue, and with which 
 the gland or glands in general communicate, and which is sometimes 
 open at its two extremities like the alimentary canal, or at one only, 
 like all the others. The nature of the parietes of this canal varies ex- 
 tremely ; they are, however, always formed of at least two superim- 
 posed layers, the external of which is condensed cellular tissue, and the 
 internal a mucous membrane. The mucous membrane is covered 
 sometimes in every part, as in the alimentary canal, sometimes here 
 and there by a muscular tunic. 
 
 8th. These organs, if we except the genital organs, are, next to the 
 centres of the nervous and circulatory systems, the most necessary for 
 the support of life, although some of their parts may be primitively de- 
 ficient, or be destroyed in some manner without occasioning severe 
 accidents, and although very considerable alterations do not occasion 
 immediate death, 
 
196 
 
 DESCIUrXIVE ANATOMY. 
 
 CHAPTER I. 
 
 OF THE DIGESTIVE ORGANS. 
 
 § 2041. The digestive organs comprise an uninterrupted canal 
 open at its two extremities, and several appendages, which, communi- 
 cate directly or indirectly with different parts of this canal, within 
 which they empty a fluid prepared by them. 
 
 This passage is termed the alimentary canal or tube ( canalis , s. 
 ductus cibarius). Its upper extremity is the mouth (os), and the lower 
 the amts ; both are situated opposite each other, and nearly on the 
 same line. The canal is imperfectly divided by valvular prominences 
 into several separate portions, which are named according to their 
 form or functions. It is very convenient to admit three parts, which 
 differ in functions, structure, and situation, but which are all repeti- 
 tions of the same type ; these are the upper, the middle, and the lower 
 portion. The first occupies the head, the neck, and the chest ; the 
 other two, which form most of the digestive system, fill almost entirely 
 the cavity of the abdomen. The upper portion is composed of the oral 
 cavity ( cavmn oris), the pharynx, which is smaller than the mouth, 
 and the esophagus ( gula , oesophagus), which is still narrower, and with 
 which the pharynx is continuous. ■ Directly after passing through the 
 diaphragm the alimentary canal enlarges to form a second pouch, 
 called the stomach ( ventricidus , stomachus), which is the commence- 
 ment of the middle portion. Next comes a second narrower portion, 
 the small intestine ( intestinum tenue), which is divided, from slight and 
 inessential differences, into the duodenum, the jejunum, and the ileon. 
 The latter is continuous with the terminating portion of the intestinal 
 canal, the large intestine or the colon ( intestinum colon, s. crassum), 
 which is divided according to the situation and direction of its different 
 parts into an ascending, a transverse, and a descending colon. The 
 latter is continuous also with the rectum, which opens at the anus. 
 The small and the large intestines are termed the intestinal canal 
 ( ductus , s. canalis intestinalis) . 
 
 The appendages of the intestinal canal are glandular organs re- 
 sembling conglomerate glands ; they are, the salivary glands and the 
 liver. 
 
 The salivary glands ( G . salivares) are situated around the cavtiy of 
 the month, into which their secretion goes, and in the abdominal ca- 
 vity near the upper extremity of the small intestine. They are con- 
 sequently divided into the oral and the abdominal salivary glands ( G. 
 salivares orales et abdominales). 
 
 The liver ( jecur , heparj also occupies the cavity of the abdomen. 
 The fluid it secretes is termed bile, and is poured into the duodenum 
 near the last salivary gland. 
 
OF THE DIGESTIVE SYSTEM. 
 
 197 
 
 We also find in the abdomen a glandular organ, which has no ex- 
 cretory canal, called the spleen ( splen , lien). 
 
 All the portions of the digestive system in the abdomen, except the 
 lower part of the rectum, are surrounded by a common serous mem- 
 brane, the peritoneum. 
 
 § 2042. The alimentary canal(l) presents several general charac- 
 ters which are simply modified in its component parts. 
 
 The tube it represents is formed of several layers which belong to 
 different systems, so that each concurs specially to the general func- 
 tion. 
 
 The most internal and the most essential of these layers is the mu- 
 cous or villous membrane ( tunica mucosa , a. intima , s. cribrosa , s. 
 villosa). It is soft and more or less vascular, incloses numerous small 
 culs-de-sac or small muciparous glands, and its surface is moistened 
 by the mucus which it constantly secretes, and a thinner fluid which 
 is exhaled from it. It is in direct contact with the ingesta. The liquid 
 which it secretes has .a chemical and also a dynamical relation with 
 the ingesta, since its action changes their composition, and they are 
 divided into two parts, one of which, the chyle (cliylus), serves for 
 nutrition, while the other, the fecal matter {faces), being useless, is ex- 
 pelled from the body. The chyle in its turn is so modified that it enters 
 into the absorbing vessels which exist in this tissue. 
 
 The differences in this membrane relate principally . 
 
 1st. To its thickness. 
 
 2d. To its vascularity. 
 
 3d. To its color, which depends on the number of its vessels. 
 
 4th. To its solidity. 
 
 5th. To its extent, compared with the other membranes. 
 
 6th. To the presence or absence of prolongations and folds which 
 project within it and vary in size, the former of which are called valves, 
 the others mllosities. 
 
 7th. To the nature of its surface, which is smooth or corrugated, 
 and which depends on the preceding circumstance. 
 
 8th. To the number of the muciparous glands. 
 
 9th. To their size. 
 
 10th. To their situation and arrangement. 
 
 We may mention as a general law that the development of the 
 inequalities on the inner face is inversely as that of the muciparous 
 follicles, or still more generally that the prominences are inversely as 
 the depressions ; that the first are more distinct, the more nutrition there 
 is in the contents of the intestinal canal, and that the cavities are more 
 marked, the greater the quantity of fecal matter in the canal. 
 
 Considered from the commencement of the stomach to the extremity 
 of the intestinal canal, the general character of this membrane is that 
 it is perforated by very , numerous small openings, which are the ori- 
 
 (1) F. Glhson, De oentriculo et intestinis, London, 167(5. 
 
 Vol. Ill 2.6 
 
198 
 
 DESCRIPTIVE ANATOMY 
 
 lices of single minute glands, and which are arranged very corn- 
 pactly.(l) 
 
 On its surface is a second membrane termed the nervous , or rather 
 the cellular coat ( tunica nerve«, ccllulosa). 
 
 This membrane is only condensed cellular tissue, in which the 
 largest trunks of the vessels and nerves are distributed before arriving 
 at the mucous membrane. 
 
 It contributes much to determine the form of the intestinal canal 
 and of its folds. 
 
 The most external membrane is the muscular tunic ( tunica muscu- 
 lo sa.) 
 
 This membrane is composed in every part by several, at least two, 
 superimposed layers, situated one above the other, and separated only 
 by a very thin layer of mucous tissue. 
 
 The external layer is generally composed of longitudinal fibres, 
 which are parallel to the axis of the intestinal canal and of the body 
 It is thinner than the internal, and it is extended on the intestine less 
 uniformly. 
 
 The internal, on the contrary, is composed of circular fibres, is 
 stronger than the external, and completely surrounds the intestinal 
 tube. 
 
 The differences presented by this muscular tunic in the different 
 regions of the alimentary canal relate : 
 
 1st. To the relation between it and the mind, according as its mo- 
 tions are voluntary or involuntary ; in most of its extent these are 
 involuntary ; they, however, are voluntary at its upper and lower part 
 
 2d. To its thickness and strength. 
 
 3d. To its more or less complex texture. 
 
 4th, To its color. 
 
 5th. To its attachments, according as it is inserted in the bones or 
 connected with the adjacent parts by mucous tissue. 
 
 Besides these three layers there are also two others which are not 
 so generally distributed : one resembles the epidermis, and covers the 
 inner membrane ; the other is given off by the peritoneum, and enve 
 lops the external tunic. 
 
 The most general character of the glandular appendages of the 
 alimentary canal is, that these parts, except the spleen, are prolonga- 
 tions of the mucous membrane and of the cellular tunic, each of which 
 ramifies like a tree. They differ then from the muciparous glands on 
 the external face of the villous tunic, because they are rather more 
 distinct and are more concentrated in some parts of the alimentary 
 canal. 
 
 (1) Galoati, Dc tunica Lntestinorum cribrosu; in (lie Comm. Bonon, t vol. i. — 
 Duverney, Œuvres anatomiques, vol. i,, p. 480.— A. Muck cl, > Sur la structure dc la 
 membrane muqueuse des intestins dans l'homme et dans quelques animaux ; in the 
 Journ. compt. des sc, mcd., vol. vii., p. 209. 
 
OF THE DIGESTIVE SYSTEM 
 
 199 
 
 ARTICLE FIRST. 
 
 UPPER PORTION OF THE ALIMENTARY CANAL, 
 
 § 2043, The upper portion of the alimentary canal may be subdi- 
 vided into two regions, a cephalic and a cervical region 
 
 I CEPHALIC PORTION OF THE ALIMENTARY CANAL 
 
 § 2044. The cephalic portion of the alimentary canal comprehends 
 the cavity of the mouth and the parts within it 
 
 A. ORAL CAVITY GENERALLY, 
 
 I. PERFECT STATE. 
 
 § 2045. The oral cavity ( cavum oris ) occupies the lower part of 
 the face. It extends backward to the fauces and forward to the lips, 
 by which it is continuous with the face. It is separated from the 
 nasal fossæ above by the bony palate ( palatum osseum, s. dumm), and 
 backward by the soft palate ( palatum molle, s. velum palati). At its 
 base is the tongue, and on its sides the lower jaw, the zygomatic arch, 
 and the. muscles, some of which are attached to these hones, others to 
 other pieces of bone, and several of which also go to the mouth. 
 
 As the oral cavity is circumscribed by muscles and by bones which 
 are movably articulated with each other, its form varies, although in 
 general it is rounded and oblong. The alveolar portion of the upper 
 and lower maxillary bones, together with the teeth which are inserted 
 there, divide it into two halves, an anterior, which is smaller, and which 
 may be called the vestibule of the oral cavity, and the posterior, which 
 is larger. The first is included between the alveolar processes and 
 the lips ; the second is situated behind the alveolar arches. These 
 two halves are perfectly separated from each other when the jaws are 
 closed by the two rows of teeth which touch and fit each other from 
 before backward. When perfectly at rest the posterior half contains 
 the tongue and receives the excretory. ducts of the inferior salivary 
 glands, while those of the superior open into the anterior half. The 
 oral cavity is covered on the outside by the common integuments, below 
 which are the bones and muscles, then the buccal membrane {mem- 
 brana oris), which envelopes every part of it. 
 
 The buccal membrane in fact begins at the upper part of the ex- 
 ternal faces of the lips, where the.skin suddenly becomes softer, thinner, 
 and redder. 
 
200 
 
 DESCRIPTIVE ANATOMY. 
 
 It lines all the parts which circumscribe the cavity of the mouth, 
 so that it perfectly closes the openings in the bony portion of the 
 palate, the anterior and posterior palatine foramina. Around the 
 alveoli it is uninterruptedly continuous with the membrane which 
 covers them. 
 
 It forms folds in several places. Four of these folds are situated on 
 the median line. The two most anterior exist between the centre of 
 the anterior faces of the two maxillary bones and the upper and 
 lower lips. They are both termed the frena of the lips ( frenu- 
 lum labii superioris et inferioris). The upper is much more distinct 
 than the lower, which generally is hardly visible. The third is si- 
 tuated between the posterior face of the lower jaw and the anterior 
 part of the inferior face of the tongue ; it is called the frehum of the 
 tongue ( frenulum lingua). 
 
 When too long or too short it is equally unfavorable to deglutition 
 and speaking. 
 
 The fourth extends from the posterior extremity of the upper face of 
 the tongue to the middle of the anterior face of the epiglottis. 
 
 The buccal membrane also forms : 
 
 1st. Two lateral folds, which extend from the upper face of the 
 tongue to the edges of the epiglottis, where they terminate. 
 
 2d. Two lateral folds, situated on the anterior part, which extend 
 from the alveolar edge of the two jaws to the inner face of the ramus 
 of the lower jaw. 
 
 3d. Two other lateral folds, which cover the two arches of the soft 
 palate. 
 
 Of these folds the most remarkable are those on the median line, as 
 they make a part of the septum which extends all along the body. 
 
 The texture of the buccal membrane is not the same in every part 
 It however always presents two general characters : 
 
 1st. It is covered in every part by a soft, thick, and moist epi- 
 dermis. 
 
 2d. It presents almost in every part single and large muciparous 
 glands. 
 
 II. DIFFERENCES DEPENDENT ON DEVELOPMENT. 
 
 § 2046. The form of the oral cavity changes remarkably. In the 
 early periods of life it is proportionally shorter from before backward, 
 especially at its lower part, than when the subject is fully grown. At 
 this time the lips do not exist, so that the oral cavity is uninterruptedly 
 continuous with the face, and its roof, the palate, not being closed, it is 
 blended with the nasal fossæ, toward the upper part of which is the 
 tongue, then proportionally very large. This horizontal septum is 
 gradually developed from before backward by the union on the median 
 line of the palatine portions of the superior maxillary and the palatine 
 bones, and also the soft palate on each side. This union is rarely 
 
OF THE DIGESTIVE SYSTEM. 
 
 201 
 
 perfect before the third month of fetal existence. The soft palate is 
 perfect on the median line even before its two lateral parts are tho- 
 roughly united posteriorly, and the uvula descends from their centre 
 between them as an entirely distinct and separate appendage. This 
 soft palate is at first very broad, presents no appearance of an appen- 
 dage, and is divided in its whole extent into two lateral halves. This 
 division soon disappears, and at the same time the two lateral halves 
 of the soft palate approach each other still nearer, and thus push the 
 uvula a little forward, so that it ‘covers the small fissure still existing 
 in the anterior region of the palate. At this time its upper part is 
 united to the two lateral halves, and the inferior passes downward a 
 little below it, Finally the two halves of the soft palate completely 
 unite with each other and with the uvula, and the formation is com- 
 pleted by the gradual prolongation of the latter. The perfect union of 
 the uvula with the soft palate occurs at the middle or end of the fourth 
 month of pregnancy. The uvula, however, until the end of the fifth 
 month continues to be bifurcated, compared with its state in the adult, 
 although it is united on each side with the soft palate, so that perhaps 
 this period of its development is frequently extended beyond the usual 
 time, although terminated before the end of gestation. 
 
 III. ABNORMAL STATE. 
 
 § 2047. The most remarkable abnormal state of the cavity of the 
 mouth is when its primitive formation continues, that is, when it com- 
 municates with the face and nasal fossæ, and the primitive fissures are 
 not obliterated. This state of the upper lip is termed liare-lip , and that 
 of the arch of the palate is termed fissure of the palate. (1) Generally 
 then the solution of continuity in the lip or palate, excepting in the 
 uvula, does not correspond to the median line, but occurs on one of the 
 two sides, since it is situated also like the fissures by which the lips 
 communicated primitively with the face. Farther, in the simple fissure 
 of the palate we generally remark that the anterior and intermaxillary 
 portion of the upper maxillary bone on one side is separated from the 
 posterior ; at least the solution of continuity is rarely situated on the 
 median line, and the intermaxillary bones are seldom attached each to 
 the corresponding maxillary bone, and the two maxillary bones with 
 the 'palatine bones are not often separated symmetrically from each 
 other and from the septum of the nasal fossæ. (2) The mode in which 
 the uvula is developed explains why fissures in it are situated on the 
 median line. 
 
 (1) Sandifort, De labio leporino congenito, duplici el complicata ; in the Obs, anal, 
 pathol., book iv., ch. iii. — Tenon, Sur quelques vices de la voûte palatale; in liis 
 Mém. et obs. sur V anatomie, Paris, 1810, p. 296. 
 
 (2) Tenon, loc. cit., obs. i. 
 
202 
 
 DESCRIPTIVE ANATOMY 
 
 It 13 curious that however great this deviation of formation, it some- 
 times disappears at a more advanced period, and assumes the normal 
 conditions of the regular type ; the bony palate increases either alone 
 or after the hare-lip is united, and the space between the oral and 
 nasal cavities gradually fills up. This fact supports our previous con- 
 jecture that the two halves of the uvula sometimes unite in the fetus 
 after the usual period of union. 
 
 The oral cavity presents those alterations of texture observed in all 
 the mucous membranes. One of the rarest anomalies of this class is 
 the development of hairs, which have been observed once on the sur- 
 face of an encysted tumor in the fauces of a newly born infant.(l) 
 It has been asserted that they have been seen also on the tongue. (2) 
 
 B. TARTS WHICH COMTOSE THE ORAL CAVITY. 
 
 § 2048. The different regions of the oral cavity are : 
 
 1st. The lips. 
 
 2d. The cheeks. 
 
 3d. The palate. 
 
 We proceed to describe also : 
 
 4th. The tongue. 
 
 5th. The teeth. 
 
 6th. The oral salivary glands 
 
 1, LIPS AND CHEEKS. * 
 
 A. FOHM. 
 
 § 2049 The lips (labia) are prolongations which coper the anterior 
 face of the alveolar edge of the jaws, being parallel with it. Their 
 loose edges which look towards each other are more or less enlarged 
 and turned over, that of the lower always more than the upper. The 
 opening between them is termed the mouth (os). 
 
 The upper lip is longer and more prominent than the lower. We 
 remark in it. on the median line a longitudinal depression called the phil 
 tram, which extends from the septum of the nose to the place where 
 the skin becomes much thinner. This depression is remarkable on 
 account of the space which primitively existed at the same place be- 
 tween its two lateral halves. 
 
 In the lower lip there is nothing similar, a difference which should 
 be considered : 
 
 1st. Because we know of no instance of a fissure of the lower lip. 
 
 (1) Ford, in the Méd. communie ,, vol. i., no. 51- 
 
 (2) Amatus Lusitanus, Cœs. vied. cent., ch vi., p 63. 
 
or THE digestive system. 
 
 203 
 
 2d. Because the depression of the upper lip seems to depend on the 
 greater extent of the superior frenum, and on the separation of the su- 
 perior maxillary bones, which always continues during life. 
 
 ' The places where the two lips unite are termed the angles of the 
 mouth ( anguli oris.) 
 
 The lips are insensibly continuous on each side with the cheeks. 
 
 Both regions are formed by a cutaneous, a muscular, and a mucous 
 layer. 
 
 B. MUSCLES OF THE LIPS. 
 
 § 2050. The different changes in the form of the cavity of the 
 mouth, are produced by the action of the following muscles winch 
 occupy the regions of the lips, the cheeks, and the chin. 
 
 a. Orbicularis oris. 
 
 § 2051. The orbicularis oris muscle, buccal , Ch. ( M . annularis , 
 orbicularis oris, sphincter oris), principally forms the fleshy layer of 
 the lips, surrounds the mouth, and is situated between the skin and 
 the mucous membrane. It is oval, thin, flat and broad, and is formed 
 of concentric fibres The external blend insensibly with those of its 
 antagonists, or are prolongations of fibres of these different muscles 
 which interlace together. These external fibres, however, are distinct, 
 and are not blended. The internal form a separate order. They are 
 found near the loose inner edge of the muscle and of the bps ; but they 
 insensibly disappear in the external fibres. 
 
 This muscle is united more intimately with the skin than with the 
 mucous membrane. It contracts and closes the mouth, and draws up 
 its angles. 
 
 b. Buccinator. 
 
 § 2852. The buccinator muscle, bucco-labial , Ch., is situated be- 
 tween the upper and lower maxillary bones and the orbicularis oris 
 muscle. It is square, broad, thin, and flat. Its fibres have generally 
 a transverse direction ; the upper, however, go obliquely from above 
 downward and from behind forward, the inferior proceed in the op- 
 posite direction, and the central alone are straight. Its fixed points 
 are the superior and the inferior maxillary bones. It arises from the 
 external face of the alveolar edge of these two bones ; its attachments 
 commence behind the last molar tooth, and extend to about the second 
 anterior. It also arises at its posterior part from the summit of the in- 
 ternal wing of the pterygoid process, and from a ligament which ex- 
 tends from that point to the alveolar edge of the lower maxillary bone. 
 It is blended forward with the orbicularis oris muscle. The canal of 
 Steno passes through it, near its anterior extremity. 
 
204 
 
 DESCRIPTIVE ANATOMY. 
 
 It draws the lips and the whole mouth directly backward, contracts 
 the cavity of the mouth, and consequently expels the substances in 
 tins cavity, so that it acts in blowing, whistling, expelling liquids from 
 the mouth, sucking, forming the mass of food on the tongue, and in 
 swallowing. 
 
 § 2053. We may distinguish into upper and lower the following 
 muscles which contribute to open the mouth. 
 
 The upper are, considering them from without inward : 
 
 c. d. Zygomatici. 
 
 § 2054. The zygomatici muscles, zygomato-labiaux , Ch., arc two in 
 number, a large and a small (JVI. zygomalicus major el minor). Both 
 are elongated and thin. The large is more round than the small, and 
 is also situated further outward and backward. Both arise from the 
 external face of the malar bone ; sometimes, however, the small comes 
 only from the external and inferior part of the orbicularis palpebrarum 
 muscle, which generally sends some fibres to them. Both go ob- 
 liquely from above downward, from without inward, and from behind 
 forward. They blend with the orbicularis oris muscle ; the small with 
 that portion of this muscle which makes part of the upper lip ; the 
 large with that which extends to the angle of the mouth and to the 
 lower lip. • 
 
 Sometimes the zygomaticus minor muscle is deficient; in other cases 
 its lower extremity is bifurcated ; in some subjects it does not descend 
 to the orbicularis oris muscle, but terminates in the outer face of the 
 levator labii superioris arid the levator anguli oris muscles. 
 
 These muscles draw the skin of the cheeks, the commissure of the 
 lips, and the whole mouth, downward and outward. They conse- 
 quently contribute to enlarge the mouth, particularly when they act 
 on both sides at once. 
 
 e. Levator anguli oris. 
 
 § 2055. The levator anguli oris muscle, petit sus-maxillo-labial, Ch. 
 (M. levalor anguli oris , s. caninus), is broader than the preceding, and 
 is flat and elongated. It arises in the canine fossa below the infra- 
 orbital' foramen, descends almost perpendicularly, becoming thicker 
 and narrower, and blends in the angle of the mouth behind the zygo- 
 rnaticus major muscle with the orbicularis oris, and still more with the 
 depressor labii inferioris muscle. 
 
 It raises the angle of the mouth and the upper lip. 
 
 f. Levator labii super ioris. 
 
 § 2056 The levalor labii superioris muscle, moyen sus-maxillo 
 labial , Ch., is much larger than the preceding, and partly conceals its 
 upper extremity, being covered in this place by the orbicularis palpe- 
 
OF THE DIGESTIVE SYSTEM. 
 
 205 
 
 brarum ; it has nearly the same form but a different direction, for it 
 descends obliquely from without inward. It arises from the upper 
 maxillary bone above the infra-orbitar foramen and is attached to about 
 the middle of the upper lip, so that its fibres blend with those of the 
 orbicularis oris, before which it descends. 
 
 It draws the upper lip obliquely upward. 
 
 g. Anomalus faciei. 
 
 § 2057. Below the preceding and the levator alæ nasi labiique su- 
 perioris muscle we not unfrequently find a long muscle which arises 
 near the canine fossa of the upper maxillary bone, and is attached 
 directly above the origin of the preceding ; it is termed the anomalus 
 faciei by Albinus :(1) the rhomboideus by Santorini. (2) 
 
 It assists to raise the upper lip, and wrinkles the skin which 
 covers it.. 
 
 h. Levator alæ nasi labiique superioris. 
 
 This muscle has already been described. 
 
 § 2058. The lower muscles of the mouth, considered in the same 
 order as the preceding, are, the depressor anguli oris, the depressor 
 labii inferioris, and the levator menti muscles. 
 
 i. Depressor anguli oris. 
 
 § 2059. The depressor anguli oris muscle, maxillo-labial , Ch., called 
 from its form the triangular muscle of the lips , arises from the anterior 
 part of the lower edge and the anterior face of the lower maxillary 
 bone. It ascends, contracting and becoming thicker towards the angle 
 of the mouth, where it blends with the orbicularis oris, the zygo- 
 maticus major, and particularly the levator labii superioris muscle, so 
 as to form with this latter a single muscle very much contracted in its 
 centre, the fibres of which, however, are not interrupted by a median 
 tendon. 
 
 When the lower part of the muscle formed by the union of the le- 
 vator labii superioris and the depressor anguli oris acts alone, it draws 
 the angle of the mouth and the lower lip downward, as in weeping. 
 This muscle also enlarges the mouth transversely by its external 
 fibres. When acting alone it contributes to raise the lower jaw. 
 
 (1) Hist, muse ., p. 167. 
 
 (2) Obs. anal., ch. i., § 25. 
 
 VOL. Ill 
 
 27 
 
20G 
 
 DESCRIPTIVE ANATOMY 
 
 j. Depressor labii iiiferioris. 
 
 § 2060. The depressor labii iiiferioris muscle, mento-labial , Ch. 
 (quadratics menti), is thin and square. It is covered at its lower part 
 by the preceding, and slightly above by the base of the zygomaticus 
 major muscle ; it arises farther forward and lower than the depressor 
 anguli oris muscle, ascends obliquely from without- inward towards the 
 lower lip, interlaces and intercrosses with that of the opposite side by 
 its upper and inner part, and terminates in the orbicularis oris muscle. 
 
 It draws the lower lip obliquely downward and turns it over. 
 
 This muscle and the preceding generally blend with the upper part 
 of the platysma myoides muscle. 
 
 k. Levator menti. 
 
 § 2061. The levator menti muscle is small, thick, semicircular, and 
 unmated. It is attached on each side to the anterior face of the lower 
 jaw, below the alveolar process of the canine tooth, occupies the trian- 
 gular space between the two depressor muscles, and terminates in the 
 skin of the chin. 
 
 It raises the lower lip and skin of the chin. 
 
 II. PALATE. 
 
 A. FORM. 
 
 § 2062. The palate ( palatum ) forms the arch of the mouth, which 
 it separates from the nasal fossæ. We distinguish in it two portions, 
 an anterior or osseous portion, and a posterior or soft portion. 
 
 The osseous palate is composed of the horizontal or palatine portion 
 of the superior maxillary and palatine bones, and also of the mucous 
 membrane extended on their surface. This membrane incloses a layer 
 of muciparous glands which is much thicker and more complex than 
 that of the two preceding regions. 
 
 § 2063. The soft palate, called also the veil of the palate ( palatum 
 molle , s. velum palatinum ), forms a fold which extends obliquely from 
 _ above downward and from before backward from the posterior edge of 
 the horizontal portion of the palatine bones toward the base of the 
 tongue. Its lower edge is loose, and presents in the centre a rounded 
 prolongation, termed the uvula, (l) on each side of which is a fissure. 
 These two fissured halves of the lower edge form the inferior arches oj 
 the palate (Jl. palatini inferiores). The superior arches ( A . palatini 
 
 (1) List'ranc, Considérations anaiomiqu.es, physiologiques cl pathologiques sur la 
 luette ; in the Revue médicale, vol. xi., p. 233. 
 
OF THE DIGESTIVE SYSTEM, 
 
 207 
 
 supcrioves) are situated a. little above. Both are continuous on the 
 median line in the uvüla. 
 
 The soft palate is formed of two layers of mucous membrane which 
 cover its anterior and posterior faces, and are continuous with the pi- 
 tuitary membrane, of a very dense layer of muciparous glands situated 
 between the two membranes, and of several muscles which contract 
 and vary the form of the isthmus of the fauces ( isthmus faucium). 
 
 A prominence resembling a cicatrix exists along the anterior face of 
 the soft palate and the greater upper part of the uvula ; this marks 
 the primitive division of this part into two halves. 
 
 B. MUSCLES OP THE SOFT PALATE. 
 
 § 2064. The muscles of the soft palate are distinguished into those 
 which depress it and those which raise it. The first contract the isthmus 
 of the fauces, the latter dilate it. 
 
 The muscles which contract the isthmus of the fauces are situated 
 in the two arches ; those which dilate it descend from the base of the 
 skull and are directed from without inward. 
 
 a. Constrictors of the isthmus of the fauces. 
 
 § 2065. The constrictor muscles of the isthmus of the fauces are 
 two, the palatopharyngeus and the glosso-pharyngeus muscles. 
 
 a. Palato-pharynsreus. 
 
 § 2066. The palato-pharyngeus muscle or the superior constrictor 
 •of the isthmus of the fauces (JVf. palalo-pharyngœus, s. constrictor 
 isthmi faucium superior ) arises from the upper part of the lateral wall 
 of the pharynx, where its fibres blend with those of the superior and 
 middle constrictors. Thence it enlarges, goes upward and inward, 
 enters the soft palate, divides into an anterior and a posterior layer, 
 which receive between them the levator palati mollis muscle, extends 
 to the posterior extremity of the bony palate, and unites on the median 
 line with that of the opposite side. 
 
 It depresses the soft palate. 
 
 b. Glosso-pharyngeus muscle. 
 
 § 2067. The glosso-pharyngeus muscle, of the inferior constrictor 
 of the isthmus of the fauces {M. glosso-pharyngceus, s. constrictor 
 isthmi faucium minor, s. inferior, s. proprim ), a similar but much 
 smaller muscle, ascends from the root of the tongue in the soft palate 
 before the palato-pharyngeus muscle, with which it unites and arrives 
 
208 
 
 DESCRIPTIVE ANATOMV. 
 
 at the lowev arch, where it joins with that of the opposite side at the 
 base of the uvula. 
 
 It depresses the soft palate, and particularly the uvula. 
 
 b. Muscles which dilate the isthmus of the fauces. 
 
 § 2068. There are two muscles also which dilate the isthmus of the 
 fauces, the levator and the tensor palati mollis muscles. 
 
 a. Levator palati mollis. 
 
 § 2069. The levator palati mollis muscle (JVT. levator palati mollis, 
 s. petro-salpingo-staphylinus), pétro-staphylin, Ch., is oblong and almost 
 rounded ; it arises from the centre of the anterior edge of the petrous 
 process, and from the osseous portion of the Eustachian tube, and also 
 from the posterior part of the commencement of its cartilaginous por- 
 tion, by a short and strong tendon, goes inward and downward, en- 
 larges but becomes thinner, and blends with that of the opposite side ; 
 it forms in the soft palate between the two layers of the palato-pha- 
 ryngeus muscle an arch the convexity of which looks upward and 
 the concavity downward. 
 
 It raises the soft palate, and extends it transversely. 
 
 b. Tensor palati mollis. 
 
 § 2070. The tensor palati mollis muscle, ptérygo staphylin, Ch. 
 (M. tensor palati mollis, circumflexus palati, plerygo-salpingo-staphy- 
 linus), is broad, thin, and quadrilateral. It arises a little inward and 
 forward from the upper extremity of the pterygoid process behind the 
 pterygoid fossa on the inside of the oval foramen of the sphenoid bone ; 
 it frequently comes also from a greater or less exteht of the posterior 
 edge of the internal layer of the pterygoid process, and from the outside 
 of the cartilaginous portion of the Eustachian tube. It goes inward 
 and downward and becomes a flat tendon, which turns on the hook of 
 the pterygoid process, a mucous bursæ existing between them ; it 
 is attached by its anterior edge to the posterior edge of the palatine 
 arch, and always blends with the tendon of that of the opposite side to 
 form the upper part of the soft palate. 
 
 This muscle extends the soft palate and draws it outward, and con- 
 tributes, like the preceding, to dilate the isthmus of the fauces. 
 
 c. Palato-staphylinus. 
 
 § 2071. The uvula or the central portion of the palate, the base of 
 which is pointed, is composed of numerous muciparous glands, which 
 are every where surrounded, sometimes by one sometimes by two 
 
OF THE DIGESTIVE SYSTEM. 
 
 209 
 
 muscles, termed the palato-staphylinus (M. uvulœ , s. azygos uvulœ) 
 This muscle is always very long, and descends from the palatine spine 
 and the anterior face of the tendon of the tensor palati mollis muscle. 
 By contracting, it shortens the uvula. 
 
 III. TONGUE. 
 
 A. NOBMAL STATE. 
 
 § 2072. The tongue ( lingua){\ ) is the principal organ of taste, and 
 also of speech and deglutition. 
 
 We may consider it as the lower part of the cavity of the mouth, 
 and consequently of the alimentary canal, which is considerably en- 
 larged, and which from this fact projects within the cavity. 
 
 Its form is oblong, its edges are rounded, and it gradually becomes 
 thin from behind forward. 
 
 Its posterior part is termed the root, and the anterior part the point 
 or apex. It extends forward and on the sides much beyond its base of 
 support, so that it is loose in these two regions, which form most of it. 
 Its integuments are uninterruptedly continuous with the buccal mem- 
 brane, which forms below its point a longitudinal fold of a very firm 
 tissue, which is attached to the centre of the inner face of the lower 
 maxillary bone, fixes the organ more firmly to the part it occupies, 
 and is termed the frcenum linguae. 
 
 As the tongue is formed chiefly by muscles, it assists in articulation 
 and deglutition, while on account of its membranes it is the organ of 
 taste. . 
 
 Its base is formed posteriorly by the hyoid bone. 
 
 a. Muscles of the tongue. 
 
 § 2073. The muscles of the tongue(2) may be distinguished into 
 the muscles of the hyoid bone and the proper muscles of the tongue. 
 
 (1) M. Malpighi, De lingua , Bologna, 1665. — G. Fracassati, De lingua. — L. Bel- 
 lini, Gustus organon novissime detectum, Bologna, 1665. — L. Heister, De lingua 
 sana et œgrota, Altdorf, 1716. — A. F. Walter, De lingua Humana, Leipsic, 1724. — J. 
 Reverhorst, De fabriea et usu linguae, Leyden, 1739.— Royen, De fabrica el usu 
 linguae, Leyden, 1742. — J. A. Rinder, -De linguae involucris, Strasburg, 1778. — 
 Bauer, Sur la structure de la langue ; in the Journal compl. des sc. méd., vol. xiv., 
 p. 181. — Gerdy, Discussions et propositions d'anatomie, de physiologie et de patho- 
 logie, Paris, 1823, p. 19, pl. i. and ii. — Blandin, Sur la structure et les movvemens de 
 la langue ; in the Archiv, gén. de méd., vol. i., p. 437. 
 
 (2) Isenflamm, De motu linguae, F.rlangen, 1793. 
 
21.0 
 
 DESCRIPTIVE ANATOMY 
 
 a Muscles of the hyoid bone 
 
 1. Mylo hyoideus. 
 
 § 2074. The mylo-hyoideus muscle transversus mundibulœ, s. 
 mylo-hyoideus) fills the larger anterior part of the space between the 
 two halves of the lower jaw, viz., the two halves of the horizontal 
 portion and the body of the hyoid bone. It is loose outward in nearly 
 its whole extent, and is covered in its centre by the anterior belly of 
 the digastricus muscle of the lower jaw. 
 
 It is a triangular and thin muscle, the external convex edge of 
 which arises from a corrugated line on the inner face of the horizontal 
 portion of the lower jaw, and proceeds from before backward and from 
 within outward. It enlarges considerably from before backward. Its 
 anterior fibres are transverse. The posterior are directed from before 
 backward and from without inward, and proceed toward those of the 
 opposite side. It descends from without inward, and unites with the lat- 
 ter on the median line, being separated from it only by a narrow tendinous 
 band which extends from before backward to the single muscle formed 
 by this union. It is attached by the inner portion of its posterior 
 edge to the centre of the anterior face of the middle piece of the hyoid 
 bone. 
 
 This muscle supports those of the tongue, which rest on it, and also 
 the sublingual gland, compresses the canal of Wharton, and the ex- 
 cretory ducts of the sublingual gland, sustains these parts, and- raises 
 the hyoid bone. 
 
 2. Genio-hyoideus. 
 
 § 2075. The genio-hyoideus muscle is situated directly above the 
 centre of the preceding, next to the synonymous muscle of the opposite 
 side. It has the form of a very elongated triangle, and arises from the 
 upper part of the anterior face of the body of the hyoid bone, goes from 
 behind forward and from below upward, gradually becomes thinner 
 and rounder as it ascends, and is attached to the lower part of the in- 
 ternal mental process directly above the mylo-hyoideus muscle. Its 
 anterior and posterior attachments are by very short, tendinous fibres. 
 
 It draws the hyoid bone upward and forward. When this bone is 
 fixed by its depressor muscles it brings the lower jaw downward 
 and backward, so that it acts like the digastricus muscle of the lower 
 jaw. 
 
 Sometimes it is deficient, or rather it is imperfectly developed, and 
 is replaced by a smaller muscle, which arises from the median tendon 
 of the preceding, and is attached to the digastricus muscle.(l) 
 
 (1) Duille, Far. muse., Landshut, 1815, p. 5. 
 
Oj? THE DIGESTIVE SYSTEM 
 
 2 iî 
 
 3. Stylo-hyoideus. 
 
 § 2076. The stylo-hyoidèus muscle (JVT. stylo-hyoideus, s. levator 
 ossis hyoidei) is thin, elongated, and rounded. It arises bj a short 
 tendon at about the centre of the external face of the styloid process, 
 goes forward, downward, and inward, presents near its lower extremity 
 a fissure for the tendon of the digastricus muscle, and is attached to 
 the anterior half of the external edge of the large horn of the hyoid 
 bone opposite the thyro-hyoideus muscle. 
 
 It chaws the hyoid bone upward and backward. 
 
 It is frequently doubled, which anomaly depends on the presence of 
 a small accessory muscle. 
 
 4. Sterno-hyoideus. 
 
 § 2077. The sterno-hyoideus muscle (JVT. depressor ossis hyoidei , s. 
 sterno-hyoideus ) is thin and elongated. It conies from the inner face 
 of the first piece of the sternum and of that of the cartilage of the first 
 rib, and sometimes also from the inner extremity of the clavicle ; 
 thence it goes directly upward, in its course approaching that of the 
 opposite side, and becomes thicker and narrower. It is finally attached 
 to the lower edge of the middle piece of the hyoid bone, directly at the 
 side of the median line. 
 
 It draws the hyoid bone downward, and as this bone is attached 
 to the lower jaw, when the other is not fixed by its levator muscles, it 
 is also depressed so that it acts on opening the mouth. 
 
 Sometimes it blends below with the sterno-thyroideus muscle,(l) or 
 arises from the centre of the clavicle. (2) 
 
 5. Omo-hyoideus. 
 
 § 2078. The omo-hyoideus muscle, scapulo-hyoidien , Ch. (JYI. re- 
 tractor ossis hyoidei , omo-hyoideus , coraco-hyoideus ), is a very long, 
 thin, and digastric muscle. Its inferior belly arises from the upper edge 
 of the scapula, sometimes also from the small ligament extended over 
 the coracoid fissure ; goes upward and forward ; between the sterno- 
 cleido-mastoideus and the scalenus anticus muscles it becomes a 
 tendon whence the superior belly arises, which is attached to the 
 middle piece of the hyoid bone on the outside of the preceding, and 
 blends more or less with the stylo-hyoideus muscle. 
 
 It draws the hyoid bone downward, backward, and a little to the 
 side. This muscle frequently presents anomalies. It is rarely entirely 
 
 (1) Albinus, HistjUnusc., p. 202. 
 
 (2) Kcleh, Bcytrage zur pat hol. Amt., Berlin, 1714, p. 32. 
 
212 
 
 DESCRIl’lT VJJ ANATOMY. 
 
 deficient : we have observed it once, on the left side, without a substi- 
 tute. Its origin frequently varies. Sometimes the inferior belly is 
 broader, so that it extends to the upper angle of the scapula.(l) 
 Sometimes it arises from the clavicle,^ 2) and it is then unusually 
 short. In some subjects the lower belly is divided into two heads, to 
 which its simple enlargement is an approximation. (3) One of these 
 heads is sometimes attached to the clavicle. (4) In some cases it 
 unites with the sterno-thyroideus muscle by its superior belly or by 
 a special head. (5) More rarely it is not inserted in the hyoid bone 
 but in the transverse process of the sixth(6) or second ? cervical(7) ver- 
 tebra. 
 
 b. Proper muscles of the tongue. 
 
 1 . Genio-glossus muscle. 
 
 § 2079. The genio-glossus muscle (JVl. txpulsor , utlrahens linguae, 
 s. genio-glossus), the largest of all the muscles of the tongue, arises 
 from the lower jaw by tendinous fibres which aïe inserted directly 
 above the genio hyoideus muscle. It is situated against that of the 
 opposite side, which it does not leave because its direction is that of the 
 median line ; it goes backward, enlarges much like a fan, and forms 
 the greater inner part of the tongue the whole length of this organ. It 
 also gives off some fibres which go outward, pass on the following 
 muscle, sends several to the upper part of the pharynx, and furnishes 
 a few to the upper horn of the hyoid bone and the epiglottis. 
 
 It brings the tongue, the hyoid bone and the pharynx forward. 
 
 2. Hyo-glossus. 
 
 § 2080. The hyo-glossus muscle (JVT. depressor linguae, s. hyo- 
 glossus, s. basio-cerato-chondro-glossus) is thin, and has a long square 
 form. It arises from the outer part of the body of the bone, from the 
 external edge of its great horn, and from the summit of the small 
 horn, ascends toward the lateral part of the tongue, and contributes 
 to form it. 
 
 It draws the tongue downward. 
 
 (1) Albinus, Hist, muse., p. 200. 
 
 (2) Albinus, loc. cit., p. 201. 
 
 (3) Duille, loc. cit., p. 11. 
 
 (4) Kelch, loc. cit., p. 31. — Sels, De musc, variet., Berlin, p. 6. 
 
 (5) Sels, loc. cit., p. 5. 
 
OF THE DIGESTIVE SYSTEM. 
 
 213 
 
 3. Stylo-glossus. 
 
 § 2081. The stylo-glossus muscle (JVE. retractor linguae , s. stylo- 
 glossus ), the shortest of the small muscles which come from the hyoid 
 bone, arises directly from its summit and also from the upper part of 
 its circumference, and arrives at the root of the tongue, in which it 
 expands like a fan to its point, interlacing more or less with the hyo- 
 glossüs and the genio-glossus muscles. 
 
 It draws the tongue obliquely backward to its side, and enlarges it 
 when it acts with its synonymous muscle. 
 
 We have once found it double on both sides. 
 
 4. Lingualis. 
 
 § 2082. The lingualis muscle is thin and narrow. It extends from 
 before backward the whole length of the tongue, and interlaces prin- 
 cipally with the hyo-glossus and the genio-glossus muscles. 
 
 It shortens the tongue, and carries its point backward. (1) 
 
 (1) Gerdy has described better than any one before him the lingual portion of the 
 special muscles of the tongue, and has followed them through its whole extent. His 
 conclusions are as follow : 
 
 The tongue is composed of a membrane, a peculiar yellow tissue, a superficial 
 lingual, two deep lingual, the transverse lingual, and the vertical lingual muscles, 
 all of which are distinct, of the two stylo-glossi, the two liyo-glossi, the two genio- 
 glossi, the two glosso-staphylini muscles, and the fasciculi of the hyo-glosso-epi- 
 glossus. 
 
 The lingual membrane is thick and cartilaginous on its lower surface, in which 
 the subjacent muscular fibres are inserted. 
 
 The yellow tissue covers at the base of the tongue the enveloping membrane, which 
 has no cartilaginous texture in this place. It adheres to the hyoid bone, to the epi- 
 glottis, and to many muscular fibres. Follicles exist within it. 
 
 The superficial lingual muscle covers the upper face and the edges of the tongue, 
 adheres closely to its membrane, and is attached posteriorly to the yellow tissue. Its 
 fibres go forward, some on the upper face of the tongue, converging: toward the 
 median line, others above and below its edges to its apex. 
 
 The deep lingual'muscles are two small fasciculi situated on each side under the 
 posterior two thirds of the tongue, between the hyo-glossi and the genio-glossi 
 muscles. Their fibres are attached posteriorly to the yellow tissue. 
 
 The transverse lingual muscles are situated under the superficial lingual, pass 
 through the whole breadth of the tongue and between the lateral fibres of the su- 
 perficial lingual muscle, which they cross at a right angle, and are attached to the 
 membrane of the tongue under the edge of this organ. They are divided on the 
 median line by a fibro-cellular raphe. They gradually curve more and more to- 
 wards the base of the tongue. 
 
 The vertical lingual muscles extend from the upper to the lower lingual mem- 
 brane, passing through the whole thickness of the tongue and the transverse lingual 
 muscles, with which they intercross. They curve and become more and more 
 oblique toward the base of the organ. 
 
 The fibres of the stylo-glossi muscles blend with those of the superficial lingual 
 muscle above and below the edges of the tongue, and send a transverse fasciculus 
 under the yellow tissue, which unites to that of the opposite side. 
 
 The hyo-glossi muscles are situated between the stylo- and the genio-glossi. Their 
 anterior fibres are directed from the hyoid bone very obliquely upward and forward 
 
 Vol. III. 28 
 
214 
 
 DESCRIPTIVE ANATOMY. 
 
 b. Envelops of the tongue.(I) 
 
 § 20S3. The mucous membrane which covers the tongue is charac- 
 terized principally by the great development of its papillary tissue, and 
 by the facility with which the epidermis is detached from it. 
 
 The dermis is united to the muscular membrane more intimately 
 than with the subjacent parts in any other region of the body. 
 
 Its upper face is extremely corrugated. The inequalities there ob- 
 served are : 
 
 1st. Folds. These folds are seen principally on the posterior part 
 and on the edges of the tongue. They are generally arranged regu- 
 larly, converge from without inward and from before backward, and 
 are very compact. They are about half a line high and broad. The 
 anterior present numerous transverse grooves. The posterior are 
 smooth, and consequently their surface is less extensive than that of 
 the preceding. Those at the most anterior part of the tongue are less 
 regular and constant. In the middle of the back of the tongue there 
 is frequently a more or less evident longitudinal depression. 
 
 2d. Papillæ. (2) The papillæ of the tongue are arranged very com- 
 pactly, and cover almost all its dorsal face. They are insulated only 
 at the root of the organ, where also they enlarge very much. 
 
 They vary much in form, and hence have been reduced into several 
 classes. 
 
 They are generally small, thin, triangular, and terminated by a 
 blunt or pointed summit. 
 
 The latter are very much developed on the centre of the tongue for- 
 ward and on the edges. They are termed the filiform papillæ ( papillæ 
 filiformes) . 
 
 Others which are much larger, more distinct but fewer, do not exist 
 in every part, and arc enlarged at their loose extremity into a rounded 
 
 to about the centre of the tongue. Some of the posterior rise perpendicularly to the 
 base of the tongue ; others blend with those of the superficial lingual muscle on the 
 edges of the organ. 
 
 The genio-glossi muscles are situated side by side on the inside of the hyo-glossi 
 and the deep lingual muscles : their fibres radiate from the malar process to the 
 three posterior fourths of the tongue, on the median line, to the hyoid bone, the 
 yellow tissue, and the lingual membrane. They pass from below upward through 
 the transverse and the superficial lingual muscle, and curve slightly upward and 
 outward in the thickness of the tongue. 
 
 The glosso-staphylini muscles go from the sides of the soft palate on the edges 
 of the tongue, where they blend with the superficial lingual and the stylo-glossus 
 muscle. 
 
 The hyo-glos30 epiglossus is formed of small fasciculi, generally deficient in man, 
 which go from the hyoid bone to the yellow tissue, others from this tissue to the 
 epiglottis, others also from the epiglottis to the hyoid bone. F. T. 
 
 (1) J. A. Rinder, Dc lingua: involucris , Strasburg, 1778. 
 
 (2) Albinus, Dc diversitate papillarum lingua: humanœ ; in the Annotât, acad., 
 book i., cli. xiv.— Sccmmerring, Inc. cit, tab. i., fig. 1-3. 
 
OF THE DIGESTIVE SYSTEM 
 
 215 
 
 head, whence they are termed the conical or fungiform papillæ (papil- 
 læ fungif ormes, s. clavatœ). 
 
 We must however remark, that in this respect they are frequently 
 replaced by single filiform papillæ, which are longer and larger than 
 the others. The fungiform papillæ lead to the largest of the papillæ 
 of the tongue, which are situated at the base of the organ, vary 
 much in number and size, and are arranged in two oblique series, 
 which touch at one of their extremities, and thus form a V, the point 
 of which looks backward. Their form is generally but not always 
 conical, so that they enlarge considerably from their base to their ex- 
 tremity. They are situated in a depression which is continuous with 
 the surface of the tongue by a sack with reversed edges. They are 
 termed ihelenticular papillæ (papillæ truncatœ,capitatœ,circumvallatœ') : 
 they are from three to twenty in number. Each depression commonly 
 contains only one, but sometimes three or four, although this circum- 
 stance has no effect on their whole number or on their size. They are 
 not arranged symmetrically, although generally there is one which 
 corresponds very nearly to the median line, and forms the point of 
 the V. 
 
 This latter occupies the deepest of all the cavities, that which is 
 termed the lacuna , the foramen cæcum of the tongue ; beside which 
 there is another situated behind it, and which incloses no papillæ. 
 
 We have several times thought, but wrongly, that we have disco- 
 vered in this foramen cæcum the excretory ducts either of the salivary 
 glands or of the thyroid gland.(l) 
 
 § 2084. The papillæ of the tongue appear to the naked eye, and 
 frequently when viewed by the microscope before they are injected, 
 smooth in their whole extent and single ; but when their vessels are 
 injected, their surface presents several small asperities, which seem 
 formed by collections of several fasciculi or filaments, placed one 
 against another. This texture is more apparent in the larger and an- 
 terior, than in the smaller and posterior part. 
 
 Each filament contains at least one vessel ; and when well injected, 
 the whole surface of the tongue becomes red. These vessels form 
 very complex arches and plexuses on the surface of the papillæ, since 
 they frequently anastomose, and their loose extremities incline toward 
 each other. 
 
 Each filament is also composed of a soft and whitish mass which 
 probably contains nervous substance. At least some filaments of the 
 glosso-pharyngeal nerve have been traced into the posterior papillæ of 
 the tongue, and some filaments of the lingual branch of the fifth pair 
 into the others. 
 
 (1) Coschwitz, Dc ductu salivali novo , Halle, 1724. — Refuted by Duvernoy ( De 
 ductu salivali Coschw., Tubingen, 1725), ancl by Haller {E.vp. et dub, circa ductum 
 Cosclno., Leyden, 1727). 
 
216 
 
 DESCRIPTIVE ANATOMY. 
 
 The arrangement of the vessels is more apparent in the anterior 
 than in tho posterior papillæ of the tongue, because they inclose pro- 
 portionally more mucous tissue. (1) 
 
 § 2085. Behind the lenticular papillæ, the surface of the tongue is 
 smooth, presenting only numerous muciparous glands ; its sides are also 
 smooth. We only remark on the limit between them and the lower 
 part of the cavity of the mouth, the orifices of the excretory canals of 
 the submaxillary gland. 
 
 § 2086. The tongue is covered in every part, especially on its upper 
 face, by a thick, whitish and moist epidermis, (periglottis)( 2), which is 
 formed exactly like the papillary tissue, and which consequently pre- 
 sents on its upper face numerous elevations, and on its lower face, 
 which looks towards the papillæ, a corresponding number of rounded 
 depressions, so that at first glance it seems perforated with foramina, 
 although this is not the case. 
 
 § 2087. We have already described the nerves of the tongue, and 
 have given our reasons for thinking the lingual twig of the fifth pair 
 is the principal conductor of the sensations of taste, while the hypo- 
 glossal nerve should be considered as only the nerve of motion. 
 
 Although the tongue receives many nerves, and although its surface 
 is very sensible, its substance is but slightly so. This explains how it 
 can be very much bruised, or how considerable portions of it may be 
 tied, without giving rise to general nervous affections. (3) 
 
 § 2088. The tongue is the principal organ of taste; it acts also in 
 articulation, and contributes to the first changes of the food in the ali- 
 mentary canal. 
 
 The faculty of taste resides principally at its point, next on its 
 edges, finally at its base, and very slightly or not all in its centre. It 
 however is not the only organ of taste, for the soft palate is sensible, at 
 least to certain tastes, for instance that of bitter substances. Hence 
 why the loss of the tongue is not necessarily attended with that of 
 taste. 
 
 The tongue assists also in articulation, inasmuch as several conso- 
 nants hence termed lingual , are formed, or at least articulated more 
 distinctly, by its motions in different directions. 
 
 It also contributes to change the food in the mouth by carrying it to 
 different parts of this cavity, so that it becomes perfectly moistened 
 with the saliva, and also prevents its escape from the mouth. 
 
 We shall return to this use of the tongue, and shall mention its part 
 in deglutition when describing the pharynx. ■ 
 
 (1) Albinus, De fabrica papillarum lingUœ humanœ ; in the Annot. acad. 1. i. c. 
 xv. tab. 1. — Hewson (Exp. Inq., vol. ii. p. 186. — Scemmerring, loc. cit., tab. 1., 
 fig. 6-9. 
 
 (2) Albinus, Dc pcriglottide et corpore rcticulari linguae; in the Annot. acad. 1 . i. 
 c. xvi. 
 
 (3) E. Home, Obs. on the structure on the tongue , illustrated by cases in which a 
 portion of that organ had been removed by ligature ; in the Phil, tr., 1805, p. 205-214. 
 
OF THE DIGESTIVE SYSTEM, 
 
 217 
 
 § 2089. The changes in the tongue during its development are tri- 
 fling. At first its proportional volume is greater than when the or- 
 ganism is perfect. It is also broader, and is attached to the lower wall 
 of the cavity of the mouth in a smaller portion of its lower face, which 
 resembles to a certain extent the peculiar formation of frogs. 
 
 Br ABNORMAL STATE. 
 
 § 2090. Sometimes the tongue does not exist, either from primitive 
 deviations of formation, or from ulcers which have destroyed it. 
 
 Its frenum is not unfrequently too solid, too short, or too long. It 
 is rarely bifurcated at its point. 
 
 The lenticular papillae also are rarely entirely deficient, and replaced 
 only by skin destitute of papillæ.(l) 
 
 The excess in the size of the tongue is rarely congenital. It is ob- 
 served more frequently during life after some accident, particularly 
 from metastasis. 
 
 In this case a portion of the organ may be extirpated without incon- 
 venience. This phenomenon seems to affect females more frequently 
 than males. 
 
 The turning of the tongue backward, which produces suffocation by 
 closing the entrance of the larynx, may be caused by its frënum being 
 entirely divided.(2) 
 
 The principal alterations of the texture of the tongue are scirrhus 
 and cancer. 
 
 IV. ORAL GLANDS. 
 
 A. ABNORMAL STATE. 
 
 § 2091. The oral glands ( Gl . orales) are of two kinds, the mucipa- 
 rous and the salivary glands. 
 
 a. Muciparous Glands. 
 
 § 2092. The muciparous glands are distinguished into the anterior 
 and the posterior. 
 
 The anterior are more insulated and lenticular. Then greatest 
 diameter is only two lines, and they are found principally in the lips 
 and cheeks, opposite the upper posterior molar teeth, between the buc- 
 cal membrane and the muscles it covers, They are divided according 
 
 (1) Louis, Mémoire 'physiologique et pathologique sur la langue ; in the Mém. de 
 ■Vac. de chir. vol. r., p. 486-520. — Breidenstein, De morbis linguœ, Erlangen, 1791. 
 
 (2) We doubt whether death is ever produced by this cause, although travelers 
 
 often speak of negroes swallowing their tongues. Superficial observers have been 
 led into error by a phenomenon which is proved possible by Bourdon’s researches, 
 in giving reason to think, that the greatest effort in a robust person would cause 
 death, and thus in some measure one commit suicide. ( Recherches sur le mécanisme 
 de la respiration et sur la circulation du sang , Paris, 1820, p. 84.) F. T. 
 
218 
 
 DESCRIPTIVE ANATOMY. 
 
 to their situation into labial, buccal, and molar ( gl . labiales, buccales, 
 et molares ). These latter are rarely blended in one mass, the excre- 
 tory passages of which unite in one. 
 
 The posterior are the palatine glands and the amygdalae. 
 
 The palatine glands (gl. palatincz ) form a continuous layer from 
 one to two lines thick, which covers all the palatine arch and all the 
 soft palate, the posterior face of which they occupy. 
 
 The amygdalae or the tonsils (Amygdalae, s. tonsillœ) are oval bodies, 
 about six lines long, three thick and broad, which exist in the soft pa- 
 late between the anterior and posterior arches. The fluid they secrete 
 enters the cavity of the mouth through several broad openings, situated 
 on their anterior face. 
 
 b. Salivary Glands. 
 
 § 2093. The three oral salivary glands (gl. salivates orales ) which 
 belong to the class of conglomerate glands(l) are situated around 
 the cavity of the mouth and near the lower jaw. They are the pa- 
 rotid, the submaxillary, and the sublingual glands. All secrete a pe- 
 culiar fluid, the saliva, (2) which is one of the most aqueous fluids of 
 the body, and contains a peculiar principle which cannot be coagulated 
 by boiling, by tannin, or by the acetate of lead. We also find in it a 
 white mucous substance, and the common salts of the serum of the 
 blood. It is also remarkable for its great affinity for oxygen.(3) 
 
 Beside the general characters of the class to which they belong, 
 these glands also present several common peculiarities, the principal of 
 which are as follow. 1. Their rounded form. 2. Their reddish co- 
 lor. 3. They have no special membranous capsule, are surrounded 
 only by condensed cellular tissue, and are loosely attached to the ad- 
 jacent parts. 4. They are so situated that they are affected by the 
 mechanical action of the muscles, and even partly by that of the lower 
 jaw when it is moved. 5. The fluid they secrete possesses probably in 
 every part the same properties. 
 
 Notwithstanding these general points of resemblance, they differ so 
 much in form, size, texture, situation, and color, that we must describe 
 each of them separately. 
 
 (1) N. Stenon, De glandulis oris et nuper observatis inde prodeuntibus vasis, 
 Leyden, 1661.— A. Nuck, Sialographia ductuwm aquosorum anatome nova, Leyden, 
 1690. — J. B. Siebold, Historia Systematis salivalis physiologice et pathologice consi- 
 dérait, Jena, 1797. 
 
 (2^ G. T. Fischer, Diss. de saliva physiologies et pathologice considerate, Breslau, 
 
 1817. 
 
 (3) Berzelius, Fortscritte der thicrischen Chemie, Nuremberg', 1815, p. 47. — John, 
 Recherches chimiques sur la salive et la liqueur que les ventricules de cerveau ren- 
 ferment dans l'hydrocéphale ; in the Joum, compl. des sc. méd., vol. vi., p. 270. 
 
OF THE DIGESTIVE SYSTEM. 
 
 219 
 
 a. Parotid gland. 
 
 § 2094. The parotid gland (parotis), ( 1) is the largest oral salivary 
 gland, and in the adult it usually weighs from four to five drachms. 
 
 Its form is irregularly square. It is usually more high than broad, 
 narrower from within outward than in any other direction, and its 
 thickness is much less than its height and breadth. Its lower half is 
 considerably thicker and broader than the upper. 
 
 It is situated directly under the skin, before the lower half of the ex- 
 ternal ear, between the space in the ascending ramus of the lower 
 maxillary bone forward, and backward between the auditory foramen 
 and the mastoid process of the temporal bone. 
 
 Its upper extremity, which is also the smallest edge, extends to the 
 posterior extremity of the zygomatic arch, and covers the head of the 
 ascending ramus of the lower maxillary bone. Its smaller anterior 
 half corresponds in its whole extent to the posterior part of the ascend- 
 ing ramus of the lower maxillary bone and of the masseter muscle. 
 The posterior half is larger than the preceding, and fills the space we 
 have mentioned. It covers the petrous portion and the styloid process 
 of the temporal bone, also the external parts of the pterygoidei muscles 
 and the upper part of those which arise from the styloid process. Pos- 
 teriorly, the gland terminates by nearly a straight edge, which is, how- 
 ever, slightly grooved anteriorly. Its lower extremity descends below 
 the angle of the lower jaw ; it is in contact with the posterior part of 
 the submaxillary gland, and with the middle tendon of the digastricus 
 muscle. 
 
 The lower straight edge descends obliquely, covers the posterior 
 belly of the digastricus muscle, and also generally a small portion of 
 the upper extremity of the sterno-cleido-mastoideus muscle. 
 
 The posterior concave edge is adapted to the lower part of the car- 
 tilaginous portion of the auditory passage. 
 
 The parotid gland is formed of small, rounded, and distinct granu- 
 lations. 
 
 At about the upper extremity of the middle third of its anterior edge 
 an excretory duct emerges, called the canal of Steno ( ductus Slenon- 
 ianus)(2) The parietes of this passage are considerably thick in 
 proportion to its capacity, and it proceeds from behind forward and 
 
 (1) Murat, La glande parotide considéré dans ses rapports anatomiques et patho- 
 logiques -, Paris, 1803. 
 
 (2) Although this term is generally applied to the parotid canal, it is not certain 
 that it was discovered by Steno, and not by Needham or Blaes. — N. Steno, Diss. 
 dc glandulis oris ct nuper observatis inde prodeuntibus vasis, Leyden, 1661. — Id., 
 Obscrv. anat. quibus varia oris, oculorum et narium vasa describuntur, noviqve 
 saliva: lacrymarumque et muci fontes detegunlur ct novum Bilsii commentum reji- 
 c fur Leyden, 1662.— Needham, De formatu fœlu, London, 1667; in the preface.— 
 G. Blaes, Mise. an. horn, brutorumquc fabricam diversam exhibentia, Amsterdam, 
 
 1 h74 * 
 
220 
 
 DESCRIPTIVE ANATOMY. 
 
 from without inward directly under the skin and on the masseter mus- 
 cle. It is generally from three to five lines distant from the lower edge 
 of the zygomatic process. The transverse facial artery and some 
 twigs of the facial nerve accompany it. It passes on the anterior edge 
 of the masseter muscle, penetrates between the fibres of the buccinator 
 muscle, and opens in the lateral walls of the cavity of the mouth 
 opposite the first posterior molar tooth of the upper jaw, consequently 
 before the range of the teeth. Its orifice is single, and presents a 
 warty prominence. 
 
 We not unfrequently find an accessory parotid gland ( Gl . parotis 
 acccssoria ), situated more or less before the normal parotid gland, on 
 the malar bone and the zygomatic arch. This gland never communi- 
 cates with the proper parotid gland, and sometimes divides into two 
 lobes ; it opens by a small passage into the parotid candi. It may be 
 compared with the orbitar gland of several mammalia. 
 
 b. Submaxillary gland. 
 
 § 2095. The submaxillary gland (67. maxillaris , s. submaxillaris )(\ ) 
 is but half the size of the parotid gland. It has the form of a rounded 
 triangle. It is thicker below than above, and is situated on a level 
 with the angle of the lower jaw, between its inner face and the body 
 of the hyoid bone. 
 
 On the outside it touches the lower part of the inner face of the 
 pterygoideus internus muscle. Forward it sends a small prolongation 
 above the posterior edge and the posterior part of the lower face of the 
 rnylo-glossus muscle. It rests inward on the posterior extremity of 
 the anterior belly of the digastricus muscle, posteriorly on the stylo- 
 glossus muscle. 
 
 Although this gland is much smaller than the preceding, it is, how- 
 ever, composed of much larger lobes. 
 
 The excretory duct, called the canal of Wharton ( ductus Wharton- 
 ianus), arises from the anterior extremity ; its parietes are very thin in 
 proportion to its diameter, and it is larger compared with the size of 
 the gland than the duct of Steno. Its direction is obliquely from 
 without inward and from behind forward ; it passes above the rnylo- 
 glossus muscle, below and on the inside of the submaxillary gland, on 
 the outside of the upper edge of the hyo-glossus muscle, and terminates 
 by a small verrucous prominence on the sides of the frenum of the 
 tongue, consequently behind the range of the lower teeth. 
 
 Farther inward the substance of the gland sends off a prolongation 
 some lines thick, which follows the same direction, but does not extend 
 so high, passes through the inner part of the posterior extremity of the 
 
 (1) Wharton, Adenographia, ch. xxi. — Van Horne, Dc duclibus salivalibus disp. 
 
 111 . , 1656, 1658. 
 
OF THE DIGESTIVE SYSTEM. 
 
 221 
 
 sublingual gland, and opens at the side of the canal of Wharton, some- 
 times in common with a small excretory duct which leaves this lat- 
 ter gland. This common duct is called the canal of Bartholini 
 (ductus Bartholinianus).( 1 ) 
 
 c. Sublingual gland. 
 
 § 2096. The sublingual gland (Gl. lingualis, s. sublingualis)(2) is 
 situated before the preceding, so that the posterior extremity touches 
 the anterior extremity of the latter, occupies on each side the whole 
 length of the tongue, and may be found directly under the buccal mem- 
 brane, through which it is easily felt, and is even visible, on account of 
 its inequalities and prominences. It is situated between this mem- 
 brane, the myo-glossus, the genio-glossus, the genio-hyoideus, and the 
 hyo-glossus muscles. It is formed like an elongated triangle, and it 
 is nearly as large as the submaxillary gland. 
 
 It is composed of smaller lobes than the preceding, is whiter and 
 harder than it, and opens not like the two glands previously described 
 by one orifice, but by several, usually seven or eight ; it, however, 
 forms no distinct excretory duct. We perceive these openings on the 
 lower face of the cavity of the mouth on each side below and near the 
 tongue. There are also several ducts from its anterior portion ( ductus 
 Riviniani ), which unite with that of the submaxillary gland ; some- 
 times one only anastomoses with a passage formed by a division of this 
 latter, and thus give rise to the passage of Bartholini (§ 2095). 
 
 § 2097. There are in fact no other salivary glands or other pas- 
 sages which carry saliva. Although several anatomists(3) have ad- 
 mitted others, it has long been proved that the parts considered as 
 such are simply those of the muciparous glands at the root of the 
 tongue or around the larynx, or even of the veins of the back of the 
 tongue. (4) 
 
 § 2098. The oral glands present no differences in respect to their 
 development, except those generally remarked in all glands. 
 
 (1) G. Bartholini has discovered it in the lion {De duclu salivali hactenus non 
 descripto observation Leyden, 1684). 
 
 (2) A. F. Walther, De lingua Humana novis inventis octo sublingualibus salivœ 
 viis , nunc ex suis functionibus , glandulis sublingualibus eductis , Leipsic, 1724. 
 — C. J. Trew, De tasis linguae salivalibus atque sanguiferis epistola, Nuremburg, 
 1734. 
 
 (3) A. Vater, Novus ductus salivalis, qui in linguæ superficie superior e circa ejus 
 medium notdbili orificio hiat, Wittemberg, 1720. — Id., Novus ductus salivalis isque 
 prœcipuus in lingua excretorius glandulœ insignis ad latera linguæ et sub eadem 
 sitce itemque super radicem linguæ , epiglottidem , circa glottidem super arytœ- 
 noideas usque intra œsophagum expansæ, Wittemberg, 1721. — Id., De ductu salivali 
 in lingua noviter antehac detecto, nunc dilucidato, confirmato , novisque experiments 
 adducto, una ductus excretorius tonsillarum ac glandulæ thyrcoideœ, Wittemberg, 
 1723. — G. D. Coschwitz, De ductu salivali novo , Halle, 1724. — Id., Continuatio obser- 
 vationum de ductu salivali , Halle, 1729. 
 
 (4) Trew, loc. tit. 
 
 VOL. III. 
 
 29 
 
222 
 
 DESCRIPTIVE ANATOM V 
 
 B. ABNORMAL STATE. 
 
 § 2099. The anomalies of the oral glands, generally speaking, pre- 
 sent nothing peculiar. 
 
 Primitive deviations of formation are very rare. 
 
 We must, however, mention as such the abnormal union of the 
 parotid and submaxillary glands. 
 
 These organs, particularly the parotid canal, are easily wounded ; 
 this causes the saliva to flow outward, and thus forms salivary fistula. 
 
 The closing of the orifice of the excretory canal of the submaxillary 
 gland is often at least the cause of ranula , although this affection 
 depends very frequently on a newly-formed cyst.(l) 
 
 Simple enlargement is rare. The swelling of the parotid gland in 
 inflammation is situated in the cellular tissue between its lobes. 
 
 So too the general alterations of texture, as scirrhus and cancer, 
 which are also attended with an increase of volume, generally occur 
 not in the glandular tissue, but in the lymphatic glands, which are 
 situated on the inside and below the salivary glands, since the glan- 
 dular tissue is generally unaffected in this case. (2) 
 
 The tumors developed in the lower jaw are also situated in the 
 lymphatic glands of the neck. Sometimes we meet here, as in other 
 parts of the system, accidental ossifications with formations entirely 
 abnormal. (3) 
 
 Calculous concretions are formed in the amygdalae and the salivary 
 passages, especially in the excretory ducts of the submaxillary gland. 
 These calculi are composed, according to Fourcroy,(4) of an animal 
 matter and of phosphate of lime. If however we may judge from 
 external characters, a salivary calculus described by us(5) seems more 
 similar to those biliary concretions which have cholesterine for their 
 base. 
 
 The calculi developed in the amygdalæ are of a dirty white color. 
 The disagreeable odor which they generally possess probably de- 
 pends, (6) at least in great part, on the decomposition of animal 
 matter which surrounds them and enters into their composition ; for 
 frequently this matter alone is very disagreeable, and, like the forma- 
 
 (1) Breschet, Considérations sur la tumeur nommée communément ranulc ou 
 grenouillette ; in the Journ. univ. dessc. méd., vol. viii., p. 296. 
 
 (2) Burns, Anatomy of the head and neck , p. 270. 
 
 (3) Burns, loc. cit., p. 283. 
 
 (4) Syst, des conn, chim ., vol. ix., p. 312. — John has found nothing- else in two 
 salivary calculi, one of which come from th,e tissue of the parotid gland : Chemische 
 Zerlegung einer Concretion der Parotis; in the Deutsches Arch, für die Physio- 
 logie. vol. iv., p. 602 : Chemische Zerlegung einer Speichelsteins ; same journal, voL 
 vi., p. 603. 
 
 (51 Handhuch der pathologischen Anatomie , vol. ii., pt. ii., p. 467. 
 
 (6) Burns,, loc. cit.. p. 265. 
 
OF THE DIGESTIVE SYSTEM. 
 
 223 
 
 tion of the calculi of which we are speaking,(l) depends on a derange- 
 ment of the digestive function. 
 
 V. TEETH. 
 
 § 2100. The teeth (dentes) { 2) are the hardest parts of the body. 
 In their chemical and physical properties they resemble the bones, but 
 they differ from them in their mode of union with the body, in their 
 mode of development, and in their vital phenomena. In all these res- 
 pects they are more similar to the epidermoid parts, particularly the 
 nails and hairs. 
 
 A. NOBMAL STATE. 
 
 a. Perfect state. 
 
 § 2101. 1st. Situation. The teeth are inserted in most of their extent 
 in the alveolar processes of the two jaws, which closely embrace them, 
 and articulate with them by gomphosis. The portion in the alveolar 
 process is termed the roow*radix dentis ). The rest of the tooth,ls not 
 free. The centre, which is the smallest part, is termed ihe neck 
 ( collum , s. corona dentis), and is surrounded by the gum 5 -all the por- 
 tion above projects, and is exposed in the cavity of the mouth ; this 
 is the body or crown of the tooth (corpus, s, corona dentis). 
 
 (1) Burns, loc. cit., p. 265. 
 
 (2) Treatises on the teeth generally treat of their anatomy, physiology, pathology, 
 and therapeutics, and differ only by speaking more at length on one of these heads. 
 We mention several works almost entirely pathological, as many of them contain a 
 number of special or general remarks in regard to their anatomy and physiology : 
 Eustachius, De dentibus libellus, Venice, 1563. — B. Martin, Dissertation sur les 
 dents, Paris, 1679.— A. C. G. Cumme, Diss. sist. dentium historiam, Helmstadt, 
 1715. — P. Fauchard, Le chirurgien dentiste, ou traité des dents, Paris, 1728. — Le- 
 cluse, Nouveaux élémens d'odontologie, Paris, 1754. — Bourdet, Recherches et obser- 
 vations sur toutes les parties de l'art du dentiste, Paris, 1757. — Curtis, A treatise on 
 the structure and formation of the teeth, Oxford, 1769. — F. X. de Wasserberg, 
 Aphorismi anatomico-physiologici de dentibus, Vienna, 1770.— J. Hunter, Natural 
 history of the human teeth, London, 1778. — H. G. Courtois, Le dentiste observateur, 
 Paris, 1775. — Broussonet, Considérations sur les dents en général et sur les organes 
 qui en tiennent lieu ; in the Mém. de l’ac. des sc., 1787, p. 550. — A. G. Berger, Diss. 
 de dentibus, Kiel, 1788. — S. H. Bring, Observationes in hodiernam de dentibus, 
 præcipue hominum, doctrinam, Lund, 1793. — F. Hirsch, Praktische Bemerkungen 
 über die Zahne, Jena, 1801. — R. Blake, Essay on the structure and formation of the 
 teeth in man and various animals, Dublin, 1801. — J. Fox, Hist. nat. et maladies des 
 dents de l’esp. humaine, Paris, 1821. — A. Serres, Essai sur l’ anatomie et la phsio- 
 logie des dents, ou nouvelle théorie de la dentition, Paris, 1817. — F. Lavagna, Espe- 
 rienze e riflessioni sopra la carie dei denti, Genes, 1821. — Heilbronn, Diss. de denti- 
 bus, Berlin, 1821. — C. G. Kaathover, De dentium formatione atque natura, Leyden, 
 1821. — J. Lemaire, Traité sur les dents, Paris, 1822. 
 
224 DESCRIPTIVE ANATOMY. 
 
 The root and neck of the teeth are covered with a thin membrane ; 
 this is continuous below with a nervous and vascular tissue which 
 fills the cavity of the tooth, and above with the gum ; it is termed the 
 dentar periosteum , although the history of dentition seems to demon- 
 strate that its relations with the teeth are not the same as those be- 
 tween the periosteum and the bones. 
 
 The alveolar processes are also covered by a fibrous and thick mem- 
 brane, which in the normal state does not unite with the preceding, 
 but is continuous with the upper part of the gum, and is termed the 
 alveolar periosteum. 
 
 The gums ( gengivœ ) are a firm, resisting cellular tissue about half 
 a line thick, which adhere intimately with the buccal membrane, and 
 receive but few vessels or nerves. They cover the neck of the teeth, 
 and also the two faces of the alveolar edges of the jaws, and furnish 
 thin prolongations which extend between each two teeth, from the 
 anterior to the posterior face. 
 
 The teeth of each jaw collectively form an arch which is concave 
 backward and convex forward. 
 
 They are generally arranged very compactly, and are placed at 
 equal distances from each other. The upper and the lower touch at 
 their summits. The arch formed by the upper teeth is a little longer 
 than the other. Hence the upper teeth slieîtly project outward, and 
 the anterior, which are thinner, cover the otimrs. The posterior and 
 inferior t#eth have their summits slightly inclined inward, while those 
 of the uppesare turned more directly downward. 
 
 2d. Form. All the teeth are more or less elongated ; their lower 
 extremity is slightly pointed, and there presents a small opening which 
 leads into the cavity of the tooth ( cavum dentis). This cavity extends 
 from the summit of the roots to the crown, and is very narrow in pro- 
 portion to its length, represents the form of the tooth, and lodges its 
 vessels and nerves, which are connecte I by cellular substance. 
 
 3d. JYumber. The number of the teeth is the same in the two jaws, 
 on the two sides, and in the two sexes. In a well developed man 
 there are thirty-two. 
 
 4th. Texture. The tissue of the teeth is very hard and solid. They 
 are composed of two substances, the osseous substance and the enamel. 
 
 § 2102. The osseous substance or the ivory forms the largest part of 
 the tooth, the root, the neck, and almost all the crown. It conse- 
 quently represents the form of the whole tooth. Its hardness, which 
 exceeds that of the bones, depends upon its mechanical arrangement 
 and on its chemical composition. In fact it contains no cellules. 
 We perceive in it but not very clearly only longitudinal layers, 
 situated one upon another from without inward, and it contains 
 more of lime than the other bones. Berzelius asserts(l) that one 
 
 (1) Gehlen, Journ. fur die Chimie und Phys., vol. iii., part i., p. 19. 
 
OF THE DIGESTIVE SYSTEM. 
 
 225 
 
 hundred parts of this substance contain 51.04 of phosphate of lime ; 
 2.00 of fluate of lime ; 11.30 of carbonate of lime ; 1.16 of phosphate 
 of magnesia ; 1.20 of soda ; and an indeterminate quantity of hydro- 
 chlorate of soda. Pepys states that they contain 0.64 of phosphate of 
 lime; 0.6 of the carbonate; 0.20 of gelatine; and 0.10 of water, in- 
 cluhng the loss.(l) 
 
 I 2103. The enamel {substantia vitrea) (2) is milk white, brilliant, 
 semitransparent, and still harder and firmer than the osseous substance. 
 It covers all the crown of the tooth, is molded exactly upon it, and 
 preserves all the inequalities of its masticating surface, where it is 
 thickest. It gradually grows thinner towards the neck. It is com- 
 posed of oblique, undulating, serrated bands, concave upward, convex 
 downward, which are arranged compactly from above' downward, and 
 exactly fit to each other.(3) 
 
 The enamel contains still more of earthy salts than the osseous sub- 
 stance. We find in it, according to Morichini :(4) 0.33 of lime ; 0.09 
 of magnesia ; 0.05 of alumina ; 0.22 of fluoric and phosphoric acids ; 
 Ö.01 of carbonic acid ; and 0.30 of animal substance. 
 
 According to Hatchett(5) it contains very little of gelatine, and is 
 mostly formed of phosphate of lime. 
 
 Foucroy and Yauquelin(6) state that it is composed of 72.90 of 
 phosphate of lime, and 27.10 of gelatine and water. 
 
 Pepys asserts(7) that it is formed of 0.78 of phosphate of lime ; 0.60 
 of the carbonate ; and 0.16 of water. 
 
 Finally, Berzelius(8) mentions as its component parts : 85.3 of the 
 phosphate ; 3.3 of the fluate ; 8.0 of the carbonate of lime ; 1.5 of the 
 phosphate of magnesia ; and 2.0 of animal substance and water. 
 
 § 2104. The vessels and nerves of the teeth are proportionally very 
 large. The first arise from the internal maxillary artery ; the nerves 
 come from the second and third branch of the trifacial nerve, penetrate 
 through the openings at the summit of the roots, correspond perfectly 
 to them in number, descends into the cavity of v the tooth, where, 
 united by cellular tissue, they form the nucleus or pulp of the tooth 
 ( pulpa , s. nucleus). These nerves enlarge near the neck of the tooth, 
 
 (1) Fox, loc. cit. 
 
 (2) Ludwig-, De cortice dentium, Leipsic, 1753. — Schreg-er, Uber den Zahn- 
 schmelz ; in Rosenmullcr and Isenflamm, Beiträge zur Zergliederungskunst, vol. 
 i., part i. 
 
 (3) Cumme, loc. cit., p. 9. — Schreger, loc. cit. 
 
 (4) Analisi delta smalto di un dente di elefante c dei denti umani ; in the Memoire 
 della societa italiana, vol. x., pt. i., p. 162 ; vol. xii., pt. ii., p. 73. 
 
 (5) Phil, trans., 1799. 
 
 (6) Mém. de V Institut., vol. ii., p. 283. — Annales de chim., vol. lv., p. 265 ; vol. 
 lvii., p. 37. 
 
 (7) Loc. cit. 
 
 (8) Gehlen, Journ.für phys. und Chem., vol. iii., part i., p. 27. 
 
226 
 
 DESCRIPTIVE ANATOMY. 
 
 become soft and reddish, and seem covered with a network of ves- 
 sels.^) 
 
 § 2.105. These characters are common to all the teeth ; but there are 
 others in respect to which they differ, and hence they may b^divided 
 into several classes. 
 
 They differ from each other in several respects, but principally in 
 regard to : \ 
 
 1st. Their situation. 
 
 2d. Their form. 
 
 3d. Their duration. 
 
 4th. The period of life at which they appear. 
 
 § 2106. In respect to situation , the most general difference is that 
 which exists between the teeth of the upper and those of the lower 
 jaw. The latter differ from the former in being a little smaller, so that 
 the curve represented by their union is narrower and shorter ; hence 
 the upper row of teeth projects a little beyond the lower in every part. 
 
 § 2107. The teeth sj( the same jaw differ from each other in form ; 
 hence their division into three classes, the incisors , the canine , and the 
 molar teeth. 
 
 § 21 OS. The incisors ( dentes incisivi , incisores, primores ) are eight 
 in number, four in each jaw, occupying the most internal and the most 
 anterior part. They differ most from the others in the form of their 
 crown. The latter is chisel-shaped, and becomes much thinner from 
 the neck to the summit, which presents the cutting surface. The 
 posterior face is vely concave and the anterior is convex, but not in 
 the same proportion. The incisors begin to become extremely thin 
 from their centres. In the perfect state, when they have not been used 
 for mastication, their edge is divided into a middle and two lateral 
 small grooves ; but these grooves soon disappear, and the summit of 
 the tooth then forms only a- thin straight line, which extends the whole 
 breadth' of the crowp. , 
 
 These teeth have but one root. It diminishes imperceptibly from 
 the crown to its extremity. A depression not unfrequently exists its 
 whole length on each side, indicating the division of this root into two 
 halves, an anterior and a posterior ; and even the summit is divided 
 into two small grooves, an anterior and a posterior. 
 
 The incisors differ from the other teeth in their direction ; they are 
 situated more transversely, so that their loose face looks forward ; the 
 other is turned backward, and their cutting edge extends from one side 
 to the other. 
 
 §2109. The incisors also differ much from each other. The dif- 
 ference between the synonjnnous teeth of the two jaws is no where so 
 striking as in them, even when they are most similar in size. Those 
 of the upper jaw, however, extend half a tooth farther outward than 
 
 (1) Serres, loc, cit., p.52. 
 
OF THE DIGESTIVE SYSTEM. 
 
 227 
 
 those of the lower jaw. The superior are twice as large as the in- 
 ferior. 
 
 The incisors of the lower jaw differ also from the others both in size 
 and for«. In fact they all have a chisel-like form, and their external 
 edge is about as high as their internal. Sometimes, even, they are 
 all similar in this respect. But most commonly their external edge 
 descends a little lower than the internal, and is continuous with the 
 other by a rounded angle. 
 
 The internal inferior incisors possess this form very seldom, and the 
 others very generally. In the external superior incisqjs the internal 
 edge is a little convex outwardly, and is insensibly continuous with the 
 lower, although a little farther downward, so that the cutting surface 
 is narrower than the greatest breadth of the tooth. 
 
 These differences in form deserve notice, as they establish the gra- 
 dual transition from the internal inferior incisors to the canine teeth 
 through the medium of the others. 
 
 In respect to the size, the inner pair of incisors in the upper jaw are 
 a little and ofteir much larger than the outer ; while in the lower jaw 
 the incisors are about the same size, or the outer pair is a little larger 
 than the inner. 
 
 § 2110. Next to the incisors come the four canine teeth ( dentes 
 canini , ferini, cuspidati ), one on each side. Their crown is much 
 thicker from before backward than that of the incisors, but it does not 
 diminish as rapidly from above downward ; hence why their summits 
 are less cutting. This summit is also pointed, because the lower face 
 does not describe a straight line, as the two lateral faces terminate 
 higher than in the incisors, and as the crown of the canine teeth is as 
 elevated as that of the latter, it follows that the lower face is composed 
 of*two parts which unite in the centre at an acute angle, Conse- 
 quently the crown is more rounded and more conical ; it extends both 
 inward and outward above that of the incisors. On the posterior face 
 we perceive from ab^ve downward in the centre a slight prominence, 
 between which and the edges there is a small depression. This ar- 
 rangement is more evident in the inferior than in the superior canine 
 teeth. 
 
 Of all the teeth the canine have the longest roots. These roots are 
 single and pointed. We generally observe in them the groove men- 
 tioned when speaking of the external incisors. 
 
 § 2111. In the posterior part of the jaw are the twenty molar teeth 
 (dentes molares), ten in each jaw, five on each sid^ They are similar 
 to each other, and differ from the other teeth : 
 
 1st. In the greater breadth of their triturating surface, which de- 
 pends on the fact that the posterior face of the crown does not descend 
 obliquely to meet the anterior, but is parallel with it. 
 
 2d. In the square or rounded form of this surface generally. 
 
 3d. In the considerable elevations and depressions in this triturating 
 surface. 
 
228 
 
 DESCRIPTIVE ANATOMY. 
 
 4th. In the lowness of their crown. 
 
 5th. In the division of their roots into several distinct branches, or 
 at least they are much more distinct than any other teeth where this 
 division is only indicated. 
 
 § 2112. Notwithstanding this general similarity they differ very 
 much’ particularly the two anterior and the three posterior. The first 
 are .termed the small molar or bicuspid teeth ( molares anteriores , s. 
 minores , s. bicuspidati) , and the others, which are larger, the great 
 molar or multicuspid ( molares posteriores, s. majores, s. multicuspi- 
 dali). 
 
 § 2113. mie small molar teeth differ from the great : 
 
 1st. By their smallness. They are at least one half smaller. 
 
 2d. By their compression from one side to the other. 
 
 3d. By their triturating surface, which is less uneven. 
 
 4th. By the form of their roots. The latter are at most bicuspid, 
 and even when they assume this form they are so only in the part 
 farthest from their crown, that is, they never present as deep a fissure 
 as the posterior molar teeth. In most cases they are broader from 
 within outward than those of the incisors and the canine teeth, are 
 terminated by a blunter summit, and their lateral grooves are more 
 superficial. 
 
 The triturating surface of the small molar teeth generally presents 
 two eminences, one anterior and external, the other posterior and in- 
 ternal. From this they take their name. This arrangement is more 
 evident in the upper jaw, because the two eminences are there sepa- 
 rated by a deep transverse groove. In the lower jaw the eminences 
 of the small molar teeth are, on the contrary, united by a crest, the 
 direction of which is from without inward. This difference deserves 
 notice, because the canine teeth of the two jaws (§ 2110) differ from 
 each other in the. same manner. The external anterior eminence is 
 always higher than the internal, particularly in the first small inferior 
 molar tooth, where the internal is but slightly developed, and which, in 
 these two respects, evidently makes the transition from the canine to 
 the other molar teeth. 
 
 But this is not true of the second small anterior molar tooth. In 
 this we usually observe, behind the posterior eminence, a smaller and 
 more prominent tubercle, or sometimes the posterior eminence is di- 
 vided into two equal halves. At the same time the external is lower, 
 the crown and the triturating surface are still more rounded, so that 
 this tooth evidenth^tnakes the transition from the anterior to the pos- 
 terior molar teeth ; it is also a little larger than the internal. 
 
 The small superior molar teeth are more similar to the large than 
 the inferior are, on account of the greater development of their posterior 
 tubercle. 
 
 § 2114. The three posterior molar teeth generally present four blunt 
 tubercles, two on the outside, and two- on the inside, which are sepa- 
 rated by a crucial depression. But we usually observe also between 
 the posterior two, on the edge of the triturating surface, a fifth, which 
 
OF THE DIGESTIVE' SYSTEM. 
 
 229 
 
 Is smaller. These tubercles are also rough. The external prominences 
 are generally the largest and most numerous, and frequently the in- 
 ternal tubercle is single, especially in the last two molar teeth. The 
 last great molar tooth is usually the smallest, and the first the largest. 
 
 Most generally the roots of these molar teeth present three branches, 
 into which they frequently divide near their crown. The last, it is 
 true, generally has but one root, but this root is never as pointed as hi 
 the canine teeth and the incisors, and it always presents at least two 
 very deep and very broad grooves, which indicate a tendency to divide. 
 Sometimes also the other two great molar teeth have only two branches 
 at their root ; but in this case one of the branches is always much 
 broader than the other, and also presents a broad and deep groove. In 
 some subjects this broad unmated branch bifurcates below into two 
 small points. The branches of the roots of the molar teeth are usually 
 more curved than the simple roots of the incisors and canine teeth ; 
 they begin by separating from each other ; they then converge more 
 or less at their lower extremity, where they even touch each other, 
 and blend together at their summits, so that they intercept between 
 them a portion of the upper maxillary bone. 
 
 § 2115. The characters which we have mentioned are those by 
 which we distinguish the teeth which remain in the jaws during most 
 of fife. But there are other different teeth which exist but a short time, 
 in youth, and are termed the deciduous , or milk teeth ( dentes clecidui, s. 
 infantiles , s. lac lei), in opposition to the first, which are termed the per- 
 manent teeth {dentes permanentes). 
 
 The teeth which appear at first do not continue during life ; many 
 of them remain only till the seventh year, and at the fourteenth year 
 all are replaced by new permanent corresponding teeth. 
 
 § 2116. The two classes of teeth differ from each other in number 
 and form. 
 
 In the first respect, we ought not to find more than two molar teeth 
 in each half of the jaw, during the period of the deciduous teeth, whence 
 there are only twenty deciduous teeth, while there are thirty-two per- 
 manent teeth. 
 
 In respect to form, we distinguish also among the deciduous teeth, 
 the incisors, the canine, and the molar teeth. The incisors and the 
 canine teeth resemble the permanent teeth in form, number, and 
 situation ; but all the deciduous teeth, and particularly the molar 
 teeth, differ from their corresponding permanent teeth. 
 
 1st. Their crown is much stronger in proportion to their root. 
 
 2d. They are less elevated. 
 
 All do not present the same peculiarities in respect to size. The 
 deciduous incisors and canine teeth are much smaller than the perma- 
 nent teeth, particularly in the lower jaw. The contrary occurs in the 
 molar teeth ; they come immediately after the canine teeth, the two 
 small anterior molar teeth replace them, and the three molar teeth 
 behind them are permanent. Hence the small anterior molar teeth 
 among the permanent teeth are those which correspond to the decidu- 
 
 Vol. III. 30 
 
230 
 
 DESCRIPTIVE ANATOMY. 
 
 ous molar teeth at least in respect to situation. But the latter are 
 much larger ; they have not the same form as the small permanent 
 molar teeth, for instead of being flattened from before backward, they 
 are extremely broad, have a broad square crown, and also several, 
 usually five tubercles, which are arranged around a very deep median 
 groove. The anterior is nearly one half smaller than the posterior, 
 although the posterior is almost as large as the largest of the perma- 
 nent teeth. Besides, they have always at least two and usually three 
 roots. Thus they correspond to the permanent small molar teeth only 
 in number and situation, for in respect to size and form, that is, in two 
 respects much more important than the two preceding, they are analo- 
 gous to the three permanent great molar teeth. 
 
 b. Differences depending on development. (I) 
 a. General remarks. 
 
 § 2117. The teeth pass through several periods, during which per- 
 haps they differ more than any other part of the body. 
 
 The history of their development presents several very curious phe- 
 nomena. The most essential points to consider, are their mode of 
 development, the period at which they appear, and their changes 
 during life. 
 
 1st. The teeth are developed in small rounded and close sacs, which, 
 adhere very closely to the gums. These sacs are composed of two 
 membranes. Hunter thinks that the internal alone is vascular, while 
 Black admits this only of the external. But we have ascertained 
 
 (1) Besides the works mentioned previously, which also treat on this subject, we 
 may consult the following : J. J. Rau, De ortu et generatione dentium, Leyden, 1694. 
 — J. A. Ungebauer, De dcntitione secundâ ; in Haller, Coll, diss., vol. vi.— J. G. Jancke, 
 De ossibus mandibularum puerorum septennium, Leipsic, 1751. — B. S. Albinus, Ds 
 dentium ortu ét incremento ; in Annot. acad.. vol. ii. eh. ii., Quot dentes mutet puer, 
 et quos, ibid., ch. iii., De dentium mutatione, ibid., ch. i. — Jourdain, Essai sur la 
 formation des dentes comparée avec celle des os, suivi de plusieurs expériences sur les 
 os et sur les parties qui entrent dans leur composition, Paris, 1766. — A. A. Brunner, 
 De eruptione dentium lacteorum ; in Wasserberg, Opp. min.,fasc. I, Francfort, 1775. 
 — M. Girardi, De re anatomicâ oratio, Parma, 1781, tab. i. — Andree, De prima pue- 
 rorum dentitione, Leipsic, 1790. — Léveillé, Mémoire sur les rapports qui existent 
 entre les premières et les secondes dents, et sur la disposition favorable de ces der- 
 nières au développement des deux mâchoires ; in the Mém. de la soc. méd. d’Emul., 
 voL viii., Paris, 1811. — Mie), Quelques idées sur le rapport des deux dentitions et sur 
 V accroissement de la mâchoire dans l’homme ; same journal. — Duval, Mémoire sur 
 la position relative de l’ouverture externe du canal maxillaire, pour servir à la dé- 
 monstration de l’accroissement delà mâchoire inférieure, Paris, 1812. — J. F. Meckel, 
 Essai sur le développement des dents chez l’homme ; in the Journ. compl. des sc. méd., 
 vol. i. p. 365. — Miel, Note sur la manière, dont les dents sortent des alvéoles et traver- 
 sent les gencives ; in the Journ. de méd., vol. xxxix. p. 235. — J. E. Oudct, Observa- 
 tion d’une altération de la racine d’une dent canine, présentant les caractères exté- 
 rieurs de la maladie des os, connue sous le nom de spinu veniosa, précédée de quelques 
 considérations générales sur la phys. dentaire ; in the Archiv, gén. de méd., vol. i., 
 p. 340. — Geoffroy Saint Hilaire, Système dentaire des mammifères et des oiseaux, 
 embrassant sous de nouveaux rapports les principaux faits de l'organisation den- 
 taires chez l'homme , Paris, 1824. 
 
OF THE DIGESTIVE SYSTEM. 
 
 231 
 
 from examining the human fetus, and those of animals, and Fox has 
 also determined that these two membranes receive vessels ; the blood, 
 however, seems to flow more abundantly to the external than to the 
 internal. A serous fluid exists between these two layers, and the dis- 
 tance between them is much greater the younger the fetus is, although 
 the layers themselves are more difficult to demonstrate than in fetuses 
 of a certain age, on account of their extreme smallness. 
 
 The external layer is more spungy, looser, thicker, and softer, 
 than the internal. It is very distinctly continuous with the gum, 
 whence it is easy, in the fetus, especially during the early months of 
 pregnancy, to extract the alveoli attached to the gum. 
 
 The internal layer is harder, but thinner than the external. We can 
 demonstrate that it forms a sac entirely distinct from the external and 
 from the gum. Its relations with the teeth are more intimate than 
 those of the external layer, for it is the proper organ of formation. 
 The vessels of the teeth are distributed there much more evidently, 
 and when injections succeed, it appears entirely red. 
 
 2d. The small sacs or follicles appear very early. About the tenth 
 week we observe very distinctly in each half of the two jaws, four, two 
 anterior which are smaller, and two posterior which are larger ; they 
 are arranged very compactly in pairs, but the anterior and the pos- 
 terior are separated by a considerable space. At the end of the third 
 month we find a third sac between the two pairs, and thus at this 
 period the whole number of follicles is twenty. We generally discover 
 -at the end of the fourth month, a sixth, situated entirely backward, 
 and which is destined for the most anterior permanent molar teeth. 
 
 3d. At first these small sacs contain only a reddish fluid, which 
 afterwards becomes yellowish white. After a certain time, at the 
 fourth month of pregnancy, a small reddish and soft body rises from 
 the base of the internal membrane ; this gradually becomes more con- 
 sistent, and forms the germ or pulp of the tooth (pulpits dentis). Nu- 
 merous vessels and nerves given off from the base of the inner mem- 
 brane, are distributed in this small body, which seems to be enveloped 
 by a vascular membrane, which is difficult to be detached from its own 
 proper substance. It is at first very low, is single in every part, and 
 terminated by a rounded summit; but it soon assumes the peculiar 
 form of each kind of tooth, and presents its exact image, and is, in fact, 
 the nucleus around which the tooth is molded. The latter is so 
 developed that the loose portion appears first, and presents all the de- 
 pressions and the eminences which exist upon it, while the rest is not 
 yet formed. 
 
 The teeth begin to ossify about the middle of pregnancy. On the 
 loose face of the germ very delicate, thin, and elastic small points first 
 appear ; these are primitively soft, but gradually become thicker and 
 more consistent. These points are grooved and very slightly elevated. 
 They are seen first on the most prominent part of the germ, and repre- 
 sent the tubercles of the future tooth. One is developed on each 
 prominence of the pulp of the tooth ; they gradually unite with each 
 
232 
 
 DESCRIPTIVE ANATOMY, 
 
 other ; they begin to develop themselves only when a portion of the 
 region of the germ corresponding to the crown is formed, and embrace, 
 that part of the pulp, which they covër so closely, that some exertion 
 is necessary to separate them. Their internal face and the external 
 face of the germ are, however, perfectly smooth. The difficulty in 
 separating them depends only on the exact manner in which they are 
 fitted to the latter, since by removing one scale, we can extract the 
 whole germ through the space thus formed. Hence, it is very probable 
 that there is no organic attachment between the pulp and the osseous 
 substance, so that these two parts of the tooth are united by vessels, 
 by cellular tissue, or by some other analogous substance. But it is 
 very curious that the germ is redder in the parts covered by the osseous 
 substance, and that the progress of this redness is in direct ratio with 
 that of ossification. 
 
 The points soon enlarge, so that they are much thicker in the parts 
 first developed, that is, on the triturating surface. They become much 
 thinner posteriorly, where they are much softer. The crown gradu- 
 ally enlarges, and its development is finally completed. Its lower ex- 
 tremity contracts and becomes the neck of the tooth. The roots are 
 prolongations of the crown, in forming which the germ follows pre- 
 cisely the same course as in giving rise to the latter. The number of 
 the roots, even when the germ has formed only the crown of the tooth, 
 is indicated by that of the distinct branches given off by its vessels. 
 
 The osseous substance forms from without inward, so that the small 
 tubercles which first appear are also the parts which always remain 
 exposed, and the triturating surface, like the existing portion of the 
 tooth, has already its normal volume, while it is still very thin, and its 
 internal cavity is very large. This phenomenon demonstrates, un- 
 doubtedly, that the bony portion of the tooth is not formed by the inner 
 face of the capsule, but by the external face of the germ, since if this 
 were not true, the opposite arrangement would exist. This osseous 
 portion gradually thickens, and the pulp and the dental cavity diminish 
 in the same ratio, although we cannot suppose that the germ ossifies. 
 
 Shortly after the development of the osseous points, or during their 
 formation, the secretion of the enamel commences, by the inner face of 
 the inner fold which surrounds the crown of the tooth, so as to be per- 
 fectly molded upon its prominences and depressions. The fluid ex- 
 haled by this membrane deposits the enamel on the osseous substance, 
 which is so soft, and adheres so slightly to this latter in the full grown 
 fetus, that they maybe very easily separated. It can be detached 
 also, even in the perfect state, from the influence of certain causes, 
 among others, by the action of heat. We discover no special gland 
 for its secretion. It may, however, be easily separated from the pro- 
 longations of the internal layer. These prolongations which arise 
 from the portion of the capsule attached to the germ, are at first very 
 thick and moist ; they gradually disappear as the enamel forms, so 
 that we may consider them as the germ of this production, and similar 
 
OF THE DIGESTIVE SYSTEM. 
 
 233 
 
 to that which arises from the bottom of the capsule to secrete the 
 osseous substance of the tooth. 
 
 The different kinds of teeth do not ossify after the same type in re- 
 spect to time and form. The internal incisors are the first, and the 
 posterior molar teeth the last to appear. In regard to the intermediate 
 teeth, the deciduous teeth differ from the permanent teeth. The in- 
 cisors and the canine teeth arise by one small point, and the molar 
 teeth by several, viz. the small by two, and the large by four or five. 
 Each point always possesses a thin triangular form on its appearance, 
 which is the constant form of the crown of the canine tooth. • In the 
 incisor and molar teeth these points extend, and those of the incisor 
 teeth present two small accessory points, which do not arise by special 
 nuclei. Among the different points of the canine teeth the external 
 and the anterior are developed the first, and next the internal. In the 
 large posterior molar teeth the anterior external is first seen, then the 
 anterior internal, and the two points of the first posterior form in the 
 same order. The different points unite according to the same law, so 
 that judging from their development, the large molar teeth seem to be 
 formed by two smaller teeth. 
 
 The inferior arise or are developed before the. superior. The points 
 of the anterior deciduous molar tooth are already united to the lower 
 jaw in the full grown fetus, while this is not the case in the upper jaw. 
 In one case where the first inferior permanent molar tooth presented 
 five osseous points, there were only three in the superior. 
 
 § 2118. When is the formation of the tooth completed? It is not 
 certainly when it appears, since the tooth cuts through the gum before 
 it is perfectly developed ; but we have now to inquire if the tooth 
 ' undergoes any other internal changes after the root is perfectly 
 formed. 
 
 Those who maintain this fact adduce the following arguments : 
 
 1st. The change in the tooth in animals fed with madder. 
 
 2d. The projection of one tooth above the rest, when the corres- 
 ponding tooth in the opposite jaw is extracted. 
 
 3d. The union of fractured teeth. 
 
 Thp following arguments have been adduced in favor of the conti- 
 nual reproduction of the enamel : 
 
 4th. The pathological changes in this substance, particularly the 
 black spots, which do not reappear after being removed until a new 
 disease supervenes.(l) 
 
 5th. The duration of the enamel, which cannot be explained when 
 we consider the continual friction of the teeth, except by admitting it 
 is constantly forming. (2) 
 
 The following are objections to these different arguments : 
 
 (1) Hirsch, loc. cit., p. 17. 
 
 (2) Ibid. 
 
234 
 
 descriptive: anatomy. 
 
 let. The coloring of the hones generally by madder does not prove 
 that their substance is constantly reproduced.(l) 
 
 2d. Probably we have less right to admit an increase in the size of 
 the tooth than its expulsion from the alveolar process. Beside the 
 phenomenon to which it alludes does not occur in man or in most 
 mammalia, although observed in some of them, particularly the 
 gnawers, (2) the teeth of which project after being extracted or cut off. 
 
 3d. The union of fractures of the teeth does not prove that their 
 substance is continually reproduced, but only that in some cases the 
 germ of the tooth can restore a fractured part by a process analogous 
 to that, when at the commencement it secretes the osseous substance 
 in every part. 
 
 4th. It is nowhere proved that the enamel is formed again in the 
 pathological cases adduced. 
 
 5th. The duration of the enamel depends on its solidity. 
 
 Thus the arguments in support of the continual formation of the 
 teeth in general, and particularly of the enamel, are by no means con- 
 clusive. On the contrary the second fact contradicts it. Beside the 
 mode in which the enamel is developed does not, admit this theory. 
 
 §2119. Beside the. whole duration of pregnancy, a long time ad- 
 vances, usually six months after birth, before the teeth appear, at least 
 externally. 
 
 During this period we find in the place afterward occupied by them, 
 a very hard and in fact a cartilaginous mass, which projects and 
 presents numerous grooves some lines deep and entirely different from 
 the gum ; this arises above the surface of the alveolar edges and 
 fulfills the function of the teeth, that is, it serves principally to retain 
 the nipple. 
 
 This substance may be called the dental cartilage ( cartilago den- 
 tulis). It is worthy of notice as analogous to the horny beak of birds 
 and reptiles. It disappears as the teeth are developed and perforate 
 the gum. 
 
 We discover in this substance, particularly in the region of the molar 
 teeth and on its inner and concave side, several follicles of different 
 sizes, containing a shining and yellowish substance ; these are at most 
 but half a line in diameter, and apparently have no external orifice. 
 Serres first mentions these follicles. (3) He thinks that they soften the 
 gum of the child before the teeth appear, and afterwards secrete the 
 tartar of the teeth. We however have never observed them until the 
 period when the teeth appear, so that hitherto we have considered 
 
 (1) B. Gibson, On the effect of madder-root on the hones of animals ; in the Mem. 
 of the literary society of Manchester, 2 d series, vol. i., p. 146-164. 
 
 (2) Lavaçna, Osservaz. sulla carie dei dcnti, Genoa, 1812. — Ondet, Expériences 
 sur V accroissement continu et la reproduction des dents chez les lapins , considérées 
 sous le rapport de leur application à l'étude. de l’organisation des dents humaines ; 
 in the Journ. dephys, expér., vol. iv., p. 70. 
 
 (3) Loc. cit., p. 28-33, pl. 4, f. 6. 
 
OF THE DIGESTIVE SYSTEM. 
 
 235 
 
 them simply as new formations, caused by the irritation of the teeth 
 which are soon to appear ; they probably do not differ in their nature 
 from abscesses. 
 
 § 2120. The triturating surface of the permanent teeth, like that of 
 the deciduous teeth, changes more or less during life. The enamel is 
 gradually used by friction so that the osseous substance is exposed, 
 and the triturating substance, formed at first entirely of enamel, pre- 
 sents only a layer of osseous substance when the cutting edges and 
 the pointed summits of the crowns are blunted. When the tooth is 
 still more worn, so that the osseous substance is destroyed to the 
 dental cavity and the latter is open, there is generally formed in the 
 same proportion at the summit of this cavity a brownish substance re- 
 sembling bone, but a little softer, which closes the opening and protects 
 the parts within the cavity.(l) These phenomena can also be ad- 
 duced against' the opinion of those who assert the continual reproduc- 
 tion of the enamel. 
 
 Nutrition however gradually declines in the teeth, and their nutri- 
 tious foramina are finally obliterated. Being retained in the alveolar 
 processes by no organic attachment, they become loose and fall out. 
 The alveolar processes collapse and the alveolar edge entirely disap- 
 pears after the gum has closed the alveolar openings. 
 
 b. Special remarks. 
 
 § 2121. The different kinds of teeth do not pass through the dif- 
 ferent periods generally mentioned in the same time, but very irregu- 
 larly and more or less in succession. We may mention generally : 
 
 1st. That they pass through the different periods after the same 
 law, so that the germ of the tooth in which the follicle first appears is 
 also the fust to be developed and ossified. 
 
 2d. That the synonymous teeth in the same jaw correspond very 
 exactly in this respect. 
 
 3d. That the lower teeth are developed before the upper, and the 
 anterior before the posterior. 
 
 4th. That the gradual development of the human teeth corresponds 
 to permanent forms in the mammalia. 
 
 1. Deciduous teeth. 
 
 § 2122. The deciduous teeth, in accordance with the first law, 
 appear sooner than the permanent teeth. The period at which their 
 follicles are developed and the order in which these latter are seen have 
 
 (1) Hunter, loc. cit ., p. 108. — Prochaska, Obs. de decremento dcnliwn ; in the 
 Annot. acad.jfasc. I. 
 
236 
 
 DESCRIPTIVE ANATOMY. 
 
 already been mentioned above. The two internal follicles are those 
 of the incisor teeth, and the external those of the molar teeth ; the fifth 
 intermediate is that of the canine tooth. 
 
 Ossification begins at the fifth month in the inner incisor teeth, a 
 little sooner in the lower than in the upper. Next comes the external 
 incisor tooth,' then the anterior molar tooth. About the end of the fifth 
 month we find osseous substance in these three teeth, while only the 
 germ exists in the other two. We have as yet been unable, to deter- 
 mine whether the canine or the posterior molar tooth is ossified first, 
 because, except in one instance, we have always found these teeth 
 with or without traces of the osseous germ at the same time. Pro- 
 bably, however, ossification commences first in the former, not only 
 because we have once found in it an osseous germ, while there was 
 none in the posterior molar tooth, but because its osseous nucleus has 
 always seemed to us more extensive than that of the latter, and finally 
 because it is cut first. But these three reasons, particularly the last 
 two, do not establish our opinion with certainty. 
 
 At the seventh month of pregnancy all the deciduous teeth contain 
 osseous nuclei. (1) 
 
 The number and arrangement of the pieces of bone which form the 
 teeth are not always exactly the same. 
 
 Hunter(2) and Rudolphi(3) think that the incisors are composed of 
 three pieces, a central and two lateral pieces, which are smaller. The 
 canine teeth arise by a single osseous germ according to Hunter ; but 
 Rudolphi thinks by two lateral halves. Both admit that the anterior 
 molar tooth is formed of an anterior portion and of one or two posterior 
 pieces, and that the posterior is formed by an anterior germ and several 
 posterior nuclei. Hunter however is very brief on this subject, al- 
 though he seems to speak from observation. Rudolphi’s assertions 
 are grounded, not on researches in regard to the development of the 
 teeth in the fetus, but upon chemical experiments, having for their 
 object the action of the acids on perfect teeth, which action reduces 
 them to the number of pieces mentioned by this physiologist. Nume- 
 rous observations on the fetus have convinced us that the canine and 
 the incisor teeth are developed by a single germ, which arises at the 
 centre and gradually extends to the sides. We cannot then consider 
 as natural, conclusions drawn from the action of acids on perfect teeth; 
 and farther, because other writers, as Àlbinus,(4) and Blake, (5) for- 
 mally assert that the incisor and the canine teeth are developed by one 
 nucleus of ossification. But the molar teeth in fact arise by several 
 
 (1) Blake (Essai, p. 23) states only that he has found osseous substance in all the 
 teeth in a fetus of eight months. 
 
 (2) Loc. cit., p. 88. 
 
 (3) lieber die Zähne ; in his Anatomisch-physiologische Untersuchungen, p. 126. 
 
 (4) Ue dentium orlu et incrcmenlo ; in the Annot. acad„ book ii., ch. ii., p. 16. 
 
 (5) Loc. cit., p. 6. 
 
OF THE DIGESTIVE SYSTEM. 
 
 237 
 
 osseous nuclei, each of which corresponds perfectly to the first rudi- 
 ment of a single incisor or canine tooth. 
 
 First the anterior piece, which is the largest, appears ; this corre- 
 sponds peculiarly to the incisors, and is narrower according to its 
 height than it is afterwards. Next is seen the posterior piece, which 
 is much smaller ; it igradually extends and unites to the other directly or 
 on one of the two sides by a third which is developed at a later period. 
 The second molar tooth arises by several pieces, at least three and 
 generally four in number, an anterior, two lateral, and a posterior. 
 The anterior piece is always larger than the others. 
 
 All the pieces except the small one, which belongs to the posterior 
 molar tooth, are usually fused at birth. 
 
 About this period the development of the first and second incisor 
 tooth is nearly equally advanced in regard to the whole crown. Next 
 comes the anterior molar tooth, the crown of which has not yet how- 
 ever acquired all its height. The third is the canine tooth. The 
 most imperfect is the posterior molar tooth, the very thin crown of 
 which presents in one or more points considerable spaces in its central 
 portion, and a piece which is entirely distinct from the others. The 
 posterior molar teeth of the lower jaw not unfrequently form a single 
 piece in the full grown fetus. Beside the spaces and the separation 
 mentioned disappear in the two jaws in the first few months after 
 birth. 
 
 The cutting of the deciduous teeth usually commences at the be- 
 ginning of the seventh month after birth. The lower internal incisors 
 are generally first seen ; some weeks after, the upper internal incisors 
 are cut ; one or two months afterward, the upper and lower external 
 incisors ; at the end of the first year, the lower anterior molar teeth ; 
 some time afterward, the upper anterior molar teeth ; at the age of 
 eighteen months the inferior, and soon after the superior canine teeth ; 
 toward the end of the second year, the posterior molar teeth : so that 
 at the age of three years all the deciduous teeth are seen. 
 
 The deciduous teeth receive a distinct artery, which comes from the 
 dental artery, and which passes through a canal in the jaw, into which 
 it enters through a special foramen.(l) 
 
 2. Permanent teeth. 
 
 § 2123. The permanent teeth are developed and appear nearly in 
 the same order as the deciduous teeth. They however pass through 
 their periods much more slowly. 
 
 We observe first just before the end of the first month of pregnancy 
 the follicle of the anterior molar tooth. Those of the incisors do not 
 
 (1) Serres, loc. ciL, p. 16. 
 
 31 
 
 VOL. III. 
 
23S 
 
 DESCRIPTIVE ANATOMY. 
 
 form till the commencement of the eighth month ; next that of the 
 Canine, and next that of the middle great molar tooth. That of the 
 anterior small molar tooth forms some months after birth, rarely 
 betöre the seventh or eighth. Next appears that of the posterior 
 small molar tooth, and usually at four years of age that of the third 
 great molar tooth, which is situated the most posteriorly. The os- 
 seous germs are visible nearly at the same time as the follicles. 
 
 Ossification commences in the anterior great molar tooth. Usually 
 the external anterior point of this tooth presents at the end of the 
 last month, of pregnancy, a small osseous piece, to which four or 
 five others are gradually attached separately ; these do not unite till 
 the end of the first year. We however have sometimes found in a 
 very large full grown fetus five points, in fact entirely distinct from 
 each other, the posterior of which was still very small. 
 
 All the permanent teeth have not the same situation in respect to 
 the deciduous teeth. The three posterior molar teeth are situated on 
 the same range as these latter, but farther outward, while those which 
 should be properly called the replacing teeth are included between 
 them and the posterior wall of the alveolar processes, the incisors, the 
 canine and the molar teeth, behind those to which they correspond. 
 The follicles of the permanent teeth are at first contained in the same 
 alveolar processes as the old teeth. The manner in which they are 
 developed is very curious. They leave the upper and posterior part of 
 the dental follicles already existing, so that they may be considered to 
 a certain extent as arising from these latter by gemmation. They first 
 rest directly on them, and even afterwards when they are elongated 
 they communicate with them by long and thin cords. 
 
 Our observations, however, have established that this communica- 
 tion is only between the external layers of the dental follicles, that the 
 internal layers are much more essential, and entirely distract from each 
 other, so that the new internal dental sac is developed in the old, be- 
 tween it and the external layer, although their cavities are uncon- 
 nected. If they communicate, it must have been at a very remote 
 period, since we have never been able to discover it even on examining 
 the follicles of the permanent teeth when they first appear. 
 
 The new sacs are gradually separated from the old by the formation 
 of new alveolar cavities. These cavities seem at first slight depres- 
 sions in the posterior wall of the old ; these depressions, like the 
 follicles, are much shorter than these latter, and extend much farther 
 beyond the alveolar edge than those which existed previously. A 
 septum gradually arises from the base of the alveolar processes, and 
 goes towards its orifice. The two alveolar processes, however, con- 
 tinue to communicate by a considerable opening, through which passes 
 the cord which unites the two sacs. The elongation and the thinness 
 of this cord depend on the increase in the height of the jaws. 
 
 The openings between the incisors and the canine teeth are visible 
 on the posterior face of the jaws. That of the internal incisor tooth 
 corresponds to the cavity of the deciduous internal incisor tooth. That 
 
OF THE DIGESTIVE SYSTEM, 
 
 239 
 
 of the external is situated between the cavity of the deciduous external 
 incisor tooth and that of the deciduous canine tooth. That of the 
 canine tooth is situated behind the cavity of the deciduous canine 
 tooth. The communications of the anterior molar teeth with the 
 cavities of the deciduous molar teeth, are not visible externally, ac- 
 cording to several anatomists,(l) but exist at the bottom of those latter; 
 we, however, have observed that they are situated like the first, on the 
 inside, and behind the alveolar opening of the deciduous tooth, and that 
 they are generally narrower than the others.(2) The follicles of the 
 second and third permanent molar teeth emerge in the same manner, 
 the first on the outside of the deciduous molar tooth, the other after- 
 ward, on the outside of the second. The foramina of communication 
 between their cavities are situated at the upper part of the septum 
 which separates them. As the jaw and the deciduous teeth gradually 
 arise by the development and completion of their roots, as the per- 
 manent teeth which replace the latter do not increase proportionally in 
 this direction, and as they are much broader than the deciduous teeth, 
 it follows that they are situated lower, and also a little on the outside 
 of them. The permanent internal incisor teeth are situated behind the 
 internal and a part of the external deciduous teeth; the permanent ex- 
 ternal teeth behind these latter and the deciduous canine teeth ; finally, 
 the anterior molar teeth behind the deciduous molar teeth and between 
 their roots. The crowns of the latter nearly touch the roots of the 
 permanent internal incisor teeth, and the canine teeth are on the out- 
 side of the row, more remote from the alveolar edge, and are carried 
 farther forward than the others. 
 
 § 2124. At the age of six or seven years the second dentition com- 
 mences ; the deciduous teeth fall out and the permanent teeth appear. 
 At this time the artery of the deciduous teeth and its canal disappear 
 more or less perfectly, (3) so that the dental capsules receive no more 
 nutritious fluid. Usually, and in fact almost always, the permanent 
 anterior molar teeth begin to appear before the time of the second 
 dentition, which has deceived some writers, and led them to admit 
 twenty-four deciduous teeth. Among the teeth which alone deserve 
 to be called permanent teeth, the inferior internal incisor teeth usually 
 appear first. Next come the superior internal, then the external ; after- 
 ward, and usually at the age of from thirteen to fourteen years, and 
 almost always at the same time, the canine and the middle great molar 
 teeth appear ; finally, at a variable period, between sixteen and twenty 
 years, and sometimes later, the last great molar teeth appear, which 
 are hence called the wisdom teeth ( dentes sapientice). Thus, although 
 the permanent canine teeth appear much sooner than the small molar 
 teeth, they however normally are cut afterward, between the appear- 
 ance of these latter and the posterior molar teeth, exactly as the deci- 
 
 (1) Albinus, loc. cit., p. 13-15.— Blake, loc. cit.. p. 40.— Serres, loc.cit. p. 38. 
 
 (21 Meckel, loc. cit. 
 
 (3) Serres, loc. cit. p. 19. 
 
240 
 
 DESCRIPTIVE ANATOMY. 
 
 duous canine teeth appear in the jaws between the two deciduous 
 molar teeth. <e- 
 
 The order then in which the teeth are cut, is nearly the same for the 
 deciduous and the permanent teeth. 
 
 Both resemble formations which are permanent in animals. 
 
 The appearance of the incisors before the others deserves notice, as 
 it resembles the development of the intermaxillary bone, and the cor- 
 responding - middle portion of the lower jaw which exist particularly 
 in fishes, and more or less in all animals. The earlier development of 
 the lower represents remarkably the formation of the ruminantia, and 
 the regular existence of the incisors and the molar teeth without the 
 canine teeth in the rodentia. 
 
 The deciduous teeth change in certain respects before falling out. 
 Their roots disappear ; they become both shorter and thinner, so that 
 their inner part diminishes as they terminate more or less in a point. 
 
 The more or less narrow canal in which the cavity of the per- 
 manent tooth is first situated, gradually enlarges, as w T ell as its orifice, 
 as the tooth advances ; finally, the septum which seperates the alveolar 
 process of the permanent tooth from that of the deciduous tooth, is de- 
 stroyed, and the two teeth are then situated in the same cavity as they 
 were originally, with this difference, however, that the permanent 
 tooth, from its greater size, always penetrates partly into the alveolar 
 process of the adjacent deciduous tooth. 
 
 The destruction of the root of the deciduous tooth doubtless depends 
 on the mechanical action of the permanent tooth upon it, in accordance 
 with the law, that long continued pressure on a part, causes it to dis- 
 appear by obstructing nutrition, or by accelerating the destructive pro- 
 cess. This is proved not only by the disappearance of the deciduous 
 tooth, but also by the well known fact that those temporary teeth 
 which are not replaced by the permanent teeth, continue very long 
 even in the adult, and sometimes even during existence^ 1) Although 
 the tooth which continues longer than usual often finally falls out, (2) 
 we must not conclude that the permanent teeth have no effect in the 
 normal state independent of their influence, but only that the decidu- 
 ous teeth from their primitive destination, exist so short a time that 
 this action is not absolutely necessary to determine their decay. 
 Finally, the continuance of the deciduous teeth even after their vessels 
 and nerves have completely disappeared, is favored by the adhesions 
 between their root and the inner face of the alveolar process. (3) 
 
 The permanent tooth causes the decay of the deciduous tooth prin- 
 cipally by pressing upon the vessels and nerves of this latter, and like- 
 wise its adhesions with the alveolar process, and destroying them. 
 The destruction of the root is not indispensible, nor even constant, as 
 the deciduous teeth are sometimes shed, preserving their roots entire. (4) 
 
 (1) Hunter, loc. cit., p. 99. — Hudson, in Blake, p. 67. — Fox, loc. cit., p. 40. 
 
 (2) Fox, loc. cit. 
 
 (3) Serres, loc. cit., p. 97, 
 
 (4) Idem, loc. cit., p. 102. 
 
OP THE DIGESTIVE SYSTEM. 
 
 241 
 
 This is the proximate cause of the loss of the tooth, and not, as has 
 been asserted, the space formed by the disappearance of the septum 
 between the alveolar processes, the only effect of which space would 
 be to fix the tooth less firmly.(l) In fact, there is no space, since the 
 permanent tooth, in proportion as it destroys the septum, prevents the 
 space from forming, as it enters the alveolar process of the deciduous 
 tooth. 
 
 § 2125. From our preceding remarks it follows, that the teeth re- 
 semble the bones generally in their chemical composition and hardness. 
 They however differ from them in these two respects : 
 
 1st. They are harder. 
 
 2d. Their tissue is much more solid. 
 
 3d. They are composed of two substances. 
 
 4th. They contain a much greater proportion of earthy salts. 
 
 They differ also from the bones. 
 
 5th. They are unattached in most of their extent. 
 
 6th. In their mode of connections with the rest of the body, and in 
 their relations with the germ of the tooth. 
 
 7th. In their mode of development. 
 
 8th. Because they do not participate in the diseases of the osseous 
 system. 
 
 9th. They receive no vessels. 
 
 10th. They resist much more the action of chemical agents and 
 spontaneous decomposition after death. 
 
 In all these respects, on the contrary, they are very similar to the 
 epidermoid parts, which analogy is confirmed by comparative ana- 
 tomy.(2) 
 
 (1) Serres, loc. cit., p. 104. 
 
 (2) Mayer and Kathoven are the first who arranged the teeth as belonging to the 
 horny system, which has been followed by Heusinger, but opposed by Rudolphi, but 
 very wrongly. Bonn (De contin. membran., 1763, § 1 6), Walther ( Physiologie , vol. 
 i. p. 176), and Lavagna (loc. cit., p. 164), had already mentioned the analogy between 
 the teeth and the hairs. This point of doctrine had been carefully developed by 
 Lavagna, and afterwards by Heusinger. The reasons alledged by the latter are, 1st. 
 The teeth in the different mammalia present imperceptible transitions, from those 
 which are most similar to the bones, to the different parts of the horny system, par- 
 ticularly the nails, the horns, and the hairs. 2d. The teeth of several of the mam- 
 malia have a lamellar texture like the nails and the horns, and this texture, although 
 very evident in all, sometimes seems effaced from the greater accumulation of the 
 earthy salts. 3d. The development of the teeth is very similar to that of the nails 
 and horns. 4th. Certain teeth are shed and reproduced, as are also the nails and the 
 horns. 5th. The teeth are not nourished, they are formed entirely of one piece, and 
 the substance which forms them is not renewed. These views are in part those of 
 Coiter, Hérissant, Cuvier, and Serres. G. F. St. Hilaire has adopted them entirely. 
 The tooth, he says, ti produced by transudation ; it is an inorganic body, anatomi- 
 cally speaking, a mass composed of several layers, in which there is nothing to be 
 compared with osseous tissue. But this naturalist has extended these ideas very 
 much by demonstrating that we must refer the beak of birds to the formation of the 
 teeth, a curious fact, and one of the highest importance, which fully justifies the 
 analogy established between this formation and the epidermoid tissue. He advances 
 also another idea, which we shall mention here briefly, although connected with im- 
 portant physiological considerations, it is foreign to this work, viz. that if the teeth 
 afterwards serve for mastication, it is fortunate for those animals who possess and 
 
242 
 
 DESCRIPTIVE ANATOMY. 
 
 B. ABNOnMAL STATE. 
 
 §2126. The teeth not unfrequently vary from the normal state ; 
 and most generally present anomalies in their texture. The most fre- 
 quent alterations of texture are those which relate to the period of 
 development and the order in which it occurs ; next, those which relate 
 to the number of the teeth. Next come the anomalies in situation and 
 direction, and finally those in form, size, and continuity of tissue. 
 
 a. Deviations of formation. 
 
 §2127. 1st. Anomalies in the development. These are the slightest. 
 Not unfrequently all the teeth, or some of them only, appear unusually 
 late. This is seen particularly in the last molar teeth, in regard to 
 which we should remark, that their unusually late appearance is only 
 ■an extension of time between their appearance and that of the other 
 teeth, as between the appearance of these latter compared together. 
 It is less common for all or some of the teeth to appear sooner than 
 usual ; sometimes, however, children are born with several teeth. It 
 is curious, although the fact agrees veiy well with the laws and the 
 other phenomena of vegetative life, that this early development 
 seems evidently to be favored by the longer continuance of the fetus in 
 the uterus, since in a proportionally great number of children who had 
 continued in the fetal state some weeks beyond the common period, 
 teeth existed at birth. 
 
 We must mention among the anomalies in the development, the 
 continuance of the deciduous teeth beyond the usual period, which 
 does not necessarily oppose the appearance of the permanent teeth, 
 and causes so much irregularity in their arrangement and situation, 
 that we are led at first view to believe the number of the teeth to be 
 increased. But the deciduous teeth frequently remain, although the 
 permanent teeth do not appear, and this anomaly must even be attri- 
 buted to the absence of these latter. 
 
 Beside these differences in the development which relate to the 
 quantity, there are others dependent on the quality. Thus, sometimes 
 all the lower incisor teeth appear before one of the upper is seen. It is 
 much more rare that the superior incisors appear before the inferior, 
 the external before the internal, the anterior molar teeth before the ex- 
 ternal incisors, and the posterior before the canine teeth.(l) The rarest 
 case is where the canine teeth appear before the anterior molar teeth, 
 
 profit by them, but that when the formations of the teeth begin to appear in the fetus, 
 they are real organs of the fetus ; in this sense they arise, like all the organs of sense 
 to form a termination to the circulatory system of the advanced parts of the head, 
 tojlimit a certain number of vascular trunks. F. T. 
 
 (1) Blake, p. 25.— Fox, loc. cit., p. 7. — Serres, p. 85. 
 
OF THE DIGESTIVE SYSTEM. 
 
 243 
 
 although several authors mention this as the normal order, or at least 
 state it to be as frequent as that mentioned above. (1) 
 
 2d. Anomalies in the number. These teeth which most frequently 
 appear later than the common period, the posterior molar teeth, are 
 also those which are most commonly deficient. Instances, however, 
 are known of the deficiency of every tooth. (2) In one subject there 
 were only four permanent teeth in each jaw. In another there was 
 only one incisor in the upper jaw. Sometimes the teeth have been 
 entirely deficient. (3) 
 
 It is more rare to find an excess than a deficiency of teeth. This 
 anomaly, leaving out of view that which is only apparent, and which 
 we have just mentioned, appears principally under two different forms. 
 Sometimes the supernumerary teeth exist simultaneously with the 
 others; sometimes, however, they appear after them. 
 
 In the first case they make part of the same range with the others ; 
 sometimes are found out of this range, so that when several exist they 
 form a second series. They are generally situated behind the normal 
 teeth, that is, the same relation exists between them and these latter 
 as between the deciduous and the permanent teeth. This anomaly 
 varies in the same manner as that which depends on the abnormal 
 situation of the teeth in general. 
 
 The first degree of the redundancy of the teeth is the development 
 of one or more rounded eminences on the sid'es of the crown ; hence 
 are formed what are termed the dentes proliferi.( 4) This anomaly 
 seems to belong almost exclusively to the molar teeth, and it is curious 
 as it is a greater development of one of their peculiar characters, the 
 existence of several points on their crown. 
 
 The anomaly is still greater when other smaller separate teeth exist 
 on a normal tooth, and which are seemingly formed by special germs. 
 In the only case of this anomaly known to us, and which existed on 
 a canine tooth, there were three accessory teeth ; these small teeth 
 were much smaller than the normal canine teeth, but were all formed 
 after the same type ; they rested on the base of the crown and had 
 the same direction. (5) 
 
 The supernumerary teeth are observed most frequently in the upper 
 jaw and forward, near the canine teeth and the incisors. This pecu- 
 liarity is very remarkable, since in several animals the anterior teeth 
 are more numerous in the upper than in the lower jaw. They usually 
 
 (1) Miel, Bull, de la soc. méd. d'èmul., 1817, p. 94. 
 
 (2) Fox mentions several instances of this. 
 
 (3) Fox. loc. cit., — Sabatier, Anat., vol. i. p. 78. 
 
 (4) Bartholin, Hist. anat. rar., ch. i., p. 49. — Serres, loc. cit., p. 160. — Linden, 
 Medic, phys., cap. xiii., art. 3. — Oudet, Bull, de la fac. de méd., 1821, no. i., p. 369. 
 — G. Saint Hilaire has described and figured one of these teeth ( Syst . dentaire des 
 mammif. et des oiseaux, p. 77, pl. i., fig. 18). 
 
 (5) Lemaire, Deux observations d'anatomie pathologique sur les dents; in the 
 Journ. de méd., vol. xxxvi., p. 252. 
 
244 
 
 DESCRIPTIVE ANATOMY. 
 
 differ from all tlie normal teeth in form and size, being smaller and 
 conical, sometimes bicuspid. When they occur at the posterior part 
 of the mouth they do not resemble the wisdom teeth. Their number 
 varies. Generally they are few, but sometimes they are many ; in 
 one case even the whole number of teeth was seventy-two, viz. eight 
 incisors, four canine and twenty-four molar teeth in each jaw.(l) Pos- 
 sibly, however, this statement is not perfectly correct, and should be 
 considered only as an instance of the coexistence of the deciduous and 
 permanent teeth. Sometimes also when the number T>f teeth is unu- 
 sually large, this anomaty is caused by the division of one or more 
 into several. 
 
 The second mode in which the number of teeth is increased has 
 been termed the third dentition. There is even sometimes a fourth 
 dentition, although the instances mentioned of this are hardly credible. 
 The principal circumstances of this remarkable phenomenon are as 
 follow : 
 
 a. The third dentition is attended with the same symptoms as those 
 of the first and second. The new teeth are smaller than those they 
 replace ; they are less permanent and soon decay. 
 
 b. The period of their formation is not determined. If we may 
 judge of them from some facts, they are formed before they appear : 
 probably, however, individuals differ in this respect. 
 
 c. The third dentition usually occurs at a very advanced period of 
 life. 
 
 d. The time between the third and second dentition varies. Ge- 
 nerally, however, the third teeth appear shortly after the second 
 decay. 
 
 e. In this respect there are differences, some of which depend on 
 the quantity, others on the quality. Usually however one or more 
 teeth are replaced more frequently than all. The posterior molar 
 teeth seem to be those which are renewed most frequently, and even 
 if this be not true it is a fact that when they are replaced by others 
 the same phenomena are presented as at the second dentition. 
 
 3d. Anomalies in situation and direction. They differ conside- 
 rably : 
 
 a. Situation. In this respect the teeth are rarely abnormal, and if 
 they are situated in the range they change their place, so that this 
 anomaly belongs to the history of the lateral inversion. Thus the 
 canine tooth sometimes exists between the two incisors. In other 
 cases the canine tooth is replaced by the first anterior molar tooth, and 
 exists between it and the second.(2) Sometimes also the teeth are 
 developed in parts of the jaws where they are not generally found. 
 These abnormal teeth are seen most frequently in the palatine process 
 
 (II Arnold, Obs. phys. tried., p. 69. 
 
 (2) Miel, Observation sur un cas très rare de transposition des denis ; in the Journ. 
 de méd., vol. xl., 1817, p. 88. 
 
OF THE DIGESTIVE SYSTEM. 
 
 245 
 
 of the upper maxillary bone, directly or at some distance behind the 
 normal teeth. They are in the lower jaw principally situated in its 
 angle. The narrowness of the jaw causes them to project above the 
 others, and their direction is also less perpendicular. 
 
 b. Direction. Not unfrequently the teeth are oblique, which de- 
 pends particularly on the narrowness of the jaw ; but here their faces 
 look to the sides, and their edges are turned backward and forward. 
 They are rarely on the contrary reversed, that is, the summits of their 
 roots look to the alveolar edge and the crowns to the opposite region 
 of the jaw. 
 
 4th. Anomalies in the form. The form of the teeth is abnormal in 
 a great many different modes. 
 
 a. In regard to the xvhole tooth , this abnormal formation is indicated 
 by the adhesion of two adjacent teeth ; this sometimes extends their 
 whole distance, and is sometimes confined to a portion of their extent, 
 generally to the roots.(l) 
 
 b. Crown. The form of the triturating surface of the crown some- 
 times varies very much from the common form. 
 
 The first great molar tooth seems particularly to have a peculiar 
 tendency to the imperfect development of this surface ; for we have 
 sometimes found it on each side in both jaws with a great number of 
 small eminences, a curious analogy with the molar teeth of the hog. 
 
 The rest of the crown, instead of being smooth as usual, some- 
 times presents rounded, transverse, and longitudinal elevations and 
 depressions, which depend on a deficiency in the secretion of the 
 enamel.(2) 
 
 The crown more rarely presents so irregular a form that it appears 
 to be compressed from above downward and reversed. (3) 
 
 c. Roots. The roots are abnormal more frequently than the crowns. 
 Their principal anomalies are an excess in number and a variation in 
 direction. 
 
 Sometimes, although very rarely, the superior molar teeth have 
 five roots, (4) and the inferior «four. (5) More frequently these latter 
 have three. In some subjects we find two in the canine teeth and 
 more rarely in the incisors. (6) 
 
 In the abnormal direction of the roots of the teeth they are curved 
 very much in the form of a hook, (7) or they are oblique. These two 
 anomalies are most frequent, particularly in the great molar teeth, 
 which they render more solid. 
 
 (1) Fox, loc. cit., tab. viii., fig. 8-11. 
 
 (2) Idem, loc. cit., tab. viii., fig. 14. 
 
 (3) Idem, loc. cit., tab. viii., fig. 11, 12. 
 
 (4) Idem, loc. cit., fig. 13. 
 
 (5) Idem, loc. cit., fig. 11. 
 
 (6) Tesmer, Obs. ostcol., vol. i., fig. 1-4. 
 
 (7) Lemaire, loc. cit., p. 254. 
 
 32 
 
 Vol, III. 
 
246 
 
 DESCRII'TIVE ANATOMS’, 
 
 5th. Anomalies in size. The upper internal incisors are principally 
 abnormal in this respect from a primitive deviation of formation, being- 
 much larger than usual. But the size and mass of the teeth may also 
 be increased or diminished from too great or too slight activity in the 
 formative power. 
 
 The roots particularly increase in size, being affected with hyperos- 
 tosis. (1) Sometimes, although more rarely, the crown is unusually 
 large. We must also mention here the formation of a bony substance 
 in the earthy of the tooth, which sometimes adheres to the parietes 
 and sometimes is developed in the centre of the soft pulp which fills 
 this cavity. (2) 
 
 Atrophia is the opposite of hyperostosis ; when it takes place in the 
 crown it sometimes does not extend beyond the enamel, or at least it 
 begins with the layer of enamel, although it extends gradually to the 
 osseous substance. This latter is unaltered in its texture, and the 
 cavity of the tooth is not exposed. The anterior teeth are more sub- 
 ject to this disease, which attacks only their anterior face and is seen 
 particularly in scrofulous subjects. 
 
 6th. Solutions of continuity. The fractures of the teeth rarely su- 
 pervene unless preceded by an alteration of texture, which renders 
 these parts brittle. In this case, whether the scale be detached or 
 there is simply a fissure, the solution of continuity does not close, while 
 it is perfectly healed even when there is a loss of substance, when the 
 tooth is perfectly healthy. The latter applies equally to transverse 
 and longitudinal fractures. 
 
 The fractures of the roots, however, alone are consolidated. Those 
 of the crowns do not heal, which undoubtedly depends on the fact that 
 union takes place by an exudation of osseous substance on the outer 
 face of the germ of the tooth, in accordance with the law of the normal 
 formation of the tooth. It appears then from this, that the external 
 membrane, termed the periosteum of the tooth, takes no more part in 
 the cicatrization than in the primitive formation of the tooth.(3) 
 
 • 
 
 6. Alterations of texture. 
 
 § 2128. The alterations in the texture of the teeth are : 
 
 1st. Caries. It is the most common. It usually proceeds from with- 
 out inward, more rarely from within outward, begins by the destruction 
 of the enamel, and seldom extends beyond the crown. It attacks the 
 molar teeth most frequently. It is rarely or never observed at an ad- 
 vanced age. 
 
 (1) Fox, loc. cit ., tab. i. 
 
 (2) Duval, Cons. mid. sur les dents ; in the Journ. de mid., vol. xxxvi. ; Bull, de 
 lafac. de mid., p. 101. 
 
 (3) Duval, Sur la consolidation des fractures des dents; in the Journ.de mid., 
 vol. xiii., p. 275. 
 
OF THE DIGESTIVE SYSTEM. 
 
 247 
 
 Sometimes the germ inflames, suppurates, and dies, independent of 
 the solid substance of the tooth. (1) Its inflammation seems to precede 
 the caries of the tooth. (2) 
 
 2d. The teeth rarely participate in the general softening of the 
 bones. 
 
 3d. The formation in the alveolar- processes of cysts filled with 
 a liquid sometimes serous and sometimes thicker than serum. These 
 cysts partially destroy the root of the tooth. 
 
 The gum frequently softens, and then bleeds at the least touch. 
 
 The abnormal swelling of this tissue with softening constitutes 
 epulis, which term embraces, however, very different alterations of 
 texture. 
 
 II. CERVICAL AND THORACIC PORTIONS OF THE ALIMENTARY CANAL. 
 
 § 2129. The cervical and thoracic portion of the alimentary ca- 
 nals) are much more simple than the cephalic. They include the 
 pharynx and the esophagus. The first begins at the posterior extre- 
 mity of the cavities of the mouth and nose, and is uninterruptedly 
 continuous with the esophagus, which is connected with the stomach. 
 
 A. PERFECT STATE. 
 
 I. PHARYNX. 
 
 § 2130. The pharynx^ 4) extends in a straight line from the base of 
 the skull and the fauces to the lower extremity of the larynx, or to the 
 fifth cervical vertebra. Its mean measure is four inches long, and one in 
 diameter at its broadest part when moderately distended. Below this 
 point it contracts, then dilates again, becomes narrower, and is finally 
 continuous with the esophagus. 
 
 Its posterior straight face is situated directly before the five superior 
 cervical vertebras and the anterior muscles of the neck, behind the ca- 
 vity of the mouth and the larynx, between the great vascular and 
 nervous trunks of the neck. 
 
 Its upper extremity or arch ( fornix ) is united by some cellular tissue 
 to the lower face of the body of the basilar bone and the petrous por- 
 tion of the temporal bone. Some muscles to be described hereafter 
 
 (1) Duval, loc. cit., vol. xxxvi., p. 99, 100. 
 
 (2) Serres, loc. cit., p. 51. 
 
 (3) Fabricius of Aquapendente, De gulâ et ventriculo, Padua, 1618. — J. Fantoni, 
 De gulâ et ventriculo, Turin, 1742. 
 
 (4) Santorini, De phavjnge ; in the Ohs. anat., cap. vii. 
 
248 
 
 DESCRIPTIVE ANATOMY. 
 
 attach it to different parts of the head. Upward and backward are 
 the posterior nostrils, forward the orifice of the cavity of the mouth, 
 backward and on the sides those of the Eustachian tubes. These 
 different openings exist at its upper part, which is divided by the soft 
 palate to a certain extent into an anterior and a posterior passage. 
 
 § 2131. It is surrounded externally by a thin layer of cellular tis- 
 sue, which attaches it loosely to the adjacent parts. Below this layer 
 is another, which is easily separated from it ; this is also cellular and 
 is filled with fat, and intimately unites it with the subjacent muscular 
 layer. The nervous and vascular trunks which enter into the proper 
 membranes of the pharynx are distributed in them. 
 
 §2132. The muscular tunic of the pharynx is formed principally 
 by the three constrictor muscles (J\I. conslrictores pharyngis),(l) a 
 superior , a middle , and an inferior. These muscles have several com- 
 mon characters, which are : 
 
 1st. They surround the pharynx backward and on the sides ; their 
 lateral extremities are attached to the adjacent, hard parts before the 
 pharynx, especially to several bones of the face and skull, to the hyoid 
 bone and to the larynx. 
 
 2d. They are composed of fibres which proceed from below upward 
 and from without inward, and which extend by radiation from each 
 side to the median line. 
 
 3d. They partially cover each other from below upward. 
 
 4th. They are voluntary muscles. 
 
 A. CONSTRICTOR PHARYNGIS INFERIOR. 
 
 § 2133. The constrictor pharyngis inferior or the crico-thyreo- 
 pharyngcus muscle arises by from two to four triangular digitations, 
 from the cricoid and the thyroid cartilages. 
 
 The lowest and smallest is attached below the crico-thyroideus 
 muscle to the lower part of the side, and to the lower part of the pos- 
 terior horn of the cricoid cartilage. 
 
 The upper, the larger, is sometimes single and sometimes triple ; it 
 arises from all the posterior part of the side of the thyroid cartilage, 
 excepting the lower region occupied by the crico-thyroideus muscle, 
 which is situated between it and the low r er digitation. 
 
 The fibres of this muscle proceed from all these points, divided into 
 several fasciculi in a greater or less extent, and go toward the median 
 line, so that the inferior are almost transverse, while the others ascend 
 more the higher they become, and unite at angles more and more 
 acute with those of the opposite side on the median line. 
 
 (1) Santorini, Septcmdccim tabula tab. vi. 
 
OF THE DIGESTIVE SYSTEM. 
 
 249 
 
 The upper head of this muscle is only about an inch below the 
 upper extremity of the pharynx. 
 
 B. CONSTRICTOR PHARYNGIS MEDIUS. 
 
 § 2134. The constrictor pharyngis médius muscle (JVT. constrictor 
 médius pharyngis, s. glosso-hyo-pharyngeus, s. kerato-chondro pharyn- 
 geus , s. cephalo-pharyngeus) is much smaller and weaker than the 
 preceding. It arises from the hyoid bone and the tongue, generally 
 by two heads. The inferior or posterior , the smaller, termed the hyo- 
 pharyngeus muscle, comes from the posterior part of the upper edge of 
 the great horn of the hyoid bone. 
 
 The upper or anterior , which is the larger and is termed the glosso- 
 chondro-pharyngeus muscle, arises from the small horn of the hyoid 
 bone and from the base of the tongue. 
 
 Its lower fibres are transverse and even convex downward ; the 
 upper are very oblique and are generally pointed, and either alone or 
 blended with the upper fibres of the constrictor pharyngis inferior mus- 
 cle, extends as the cephalo-phamyngeus muscle ; to the basilar process 
 of the basilar bone, and is attached to its lower face by fleshy or tendi- 
 nous extremities. 
 
 C. CONSTRICTOR PHARYNGIS SUPERIOR. 
 
 § 2135. The constrictor j)haryngis superior or the glosso-mylo- 
 pterygo-pharyngeus muscle arises from the posterior part and the side 
 of -the root of the tongue, from the inner face of the lower maxillary 
 bone, near the posterior molar tooth, from the hook of the pterygoid 
 process, and from the tendon of the peristaphylinus externus muscle, 
 often also a little from the petrous portion of the temporal bone and 
 from the styloid process, and blends with the posterior part of the 
 genio-glossus and buccinator muscles, and often also with the lower 
 portion of the stylo-pharyngeus muscle. 
 
 Its lower fibres are transverse ; the upper describe an arch which is 
 convex upward. 
 
 D. STYLO-PHARYNGEUS. 
 
 § 2136. The stylo-pharyngeus muscle (M. stylo-phanjngeus , s. le- 
 vator , s. dilator pharyngis) is large, elongated, and rounded. It arises 
 by a broad and short tendon from the inner face and the lower edge of 
 the styloid process of the temporal bone. Thence it goes inward and 
 downward. It is at first separated from the constrictor pharyngis su- 
 perior muscle by a greater or less quantity of fat ; it goes from above 
 downward and from without inward, passes under the lateral part of 
 
250 
 
 DESCRIPTIVE ANATOMY. 
 
 the constrictor médius muscle, and is distributed on the lateral and 
 posterior wall of the constrictor médius, and adheres to its vascular 
 tunic very intimately by a dense cellular tissue. 
 
 Its upper fibres curve in an arch from below upward and interlace 
 with those of the superior constrictor. The inferior separate like a 
 pair of forceps. Both descend to the base of the upper horn of the 
 thyroid cartilage, and are attached to its posterior edge. 
 
 This muscle raises the pharynx and the larynx, and dilates the first 
 of these two cavities transversely. 
 
 § 2137. The vascular tunic of the pharynx which is considerably 
 thick comes next to the muscular portion. 
 
 The inner tunic or the mucous membrane is very thin, smooth, and 
 reddish white. It is uninterruptedly continuous above with that of the 
 mouth and nose, below with that of the esophagus. 
 
 II. ESOPHAGUS. 
 
 § 2138. The esophagus^ 1) is that part of the alimentary canal in- 
 cluded between the pharynx and the stomach. It is narrower 'than 
 either, and is continuous with them at its two extremities by tunnel- 
 like portions. 
 
 This canal is situated in the posterior mediastinum, and extends its 
 whole length before the vertebral column. Its upper part corresponds 
 directly to the anterior face of the spine from the fifth cervical vertebra 
 and the cricoid cartilage, where it commences, to the fifth dorsal ver- 
 tebra, although it frequently also inclines a little to the left. From this 
 point to the ninth dorsal vertebra it inclines slightly to the right ; it 
 then returns on the anterior face of the column, passes through the 
 esophageal fissure of the diaphragm, and soon terminates at the upper 
 or left orifice of the stomach. 
 
 At its upper part it is situated behind the trachea. From the fifth 
 dorsal vertebra it is found between the aorta on the left and the azygos 
 vein on the right side. It is united to the adjacent parts by a very 
 loose cellular tissue. 
 
 § 2139. The esophagus is the narrowest part of the alimentary 
 canal. Even in its greatest dilatation its diameter is not an inch. It 
 is equally broad in every part, except at most the slightly contracted 
 portion which passes through the diaphragm. 
 
 The muscular tunic is considerably thick ; it is generally at least 
 a line in thickness. 
 
 It is composed of two layers, one external longitudinal, the other 
 internal transverse, the first of which is twice as thick as the second. 
 The longitudinal fibres usually commence above by three fasciculi or 
 
 (1) J. Bleuland, Observations anatomico-mcdicœ de sana et morbosa oesophagi 
 structura, Leyden, 1785.— V. Malacarne, Suit' esafago , suite intestine, c sopra alcune 
 valvulo del tubo alimentare, Padua, 1803. 
 
OP THE DIGESTIVE SYSTEM. 
 
 251 
 
 heads, a middle and two lateral. The middle head arises by a tendon 
 from the centre of the posterior face of the cricoid cartilage directly 
 below its upper edge, and expands a little in descending. The two 
 lateral heads, which are fleshy, descend from the lower edge of the 
 constrictor pharyngis inferior muscle. These three fasciculi unite 
 some inches below the upper extremity to form a muscular membrane 
 which is uniformly extended. 
 
 The circular fibres are a continuation of the inner posterior part of 
 the constrictor pharyngis inferior muscle, but are much thinner than 
 those of this muscle. 
 
 The upper are transverse ; the next are oblique from above down- 
 ward and from without inward, intercross with those of the opposite 
 side, and describe spiral lines ; the inferior, like the superior, form 
 straight rings. This canal for about an inch at the upper ^end of the 
 esophagus presents no circular fibres on its anterior face, and as the 
 longitudinal fasciculi are not united in this place, the esophagus is 
 here much less muscular and more extensible than in other parts. 
 
 The cellular or vascular tunic comes next to the muscular, and is 
 attached to it very loosely, while it adheres strongly to the internal 
 membrane with which it forms an internal canal which is easily de- 
 tached from the muscular membrane. 
 
 In this tunic there are numerous muciparous glands arranged very 
 compactly and composed of smaller granulations, which diminish in 
 number and size as they approach the lower extremity. 
 
 The inner or villous tunic is whitish, solid, and presents, on its inner 
 face, numerous and very narrow longitudinal grooves separated by 
 parietes. We ought not to consider it as the same with the pre- 
 ceding^].) 
 
 Its inner face is covered with a thinner, more delicate, and moist mem- 
 brane, which is evidently an epidermis, and which suddenly terminates 
 at the lower part of the esophagus at the part where it is continuous 
 with the stomach. The folds of this epidermis are easily separated by 
 boiling and maceration, although it is difficult to detach it entire unless 
 it is morbidly thicker and firmer from some pathological change. 
 Farther the lower extremity of the esophagus is detached from above 
 downward in one or more parts sometime after death, which undoubt- 
 edly arises from the fact that the fluid secreted by the glands of the 
 esophagus and cardiac portion of the stpmach soften and dissolve it, 
 and also the loose cellular tissue which unites it to the cellular tunic. 
 
 (1) Scemmerring ( Eingeweidelehre , p. 216) describes these two tunics as forming 
 but one, termed the vascular or internal glandular tunic ; he says that the inner 
 membrane and the vascular membrane of the stomach are continuous with it. It is 
 true that the internal membrane of the stomach is continuous with that of the 
 esophagus, and its vascular membrane with that of this canal. Other anatomists 
 err still" more in considering the villous tunic of the stomach and intestinal canal as 
 a continuation of the epidermis of the esophagus. 
 
252 
 
 DESCRIPTIVE ANATOMV. 
 
 § 2140. After the food is masticated by the teeth in the cavity of 
 the mouth, mixed with the saliva and formed into a soft mass, the 
 muscles of the tongue, the hyoid bone, the pharynx, and the esophagus 
 propel it successively toward the stomach ; this constitutes deglutition 
 (deglutitio).( 1) In order to this, the mass of food is moved from before 
 backward in the cavity of the mouth, which motion requires the close 
 of this cavity by approximating the jaws and lips. At the same time, 
 the tongue is moved by its muscles, so that its edges are raised and its 
 centre is depressed, and it thus forms a kind of groove, which touching 
 the palate makes a canal, in which the food proceeds from before back- 
 ward, because there is the least resistance in this direction. When it 
 has passed through this course, the genio-glossi and genio-hyoidei 
 muscles, which restore the tongue to its position and carry it forward 
 also favor ^its progress, because they thus raise the soft palate, to which 
 motiottals'o the levator muscles of this latter contribute. When the 
 food has arrived at this place the constrictor muscles of the pharynx 
 contract ; at the same time the depressors of the soft palate and the 
 stylo-glossi muscles act to raise the tongue and contract the isthmus 
 of the fauces ; the contractions of the constrictor phauyngis superior 
 muscle press the pharynx against the soft palate, and thus close the 
 nasal fossæ as they had been before by raising the soft palate. The 
 stylo-pharjmgei muscles, then the constrictors of the isthmus of the 
 fauces, raise and dilate the pharynx, so that the food can enter there 
 more easily. 
 
 The genio-hyoidei, the mylo-hyoidei, the thyro-hyoidei and the hyo- 
 glossi muscles carry the larynx forward and upward ; this motion 
 favors the closing of the glottis by the epiglottis, which the pressure of 
 the food also serves to depress, so that nothing can enter the air pas- 
 sages. 
 
 All these parts being extremely irritable act very rapidly and easily. 
 Deglutition, which is at first voluntary, becomes involuntary in the eso- 
 phagus, although this passage receives its nerves from the pneumo- 
 gastric nerves. 
 
 B. ABNORMAL STATE. 
 
 I. DEVIATIONS OF FORMATION. 
 
 § 2141. 1st. Primitive deviations. Sometimes but rarely the pha- 
 rynx and the esophagus terminate in a cul-de-sac, one at its lower the 
 other at its upper part, from a primitive deviation of formation. In the 
 
 (1) Schulze, De deglutitionis mechanismo, Halle, 1739. — F. B. Albinus, De dcglu- 
 titione, Leyden, 1740. — Wentz, De deglutitionis mechanismo, Erlangen, 1780. — P. J. 
 Sandifort, Deglutitionis mcckanismus, vcrlicall seclionc narium , oris t faucium illus- 
 tratus , Leyden, 1805. 
 
OF THE DIGESTIVE SYSTEM. 
 
 253 
 
 first place the cavity of the mouth also is generally at least imper- 
 fectly developed, and the lower jaw is wholly or in great part deficient. 
 The same thing occurs when the pharynx opens in the neck by a very 
 narrow orifice. 
 
 Another primitive deviation of formation which is more rare, is the 
 division of a part of the esophagus into two passages situated at the 
 side of each other.(l) 
 
 We cannot always determine if the contractions of the esophagus, 
 which depend on the abnormal folding of the inner membrane without 
 any morbid change, are primitive deviations of formation, or are pro- 
 duced consecutively by a simple increase of this membrane. 
 
 We must however admit that this latter sometimes occurs, since 
 accidents frequently appear only a little while before death. 
 
 2d. Accidental deviations of formation. Dilatations of the esopha- 
 gus are generally accidental.. They usually occur after contractions 
 situated below them, and in this case they are general. 
 
 More unfrequently a portion of the circumference of the canal 
 appears dilated in a cul-de-sac. (2) In one case the pouch was cer- 
 tainly caused by a hernia of the internal membrane through the 
 muscular tunic, (3) while in another this latter also contributed to 
 it. (4) 
 
 Pouches of this kind occur only at the lower extremity of the pharynx 
 or at the commencement of the esophagus, doubtless on account of the 
 sudden contraction of the alimentary canal in this place, and because 
 the esophagus is less muscular there than in other parts. 
 
 Ruptures of the esophagus which are sometimes transverse(5) and 
 sometimes longitudinal, (6) are only a greater degree of the hernia 
 of the inner membrane. They are sometimes caused by abnormal 
 brittleness. 
 
 When the contractions are permanent, they generally supervene 
 after a morbid alteration of texture, as thickening and induration of the 
 coats of the esophagus, so that they are rarely pure deviations of forma- 
 tion. Sometimes, however, they depend originally on a simple abnor- 
 mal contraction of the muscular fibres, which continues even after 
 death ; and the greater hardness in this part does not result from an 
 alteration of texture, but only from a stronger contraction of the mus- 
 cular tunic, although the continual pressure of the latter on the inner 
 membrane may also change its texture, and excite in it inflammation, 
 
 (1) Blaes, Obs. medicos rariores, tab. vi., fig. 2. 
 
 (2) Meckel, Handbuch der pathologischen Anatomie, vol. ii.— Bell, Surgical obser- 
 vations, pt. i., London, 1817, p. 167, tab. ii. 
 
 (3) Bell, loc. cit. 
 
 (4) Ludlow, Med. obs. andinq., vol. iii. 
 
 (5) Boerhaave, His. morbi atrocis, Leyden, 1724. 
 
 (6) Monro, Morbid anatomy, p. 311. 
 
 VOL. III. 
 
 33 
 
254 
 
 DESCRIPTIVE ANATOMY. 
 
 followed by effusion and suppuration, which render the induration 
 permanent.(l) 
 
 II. ALTERATIONS OF TEXTURE. 
 
 § 2142. The most common alteration in the texture of the esopha- 
 gus, is an abnormal hardness, usually attended with thickening, and 
 consequently with a greater or less contraction, or even with a total 
 closing of it, (2) which state is termed a scirrhus, and in which the dif- 
 ferent tunics of the passage are more or less blended in a mass, some- 
 times homogeneous and cartilaginous, sometimes divided into several 
 compartments by tendinous septa. Commonly then the texture of the 
 inner face is altered. This alteration is not observed in all parts indis- 
 criminately; it is more frequent at the upper and lower extremities of 
 the esophagus, in the former place, on account of the sudden contrac- 
 tion of the pharynx ; in the latter, because the lower portion of the eso- 
 phagus tends to contract, since the two orifices of the stomach are per- 
 fectly closed during digestion, so that it is very easily injured by sub- 
 stances passing through it. 
 
 Abnormal communications between the esophagus and the adjacent 
 parts, particularly the trachea, (3) the lungs, (4) the aorta, (5) may oc- 
 cur from cancer or common ulcerations. This state may also be oc- 
 casioned by ulcers formed primitively in the aorta. (6) 
 
 We can sometimes, but not always, determine from the state of the 
 parts, which was the primitive disease. 
 
 Beside the alterations of texture in the membranes mentioned, ex- 
 crescences, funguses, and polypi of different kinds, are sometimes, al- 
 though rarely, developed in the pharynx and the esophagus ; these 
 arise from the inner face of this canal, (7) and usually have their roots 
 in the mucous and vascular membranes. They are sometimes so long, 
 that commencing near the upper extremity of the esophagus, they de- 
 scend to the stomach. They are sometimes formed by fibres perpen- 
 dicular to their base, (8) are sometimes lobed(9) and suppurate.(lO) 
 
 Real ossifications are still more rare.(ll) 
 
 (1) Baillie relates several instances of it : we also have seen it, and like Baillie in 
 the cadavers of females. Mauchart, De struma oesophagi ejusque coalitu, Tubingen, 
 1742. 
 
 (2) Gyser, De callosa œsop hag i anguslia, Strasburg, 1770.— J. Bleuland, De dif- 
 ficiliaut impeditu alimentorum depulsione, Leyden, 1780. 
 
 (3) VanDoever’en, Obs. anat.pathol. Leyden, 1789, obs. ii. 
 
 (4) Bleuland, loc.cit., obs. i. p. 48. fig. 112. 
 
 (5) Van Dceveren, loc. cit., obs. i. 
 
 (6) We have one very remarkable case before us. 
 
 (7) Monro, loc. cit., p. 184-189. — Baillie. 
 
 (8) Baillie, loc. cit. 
 
 (9) Monro, loc. cit., p. 188. 
 
 (101 Baillie, loc. cit. 
 
 (11) Meckel, Handbuch der pathologischen Anatomic, vol. ii. p. 2. p. 227. 
 
OF THE DIGESTIVE SYSTEM. 
 
 255 
 
 ARTICLE SECOND. 
 
 MIDDLE AND INFERIOR PORTION OF THE ALIMENTARY CANAL. 
 
 § 2143. The middle region of the digestive system comprehends 
 th ejtomacli and the small intestine , and the most important glandular 
 organs of this system, the liver, the spleen, and the pancreas. This is 
 the largest and the most important portion, because digestion takes 
 place in it, for which the preceding portion only prepares, while the 
 terminating portion serves for the expulsion of the residue. 
 
 The stomach, the liver, the spleen, and the pancreas, with the com- 
 mencement of the small intestine, the duodenum, into which the pan- 
 creas, the liver, and the stomach open, occupy the upper part of the 
 abdominal cavity. They are separated from the lower, which is larger, 
 by a large transverse fold of the peritoneum, the transverse meso-colon. 
 It is not, however, necessary to describe the lower portion of the intes- 
 tine after these glands, nor to separate the. large intestine from the 
 small, since they are both situated in the same cavity, then texture is 
 essentially the same, and they are uninterruptedly continuous with 
 each other. 
 
 It is customary to describe the peritoneum before mentioning the 
 parts of the digestive system it envelops ; but as these are not the only 
 parts covered by it, the prolongations which extend from its outer sac 
 to the organs covered by it, cannot be clearly described until the situa- 
 tion and form of these organs are well known : finally, the important 
 anomalies of this membrane, especially those which occur in hernias, 
 being dependent on those, to which several of the parts it envelops are 
 subject, it is better to defer the description of the peritoneum until we 
 mention the different systems it supports. This is the method followed 
 by Roux in the Anatomie descriptive of Bichat. 
 
 We shall not describe on this occasion the cavity of the abdomen, 
 the most general characters of which have been already mentioned. 
 
 A. PERFECT STATE. 
 
 § 2144. The different regions of the middle portion of the alimentary 
 canal, doubtless differ very much in respect to their capacity ; but they 
 are very analogous in regard to texture, in which, however, they differ 
 on the contrary, from the upper and lower portions. The longitudinal 
 fibres of the muscular tunic completely surround this portion of the 
 canal ; the vessels which go to it are more numerous, and anastomose 
 together more frequently, and finally, the inner surface of the mem- 
 brane is more or less uneven, from prominences which do not exist in 
 the other two portions. 
 
256 
 
 DESCRIPTIVE ANATOMY. 
 
 I. STOMACH. 
 
 § 2145. The stomach ( ventriculus , stomachus) ,{\) the broadest part 
 of the alimentary canal, is included between the esophagus and the 
 duodenum. The portion of this canal in the cavity of the abdomen 
 commences with it. The alimentary substances all fall directly within 
 it, assimilation there commences, and they are there changed into a 
 liquid of a peculiar character called chyme ( chymus ). 
 
 A. SITUATION. 
 
 § 2146. The stomach is situated at the upper part of the abdominal 
 cavity, under the left false ribs. Sometimes, when it is much larger, 
 it descends into the umbilical region. Its direction is oblique from above 
 downward and from left to right. Its upper extremity touches the 
 diaphragm ; the lower extends to near the lower edge of the left or 
 square lobe of the liver. 
 
 § 2147. The spleen is situated near its left extremity ; behind its 
 posterior face is the pancreas, below it the transverse colon, above it 
 the left or square lobe of the liver and the lobe of Spigel, which is em- 
 braced by its upper curve. 
 
 B. FORM. 
 
 § 2148. The stomach has the form of an elongated cone, a little 
 curved on itself, and is somewhat similar to a bagpipe. Its right ex- 
 tremity is the narrowest, and its left the broadest portion. 
 
 We distinguish in it two orifiçes, two curves, and two culs-de-sac. 
 
 The upper or left orifice, termed also the cardiac ( ostium ventriculi 
 sinislrum, s. superius , s. cardia ), occupies the highest part of the 
 stomach near its left cul-de-sac. It serves as the limit between this 
 viscus and the esophagus, which, however, are continuous with each 
 other and separated by no prominence, so that the lower extremity of 
 the esophagus gradually enlarges. 
 
 The inferior or right orifice, termed also the pijlorus ( ostium ventri- 
 culi dextrum , s. inferius , s. pylorus, s. janitor, )( 2) is the limit between 
 the stomach and the duodenum. Here the transition is not gradual 
 and imperceptible as on the left side, but occurs by a prominence, termed 
 the valve of the pylorus ( valvula pylori). 
 
 The faces and the curves of the stomach are included between these 
 two orifices. 
 
 (1) Beside, tho works of Fabricius, of Aquapcndente, Glisson, and Fantoni, already 
 cited, consult also J. D. Metzger, Ventriculus humanus anatomice et physiologies 
 consideratus , Königsberg, 1788. 
 
 (2) Leveling, Pylorus anatomice atquc physiologies consideratus, Strasburg, 1764. 
 
OF THE DIGESTIVE SYSTEM. 
 
 257 
 
 The posterior and the anterior faces, when the stomach is more 
 or less distended, are uniformly convex, but wheq the stomach is 
 empty they are straight, flat, and in contact. 
 
 The upper or small curve , the diaphragmatic edge, is situated be- 
 tween the right side of the upper, and the left side of the lower orifice; 
 it is concave and much smaller than the lower, which is also called 
 the great curve , the colic edge. 
 
 When the stomach is empty, the two curves appear as more or less 
 distinct edges, which establish a well marked separation between the 
 two faces. But when the viscus is full, they are very rounded, and 
 insensibly continuous with the two faces. 
 
 The base, tubercle, or great cul-de-sac of the stomach, the splenic ex- 
 tremity ( fundus , s. saccus cœcus), is a prolongation in the form of a cul- 
 de-sac which extends from right to left on leaving the left side of the 
 upper orifice, and which proceeds about three inches beyond the inser- 
 tion of the esophagus. 
 
 This portion of the stomach is not much narrower than its centre. 
 On leaving it and the caidiac orifice, the viscus slightly enlarges to a 
 little beyond its centre from left to right. From tips latter point to the 
 pylorus, it gradually contracts very much. 
 
 When one or two inches from the pylorus, the great curve suddenly 
 inclines inward, but immediately resumes its former direction, although 
 it does not afterward describe so great a curve as in the rest of its 
 course. Hence, there is a fissure, opposite which the right portion of 
 the small curve, instead of preserving the concave form which it pos- 
 sessed from the cardiac orifice, becomes convex outward, although in 
 this place there is no contraction, between which and the pylorus is a 
 dilatation. 
 
 The portion of the stomach farthest from the right side, is termed the 
 antrum of the pylorus, or the small cul-de-sac ( antrum pylori). 
 
 C. DIMENSIONS. 
 
 § 2149. The size of the stomach varies much in the same indivi- 
 duals, in the state of health at different periods ; as this viscus dilates 
 considerably when filled with food, and contracts when empty. Its 
 capacity is diminished particularly in the transverse direction, and 
 often to such an extent that the stomach is smaller than the large in- 
 testine is when in its usual and moderate state of distention. 
 
 Generally, when the stomach is not unusually full, it is one foot 
 long from the base to the pylorus, three or four inches high in it high- 
 est part, and about as many broad from before backward. Its surface 
 is about one square foot in extent. . 
 
 D. ATTACHMENTS. 
 
 §2150. The stomach is attached on each side at its upper orifice 
 by a short fold of peritoneum, termed the phreno-gasiric ligament ( JL . 
 
258 
 
 DESCRIPTIVE ANATOMY. 
 
 phrenico-gastrictm), which extends on the left to the commencement 
 of the hase, and descends on the right along most of the small curve. 
 This ligament is attached forward and upward to the superior lumbar 
 portion of the diaphragm. 
 
 To this ligament is attached another which is much longer, the 
 gastro-splenic ligament ( L . gastro-splenicum), which extends from the 
 base of the stomach to the fissure of the spleen, where it is attached, 
 and which is continuous below with the great epiploon. 
 
 The stomach is united to the transverse colon bj the great epiploon, 
 and to the liver by the small epiploon, internal prolongations of the 
 peritoneum, which we shall describe after giving the history of this 
 membrane. 
 
 E. MEMBRANES. 
 
 § 2151. The stomach is enveloped by the peritoneum in every part, 
 excepting a narrow ring which exists along the great and small curve, 
 and along which the blood-vessels proceed. 
 
 Below this peritoneal coat, directly on its inner face, is the muscular 
 membrane, (1) which is very strong, but stronger than in the great and 
 the small intestine, although weaker than in the pharynx and rectum. 
 It is about half a line thick, and its texture is more complex than in the 
 rest of the alimentary canal, and we may, at least in some parts, de- 
 monstrate three layers. 
 
 The external layer is formed of longitudinal fibres, which mostly 
 blend with those of the esophagus and duodenum, and are uninter- 
 ruptedly continuous with them. These fibres are very much developed 
 at the upper part of the stomach, around its small curve ; they how- 
 ever cover all its surface. 
 
 The middle layer is formed by annular fibres, representing rings, the 
 centre of which correspond to the longitudinal axis of the stomach. 
 They commence at the base of the stomach, and interlace with each 
 other, proceed a little obliquely, and cover the whole stomach to the 
 pylorus, where they are strongest. 
 
 They are termed transverse or oblique fibres. They form the thick- 
 est layer. 
 
 Below this layer there is a third, (2) which is very evident on the 
 left side, and on the small curve, and which also surrounds the stomach 
 circularly, but in an opposite direction from the preceding, that is, lon- 
 gitudinally. They are the continuation of the circular fibres of the 
 esophagus, and frequently interlace with the oblique fibres. 
 
 The vascular membrane of the stomach is thicker, more vascular, 
 and more distinct from the internal membrane than in the esophagus. 
 
 (1) D. G. Galeati, De cornea ventriculi et intestinorum tunica; in Comm. Bonort., 
 1745 . — Bcrtin, Descr iption des plans vmsuleux dont la tunique charnue de l'estomac 
 humain est composée , vol. ii. p. 235. 
 
 (2) Galeati (lor. cit., p.240) described this membrane long before Bertin. 
 
OF THE DIGESTIVE SYSTEM. 
 
 259 
 
 It is uninterruptedly continuous with the vascular tunic of this canal, 
 but not with the inner or villous membrane. 
 
 The villous membrane of the stomach is thin, soft, loose, and spungy, 
 softer and looser, but a little thicker than the corresponding membrane 
 of the esophagus. It usually assumes, soon after death, a yellowish, 
 brownish, or reddish tint.(l) Not unfrequently, especially when 
 examined shortly after 'death, it presents in a greater or less extent, 
 especially at the base and at the small curve, a very red color, caused 
 by a network of small vessels almost exclusively veins. We generally 
 consider this state as the consequence of an inflammation which had 
 affected the organ during life ; and conclude from its existence that the 
 patient had been poisoned. But attentive examination demonstrates 
 that it supervenes during the struggles of death, without any sus- 
 picions of such a cause, and is occasioned particularly by the sudden 
 suspension of the circulation in the lungs. (2) 
 
 When the stomach is not distended, its villous membrane, and con- 
 sequently its inner face, present numerous large and small wrinkles, 
 which are arranged very irregularly. But these wrinkles disappear 
 when this viscus is even very moderately distended, so that when we 
 look at the membrane with the naked eye its inner face seems smooth, 
 although when examined with a microscope this same face seems 
 divided by several small intermediate parietes ; which enlarge to- 
 ward the pylorus and by this are still more similar to the villosities of 
 the intestines, into numerous compartments ; these are arranged very 
 compactly, like the cells in a bee-hive. (3) The cellules are larger 
 but fewer in the left half of the stomach, and are separated by simple 
 septa. In the region of the pylorus, these septa present numerous 
 grooves which render them still more similar to the villosities of the 
 intestines, although they are much smaller in other respects than these 
 latter.(4) 
 
 Beside numerous slight depressions, which are the orifices of small 
 simple glands, the inner membrane of the stomach also presents, espe- 
 
 (1) The French physicians having studied for several years the alterations in the 
 
 mucous membrane of the digestive canal, they have naturally considered also its 
 normal conditions. Rousseau (Des différent aspects que présente, dans l'état sain, la 
 membrane muqueuse gastro-intestinale ; in the Archiv, gêner, de méd., vol. vi. p. 
 321) has observed, that in the healthy state it is white or slightly rosy white. This 
 primitive color varies in different parts of the alimentary canal. Thus, the mucous 
 membrane of the pharynx is slightly rosy ; that of the esophagus is white, particu- 
 larly at its lower part ; in the stomach it has a slight rosy tint as in the pharynx. 
 This rosy color becomes less intense in its pyloric portion, changes to white in the 
 duodenum, preserves this appearance in the rest of the small intestine, then becomes 
 of a pale white in the cæcum, the colon, the commencement of the rectum, and re- 
 sumes its slightly reddish color near the end of this last intestine. F. T. 
 
 (2) J. Yelloly, On the vascular appearance of the human stomach, which is fre- 
 quently mistaken for inflammation of that organ ; in the Med. chir. trans.. vol iv 
 1813, p. 371-424. 
 
 (3) Hewson, Experim. inq., vol. ii., p. 173. 
 
 (4) E. Home has figured this (Observations on the gastric glands of the human 
 stomach and the contraction which takes place in that viscus ; in the Phil. Irans 
 1817, pt. i., p. 347, pi. i, xviii, xix. 
 
260 
 
 DESCRIPTIVE ANATOMY. 
 
 cially near the two orifices, others which are larger and which lead to 
 more or less apparent large glands. These last glands form at the 
 union of the esophagus and stomach a very marked prominence from 
 three to four lines broad, which separates the two cavities to a certain 
 extent. 
 
 The villous membrane of the stomach is uninterruptedly continuous 
 with that of the esophagus and intestinal canal. But it does not seem 
 to be connected with the epidermis of the esophagus, since we may 
 without the least violence separate this epidermis from it and from the 
 villous tunic of the esophagus around the cardiac orifice. 
 
 The membranes of the stomach vary in thickness in different indi- 
 viduals, and in different parts of this viscus of the same individual, and 
 at different periods.(l) 
 
 Generally, in the first respect, they are thickest in those male 
 subjects who enjoy good health, and in the second they are thicker, as 
 is easily imagined, the less the stomach is distended. In regard to the 
 third we may admit that the peritoneal coat is equally thick in every 
 part, while the others are much thinner in this cul-de-sac of the 
 stomach than in the other parts of the viscus, and are thickest near 
 the pylorus, where they are frequently six times thicker than at the 
 base. 
 
 F. VALVE OF THE PYLORUS. 
 
 § 2152. The valve of the pylorus ( valvula pylori) is formed by 
 the circular fibres of the muscular tunic, and also by the vascular and 
 mucous tunics of the stomach and duodenum. The first two mem- 
 branes are much thicker in this place, and all three are reflected on 
 themselves from without inward. 
 
 The longitudinal fibres in the peritoneal coat only pass on this point 
 to the outside. 
 
 It is very easy to remove the valve by cutting or raising the longi- 
 tudinal fibres. But there is always a contraction at the union of the 
 stomach with the duodenum. 
 
 A peculiar glandular substance has been mentioned as situated be- 
 tween the muscular and peritoneal tunics, and as forming the pylorus 
 and determining its form-;(2) but with the utmost care in our dissec- 
 tions we have never been able to discover the least trace of this sub- 
 stance, although we always find a very thick glandular layer before 
 the pylorus, below the muscular membrane of the duodenum. 
 
 The form of the valve varies. 
 
 It generally circumscribes the whole orifice of the viscus, and it is 
 sometimes circular and sometimes more or less oval ; in the latter case 
 its longitudinal diameter usually extends from above downward. 
 
 (1) Yelloly, loc. cit ., p. 400, 402. 
 
 (2) Sœmmerriug, Eingeweidelehrc, p. 236.— Portal, An. méd. vol. v., p. 161. 
 
OF THE DIGESTIVE SYSTEM. 
 
 261 
 
 It is more unfrequently semicircular, surrounding only a part of the 
 orifice. 
 
 Between this formation and the preceding there is an intermediate 
 degree in which the valve differs considerably in its breadth, according 
 to the different parts in which it is examined. 
 
 It is sometimes larger and sometimes smaller. 
 
 It is not certain that we ought always to admit that it possesses 
 during life the form which it has after death. 
 
 We cannot determine precisely what effect a given form of the valve 
 has even, admitting its existence and permanence during life, on the 
 action of the valve and on the more or less closing of the pylorus by 
 it, since it is evident that the degree of contractilitjr in the circular 
 fibres which contribute principally to form this fold has still more 
 influence. 
 
 C. TRANSIENT MODIFICATIONS IN THE FORM AND SITUATION OF THE STOMACH. 
 
 § 2153. The stomach presents regularly transient modifications in 
 its situation, according as it does or does not contain food. These 
 modifications correspond then to the different states of digestion. 
 
 The stomach is not only smaller when perfectly empty than when 
 it contains food, but then its form is not cylindrical. Its anterior and 
 posterior faces touch and its two edges are distinct from each other, 
 while when full, its edges and faces are imperceptibly continuous. 
 
 A still more remarkable modification occurring during digestion, is, 
 that the stomach is then divided into a right and a left half ; this occurs 
 about its centre, and is more or less distinct. The left half contains 
 the fluids and the right the solid substances, and the former pass out 
 from them into the small intestine without proceeding necessarily or 
 at least entirely through the right half and the pylorus.(l) 
 
 The orifices of the stomach are more or less perfectly closed during 
 digestion ; when, however, this process has continued some time the 
 pylorus opens, and the mass contained in the stomach passes through 
 it to descend into the duodenum, in proportion as it is digested. 
 
 The situation of the stomach also changes during digestion; it turns 
 on its axis, so that its anterior face looks more upward and the poste- 
 rior downward, although this apparent change in situation depends 
 principally on that in its form above mentioned. 
 
 H. FUNCTION OF THE STOMACH. 
 
 § 2154. The inner membrane of the stomach secretes the gastric 
 juice ( succas gastricus), a fluid the. exact nature of which it is difficult 
 to determine, as it is always more or less mixed with the substances 
 
 (1) E. Home, Lectures on comparative anatomy , vol. i., p. 138. 
 
 Vol. III. 34 
 
262 
 
 DESCRIPTIVE ANATOMY. 
 
 introduced into this viscus. It generally contains an uncomhined 
 acid.(l) 
 
 It however appears to be sometimes acid and sometimes neutral in 
 the same subject. Its base seems to be an albuminous substance very 
 analogous to that in the saliva. (2) Perhaps its composition is not 
 always the same, and varies from the nature of the substances which 
 act on the inner membrane of the stomach. The action of this fluid, 
 united perhaps with that of the bile, changes the food into a mucila- 
 ginous, gray, and thick pulp, of a disagreeable odor and taste, termed 
 chyme ( chymus ). The nature of this pulp varies with that of the ali- 
 mentary substances ; it includes more solid parts and less of salts than 
 any other of the animal fluids. It contains much carbon and albumen, 
 but no gelatine, at least if we may judge from some experiments. It 
 forms gradually in the pyloric portion. (3) 
 
 The formation of chyme, or the digestion in the stomach , is singu- 
 larly favored by the closing of its two orifices. We must also mention 
 among the causes which favor this process the motions of the sto- 
 mach, which are at first vague and irregular, but which gradually 
 take place about the end of chymification from the cardiac to the 
 pyloric orifice. 
 
 I. SEXUAL DIFFERENCES, 
 
 §2155. The stomach is the only portion of the alimentary canal 
 which presents sexual differences. It is larger, shorter, and broader 
 in the male ; smaller, narrower, and longer in the female^. Its mus- 
 cular coat, like that in the whole alimentary canal, is generally also 
 thinner in the female.* 
 
 II. SMALL INTESTINE. 
 
 § 2156. The small intestine ( intestinum tenue, ){ 4) the narrowest and 
 thinnest portion of the intestinal canal, is included between the sto- 
 
 (1) This opinion has at least •-'become very general since the time of Spallanzani, 
 
 although the experiments of Montègre tend to prove that it is not always correct. 
 Prout asserts that the free or at least the unsaturated acid often existing in the 
 stomach of animals is the hydrochloric, and that the salts commonly found in this 
 viscus are the alkaline hydrochlorates (Phil, trans., 1824, p. 1); : . Children has ar- 
 rived at the same result by analyzing the fluids vomited by a man during a violent 
 attack of dyspepsia (Annals of philosophy, 1824, July). F. T. 
 
 (2) Bostock, in the Med. chir. trans., vol. iv., p. 177. 
 
 (3) Marcet, in the Med. chir. trans., vol. vi., p. 627. — Prout, Mémoire sur V héma- 
 tose et le sang en général ; in the Journ. compl. des sc. méd., vol. xi., p. 132-215. 
 
 * Beside the sexual differences, Dr. S. Th. de Sœmmerring has shown that the 
 stomach of the negro differs from that of the European, in being of a more rounded 
 form, approaching that of the ape (Am. Med. Journal, Nov., 1828). 
 
 (4) Helvetius, Observations sur la membrane interne des intestins^ grêles, appelée 
 veloutée, sur leur membrane nerveuse, et sur leur membrane musculeuse ou charnue ; 
 in the Mém. de Paris, 1721, p. 392-403. — C. B. Albiuus, Dcscriplio inieslinormn 
 tenuium hominis , Leyden, 1722, 1724. 
 
OF THE DIGESTIVE SYSTEM. 
 
 263 
 
 mach and the large intestine. It is uninterruptedly continuous with 
 both, although separated by two valvular folds, the pylorus and the 
 ilieo-cœcal valve, the closing of which can perfectly insulate its cavity, 
 which is sometimes the case. 
 
 Its outer circumference is uniform ; this is also the case with its 
 diameter in most of its extent, and hence it is cylindrical. 
 
 Its whole length from the pylorus to the commencement of the colon 
 varies much from thirteen to twenty-seven feet, although the length 
 of the body does not differ in the same proportion. 
 
 It is about an inch in diameter when moderately distended. 
 
 The description of the duodenum may be separated from that of the 
 small intestine, as it differs from this latter in several respects. 
 
 A. DUODENUM. 
 
 § 2157. The commencement of the small intestine, that portion 
 directly next to the stomach, is called the duodenum from its length. (1) 
 
 This intestine is situated in the right half of the abdomen. It de- 
 scribes a considerable arch, the convexity of which looks to the right 
 and the concavity to the left. We distinguish in it three parts, a su- 
 perior , which ascends obliquely from left to right and a little from 
 before backward; a middle, oblique from right to left and descending; 
 finally an inferior, dfjique from right to left and ascending. 
 
 It is attached to the gall-bladder and lo the commencement of the 
 transverse colon. Its upper and smallest portion is situated above, 
 and the lower and largest, below the transverse colon. It is covered 
 in most of its anterior face by the posterior wall of the peritoneum, 
 which extends forward in this place to form the transverse mesocolon, 
 surrounds it loosely, and keeps it fixed against the posterior wall of 
 the abdominal cavity. 
 
 The middle portion descends below the transverse mesocolon, and 
 when this fold of the peritoneum is raised it is seen on the right side of 
 the mesentery. 
 
 The third, on the contrary, is situated on the left side of the mesen- 
 tery, the upper part of which arises from it directly. It extends to the 
 second lumbar vertebra, goes forward in the place where the upper 
 extremity of the mesentery blends with the transverse mesocolon and 
 opens into the jejunum. 
 
 If we except its first portion, which is covered in every part by the 
 peritoneum, the duodenum is protected by this membrane only on its 
 anterior side ; the posterior is attached by a very loose cellular tissue 
 to the posterior wall of the abdomen and directly to the organs situated 
 behind it. 
 
 (1) L. Claussen, De intestini duodeni situ ct ne.ru, Leipsie, 1757. — Sand^rt, Ta- 
 bula inteslini duodeni , Leyden, 1780. 
 
264 
 
 DESCRIPTIVE ANATOMY. 
 
 The middle portion descends along the concavo edge of the right 
 kidney and on the right side of the vertebral column to the fourth lum- 
 bar vertebra. 
 
 The inferior ascending portion is situated on the right side of the 
 vena-cava and the right renal vessels, on the left side of the aorta, be- 
 hind the upper part of the root of the mesentery, the superior mesen- 
 teric artery, and the great mesaraic vein. 
 
 Its left and concave portion closely embraces the right half of the 
 pancreas. 
 
 § 2158. The duodenum is generally broader at its origin than in 
 any other part ; its concave face is corrugated, its convex face is 
 smooth and tense. 
 
 It differs from the other portions of the small intestine by its situa- 
 tion and the firm manner in which it is kept in place, and also by its 
 greater extent and the less regularity of its folds. 
 
 B. MEMBRANES OF THE SMALL INTESTINE. 
 
 § 2159. The small intestine is covered externally in all its extent 
 by the peritoneum, and, except the duodenum, it is attached to the 
 lumbar portion of the vertebral column by a long fold of this mem- 
 brane, termed the mesentery (raese/nterium) . 
 
 Below this peritoneal tunic is the thin muscular membrane,(l) which 
 is about a third of a line thick. 
 
 The external or longitudinal layer, although much thinner than the 
 internal, with which it is very intimately united and which is never 
 entirely deficient, surrounds the canal almost entirely. 
 
 The internal layer is transverse or rather oblique, and circumscribes 
 it entirely. 
 
 The vascular membrane presents nothing remarkable. (2) 
 
 The small intestine differs from the other portions of the intestinal 
 canal principally by the arrangement of its inner or mucous mem- 
 brane. (3) The principal character which distinguishes this membrane 
 is the singular increase of its extent and the greater development of 
 its surface, compared Avith that of the external membranes, especially 
 the muscular and the peritoneal tunics. 
 
 This enlargement depends on its folding from without inward, which 
 gives rise to two kinds of folds, the great and the small folds. 
 
 The great folds are termed valves ( valvules ), and the small, villosi- 
 ties (villi). 
 
 (1) V. Malacarne, Sulla structura anatomica dette intestine; in the Memorie 
 della societa italiana, vol. x., p. 27-62. 
 
 (2) B. S. Albinus, Diss. de arteriis et venis intesiinorum hominis, Leyden, 1736. 
 — J. Bleuland, Vasculorum in intestinorum tenuium tunicis subtilioris anatomes 
 opera detegendorum description Utrecht, 1797. 
 
 (3) Helvetius, loc. cit. — D. G. Galeati, De cribriformi intestinorum tunicâ ; in the 
 Comm. Bonom., vol. i., 1731, p. 359-370. 
 
OF THE DIGESTIVE SYSTEM. 
 
 265 
 
 Both are developed principally at the upper extremity of the small 
 intestine. They diminish much in number and size from the origin of 
 this organ to its termination. 
 
 C. VALVES. 
 
 § 2160. The valves are three lines high at the upper part of the 
 small intestine. 
 
 They have a transverse direction, and most of them occupy the 
 whole circumference of the intestine, so that they form circles which 
 circumscribe it. But they divide once or twice in their course, and 
 also communicate with each other by oblique or perpendicular eleva- 
 tions, which generally are less prominent and much shorter than 
 they; three or four of them always exist between each pair of 
 valves. 
 
 They are very numerous, being only a few lines distant from each 
 other. 
 
 There are but very few at the lower part of the small intestine, but 
 before entirely disappearing, they gradually diminish in elevation and 
 breadth. 
 
 They are formed only by the inner membrane and by the vascular 
 tunic of the intestine, so that they cannot move themselves, but they 
 are floated by the motions caused by the muscular tunic in the fluids 
 within the intestinal canal. When we cut the intestine, we observe 
 that they are directed towards each other, so that if we immerse the 
 organ in water they cover one another like the tiles of a roof. 
 
 Hence the term valvulœ conniventes , applied to them by Kerckring ; 
 but it is wrong to ascribe this discovery to this anatomist, from which 
 error they have deiived the name of the valves of Kerckring ( valvulœ 
 Kerckringii) . 
 
 An artery and vein usually pass through the base of each valve. 
 
 These valves delay the course of the substances in the alimentary 
 canal; hence their greater development at the upper part of the small 
 intestine is curious, since the fluid contained in this portion possesses 
 the most nutritious particles. 
 
 They are no less curious as a peculiar character of the human or- 
 ganism. Morgagni mentions their absence in some ruminantia.(l) 
 We have also looked for them in vain in many mammalia of all orders, 
 even among the apes: In fact several fishes present very analogous 
 
 transverse valves, which are often very numerous ; but they occupy 
 the end of the intestinal canal in these animals, and they have no vil- 
 losities. They present also this character in those reptiles in which 
 we have seen them. (2) 
 
 (1) Ep. an., xiv., p. 20. 
 
 (2) Deutsches Archiv, für die Physiologie , vol. iii., part ii. 
 
266 
 
 DESCRIPTIVE ANATOMV. 
 
 We may then say, in order to express the preceding proposition 
 more precisely, that man is the only being possessing both transverse 
 folds and villosities in the small intestine, and alone presents the union 
 of these two organic arrangements, which are found separately in 
 other animals. In fact most mammalia and birds, as also some rep- 
 tiles and fishes, present only the villosities, and but a few genera of 
 the last two classes the transverse folds. 
 
 D. VILLOSITIES. 
 
 §2161. The villosities(l) are small thin prolongations, which arc 
 generally rounded, sometimes cylindrical, sometimes conical, and ter- 
 minated insensibly in a point ; finally, sometimes enlarged at their loose 
 extremity ; they are attached to the mucous membrane ; hence, the 
 term villous tunic ( tunica villosa ), often applied to it. 
 
 The villosities cover all the inner face of the mucous membrane of 
 the small intestine, being very compact at its upper part, while at the 
 lower part they are more or less remote from each other. In regard to 
 their form, some authors, as Galeali, admit that they are cylindrical, 
 or pointed at the origin of the intestine, and conical at its termination, 
 but this difference is not constant. We have always found on the con- 
 trary, which agrees with the observations of Hewson, that the villosi- 
 ties at the upper part of the canal are broader in proportion to their 
 length, and that from their form, they resemble the valvulæ conniven- 
 tes, while as those of the lower part were thinner, elongated, and even 
 sometimes longer than the preceding. They are about one quarter of 
 a line long. As they are arranged very compactly, and as there are 
 about four thousand in a square inch, we may estimate their whole 
 number as more than a million, which is very moderate. 
 
 When examined by the microscope, they appear formed of a granu- 
 lar substance, and their surface is not perfectly smooth, although it is 
 not indented. When the blood-vessels of the intestinal canal are in- 
 jected, the villosities are not only more apparent and filled with injec- 
 tion, but their surface is more uneven, because a vascular net-work is 
 developed in it. 
 
 When the lymphatics are injected, we see on their surface a net- 
 work formed by these vessels. 
 
 They are then composed of cellular tissue, in which are blood-ves- 
 sels and lymphatics, the parietes of which are not distinct from its sub- 
 stance. It has long been disputed, whether the villosities open on 
 their surface or not 1 
 
 (1) Beside the works of Hclvcti us, Galeati, and A. Mec.kcl, consult particularly on 
 the villosities: — J. N. Lieberkuhn, De fabricû. ct actione villorum intestinorum 
 tenuium hominis, Leyden, 1745. — Hewson, in his Exp. inq., vol. ii. c. xii. — R. A. 
 Hedwig, Disquisitio ampullarxim Liebcrkuhnii physica-microscopica , Leipsic, 1797. 
 — C. A. Rudolphi, in his Abhandlungen, &c. p. 39'. 
 
OP THE DIGESTIVE SYSTEM. 
 
 267 
 
 Excellent observers, as Lieberkuhn, Hunter, Cruikshank, Hewson, 
 Hedwig', and Bleuland, admit these openings, and assert they have 
 seen them. Lieberkuhn and Bleuland think there is generally only 
 one at the extremity of each villosity, rarely several. Others mention 
 more, and assert they are situated in the same place. When a minute 
 injection has raised, inflated, and rendered the villosities cylindrical, 
 they appear spungy, and perforated at their extremity, while they re- 
 main smooth and united on the sides. We cannot consider these open- 
 ings as arising from accidental ruptures, since they are empty and en- 
 tirely separated from each other, and they also occur only in determi- 
 nate points, while in ruptures of a part, the vessels of which are filled 
 with injection, we should necessarily see this injection. Cruikshank 
 and Hunter have counted twenty of these openings in the villosities, 
 which were not injected, but only gorged with chyle. 
 
 The arguments of Rudolphi who has never seen these ope nin gs, 
 do not refute the assertions of the observers above mentioned. He 
 does not mention Hewson at all. The diameter of the openings 
 figured by Cruikshank and Bleuland, which seems too great to be cor- 
 rect, may depend on some individual peculiarity, on the state in which 
 the activity was at the moment of death, or even on some disease, all 
 which circumstances would render the openings more perceptible. 
 If Hewson has not figured them in all the villosities, it may depend 
 either on their diameter or on the situation of the villosities, and the 
 manner in which they were lighted. 
 
 Thus, although these ' openings are not necessary to explain the 
 phenomenon of absorption, they seem to exist. (1) 
 
 E. GLAND3. 
 
 § 2162. The inner membrane of the small intestine is covered with 
 numberless muciparous glands, which differ in their size and arrange- 
 ment. 
 
 In its whole length, and on all its surface, there are very numerous 
 distinct glands, which are the smallest (G. mucosœ , s. cryptez minima ), 
 and which cannot be seen without a microscope. (2) 
 
 (1) Strictly speaking - , the question is, whether the pores of the villosities, for they 
 
 must necessarily exist in every org-anic or inorganic substance, possess a special 
 organization, so that they may be compared to a certain extent with the lachrymal 
 puncta for instance. But it is what it does not seem to be, and we cannot but apply 
 to microscopical observations, where the illusions are so frequent and difficult to avoid 
 the axiom, that a negative assertion does not refute a positive one, when the latter is 
 supported by good authority. The researches of A. Meckel, the brother of the 
 author, also favor Rudolphi’s opinion. This anatomist does not admit vessels in 
 the villosities of the intestine, and thinks that the injection which penetrates into 
 them, transudes through the parietes of the arterial terminations, to be distributed in 
 the cellular tissue which forms them. Farther, he has found, contrary to the asser- 
 tion of all his predecessors, that the villosities are always flattened layers, most 
 generally turned on their axes, and often folded on each side, so as to form a semi- 
 canal or a groove, which arrangements vary infinitely, and by which he explains the 
 different appearances described by authors before him. F. T. 
 
 (2) Galeati, loc. cit, — Lieberkuhn, De rims intesUnormn. 
 
S68 
 
 DESCRIPTIVE ANATOMY. 
 
 Others are much larger, and divided into two classes, the solitary 
 ( G . solitariœ ) and the agglomerate (G. agminatœ). The first are 
 termed also the glan ds of Brunner, (1) and the others the glands of ' 
 Peyer. { 2) 
 
 The glands of Brunner are seen particularly at the commencement 
 of the small intestine, especially in the duodenum, where they appear 
 in the form of small, flat, rounded, lenticular bodies, at most one line in 
 diameter, situated on the posterior face of the mucous membrane, and 
 which open into the cavity of the intestine by broad orifices. 
 
 When these simple glands are very large, and project considerably 
 above the inner face of this portion, or the other parts of the canal, it is 
 al wajrs from a morbid state. 
 
 The glands of Peyer rarely exist except in the ileon, where they en- 
 large much from the commencement to the end of the intestine. 
 
 They form about thirty masses, which are generally oblong and 
 rounded, seldom triangular or almost square, the longitudinal axis of 
 which is parallel to that of the intestinal canal ; they are rarely more 
 broad than long, and they do not exist on the side of the intestine cor- 
 responding to the mesentery, but on the lateral portions, particularly 
 the anterior. 
 
 They are not prominent, or at least project but little above the sur- 
 face of the intestine, and they are distinguished only by the intestine 
 being less transparent in the points they occupy. They form on the 
 posterior face of the mucous membrane, a thin layer, which is com- 
 posed of bright, transparent, rounded, and slightly depressed points, 
 and of darker edges in the spaces between these points. 
 
 They vary in length from some lines to three or four inches ; they 
 are about nine lines broad. 
 
 At the upper part of the ileon they are five or six inches distant from 
 each other ; but at the lower part, and near its termination, they are 
 almost blended with each other, and sometimes form in the loose por- 
 tion of the edge of the small intestine, an almost uninterrupted layer 
 eight inches long. 
 
 F. FUNCTIONS OF THE SMALL INTESTINE. 
 
 § 2163. The inner membrane of the small intestine secretes the in- 
 testinal mucus ( mucus intestinalis ) and the intestinal liquid ( liquor en- 
 terions), which probably form one and the same fluid, partially favor- 
 ing the assimilation of the alimentary substances by its action upon 
 them, and also their progress by the lubricating layer on the surface 
 of the intestine. This progress is caused by the muscular tunic, which 
 alternately dilates and contracts from the commencement of the small 
 intestine to its termination, so as to send forward its contents in the 
 
 (1) Brunner, Glandulœ intestini duodcni, s. pancreas secundarius , Frankfort, 
 1715. 
 
 (2) C. Peyer, De glandulis intestinorum, Schafhouse, 1677. 
 
OF THE DIGESTIVE SYSTEM. 
 
 269 
 
 same direction. In passing through the small intestine, but particu- 
 larly in the duodenum, and from the influence of bile, aided by that of 
 the pancreatic juice, the chyme is separated into two portions, the 
 chyle ( chijlus ), a whitish fluid, similar in its chemical properties to the 
 blood and th ef cecal matter [faces). The chyle is absorbed by the vil- 
 losities of the intestine, whence it passes into the lymphatic vessels, and 
 probably also into the meseraic veins. The feces proceed into the 
 large intestine. 
 
 III. LARGE INTESTINE. 
 
 § 2164. The large intestine ( intestinum crassum , s. colon ) differs from 
 the small intestine in its situation and attachments, form, length, 
 breadth, and the arrangement of its tunics. 
 
 A. SITUATION AND ATTACHMENTS. 
 
 § 2165. The large intestine describes an arch, the direction of which 
 is from below upward, then goes transversely from right to left, and finally 
 from above downward, begins at the lower extremity of the small in- 
 testine, and terminates at the anus. It commences at the right iliac 
 region, but not always in the same point. This point is generally 
 situated at the upper extremity of the anterior face of the right iliacus 
 muscle, between this and the psoas muscle ; sometimes, also, it occurs 
 much lower, and sometimes much higher, before the right psoas 
 muscle. The small and the large intestine are intimately attached in 
 this place to the iliacus muscle by a short cellular tissue, and the first 
 is there continuous from within outward, and from below upward with 
 the second. 
 
 The higher, that is, the more abnormal the union between the two, 
 the more similar the arrangement to that in the fetus. 
 
 At the point of union the commencement of the colon presents a 
 prominence which extends below its terminating extremity, and is 
 termed the cæcum , and the cœcal appendix. 
 
 B. DIVISION OF THE LARGE INTESTINE. 
 
 A. ILEO-GOLIC VALVE. 
 
 § 2166. The small intestine is suddenly continuous with the large, 
 at the point mentioned, so that it enters there at an acute angle from 
 below upward, from left to right, and from within outward, for about an 
 inch, and there forms a prominence termed the ileo-colic valve , (1) or 
 the valve of Bauhin [valvula ileo-colica , s. Bauhini). This valve is 
 
 (1) L. Heister, De valoula coli, Altdorf, 1718. — J. N. Licberkulm, De valvulâ. 
 coli, Leyden, 1739.— Haller, De valvula coli, Göttinnen. 1742. — J. M. Rœderer, De 
 valvula coli, Strasburrr, 1768. 
 
 Vol. 111 
 
 35 
 
270 
 
 D E S C ill f T IV E ANA 3' OBI V 
 
 composed of two layers, a superior, generally a little narrower and al- 
 most horizontal, which forms nearly a right angle with the ascending 
 portion of the colon, and an inferior, which is broader, and describes a 
 more acute angle with this" same portion. 
 
 Between the two layers is a transverse and oblong opening, which 
 is the slightly contracted orifice of the small intestine. 
 
 Each is formed by the inner membrane of the vascular tunic, and the 
 circular fibres of the muscular membrane of the large and the small 
 intestine which are turned over in this place, while the longitudinal 
 fibres, and the peritoneal tunic, which do not fold, pass like a bridge 
 from the loose portion of the small intestine on the large. The muscu- 
 lar tunics of the two intestines are united with each other at their ex- 
 ternal face by mucous tissue, and when we consider only the valve, 
 they form its most internal part or its centre. When we carefully de- 
 stroy the cellular tissue which unites them, the valve entirely disappears, 
 the small intestine opens directly into the large by a broader orifice than 
 the rest of its caliber, in the form of a trumpet, and then the union of 
 the two intestines still more resembles that of the esophagus with the 
 stomach, since in both places the line of demarkation is evidently indi- 
 cated by a very evident difference in the texture of the inner membrane, 
 by the greater size of the lower portion into which the other opens, 
 and by its projecting above this latter, giving rise to a cul-de-sac. 
 
 § 2167. In the normal state the ileo-colic valve separates the small 
 from the large intestine, so as to allow the substances contained in the 
 first to pass into the second, but entirely preventing them from reas- 
 cending from the latter into the former. This effect depends both on 
 the action of the muscular fibres and the form of the valve. 
 
 B. CECUM AND VERMIFORM APPENDIX. 
 
 § 2168. The portion of small intestine which passes beyond the 
 colon, (§ 2166) is composed of the cæcum ( intestinum cæcum), and of 
 the vermiform appendix (appendicula vermiformis), (1) which originally 
 form but one, and which do not begin to be distinct until after the early 
 years of life. 
 
 § 2169. The cæcum is elongated, triangular, and as large as the 
 rest of the colon. It extends from an inch to an inch and a half beyond 
 the terminating portion of the small intestine. The muscular fibres 
 in particular, are very irregular, and very much interlaced near its 
 closed extremity. It is terminated by a blunt summit, of which the 
 vermiform appendix is the prolongation ;(2) the latter, however, rarely 
 leaves its centre, but arises from its left side a little posteriorly. It is 
 
 (1) J. N. Lieberkuhn, De valvula coli et usu processus vermicularis , Leyden, 
 1739. — J. Vosse, De intestino cœco ejusque appendice vermiformi, Gottingen, 1749. — 
 Van den Busch, Dc intestino caeca ejusque processu vermiformi, Gottingen, 1814. 
 
 (2) Louyer Villermay, Observations pour servir à l'histoire des inflammations de 
 l'appendice du cæcum ; in the Archiv, gêner, de médecine, vol. v. p. 246. 
 
OF THE DIGESTIVE SYSTEM. 
 
 271 
 
 the narrowest part of the alimentary canal. A small fold of peritoneum 
 unites it to the lower extremity of the mesentery, and to the spermatic 
 vessels which are situated below it. 
 
 This appendix is generally about three inches long. 
 
 Excepting its orifice, which is a little broader than the rest, and tun- 
 nel-shaped, its breadth is nearly equal in every part, and is about two 
 lines. It is terminated in a blunt summit. A transverse fold, a kind 
 of valve, sometimes, but not always, separates it from the ccecum.(l) 
 
 Near the end of the cæcum, the three bands which form the longi- 
 tudinal muscular layer of the large intestine, unite to form a thinner 
 and uniformly expanded membrane, which is extended on the vermi- 
 form appendix, where it assumes the same arrangement. 
 
 § 2170. The parietes of this appendix are as thick as those of the 
 large intestine, and its inner membrane forms, from its great number 
 of large and extremely compact muciparous- glands, a very complex 
 net-work, similar, although much larger than that formed by the ine- 
 qualities of the inner face of the rest of the colon. 
 
 Not unfrequently, although not always, this inner face also presents 
 larger transverse prominences, folds similiar to those at the orifice of 
 the appendix. 
 
 The vermiform appendix is not always situated exactly in the same 
 place ; it sometimes descends almost entirely into the pelvis, the edge 
 of its mesentery opposite to that which adheres to it, being loose. 
 Sometimes it goes upward, passing under the commencement of the 
 large intestine. Sometimes then it assumes this ascending direction in 
 its whole extent, and sometimes its lower extremity again curves 
 downward in a greater or less extent. 
 
 C. ASCENDING COLON. 
 
 § 2171. The large intestine begins with the right or ascending 
 colon (I. colon dextrum , s. ascendens) ) which is its shortest portion, as- 
 cends before the right kidney, with w r hich it is intimately united by the 
 right lumbar meso-colon , and extends to the anterior part of the lower 
 face of the right lobe of the liver. In this place it describes a right or 
 an acute angle under the base of the gall-bladder, with which it has 
 normally no connection, goes to the right, and is continuous with the 
 transverse colon. 
 
 D. TRANSVERSE COLON. 
 
 § 2172. The transverse colon (colon transversmn) is attached to the 
 posterior wall of the abdomen by a much broader fold of the peritoneum 
 than that of- the preceding, termed the transverse meso-colon ; it is situ- 
 ated below the stomach, with which it is always more or less intimate- 
 
 (1) Morgagni, Advers. anat. Anim. XI V— Bonazzoli, Observ. in intesi. et rcnibus 
 habilœ ; in the ( Somm . Horton., vol ii p. 2. p. 1.38 
 
272 
 
 DESCRIPTIVE ANATOMY, 
 
 ly united by the great epiploon, and always descends more or less be- 
 fore the folds of the small intestine, usually to the umbilical region, 
 sometimes even into the small pelvis. It is always much longer than 
 the ascending colon, and sometimes very much exceeds it in size, and 
 then describes several circumvolutions. It extends from the right to 
 the left side. Its two extremities are intimately attached to the duo- 
 denum by the meso-colon, which is much shorter in these two parts 
 than in its centre. On the centre of the anterior face of the right kid- 
 ney, and at the lower extremity of the spleen, it is continuous with the 
 descending colon, describing either an arch, or a more or less acute and 
 sometimes a double angle. 
 
 E. DESCENDING COLON. 
 
 § 2173. The descending colon (I. colon descendens) extends from 
 the lower extremity of the spleen to the pelvis, passing along the lower 
 half of the anterior face of the left kidney, then the quadratus lumborum 
 muscle, and finally the upper and inner part of the left iliacus muscle. 
 It is continuous with the rectum before the right sacro-iliac symphasis. 
 
 It is attached to the posterior wall of the abdomen, above by a short, 
 and below by a very large fold of the peritoneum. 
 
 This lower part projects more or less forward, and to the right, and 
 sometimes adheres to the cæcum ; it describes a curve, hence it is called 
 the *S, or sigmoid flexure of the colon ( flexura sigmoidea, s. iliaca , s. 
 S. romanum ), 
 
 F. RECTUM. 
 
 § 2174. The rectum ( 7 , rectum) is the last portion of the intestinal 
 canal, and it opens externally by the. anus. It begins at the lower 
 extremity of the colon, is attached to the left half of the anterior face of 
 the sacrum in a slight portion of its upper extremity, by a short fold of 
 the peritoneum, termed the meso-rectum , and in the rest, simply by cel- 
 lular tissue ; it goes from left to right, and from above downward, so 
 long as it is surrounded by the peritoneum, and does not begin to de- 
 scend in a straight fine until this membrane leaves it. 
 
 Sometimes it descends in the pelvis on the right, and not on the left 
 side of the sacrum. In one case of this kind observed by us, the great 
 inferior left curve or the sigmoid flexure of the colon, advanced very 
 much toward the right, united very intimately at its centre with the 
 commencement of the ascending colon, and was attached in this man- 
 ner to the right side. Its ascending and descending portions were also 
 attached and separated a little from each other interiorly. Below this 
 point, the commencement of the curve and that of the rectum were also 
 united by a fold of peritoneum, whence there was a considerable de- 
 pression, which might easily receive a portion of small intestine several 
 inches long, and thus give rise to an internal hernia. 
 
OF THE DIGESTIVE SYSTEM. 
 
 273 
 
 Although we may justly consider the rectum as the lower part 
 of the large intestine, the rectum differs from it in several respects. 
 In fact : 
 
 1st. It is almost always much broader, and in this respect it ex- 
 ceeds more or less the other portions. 
 
 2d. The peritoneum covers it only in its upper region ; even ihere 
 it covers, in most of its extent, only its anterior face, and forms no epi- 
 ploic appendages on its surface. 
 
 3d. Its muscular fibres are much stronger, and the longitudinal 
 layer surrounds it in every part. 
 
 The inner membrane is also smooth and filled with simple mucipa- 
 rous glands, but these glands are smaller and fewer. (1) 
 
 (1) The recto-vesical operation for stone, introduced by SansoD, which becomes 
 more extensively known every day (J. L. Sanson, Des moyens de parvenir à la vessie 
 par le rectum , Paris, 1817), requires a more detailed description of the anatomical 
 relations of the rectum. Taken as a whole, this intestine extends from the upper 
 strait of the pelvis to the anus. Its direction is at first a little oblique from left to 
 right, and it curves toward the lower part of the cavity of the pelvis to go from 
 behind forward, under the bladder, to the level of the prostate gland, below which 
 it again curves from above downward, and a little from before backward. We may 
 then consider it formed by three pkrts separated by these two curves, and distinct 
 in their situation and structure, and the nature and importance of their connections. 
 The first or superior is directed from above downward, and a little obliquely froni 
 left to right ; it extends from the end of the sigmoid flexure of the colon to the place 
 where the intestine leaves its peritoneal envelop, and curves to go below the bladder : 
 it forms more than half of the rectum. It is tortuous, loose, smooth, covered by the 
 peritoneum, and attached loosely to the posterior wall of the cavity of the pelvis by 
 a fold of this membrane. The second or central part is included between the two 
 curves, and is about three inches long; its direction is oblique from above down- 
 ward and from behind forward ; it is slightly curved in the same direction, is fixed 
 and immovable, and constantly corresponds posteriorly to the lower part of the sa- 
 crum, the coccyx, and the base formed by the ischio-coccygei muscles : forward to 
 the base of the bladder, from which it is separated downward and outward by the 
 seminal vesicles and the vasa deferentia, and still lower by the prostate gland : 
 finally, on the sides to an abundance of cellular tissue. It differs in structure and 
 organization from the upper portion, being wholly destitute of the peritoneum, ex- 
 cept sometimes at the highest part of its anterior face, when the bladder is consi- 
 derably retracted ; its muscular coat also is much thicker, and formed of much 
 stronger and more numerous longitudinal fibres ; it is every where surrounded by 
 a cellular tissue, compact only below the prostate gland, loose and very abundant in 
 the rest of the circumference of the intestine. Finally the lower portion of this 
 latter commences below and on a level with the prostate gland, and terminates at 
 the anus. It varies in length from one inch to an inch and a half. It is broader 
 above than below. Its direction is oblique from above downward, and a little from 
 before backward. Near its origin it is every where surrounded by an abundant 
 cellular tissue, except forward, where it corresponds to the prostate gland ; in the 
 rest of its extent it is enveloped by the sphincters. Its structure differs much from 
 that of the other portions. In fact, when the rectum curves a second time below 
 the prostate gland, its fleshy tunic, which is very thick, and composed of numerous 
 longitudinal fibres, terminates suddenly; the mucous membrane alone extends 
 to the skin, surrounded by the round muscular fibres of the sphincters, which meet 
 and form a kind of ring, much thinner at its origin than on the side of the skin, 
 where it becomes much thicker, and gives rise to two caudiform prolongations, of 
 which the anterior, the longer, goes toward the bulb of the urethra, and there blends 
 with the bulbo-cavernosus muscle, while the posterior proceeds to the coccyx. This 
 muscular ring is covered internally by the end of the mucous tunic of the intes- 
 tine, is united forward and upward to the prostate gland, and is adapted in every 
 part to very abundant and fatty cellular tissue. Thus the upper portion of the 
 
274 
 
 DESCRIPTIVE ANATOMY. 
 
 C. FORM. 
 
 § 2175. The large intestine is not uniformly cylindrical like the 
 other sections of the intestinal canal, but presents numerous elevations 
 and depressions, which render its surface uneven. In fact the longi- 
 tudinal fibres are there united in three bands separated by spaces, and 
 the muscular membrane considered generally is shorter than the inner 
 tunics. Hence it follows, that when the cavity of the large intestine 
 receives the residue of digestion, it forms between the three bands three 
 series of rounded bursae which vary in size, and are termed cellules 
 ( cellulœ , s. haustra). 
 
 These bursæ are all similar but are not perfectly alike, and are no 
 where arranged symmetrically. Their origin from the cause men- 
 tioned proved by the fact that on cutting the bands the inequalities 
 disappear in the place corresponding to the incision, and the canal 
 there possesses a perfectly cylindrical form. 
 
 D. LENGTH AND BREADTH. 
 
 § 2176. The length of the large intestine is about five feet, and its 
 breadth when moderately distended varies between an inch and a half 
 and two inches. 
 
 E. ARRANGEMENT OF THE TUNICS. 
 
 A. PERITONEAL COAT. 
 
 § 2177. In most of its extent, especially in its ascending and de- 
 scending portions, the large intestine is covered by the peritoneum only 
 forward and on its sides and not on its posterior face, which is attached 
 to the adjacent parts only by very loose cellular tissue. The trans- 
 verse portion, on the contrary, is every where surrounded by the peri- 
 toneum. From the loose portion of the peritoneal coat arise the 
 epiploic appendages ( appendicces epiploicce). 
 
 B. MUSCULAR MEMBRANE. 
 
 § 2178. The muscular membrane of the large intestine, except 
 the rectum, is thinner even than that of the small intestine. It is 
 composed, as in every other part, of longitudinal and of transverse 
 fibres. 
 
 rectum is movable, and covered by the peritoneum, while the middle and inferior 
 parts, forming- together about at least four inches, arc surrounded in every part by 
 an abundance of cellular tissue, and are attached, but have no peritoneal envelop. 
 
 F. T; 
 
OF THE DIGESTIVE SYSTEM, 
 
 275 
 
 The longitudinal fibres distinguish the large intestine from all the 
 other portions of the intestinal canal in this respect, that generally 
 speaking, they are united in three bands, situated at nearly equal dis- 
 tances from each other, about from four to six lines broad, which gra- 
 dually increase in thickness from the circumference to the centre. One 
 of these bands is situated posteriorly, and corresponds to the point 
 where the intestine is kept in place by the peritoneum ; the second is 
 anterior, and proceeds in the middle portion below the insertion of the 
 epiploon ; the third occupies the inside of the ascending and the de- 
 scending portion, and the lower side of the transverse portion, where it 
 is perfectly loose. All terminate at the vermiform process and in the 
 longitudinal fibres of the rectum. 
 
 The thickness of the muscular tunic of the large intestine is dimi- 
 nished by the insulation of its longitudinal fibres. 
 
 The bands are much thicker the greater the number of these fibres, 
 from which they arise. 
 
 They are about half a line thick, so that the thickness of the mus- 
 cular tunic is considerable in the parts which correspond to them. 
 
 We also find at intervals between these three bands several distinct 
 fasciculi of longitudinal fibres ; and in subjects where the muscular 
 system is very much developed, the large intestine is entirely sur- 
 rounded by a layer of these fibres, always arranged, however, so that 
 the intermediate fibres are much weaker than the three bands. 
 
 The circular fibres constantly surround the whole of the intestine, 
 but they are much feebler than the longitudinal. 
 
 C. MUCOUS MEMBRANE. 
 
 § 2179. The mucous membrane is perfectly smooth when consi- 
 dered superficially, but when examined attentively we observe that it 
 is uneven, from numerous small, rounded, oblong, compact depressions, 
 similar to the points of pins. These depressions give it a shaggy or 
 honey-comb appearance, as is seen on the inner face of the mucous 
 membrane of the stomachal) The elevations between them occupy 
 a greater space than they, and may be considered as corresponding to 
 the villosities of the small intestine. 
 
 The arrangement of the inner membrane of the two sections of the 
 intestinal canal differs extremely at the place where they unite, and 
 these two sections are separated by a very distinctline of demarkation, 
 although uninterruptedly continuous with each other. 
 
 We cannot determine whether the function of these depressions is to 
 secrete, any more than the other parts. We know, however, that they 
 are not surrounded by a substance different from that of the rest of 
 the mucous membrane ; but this latter appears moie thin and more 
 transparent in these points than in the intervals between them. 
 
 (1) This has already been observed by Hewson (Exp. inq., pt. ii., p. 174). 
 
270 
 
 DESCRIPTIVE ANATOMY. 
 
 The mucous membrane of the large intestine presents a great num- 
 ber of muciparous glands, which are distinct or united in pairs or in 
 triplets, and situated near each other. These glands represent small 
 depressions with a more or less elevated edge. They are very evident 
 in intestines hardened by alcohol, because then the inner membrane is 
 contracted, and assumes à brownish color. They are formed partly 
 by the union of several of the smallest glands.(l) 
 
 F. MUSCLES OF THE ANUS. 
 
 § 2180. The lower extremity of the rectum is subject to the in- 
 fluence of the will, and is moved by several muscles, the sphincters, 
 the levatores ani , and the transversi perinei muscles. We shall de- 
 scribe here only the sphincters, referring the history of the others to 
 the chapter on the genital organs, with which they are more intimately 
 connected than with the anus. 
 
 § 2181. The anus has two sphincters , an internal and an external, 
 both of which result from a greater development of the circular fibres 
 of the rectum. 
 
 A. SPHINCTER ANI INTERNUS. 
 
 § 2182. The sphincter ani internus muscle proves very evidently 
 the origin above mentioned ; for the longitudinal fibres of the rectum 
 are deficient from three to four lines, the circular fibres become redder 
 and thicker, have the form of a flattened ring, which extends beyond 
 the longitudinal fibres. This ring is three or four lines high and about 
 two lines thick, and it is situated directly under the skin. 
 
 D. SPHINCTER ANI EXTERNUS. 
 
 § 2183. The sphincter ani ext emus muscle is much stronger than 
 the preceding, and although a distinct muscle, exactly surrounds it. 
 It is situated under the skin, to which it adheres very intimately. It 
 is thin and flat ; its internal fibres are less arched than the external, and 
 the anterior and the posterior unite at an acute angle. Its anterior 
 and posterior extremities are pointed. 
 
 The posterior extremity is attached to the posterior face of the last 
 piece of the coccyx either directly or by a compact cellular tissué. 
 
 The anterior blends with the transversus perinei muscle, and 
 usually also in man with the posterior extremity of the bulbo-caver- 
 nosus, in the female with the constrictor vaginæ muscle. But some- 
 times also it terminates in the perineum, either by fleshy or by tendi- 
 nous fibres, and does not extend to either of these two muscles. 
 
 (1) Galeati, loc. cit., fig. 3. 
 
OF THE DIGESTIVE SYSTEM. 
 
 277 
 
 In the male it is more oblong, and its greatest diameter extends 
 from before backward ; in the female it is more circular, and at its 
 anterior part it is broader and stronger. These differences undoubtedly 
 depend on those which exist in the two sexes in the form of the pelvis 
 and the external organs of generation. 
 
 G. FONCTIONS OF THE LARGE INTESTINE. 
 
 § 2184. The large intestine absorbs the small quantity of nutritious 
 substance still contained in its contents, and sends the rest toward the 
 anus. In this course the feces gradually become harder and more 
 solid. The action of the muscular membrane finally expels them, 
 overcoming the resistance of the sphincters with or without the con» 
 currence of the will. This expulsion always occurs periodically. 
 
 B. DIFFERENCES DEPENDING ON DEVELOPMENT. 
 
 § 2185. Of all the parts in the abdominal cavity the intestinal canal 
 is formed first ; its mode of development and the changes in its situa» 
 tion, form, and volume, present equally remarkable phenomena.(l) 
 
 A. MODE OF DEVELOPMENT. 
 
 § 2186. In respect to the mode of development one part is most in- 
 timately connected with the formation of the whole fetus, but particu- 
 larly with that of the intestinal canal, and must consequently be men- 
 tioned first : we mean the umbilical vesicle (vtsicula intestinalis , s. 
 umbilicalis). It is a small, more or less rounded pouch, situated be- 
 tween the chorion and the amnion, and is probably much larger in 
 proportion to the fetus the more recent the period of conception. It is 
 even greater than the fetus during the early periods of gestation, and 
 we have reason to think that it is always formed before it. It extends 
 first to the anterior face of the body of the fetus, which rests directly 
 upon it. But gradually and even early in the first month of gesta- 
 
 tt) C. P. Wolff, Deformations intestinorum ; in N. C. Petrop, voL xii., p. 1768. — 
 Oken, Anatomisch-physiologische Untersuchungen , angestellt an Schweinsfötus , 
 Schweinsembryonen und Hundsembryonen zur Losung des Problems über das Na- 
 betblàschen, &c., in Oken and Kieser, Heytragen , Hamburgh, 1806, 1807. — J. F. 
 Meckel, Abhandlungen aus der menschlichen und vergleichenden Anatomie , Halle, 
 1806. — Id., Bcyträgen zur vergleichenden Anatomie , Halle, 1808, vol. i., pt. i., no. 5. 
 — Id., Ueber die Divertikel, in Keil, Archiv, für die Physiologie, vol. ix. — D. Kieser, 
 Der Ursprung des Darmkanas aus dem Nabclblàschen, Gottingen, 1810. — Hoech- 
 stetter and Emmer*, Ueber das Nabclblàschen ; in Reil, Archiv, für die Physiologie , 
 vol. x. — Fleischmann, Leichenöffnungen, Erlangen, 1815, p. i— 75. — J. F. Meckel, 
 Sur la formation du canal intestinal dans les mammifères et en particulier dans 
 l’homme; in the Journ. compl. du diet, des sc. méd., vol. ii., p. 119 and 289. — L. 
 Rolando, Sur la formation du canal alimentaire et des viscères qui en dépendent ; 
 in the Journ. compl. des sc. méd., vol. xvi., p. 53. 
 
 Vol, ILL 3G 
 
278 
 
 DESCRIPTIVE ANATOMY. 
 
 tion, it diminishes much, end is situated farther from the fetus, so that 
 in the second month it is on the outside of the umbilical cord. 
 
 Do the parietes of the umbilical vesicle and the intestinal canal pri- 
 mitively communicate ? Several anatomists of great merit(l) think 
 that this communication is demonstrated neither in ihe fetuses of the 
 mammalia generally nor in that of man in particular. The following 
 facts, however, render this opinion very probable : 
 
 1st. The analogy with birds, reptiles, and cartilaginous fishes, to 
 the vitelline membrane of which the umbillical vesicle corresponds 
 perfectly, (2) and in which it is proved that the communication in dis- 
 pute exists at all periods of fetal existence. 
 
 2d. We sometimes perceive in very young fetuses a canal which 
 goes across the umbilical sheath, from the vesicle to the abdomen, and 
 by which we can at pleasure empty the vesicle of this fluid, and fill it 
 again.(3) 
 
 3d. We always find in the fetus, until the commencement of the 
 fourth month, blood vessels which go from the mesentery to the um- 
 bilical vesicle, unite first on this latter, but gradually extend only to 
 the anterior wall of the abdomen, and finally die, and are ruptured or 
 entirely effaced. These are the omphalomesenteric vessels (rasa om- 
 phalo-mesaraica), comprehending an artery and a vein, which arise 
 from the mesenteric vessels. (4) 
 
 These vessels also exist in birds, where they go to the yolk, pro- 
 ceeding along the vitelline canal. 
 
 4th. The intestines are at first very near the umbilical vesicle, and 
 are situated out of the abdomen in the umbilical sheath, which at this 
 period really makes part of the abdominal cavity. (5) 
 
 It is not unfrequent, proportionally speaking, to find in the full grown 
 fetus a canal which extends from the intestine to the umbilicus, which 
 opens in this latter place, and is always attended by the omphalo- 
 mesenteric vessels.(6.) 
 
 It is then very probable, though not certain, from all these facts, that 
 the umbilical vesicle and the intestinal canal originally communicate. 
 There are, however, others which really demonstrate the existence of 
 this communication. 
 
 Thus we have mentioned above a human fetus five lines long, in 
 which we saw distinctly a filament attached to the umbilical vesicle 
 
 (1) Emmert.— Hoesclistetter.— Cuvier, Ann. du Museum , vol. iii. 
 
 (2) Needham, De form, fœtu, London, 1667, p. 79. — Blumenbach, Spec. phys. 
 comp, inter anim. cal. sang. ov. et viv., Gottingen, 1739, p. 11.— Sœmmerring-, in 
 Haller, Grundriss der Physiologie, vol. ii., p. 799, 800. 
 
 (3) Hunter, Anatomische Beschreibung des schwang. Uterus, p. 68. 
 
 (4) Meckel, Handbuch der pathologischen Anatomie, vol. i., p. 563. — We have 
 since verified this remark in at least ten fetuses of this age. 
 
 (5) Meckel, Abhandlungen, 1806, p. 301.— Oken, Beytràge, 1806, ch. ix. 
 
 (6) We have collected, in the first volume of our Hand, der Path. Anatomie, all 
 the known cases of this anomaly, one of which wc observed and described (Reil, 
 Archiv, für die Physiologie , vol. ix). 
 
OF THE DIGESTIVE SYSTEM. 
 
 279 
 
 and extended to the intestine, and we have figured this communication 
 as it exists in fetuses of sheep and cows,(l) since admitted by Bojanus 
 also in the fetuses of sheep.(l) 
 
 Men, however, of high authority, doubt it. Emmert, Hcechstetter, 
 and Cuvier, assert that there is no continuity of substance between the 
 two organs, and that the communication existing between them, is es- 
 tablished only by the omphalo-mesenteric vessels. In fact, they admit, 
 beside these vessels, a third filament, extended between the vesicle and 
 the intestine, but they do not consider it as a canal of union, but only 
 as a simple prolongation of the peritoneum. The following are the ar- 
 guments in support of their opinions : 
 
 1st. The impossibility of passing water or any other fluid from the 
 vesicle into the intestinal canal. (3) 
 
 2d. The great difference between the white and thick substance of 
 the alimentary canal, and the thin reddish membrane of the vesicle, and 
 also the pellucid and delicate membrane which unites these two or- 
 gans, and accompanies the omphalo-mesenteric vessels. (5) 
 
 But we may reply to the first objection, that the phenomenon on 
 which it rests depends perhaps on the narrowness of the canal, and 
 also on the thinness of the vesicle, and demonstrates at most the ab- 
 sence of a hollow canal of communication, the admission of which i3 
 not absolutely necessary, since the intestinal canal of several animals 
 is solid at intervals, in the normal state. 
 
 The second objection also loses its weight, when we consider that 
 the allantoid membrane and the urachus vary at least as much from the 
 bladder, and we observe as great, or even greater constant differences 
 between different parts of the same system. This remark is more rea- 
 sonable, since we have found the opening of the communication great- 
 est in sharks, where the differences between the vitelline membrane 
 and the intestinal canal were most distinct. Farther, the differences 
 are also considerable in the cases last mentioned. 
 
 We think then that we must at present admit a continuity of sub- 
 stance between the umbilical vesicle and the intestinal canal, without 
 pretending to decide if the cavities of the two organs open into each 
 other. 
 
 From the analogy of the development of the intestinal canal in the 
 fetuses of birds, this canal is formed in the following manner. The 
 vitelline membrane, which is at first in direct contact with the vertebral 
 column, begins by forming a small prominence on each side, so that 
 originally, the intestine, which has the form of a groove, opens anteriorly. 
 
 (1) Muller, De genitalium evolutione, Halle, 1815, fig - . 1-2, p. 11. 
 
 (2) Sur la vésicule ombilicale du fœtus de brebis ; in the Journ. compl. du diet, des 
 sc. méd ., vol. ii., p. 84. — Dutrochet, Recherches sur les enveloppes du fœtus ; in the 
 Mem. de la soc. méd. d’émulation de Paris , 1816; and a note to the Réflexions du 
 professeur Emmert sur la vésicule ombilicale , in the Journ. compl. des sc. méd,, vol. 
 ii., p. 369. 
 
 (3) Emmert, in Reil, Archiv für die Physiologie , vol. x. p. 52. 
 
 (4) Emmert, loc. cit., p. 75. 
 
280 
 
 DESCRIPTIVE ANATOMY. 
 
 This groove gradually forms, by the increase of its parietes, from be- 
 hind forward, from above downward, and from below upward, to the 
 place where the cavity of the intestine communicates with the vitelline 
 sac by the vitelline canal, the diameter of which always diminishes.(l) 
 Oken’s opinion, that the intestinal canal should be considered as a kind 
 of excrescence of the umbilical vesicle, which enters already formed 
 into the abdomen from above and from below, is less probable, and is 
 unsupported by facts. 
 
 § 21S7. Does the intestinal canal always communicate with the 
 umbilical vesicle in one determinate point ? What is this point 1 
 
 First, this canal is continuous with the vesicle by its anterior edge, 
 but very probably the point to which the communication is finally con- 
 fined, always corresponds to a determinate place, although it may vary 
 in a certain extent. 
 
 Two such points have been mentioned. Oken thinks it is the point 
 of union between the large and small intestine. He considers the ver- 
 miform appendix and the cæcum as the result and the remains of this 
 communication. (2) In this view of the subject, the umbilical vesicle in 
 collapsing, and the intestinal canal on descending deeply into the ab- 
 domen, produce a contraction, a kind of neck, the parietes of which ap- 
 proach, and are finally blended. This separates the intestine from the 
 umbilical vesicle. The canal then enters into the abdominal cavity, 
 where the situation of the intestines, hitherto parallel, necessarily 
 changes, so that the anterior joins the neck at an angle, and the 
 neck becomes a prolongation of the posterior, which preserves its 
 former direction. Hence, according to Oken, the upper intestine seems 
 to penetrate into the lower, the angle of union becomes the ileo-ccecal 
 valve, and the neck gives rise to the cæcum and iis vermiform appen- 
 dix. But, 
 
 1st. We do not see why the contraction of the intestine, and their 
 entrance into the abdomen, necessarily result in causing the upper part 
 of the intestine to enter into the lower, and form a vermiform appendix. 
 This is still less probable, inasmuch as the cæcum and the ileo-colic 
 valve are rarely deficient in man from a primitive deviation of formation, 
 while they are normally absent in many mammalia provided with an 
 umbilical vesicle ; while others, in whom the cæcum is very large, 
 have no vesicle. The great differences in the length and structure of 
 the cæcum, render Oken’s opinion very improbable. It is even more 
 probable, on the contrary, that the consecprence of such a formation 
 would be a simple uninterrutped canal. 
 
 (1) Wolff demonstrated long since the manner in which the intestinal canal was 
 formed by the vitelline membrane, in birds, after very correct and careful observa- 
 tions, made at an useful time, that is, at a period very near its first formation. 
 As Needham, Blumenbach, and Sœmmcrring, have demonstrated the identity of 
 the vitelline envelop and the umbilical vesicle, Oken had no right to claim, as he has 
 done ( Beytragen zur vergleichenden Anatomie , 1806 . — Lehrbuch der Naturges- 
 chichte, 1815, p. 3), the honor of having discovered in the envelops of the fetus of the 
 hog, that the intestinal canal is formed from the umbilical vesicle. 
 
 (2) Loc. cit., part ii. p. 85. 
 
OF THE DIGESTIVE SYSTEM. 
 
 281 
 
 2d. The cause to which Oken attributes this change does not exist; 
 for the cæcum is formed long before the intestines pass into the abdo- 
 men, and is itself inclosed in the umbilical sheath. 
 
 3d. If the cæcum was the point where the intestine was detached 
 from the umbilical vesicle, it would also be the most anterior part of the 
 intestinal canal, and the nearest to the vesicle. But this never occurs, 
 for we always find a fold of the small intestine before the vermiform 
 appendix. Oken, it is true, has figured the contrary, according. to his 
 idea, that in man the intestines must detach themselves from the um- 
 bilical vesicle, (1) but unfortunately this does not exist in nature. 
 
 § 2188. Oken’s opinion is still less admissible, since arguments unite 
 to render it very probable, that the communication between the intes- 
 tine and the umbilical vesicle always exists in a determinate, but very 
 different place from that mentioned by him. This place is in the small 
 intestine, and nearer its lower than its upper extremity. 
 
 The arguments in support of this second opinion, all of which are 
 opposed to the theory of Oken, are the following : 
 
 1st. The canals between the intestine and the anterior w r all of the 
 abdomen, always proceed from this point. 
 
 2d. In one rare case, in a full grown fetus, monstrous from the deve- 
 lopment being arrested at several times, there w'as a real umbilical 
 vesicle inserted in this canal. (2) 
 
 3d. In this part of the canal, the vitelline canal in birds and reptiles 
 terminates. 
 
 4th. We find as the normal formation in most birds, and perhaps 
 also in some mammalia, and not unfrequentiy as an anomaly, in this 
 part, and never in any other, in man and other mammalia, a single 
 rounded prolongation, varying in length and breadth, and surrounded 
 by the same membranes. This prolongation, termed the diverticulum, is 
 evidently a trace of the primitive canal of communication ; it is fre- 
 quently attended both in the fetus and adult, with the remains of the 
 omphalo-mesenteric vessels. 
 
 Very probably, there is a period in the existence of the human fetus, 
 when a similar small tubercle exists regularly, after the umbilical 
 vesicle is separated from the intestine. Having found a very large di- 
 verticulum attended by the omphalo-mesenteric vessels in four human 
 fetuses three months old, which we had occasion to examine at nearly 
 the same time, we have reason to think that the appendix continues 
 regularly until this period, that is, long after the intestinal canal ha 3 
 entered the abdomen. (3) But we now renounce this opinion, although 
 it has been refuted by no one. If a diverticulum really exist for some 
 time as a normal formation, it disappears long before the end of the 
 third month of gestation, since we have seen the cæcum in the seventh 
 week, although there was no trace of a diverticulum; whence it follows, 
 
 (1) Loe. cit., p. 84. vol. iv. fig 1 2 3 . 14. 
 
 (2) Tiedemann, Anatomie der kopflosen Missgeburten , tab. iv. 
 
 (3) Handbuch der pathologischen Anatomie, vol. i. p. 565. 
 
282 
 
 DESCT iPTIVE ANATOMT. 
 
 that the omplialo-mesenteiic vessels continue much longer than it. 
 But this circumstance does not prove that the diverticulum never exists 
 normally, or that Oken’s opinion of the cæcum is correct. 
 
 5th. This is the point whence the omphalo-mesenteric vessels depart 
 to go into the umbilical sheath, after, and even before the intestines 
 have entered the abdomen. 
 
 6th. In all these cases one or two normal cæcums always exist in 
 the part where the large intestine unites with the small. 
 
 These different arguments seem to us to render the insertion of the 
 umbilical vessels on the ileon much more probable than that of this 
 organ, in the point mentioned by Oken. The diverticulum sometimes 
 found, depends either on an abnormal want of energy in the formative 
 power, or on the fact, that the neck of the umbilical vesicle, which per- 
 haps commonly dies on the surface of the intestine, does not then dis- 
 appear except in a greater or less extent. 
 
 Although these arguments were published long since, Oken still 
 continues to maintain that the cæcum is the part where the intestinal 
 canal is detached from the umbilical vesicle,(l) and he lays it down as 
 a principle either to oppose us, or to support his opinion: 1st, that 
 there is never but one cæcum ; 2d, that the cæcums of birds do 
 not deserve this name, and are only appendages of the bladder ; 3d, 
 that the cæcum exists in all mammalia, and in all birds and fishes who 
 lay large eggs, while it is so small as to be invisible in a very few of 
 these animals, the eggs of which are small ;(2) 4th, that this organ is 
 the old vitelline canal. As these assertions are published in an ele- 
 mentary work, they deserve to be examined, although it is easily seen 
 that they are totally unfounded. 
 
 In establishing his four laws, Oken has forgotten, 1st, of those 
 mammalia which possess two cæcums, as the dama and the phasco- 
 lomys ; 2d, the coexistence of the canal of the .umbilical vesicle, the di- 
 verticulum, and the cæcum, in the mammalia and birds ; 3d, the per- 
 fect resemblance in the mammalia and birds, in the relations between 
 the cæcums, the vitelline canal, the diverticulum, and the rest of the 
 intestinal canal, since the cæcums always exist on the limit between 
 the large and the small intestine, while this is never true of the canal 
 and the diverticulum ; 4th, the absolute want of facts, establishing that 
 the intestinal canal unites with the vesicle by the cæcum, while there 
 are a great number proving that it always occurs near the lower part 
 of the small intestine ; 5th, the fact that the volume has no effect on 
 the deficiency of the large or small size, and the other conditions of 
 the cæcum, since it is very large in most mammalia, and is entirely de- 
 ficient in many birds. Even when we admit that the diverticulum of 
 birds is the cæcum, which, however, is impossible, his third law would 
 still be refuted. His third remark, “ that the cæcum exists in all mam- 
 
 (1) Zoologie, 1815, vol. i. p. 2. 
 
 (2) Loc. cit., p. 10. 
 
OP THE DIGESTIVE SYSTEM. 
 
 283 
 
 malia, &c., but it is so small, as to be invisible in a very few of these 
 animals,” is difficult to understand. 
 
 Oken has also brought forward in favor of his hypothesis : 
 
 1st. The arrangement of the cæcums in fishes, in which the vitel- 
 line sac of the superior animals is divided into several culs-de-sac. 
 
 2d. The formation of the chondropterygia,(l) in which the cæcum 
 arises distinctly from the vitelline sac. 
 
 One cannot suppose that he himself believes these two arguments 
 to be valid : for 
 
 1st. Comparative anatomy demonstrates most positively, that the 
 cæcums of fishes are pancreatic glands, and no one has hitherto at- 
 tempted to compare them to the vitelline membrane, which also exists 
 in these animals. 
 
 2d. The cæcum of the chondropterygia is found at the end of the 
 large intestine, and the vitelline canal at the end of the small intestine. 
 
 3d. The vitelline canal is broadly open in the fetus, and exists at the 
 same time as the cæcum, and is entirely separate from it. This latter 
 continues during life, while the canal entirely disappears. 
 
 We then have cause to retain our opinion, as it is also supported by 
 respectable authorities, as Tiedemann, (2) Cuvier, (3) Dutrochet,(4) 
 and Jæger.(5) 
 
 B. SITUATION. 
 
 § 2189. The situation of the intestinal canal varies at different 
 periods, as one may conclude from the details already mentioned. Al- 
 though it forms on the anterior face of the vertebral column, it is, how- 
 ever, generally further from it in most of its extent, during the early 
 periods of existence than subsequently. At first only a small portion 
 of its upper and lower extremities exist in the proper abdominal cavity ; 
 all the rest is inclosed in the umbilical sheath, which for this or for 
 other reasons, is then extremely large, and should be considered as a 
 prolongation of the abdomen. At first the upper and lower extremities 
 of the intestinal canal extend in a straight line, side by side, and de- 
 scribe an angle to communicate together; but gradually, at the 
 seventh week of gestation, they proceed backward, begin to become 
 tortuous, and reunite in a fold before the umbilical opening, Only the 
 small intestine is tortuous, the large intestine is perfectly straight, and 
 its blunt extremity, the cæcum, goes forward, but always far behind 
 the anterior extremity of the small intestine. 
 
 About the middle of the third month, the intestinal canal enters en- 
 tirely into the cavity of the abdomen, where the lower part of the small 
 
 (1) Isis , 1818, p. 20. 
 
 (2) Anatomie der kopflosen Missgeburten, p. 66. 
 
 (3) Isis, 1818, p. 138. 
 
 (4) Loc. cit. 
 
 (5) Deutsches Archiv für die Physiologie , vol. iii. p. 543. 
 
284 
 
 DESCRIPTIVE ANATOMY. 
 
 intestine is the last to proceed. At this period, and sometime after, the 
 canal, especially the large intestine, varies as much as before from the 
 arrangement it will afterwards normally possess. In fact, the large 
 intestine is not formed of three portions, two lateral, which are perpen- 
 dicular, and a middle transverse portion, the right of which is attached 
 to the organs behind it only by a short fold of the peritoneum ; but it is 
 formed at first by a single perpendicular portion, attached by a long 
 mesentery, to the centre of the posterior wall of the abdomen. T his 
 portion is gradually reflected from right to left at its summit ; it then 
 descends on the right, so that the union of the great and small intes- 
 tine does not correspond to the right lumbar region until toward the 
 end of the fourth month. For a long time, and until birth, the de- 
 scending colon describes in the left iliac region, a greater curve than it 
 does in the adult, which undoubtedly depends on the narrowness of the 
 pelvis. 
 
 The situation of the stomach differs primitively from that assumed 
 by it in the adult, as it is at first almost perpendicular. The duode- 
 num is detached from it, and goes directly downward and forward 
 without any curve. When the liver diminishes in size, and the intes- 
 tines enter the abdomen, the stomach and the duodenum gradually 
 change their situation, and assume that which they afterward retain. 
 
 C. DIMENSIONS. 
 
 § 2190. The intestinal canal is much shorter and narrower the 
 younger the fetus is. At first it is no longer than the vertebral column, 
 on the anterior face of which it is developed. It then becomes more 
 extensive, and extends always in a straight line into the umbilical 
 sheath, but when it becomes longer, it is tortuous, being situated in a 
 narrow space. 
 
 The small is much broader in proportion to the large intestine, the 
 younger the fetus is. In this respect, the relation between them is op- 
 posite to that which exists in the adult, for the small intestine, for a 
 long time, is much greater than the large, and even in the full grown 
 fetus the latter is frequently not at all or but little broader than it. 
 
 On the other hand, the large intestine is much longer in proportion 
 to the small, the younger the fetus is. This difference undoubtedly 
 depends on the fact, that the small intestine is much shorter in propor- 
 tion to the body in the early periods than in the adult. 
 
 The cæcum and the vermiform process are at first very small, but 
 soon increase considerably, so that they are proportionally much larger 
 and broader than they are subsequently. They are not originally 
 separated in the same manner as in the adult; the cæcum is not en- 
 larged before it is continuous with its appendix; the latter is not as nar- 
 row, but represents the extremity of the large intestine, which is ex- 
 tended in a cul-de-sac above the ileon, gradually contracting a little on 
 itself. 
 
OP THE DIGESTIVE SYSTEM. 
 
 285 
 
 As the cæcum first appears in man, the mammalia, and birds, as a 
 small tubercle, which gradually enlarges, and of which there is not 
 the least trace at first, this circumstance alone demonstrates that it is 
 not formed in the manner mentioned by Oken, but by an enlargement 
 of the large' intestine. Before it appears, there is no mark of difference 
 between the large and the small intestine. The ileo-colic valve is at 
 first imperfect and very small ; it however begins to appear at the 
 third month of gestation, and it is perfectly developed in the full grown 
 fetus. 
 
 D. FORM. 
 
 § 2191. The intestinal canal during its development, differs con- 
 siderably in its form, and in the arrangement of its membranes. 
 
 We have already mentioned the differences which occur in the 
 cæcum, when speaking of those in dimension. We must add the 
 following remarks : 
 
 1st. The stomach is at first much longer and more rounded than 
 when the development is completed. The great cul-de-sac does not 
 exist originally, and it afterwards is larger than in the adult. 
 
 2d. The outer face of the large intestine is perfectly smooth until to- 
 ward the end of the fifth month. The enlargements, which are the 
 sources of its great size, appear first in the transverse colon. 
 
 Of the intestinal tunics, the internal particularly presents differences 
 relative to the development of the organ. 
 
 1st. It is more uniform in the different regions of the intestinal canal 
 during the early periods of life than subsequently. Of this we may be 
 easily convinced by examining the valvules or the villosities. 
 
 а. The villosities do not appear before the third month of gestation. 
 At this time they are seen first along the whole intestinal canal, in the 
 form of longitudinal folds, the surface of which is indented, and which, 
 like the indentations, gradually increase in number. Such is the origin 
 of the villosities. When they are developed in this manner, they exist 
 also in the large intestine till the seventh month of gestation, although 
 their length is less at three months than in the small intestine, and it 
 diminishes, as well as their number, from month to month, in which 
 respect, the two regions of the intestinal canal are at first perfectly 
 similar. 
 
 б. The valvules of the jejunum do not exist until the seventh month ; 
 they are even in the full grown fetus but slightly prominent, and easily 
 effaced by compression. 
 
 These two peculiarities are curious, as they are analogous to what 
 occurs in animals. 
 
 2d. The inner membrane of the stomach is thicker, and more easily 
 separated from the others in the early periods of fetal existence than 
 subsequently ; it is less easy to insulate it entirely in the form of a per- 
 fect sac. 
 
 VOL. Ill 
 
 37 
 
286 
 
 DESCRIPTIVE ANATOMY. 
 
 ARTICLE THIRD. 
 
 INTESTINAL CANAL IN THE ABNORMAL STATE. 
 
 § 2192. The abdominal portion of the alimentary canal presents 
 numerous anomalies in its form and texture.(l) 
 
 I. DEVIATIONS OF FORMATION. 
 
 A. PRIMITIVE DEVIATIONS OF FORMATION. 
 
 § 2193. The primitive deviations of formation belong principally to 
 the class of those which affect the quantity. 
 
 Among those of the first class, which essentially consist in an im- 
 perfect development of the formative power, or a continuance in the 
 peculiar type of the fetus, may be arranged the following, some of 
 which certainly belong to this class, and others may probably be 
 arranged in it. 
 
 I. GENERAL DEVIATIONS, 
 
 1st. Absence. This deviation of formation relates principally : 
 
 a To the stomach, especially in acephalia vera, where the intestinal 
 canal generally terminates in a cul-de-sac at its upper part, and is sel- 
 dom enlarged. Sometimes a portion of the stomach also is deficient, 
 particularly the pyloric valve, which is wholly or partially absent.(2) 
 
 b. To the smalt intestine. It is deficient, wholly or partially, in ace- 
 phalia vera, in which we often observe that the large intestine, or only 
 the lower part of the small intestine exists. 
 
 c. To the vermiform appendix, which is sometimes, though rarely, 
 deficient, even when the rest of the canal is not abnormal. 
 
 d. To the ileo colic valve, which is then simply replaced by some 
 strong muscular fibres. 
 
 e. To the large intestine. Here the anomaly exists in several de- 
 grees, which are commonly attended with an imperforate anus, 
 
 (1) A. Monro, The morbid anatomy of the human gullet, stomach, and intestines , 
 Edinburgh, 1811. — A. D. Stone, A practical treatise on the diseases of the stomach, 
 and of digestion. London, 1816. — T. A. Hare, View of the structure, functions, and 
 disorders of the stomach and alimentary organs of the human body, London, 1821. 
 — G. Law, Observations on derangements of the digestive organs, and some views 
 of their connection with local complaints , Edinburgh, 1821. — Scoutetten, De l’ana- 
 tomie pathologique en général et de celle du canal digestif en particulier, Paris, 
 
 1822. — Andra), Recherches sur l’anatomie pathologique du canal digestif, Paris, 
 
 1823. 
 
 (2) Fleischmann, Lcichcnôjfungcn, p. 100-102, 
 
OF THE DIGESTIVE SYSTEM. 
 
 287 
 
 ( atresia ani), because it usually attends this last deviation of forma- 
 tion. 
 
 Very rarely the large intestine is entirely deficient, existing only as 
 a small appendix in the form of a cul-de-sac of the small intestine. 
 Next in respect to frequency, come those cases, in which a small por- 
 tion of the large intestine is deficient, so that the communication be- 
 tween the large and small intestine is uninterrupted; finally, that where 
 the large intestine is developed to the entrance of the pelvis, but where 
 there is no rectum. Sometimes the rectum partially exists, but it ter- 
 minates in a cul-de-sac, and the space between it and the lower extre- 
 mity of the colon is also closed in a cul-de-sac. 
 
 In this case the rectum sometimes opens into the vagina ( aircsia 
 vaginalis ), the bladder (a. vesicalis),{ 1) or the urethra (a. urethralis), so 
 that a real cloaca is at the same time formed. 
 
 2d. Diminution in diameter. This anomaly exists in several de- 
 grees ; in the greatest degree it constitutes imperforation (a. vera). It 
 is always attended with the absence of a part, since on account of this 
 defect, the part existing terminates in a cul-de-sac. 
 
 It occurs principally in the anus, where it varies much in degree. 
 Sometimes the opening of the rectum is closed only by a thin mem- 
 brane, sometimes this intestine is replaced entirely by cellular tissue, or 
 by a full and solid cord. 
 
 Next comes the large intestine, which is imperforate at a greater 
 or less distance above the anus. The ileon and colon more rarely ter- 
 minate in a cul-de-sac. 
 
 Still more rarely, the same exists in the small intestine, either in some 
 part of its course, or at its upper extremity, or occurs in the stomach, 
 preventing a communication with the small intestine, or finally exists 
 in several points of the intestinal canal. 
 
 Strictures^) ( a . spuria) are most frequent in the rectum and anus. 
 They seem, however, not to be rare in the stomach, where they present 
 remarkable peculiarities. In this case the stomach is most generally 
 divided by a contraction near its centre, into two sacs, a right, nar- 
 rower and more elongated — a left, larger and more rounded. The upper 
 part of the left sac is usually not concave, but very convex, and the 
 form of the two curves, particularly the inferior, are very much en- 
 larged, the second presenting a deep groove. The esophagus is al- 
 ways inserted at the usual place, and the cul-de-sac is never enlarged. 
 The degree of contraction varies much, from half an inch to five inches, 
 judging from the five cases now before us ; but the right half of the 
 viscus preserves its normal direction. However, in one case we saw it 
 turned on its axis, so that the convexity looked upward and forward, 
 
 (1) Cavenne, Observation d’une imperforation de Vanus , avec ouverture de l’intestin 
 dans la vessie ; in the Archiv, gêner, de méd., vol. v. p. 63. — J. G. Hasselmann, De 
 ani intestinirumque atresia, Utrecht, 1819. 
 
 (2) Boyer, Remarques et observations sur quelques maladies de Vanus, in Journ. 
 compl. des sc.méd., vol. ii. p. 24. — G. White, Observations on strictures of the rectum, 
 Bath, 1820. 
 
288 DESCRIPTIVE ANATOMY. 
 
 and the concavity downward and backward, and descended here before 
 the right end of cardiac half. 
 
 More rarely the stomach is divided by a second contraction into three 
 sacs, of which the third undoubtedly arises from an unusual separation 
 of the cavity of the pylorus from the rest of the cavity of the organ. 
 
 All these anomalies are curious, as analogous with animals. They 
 occur principally in females. 
 
 When they exist, the texture of the stomach is unaltered in the con- 
 tracted portion. This circumstance, however, is not sufficient to justify 
 the opinion mentioned at the commencement of the paragraph, that 
 this state constitutes a primitive deviation of formation, and farther, be- 
 cause, as we have already mentioned, the stomach contracts transiently 
 at the same place during digestion, and causes of different kinds might 
 render permanent an arrangement which should be transitory. The 
 greater frequency of this anomaly in females, is equally favorable to the 
 two opinions. We then have reason to think that the contraction in 
 question does not always occur in the same manner, and this conjec- 
 ture is rendered still more probable, as it is sometimes congenital, and 
 attended with other deviations of formation, which mark an arrest 
 of development^ 1) 
 
 Not unfrequently, from a primitive deviation of formation, the sto- 
 mach is no larger than the intestine, in which case it cannot be di- 
 lated. 
 
 We might probably mention here a valvular contraction of the left 
 orifice of the stomach, which is very curiously attended with the ab- 
 sence of the pyloric valve. (2) If, however, this anomaly was not con- 
 fined to a simple contraction, we ought rather to refer it to the devia- 
 tions of formation dependent on an excess of the formative power. 
 
 3d. Shortness. Occurring sometimes in the whole of the intestinal 
 canal, but most frequently in the vermiform appendix of the cæcum 
 only. 
 
 II. SPECIAL DEVIATIONS. 
 
 § 2194. The special deviations of primitive formation are : 
 
 1st. In the stomach. 
 
 a. The absence of the base, which we have once observed in a 
 child two months old, where the cul-de-sac of the pylorus was much 
 larger than that of the cardia, which was hardly visible. 
 
 b. Its perpendicular situation, which does not always depend on the 
 abnormal enlargement of the liver, or on any other mechanical cause. 
 
 2d. In the intestinal canal. 
 
 a. The prolapsus of this canal into the umbilical sheath in a case of 
 exomphalos. Instances of this anomaly are most frequent in the small 
 
 (1) Sandifort, Obs. anat.path., vol. iii. p. 11. 
 
 (2) Fleischmaun, Leichenöffnungen, p. 100. 
 
OF THE DIGESTIVE SYSTEM. 
 
 289 
 
 intestine, as when the development is normal, this portion of the canal 
 enters last into the abdomen. 
 
 b. The more or less perfect continuance of its primitive connection 
 with the umbilical vesicle.(l) 
 
 This anomaly exists in several different degrees. 
 
 Sometimes the umbilical vesicle continues beyond the usual time, 
 and communicates with the ileon by an open canal which the ompha- 
 lo-mesenteric vessels(2) attend. 
 
 Sometimes only a canal exists ; it varies in length, and extends 
 from the same point of the ileon to the umbilicus, where it opens, and 
 the omphalo-mesenteric vessels also accompany it. (3) 
 
 Finally, sometimes a greater or less prominence exists in this place, 
 a prolongation termed the diverticulum of the ileon , this is often ac- 
 companied by the omphalo-mesenteric vessels, which float loosely at 
 its extremity, or which are attached to the umbilicus or to another re- 
 gion of the intestinal canal, so as to form a plexus. 
 
 These three anomalies are only different degrees of the same devia- 
 tion of formation. This is proved by their appearing always in the 
 same place, by their connections with the omphalo-mesenteric vessels, 
 and finally, the insensible shades which each presents in respect to 
 length and size. 
 
 That they have the signification we attribute to them, is proved : 
 1st, by our history of the development of the intestinal canal, by their 
 constant co-existence with the cæcum and vermiform appendix, and 
 finally, by the fact, that they always have the character of a primitive 
 formation. 
 
 That they depend on a primitive formation, is proved by the facts, 
 that they are always observed in the same place, that they are formed 
 by all the membranes of the intestinal canal, and that they exist simul- 
 taneously with other primitive deviations of formation, which arise 
 from the development being arrested, or which, at least, favor their pro- 
 ductions. 
 
 All these circumstances united,demonstrate that it is impossible to re- 
 gard them purely as accidental productions, (4) and consider them as 
 excrescences, (5) or as contractions, (6) or hernias(7) of the ileon. 
 
 In fact, the following arguments have been opposed to our theory of 
 the diverticula of the ileon. 
 
 (1) Meckel. Beyträge zur vergleichenden Anatomie , vol. i., pt. i., 1308. — Id., Lieber 
 die Divertikel ; in Reil, Archiv für die Physiologie , vol. ix. part iii. — Id., Handbuch 
 der pathologischen Anatomie , vol. i. p. 553-597. — Fulling 1 2 3 4 5 6 7 , Diss. de diverticulo intes- 
 tinal i sex mensium embryonis herniam umbilicalem referente, Marburg, 1807. — 
 Régnault, Observation d’ un cas singulier de volvulus ; in the Journ.univ. des sc. 
 Méd., vol. ii. p. 108. — P. Rayer, Cas mortel d'entérite et de péritonite , déterminé par 
 un diverticule de l’iléon ; in the Archiv, gén. de méd., vol. v. p. 68. 
 
 (2) Tiedemann, Anatomie der hopflosen Missgeburten , p. 66. tab. iv. 
 
 (3) Meckel, in Reil, loc. cit., vol. ix. 
 
 (4) Oken, in Jenceer Literaturzeitung , 1815, no. 35. 
 
 (5) Fleischmann, loc. cit. 
 
 (6) Littré, Mery, in M &m. de Paris , 1700-1701. 
 
 (7) Fabric iua and Morgagni, in Morgagni, Bp. an. méd, 34, a. 17. 
 
290 
 
 DESCRIPTIVE ANATOMY. 
 
 a. Their inconstancy,(l) their variety, (2) while all the transitory 
 formations do not entirely disappear when the development is regular 
 and also the vitelline canal in birds always continues. 
 
 b. The existence of several diverticula in the same intestine, or at 
 least that of real diverticula in parts of the intestinal canal beside the 
 ileon.(3) 
 
 c. Their frequent coexistence with deviations of formation by 
 doubling or arrest of development. (4) 
 
 d. The great size and thickness of their parietes, which even did a 
 canal of the umbilical vesicle exist in the early periods of life, would 
 indicate an excess in the formative power. (5) 
 
 But we have already opposed most of these objections before they 
 were brought forward, and it is easy to refute them. 
 
 The first proves nothing, for several other deviations of formation, 
 which consist essentially in the development being arrested, are still 
 more rare than the diverticula, and disappear entirely when the deve- 
 lopment is regular. We shall mention, for instance, the permanence 
 of the pupillary membrane, the absence of the extremities, the continu- 
 ance of the arterial canal, the urachus, and the omphalo-mesenteric 
 vessels, the fissure of the uterus. The analogy with birds, which has 
 been adduced, is valueless, since even in several birds, as those of prey, 
 the vitelline canal always seems to disappear entirely, and we com- 
 monly observe traces of the primitive state longer in the lower animals 
 than in the higher classes. 
 
 Against the second objection, the extreme rarity of the anomaly on 
 which it is founded, may be adduced. Farther, we may ask, if among 
 these extremely rare cases, there are not some false diverticula ; if in 
 others, the diverticulum is not produced by distension ; if in others, it 
 does not depend on the union of the intestinal canal with the um- 
 bilical vesicle at an unusual place ; finally, if the deviation of formation 
 cannot be developed as a primitive anomaly, differently from that which 
 commonly occurs, although it is impossible to conclude any thing 
 from it against this latter. 
 
 The third objection favors our views, and is opposed to the theory it 
 is adduced to support ; since even where the whole body is double, some 
 organs alone very rarely present the same tendency, for instance, a 
 supernumerary finger or eye is not common in this case ; while, on the 
 contrary, the imperfect formations, especially those depending on sus- 
 pended development, as the fissure of the vertebral column, the skull, 
 the palate, and the abdomen, the deviations in the formation of the 
 heart and the intestinal canal by defect, are then very common phe- 
 nomena. 
 
 (1) Oken, in Jeanœr Literâturzeitung, 1815, no. 26. 
 
 (2) Emmert, Reflexions sur la vésicule ombilicale ; in the Journ. compl. des sc. 
 méd. vol. ii. p. 369. 
 
 (3) Emmert, loc. cit. 
 
 (4) Jd., ib. 
 
OP THE DIGESTIVE SYSTEM. 
 
 291 
 
 The fourth objection is not more valid than the other three, since the 
 difference between the thickness of the parietes and the size of the 
 cavity of the diverticulum, depend on the period when the development 
 is suspended, or on other accidental circumstances, which exert their 
 influence afterward. The oval foramen is no less an anomaly, whether 
 it is an inch or a line in diameter, and accidental mechanical influences 
 may sometimes enlarge it during life. 
 
 c. The great size of the vermiform appendix, depending on its con- 
 tinuing to increase after the type of the fetus, although this anomaly 
 may be developed at a later period. 
 
 § 2195. The deviations of formation, which essentially consist in an 
 excess of the formative power, are much more rare than those we have 
 mentioned. 
 
 We should probably consider as such the division of the duodenum 
 into two canals, the existence of two vermiform appendices, doubtless, 
 also the unusual length of the intestinal canal, instances of which are 
 seen particularly in the large intestine, and which render it more or 
 less tortuous, and especially render the transverse colon pendant. (1) 
 Perhaps we must also refer to this class the real diverticula which oc- 
 cur in other unusual points, although we have every reason to think 
 that they should be considered as belonging to those deviations of for- 
 mation relating to the quality. 
 
 § 2196. The primitive deviations of formation which concern the 
 quality, relate to the form or situation, or to both. Among the latter, 
 we must arrange the lateral inversions of the stomach and intestinal 
 canal, since in this case, the parts are not only situated opposite their 
 usual place, but also present a figure the inverse of that they normally 
 possess. 
 
 The form of the stomach or the intestinal canal, rarely presents pri- 
 mitive deviations of formation in respect to quantity ; and the examples 
 known of them may all be referred to anomalies in the diameter. 
 
 The situation of the stomach is sometimes changed, this viscus being 
 turned on itself so that its convex edge looks upward, and its concave 
 edge downward. (2) 
 
 B. ACCIDENTAL DEVIATIONS OF FORMATION. 
 
 § 2197. The accidental or consecutive deviations of formation relate 
 to the extent, the mass, the situation, or the form. 
 
 1st. Extent. 
 
 a. Excess in extent rarely occurs in the whole abdominal portion of 
 the alimentary canal, but it is observed in all its parts, and it is produced 
 by very different causes, that is, particularly by obliteration, contrac- 
 
 (1) P. Monterossi has figured a great many cases of this kind at the end of a memoir 
 on the unusual curves of the large intestine , considered as the cause of death in new 
 born children , in Brcra, Nuovi commentari di niedicina , 1819, vol. iv. p. 3. 
 
 (2) Fleischmann, loc. cit ., p. 98. 
 
292 
 
 DESCRIPTIVE ANATOMY. 
 
 tion, atonia, the latter always from an accumulation of substances 
 within it.(l) 
 
 The abnormal distension of the vessels of the alimentary canal, 
 which not unfrequently exists, deserves tobe mentioned here. It is 
 most generally observed in the rectum, in the form of rounded tumors, 
 which project into the cavity of the intestines, and are termed haemor- 
 rhoids. (2) It is generally admitted that these tumors are situated in 
 the hæmorrhoidal veins ; doubtless also, the arteries contribute to them, 
 although we cannot admit with Cruveilhier, that they are new forma- 
 tions, an accidental development of the erectile tissue. More probably, 
 they depend in some cases on the dilatation of the small vessels, and 
 in others, on that of the larger vessels, and in the last case, where they 
 appear as sacs, the dilated portion is separated from the rest of the 
 vessel. 
 
 The vessels of the stomach are generally dilated in melena, and the 
 black substance vomited, or which is found in the stomach, is blood 
 more or less changed, which has transuded through their extremities. 
 
 b. Abnormal contractions, when not primitive, are rarely confined 
 to a simple deviation of formation. They generally succeed alterations 
 of texture, inflammation, and its consequences, effusion, scirrhus, &c. 
 The first commonly occurs when the alimentary canal is not distended 
 by the causes which habitually act upon it, consequently after long 
 fasts. 
 
 The whole canal is affected. A contraction occurs also in a por- 
 tion of this canal situated below a solution of continuity which entirely 
 divided it, consequently when an artificial anus is formed after a wound 
 or strangulated hernia. 
 
 2d. We more seldom find an increase or diminution in mass without 
 an alteration of texture; the first occurs particularly in the muscular 
 tunic, and supervenes when this membrane has been unusually exer- 
 cised. Thus it is more rare to find the stomach dilated than very 
 muscular in gluttons. The muscular membrane is similarly changed 
 in a herniary portion of intestine. 
 
 The muscular tunic becomes much thinner in a general loss of 
 flesh. 
 
 3d. Situation. Deviations in situation should be referred to the 
 chapter on hernias, since they generally occur in these affections. The 
 small intestine is particularly liable to a change in its situation, on 
 account of its greater mobility, its smaller size, and its situation. Next 
 comes the stomach, which generally emerges through the linea alba 
 or the upper part of the abdominal muscles, sometimes, however, 
 through the umbilical ring. When abnormal openings exist in the 
 
 (1) Chaussier, Observation suivie de reflexions sur une dilatation excessive de 
 l’estomac ; in the Bulletin de la soc. méd. d’émid., 1823, September, p. 505. 
 
 (2) Montegre, Des hémorrhoides, or Traité analytique de toutes les affections 
 hémorrkoidalcs, Paris, 181t). — E. Summe, Diss. de hœmorrhoidibus œcis, Berlin, 
 1820. 
 
 (3) Anat. pathol ., vol. ii. p. 145. 
 
OF THF DIGESTIVE SYSTEM. 
 
 293 
 
 diaphragm, they allow the stomach to pass into the cavity of the 
 thorax. 
 
 4 th. The principal changes in form are : 
 
 a. Inversion , in which one portion of the intestine is turned, so that 
 its inner face becomes the external, and the outer face the internal. 
 When this change occurs at the lower part of the rectum, it is termed 
 a prolapsus ani. In every other part it is called intussusception or in- 
 vagination , because the inverted part enters that below it. The first 
 state is more simple, since the portion of intestine which forms the pro- 
 lapsus is composed of two parts, situated one on the other, the external 
 of which is reversed and the internal is normal, while in the second 
 case is added a third, that into which the inverted portion enters. 
 Sometimes we find a still greater number of superimposed layers, 
 there being two invaginations, one within the other. 
 
 Several invaginations often occur at the same time. 
 
 They are most frequently situated in the small intestine, undoubt- 
 edly because it is the most movable portion of the alimentary canal. 
 
 Even those intussusceptions which commence very high may de- 
 scend into the rectum and emerge from the anus. 
 
 The most common cause of this state is the irregular action of the 
 muscular membrane. Sometimes, however, it is caused mechanically 
 by tumors, which force a portion of the intestinal canal downward and 
 inward. 
 
 Slight invaginations are doubtless not dangerous, and disappear of 
 themselves ; but when they exist to a greater extent they cause in- 
 flammation and gangrene of the herniary portion, which is usually, 
 but not always, attended with death ; sometimes, however, the gan- 
 grenous portion sloughs off, and the space is filled by adhesive inflam- 
 mation. 
 
 5th. Solutions of continuity result either from mechanical influence, 
 as the action of a cuttting instrument, a rupture, or from a previous 
 alteration of texture, as from ulcerations. They are sometimes com- 
 plete, and then affect all the tunics, sometimes confined only to the 
 muscular and peritoneal membranes, whence results a hernia of the 
 inner membrane, and the formation of a rounded tumor termed a false 
 diverticulum {cl. spurium). The false differs from the true diverticu- 
 lum by its rounded form, by the absence of several superimposed tunics, 
 and finally by its occurring in every part, even in the stomach, but 
 most frequently in the duodenum, and by the existence of several at 
 oncc.(l) 
 
 II. ALTERATIONS OF TEXTURE. 
 
 §2198. We not' unfrequently observe an alteration in the texture of 
 the intestinal canal, particularly in the stomach, which is its softening 
 
 (1) We have enlarged upon this subject in our Handbuch, der pathologischen 
 Anatomic , vol. ii„ p. II. 
 
 Vol. Ill 38 
 
294 
 
 DESCRIPTIVE ANATOMY. 
 
 or thinness, and when occurring in a still greater extent its perfora- 
 tion.(l) This alteration is seen particularly in the large cul-de-sac 
 and in the posterior wall of the stomach, and commences by the inner 
 membrane, which always appears very red in this place. The edges 
 of the perforation are very irregular, and differ from those of a perfora- 
 tion caused by an ulcer by the total absence of thickening and hard- 
 ness of the edges, which are, on the contrary, very thin and soft. 
 Sometimes this change supervenes after death ; sometimes it occurs 
 during life, but in both cases it is caused by the action of the gastric 
 juice on the stomach, and we may consider it as resulting from the 
 digestion of the membranes of the stomach by this juice, which effect 
 results when the perforation occurs during life from some change in the 
 chemical composition of the gastric fluid. (2) 
 
 (1) Chaussier has given a good description of perforations of the stomach; wc shall 
 
 quote his words. Ulcerations and perforations of the stomach vary in form, situation, 
 and extent. They are small and circular, or large enough to introduce the hand 
 into them. They may occur in any part of the stomach, but are seen particularly 
 at the base of this organ, in the portion corresponding to the spleen and diaphragm. 
 Sometimes then the food enters into the abdomen, or the thorax if the diaphragm be 
 perforated. But most generally there is no ell'usion, the ulcerated portion of the 
 stomach being connected with the adjacent parts. If we destroy these adhesions, 
 which are slight, a viscous, and sometimes a fluid, flows from the stomach, which is 
 not fetid, and sometimes has an odor like musk ; it is always brownish, and mixed 
 with blackish flacculæ or molecules, as if finely pulverized charcoal was strewed in 
 mucous serum. The edges are soft, broken, and sometimes surrounded with a more 
 or less marked blackish line. In every other part the stomach preserves its usual 
 form and consistence. It rio where presents marks of engorgement or inflammation : 
 only the capillary plexuses of its follicular membrane seem to be more developed, 
 especially around the perforation. Sometimes these changes form suddenly in a 
 few hours in healthy persons ; most generally, however, after several days of sickness, 
 and when no violent external causc'or poisoning can be suspected ( Bulletin des 
 sciences médicales du département de l’Eure, no. 53. p. 7). Consult also on this sub 
 ject which relates to one of the most important questions in legal medicine : Gerard, 
 Des perforations spontanées de l’estomac , Paris, an. xii. — Morin, Considerations 
 générales sur l'érosion, Paris, 1806. — G. Laisne, Considerations médico-légales sur 
 les érosions et perforations spontanées de l'estomac; in the journal called Médecine 
 légale, Paris, 1819, p. 135. — J. Cloquet, Sur les perforations intestinales; in the 
 Nouveau journal de médecine, vol. i. p. 107. — Serres, Observation d'une perforation 
 de V œsophage ; in the Revue médicale, vol. x. p. 166. — Id., Observations de perfora- 
 tions intestinales ; same journal, vol. x. p. 170. — E. Legallois, Plusieurs perforations 
 du canal intestinal et spécialement des gros intestins, â la suite d'une affection tuber- 
 culeuse ; in the Archiv, gén. de méd., vol. vi. p. 68. — Louis, Du râmollissemcnt avec 
 amincissement et de la destruction de la membrane muqueuse de l'estomac ; same 
 journal, vol. v. p. 5. — Abercrombie, Observations sur l’inflammation et l'ulcération 
 de l'estomac ; sanie journal, vol. v. p. 447. — Louis, Observations/elatives aux perfo- 
 rations spontanées de l’intestin grêle, dans les maladies aigues ; saine journal, vol. i. 
 p. 17. — U. Coste, Observations sur les perforations de l'estomac; in the Journ. unie, 
 des. sc. méd., vol. xxix. p. 257. F. T. 
 
 (2) This is the opinion of Hunter. We cannot admit it. It rests on Hunter’s 
 opinion in accordance with that of Spallanzani, in respect to the gastric juice. But 
 it is very evident that the gastric juice does not exist, as these two physiologists have 
 supposed, that it docs not accumulate in the stomach between meals, that it is se- 
 creted only at the moment when the viscus is filled witli food, that this secretion is 
 caused by the impression produced by the latter, and so far from being identical, it 
 always varies according to the nature of the substances from which the chyme is 
 found. Besides, perforation of the stomach has never been observed, in the cases of 
 death by starvation hitherto observed, and that cited by Ilunter should be referred 
 
OF THE DIGESTIVE SYSTEM. 
 
 295 
 
 When the stomach is thus destroyed in one part, the softening pro- 
 duced by the effused fluid extends also to the adjacent portions. (1) 
 
 §2199. The alimentary canal frequently infames, (2) especially in 
 its mucous membrane. 
 
 In regard to the inflammation of the stomach, we ought to remark 
 that the inner membrane of this viscus, which is the most subject to 
 inflammation on account of the numerous vessels it receives, the forma- 
 tive power it possesses, its connections with the skin, and the direct 
 effect of deleterious substances upon it, often presents, when not in- 
 flamed, a very deep red color, which depends on an accumulation of 
 blood in the small twigs of the veins, and is observed particularly after 
 death, from those causes which favor the stagnation of blood in these 
 vessels by opposing its return to the heart. 
 
 In inflammation of the mucous membrane, the mucus becomes 
 thicker and firmer. At the same time the fibrin is effused on the inner 
 face and in the substance of this membrane. The result of the first of 
 these phenomena is, the formation of more or less thick, hollow, or solid 
 cylinders, which pass off from the anus, and which have been wrongly 
 considered as the membranes of the intestine. The effect of the se- 
 cond is, to thicken the parietes, and thus to contract the cavity of the 
 canal. In the latter case partial adhesions sometimes, but rarely, 
 occur, and probably arise from ulcerations. (3) 
 
 In ulcers of the mucous membrane, the edges are usually lightly 
 turned over, uneven, and hard * sometimes also their edges are smooth, 
 and, as it were, cut. 
 
 Inflammation and suppuration frequently form fistula of the amis 
 ( fistula ani ), that is, a canal which commences on the inner face of 
 the rectum, descends on its sides, and terminates near the anus. Like 
 all fistulous passages, this canal is covered internally by an epidermis, 
 similar to the mucous membranes, and is surrounded with a dense cel- 
 lular tissue. (4) 
 
 In dysentery, where the inflammation is situated principally in the 
 mucous membrane of the large intestine, especially of the rectum, this 
 membrane frequently mortifies in several parts, and black and dry 
 eschars are formed on its surface. 
 
 to the erosions mentioned in the preceding' note. Consult on this subject F. G. 
 Gcedecke, De dissolutione ventriculi, sive de digestione quam dicunt ventriculi post 
 mortem, Berlin, 1823. F. T. 
 
 (1) Yelloly, Observations on the vascular appearance inthe human stomach, uhich 
 is frequently mistaken for inflammation of that organ ; in the Med. chir. trails., vol. 
 iv. p. 374-425. 
 
 (2) Scoutetten, Recherches d'anatomie -pathologique, démonstrant le rapport qui 
 existe entre l'irritation de la membrane muqueuse du canal intestinal et celle de la 
 ■méningine ; in the Journ. univ. des sc. méd., vol. xxviii., p. 257. 
 
 (3) Monro, Morb. anat... tab. vii. 
 
 (4) J. Howship, Practical observations on the most common diseases of the Imecr 
 intestines and anus , London, 1820. — C. Bell, A treatise on the diseases of the urethra, 
 vesica urinaria, prostata, and rectum, London, 1820. — T. Copeland, Observations on 
 the principal diseases of the rectum and anus, London, 1814. 
 
DESCRIPTIVE ANATOMY. 
 
 2f)6 
 
 All these phenomena are usually confined to the mucous membrane. 
 The tubercular formation, however, in which rounded, whitish, and 
 hard masses are formed, extends from this membrane to the outer face 
 of the organ, where it forms more or less evident prominences. This 
 change is commonly observed inthe latter periodof tuberculous phthisis, 
 especially in the small intestine. The ideerations thus affect all the 
 membranes of the stomach, and then gradual^ extend from within 
 outward. They do not necessarily result in the effusion into the ab- 
 domen of substances contained in the organ ; this is even propor- 
 tionally rare on account of the adhesions with the adjacent parts, or 
 because the opening communicates with another portion of the intes- 
 tinal canal, or with the exterior, when the wall of the abdomen ad- 
 heres to the diseased organ. 
 
 Inflammation of the peritoneal coat of the alimentary canal is often 
 followed by more or less general and intimate adhesions between the 
 different parts of the passage. These adhesions are sometimes so nu- 
 merous and intimate that the folds of the intestines form one mass, 
 which cannot be separated from the surrounding substance, and repre- 
 sents only a canal hollowed in an amorphous mass. 
 
 One of the most common alterations of texture in the intestinal canal 
 is the scirrhous formation, which extends from the vascular tunic and 
 the muciparous glands, where it is primitively situated, to the mucous 
 and muscular membranes. It blends together all these tunics, and 
 renders them thicker and harder ; they finally present a carcinomatous 
 ulceration.(l) This alteration of structure causes a contraction of the 
 canal, which is often very great. It is observed more particularly in 
 the pylorus, the end of the descending colon, and the rectum, which 
 depends perhaps only on the disposition of these parts to retain for a 
 longer period the substances which pass through them, and are also 
 more exposed to irritation and its consequences. But. the morbid af- 
 fection extends also a greater or less distance to its primitive source, 
 so that it sometimes attacks the whole stomach and a very great por- 
 tion of the intestinal canal. 
 
 Very probably we must arrange here tlae morbid alterations de- 
 scribed by Monro, in which albumen is deposited in the vascular tunic, 
 for all its essential characters are the same, and it differs from cancer 
 only in its form, since it appears as small rounded bodies. (2) 
 
 The fungous excrescences of the mucous membrane are much more 
 rare. They have however been found in every part of the intestinal 
 canal. Thus authors have described some cases of very large polypi 
 of the stomach, one of which extended from the cardiac orifice even 
 within the duodenum. (3) We have lately found in the cadaver of a 
 
 (11 Bourdon, Observations sur quelques maladies de l'estomac; in the Rev uc mé- 
 dicale, May, 1824. 
 
 (2) Morbid, ahat., p. 17. 
 
 (3) Breschct, ' Tumeur polypcusc développée dans l’ estomac ; in the JRull.de la 
 far. de mid., vo). v., 1817, p. 370. Ol lier cases of tills kind may be found in Monro, 
 
 ' Morbid ariat. vi. — Fabre, (/acetic de santé., June, 1815. 
 
dj? THE DIGESTIVE SYSTEM. 
 
 297 
 
 young man frequently affected with abdominal affections, and who 
 died of violent enteritis, two excrescences of the mucous membrane of 
 the small intestine, one of which was about four lines in diameter, and 
 was covered in all parts by the mucous membrane, while the other, 
 about an inch in diameter, had destroyed this membrane, and was 
 unattached. These excrescences are more common in the rectum(l) 
 than in any other part. They are similar only in form, for they differ 
 much in respect to texture ; since they are sometimes very hard and 
 solid, sometimes spungy, and of a loose and soft tissue. The first pro- 
 bably belong to the class of fibro-cartilages, and the others to that of 
 fungus hematodes. 
 
 A tumor of the internal membrane, described by Monro ' as a milt- 
 like tumor, and which affects the stomach particularly, is doubtless a 
 fungus hematodes. (2) 
 
 In fact, in examining the viscera of individuals who have died from a 
 severe attack of small-pox, we have found the inner membrane of the 
 intestinal canal very red, but have never seen in it pustules. 
 
 The normal tissues are rarely formed abnormally in the intestinal 
 canal. We must however mention here, the fatty tumors developed 
 on the inner face of the mucous membrane, (3) the hairs which are 
 found sometimes alone on the inner face of the intestine, (4) sometimes 
 attended with teeth, in the. stomach, (5) the ossifications of the inner 
 face of the intestine, (6) and finally, at least in certain cases, hemorr- 
 hoids, when they are cavernous formations. 
 
 § 2200. Foreign bodies of different kinds are common in the abdo- 
 minal portion of the alimentary canal, particularly in the intestine. 
 
 Those seen most frequently are the intestinal worms, which in fact 
 are more common here than in any other part of the body. The as- 
 caris lumbricoides, the toenia lata, s. bothryocephalus latus, and the 
 tcenia solium, live principally in the small intestine, the trichocephalus 
 dispar in the large intestine, and particularly in the cæcum, finally the 
 ascaris vermieularis, oxyuris vermicularis, Bremser, in the large intes- 
 tine, and particularly in the rectum. 
 
 These worms exist in the stomach only accidentally, and generally 
 even not till after death. The openings through which they some- 
 times pass into the peritoneal cavity are not formed by them. 
 
 Other foreign bodies, which are much more rare, are concretions 
 introduced accidentally into the intestinal canal. They are most com- 
 
 (1) Meckel, 'Handbuch der pathologischen Anatomic , vol. ii., pt. ii., p. 511. — Lnra- 
 cine, Observation sur une tumeur fongueuse pèdCculée dans le rectum ; in the Bull, 
 d.e la soc. méd. d’émul. , September, 1821. 
 
 (2) Morbid anatomy, p. 160. — Itullier, Sur le cancer de l'estomac; in the Archiv, 
 gen. de méd., vol. ii., p. 380. 
 
 (3) Meckel, Handbuch der pathologischen Anatomie, vol. ii., pt. ii., p. 124. 
 
 (4) Meckel, Mémoire sur les poils cl les dents qui se développent accidentellement 
 dans le corps ; in the Juurn.compl. dessc. méd., vol. iv., p. 122,217. 
 
 (5) Jîuysch, Advefs. anal., dec. iii. 
 
 (6) Meckel. Handbuch der pathologischen Anatomie, vol. if., pt. ii., p. 227. 
 
298 
 
 DESCRIPTIVE ANATOMY. 
 
 monly biliary calculi, which descend into it from the gall bladder. 
 Next come the abdominal concretions, which form partially or wholly 
 in the intestine.(l) 
 
 ARTICLE FOURTH. 
 
 GLANDULAR ORGANS OF THE ABDOMINAL PORTION OF THE 
 DIGESTIVE SYSTEM. 
 
 § 2201. The glandular organs of the abdominal portion of the di- 
 gestive system, (2) termed also, together with the stomach, the chylo- 
 poietic viscera ( viscera chylopoietica ), are the liver , the pancreas , and 
 the spleen. They are situated in the upper half of the abdomen, and 
 are intimately connected with each other, and with the stomach and 
 the duodenum, not only in situation but also in the vessels and nerves 
 they receive, but even, except in the spleen, in continuity of substance. 
 In fact they receive their vessels from the same trunk, the cceliac 
 artery ; their nerves come from the same source, the solar plexus ; 
 finally, the excretory canals of the liver and pancreas, which open into 
 the duodenum, are in fact folds of the inner membrane of this intestine. 
 
 I. LIVER. 
 
 A. PERFECT STATE. 
 
 A. SITUATION. 
 
 § 2202. The liver (hepar, jecur),( 3) the largest gland in the body, 
 occupies all the right hypochondriac region, the upper part of ihe epi- 
 gastric region, and in the female particularly, part of the left hypo- 
 chondriac region. It descends on the right side lower than on the left, 
 
 (1) Meckel, Remarques sur les concrétions qui se recontrent dans le canal intestinal 
 chez l’homme ; in the Journ. compl. des sc. méd ., vol. ii., p. 125. 
 
 (2) J. Fantoni, De jecore, liene et pancrcatc ; in the Disc, renov ., Turin, 1745. 
 
 (3) A. Rolfink, De hepate, Jena, 1633. — F. Glisson, Anatomia hepatis , London, 
 1654. — M. Malpighi, De hepate ; in the De viscerum structura, Bologna, 1666. — J. 
 B. Bianchi, Historia hcpalica, Turin, 1711. — A. Bertrandi, De hepate et oculo, Turin, 
 1748. — A. Franken, Hist, hepat. anat., Leyden, 174S. — J. G. Gunz, Obs. circa hepar , 
 Leipsic, 1748.— A. Ferrein, Sur la structure des viscères nommés glanduleux , et par- 
 ticulièrement sur celle des reinset du foie ; in the Mém.dc Paris , 1749, p. 709. — 
 M. Ambodick, De hepate, Strasburg, 1775. — F. A. Walter, De structura hepalis et 
 vesiculœ felloe ; in the Annot. acad., Berlin, 1786. — Saunders, A treatise on the struc- 
 ture, economy , and diseases of the liver, London, 1798. — J. M. Mappes, Disc, dc peni- 
 tiori hepatis humani structura, Tubingen, 1817. — Id., Quelques considerations sur 
 la structure du foie et du rein ; in the Journ. compl. des sc. méd., vol. xii., p. 223. — 
 J. F. Bcltz, <lu<cdam dc hepatis dignitale, Berlin, 1822. 
 
OF THE DIGESTIVE SYSTEM. 
 
 299 
 
 so that it is situated obliquely from below upward, and from right to 
 left. On the left side it terminates near the upper extremity of the 
 spleen ; its left portion covers the stomach, the right generally the 
 whole right kidney, but when the latter organ is situated lower than 
 usual, only its greater upper half. 
 
 B, DIMENSION AND WEIGHT. 
 
 § 2203. The transverse diameter of the liver in the adult is usually 
 from ten to twelve inches ; the antero-posterior is from six to seven 
 inches. The gland is two inches high in its thickest portion. 
 
 The liver generally weighs about four pounds in the adult, so that 
 its weight in proportion to that of the whole body is as 1 : 36. 
 
 c. FORM. 
 
 § 2204. The form of the liver is irregular and quadrangular. It is 
 much thicker from one side to the other than from before backward, 
 and is thinnest from above downward. 
 
 § 2205. The liver is generally divided into two halves or lobes (loin), 
 the right and the left, separated on the upper face by the suspensory 
 ligament, on the anterior edge by a deep groove, and on the lower face 
 by a deep longitudinal fissure, which extends the whole breadth of the 
 gland. 
 
 § 2206, The right lobe (/. hepatis dexter , s. major ) is about four 
 times as large as the left (l. hepatis sinister , s. minor), and much ex- 
 ceeds it in all its dimensions, but particularly in its thickness. 
 
 Its upper face is uniformly convex ; the lower presents elevations 
 and depressions which render it very uneven. 
 
 These inequalities are connected with the blood vessels, the lym- 
 phatics and the biliary vessels which enter or emerge from the liver, 
 and correspond to the fissures ( hilus ) of the other glandular organs. 
 
 The two edges of the liver, the anterior or inferior , and the posterior 
 or superior , are generally convex, but the first is more so than the 
 other. The anterior is thin and sharp, the posterior thick and blunt, 
 so that the upper and lower faces gradually unite in that part, al- 
 though there is a very distinct limit between them. 
 
 The -left portion of the lower face of the right lobe, which is the 
 smallest, and which occupies the centre of the lower face of the liver, 
 considered as a whole, has the form of an H inclined from before back- 
 ward, the transverse bar and the two legs of which are formed by the 
 fissures (sulci, s. foveœ) which converge behind the lower face of the 
 liver, between which are the elevations (lobidi). 
 
 § 2207. The transverse or median fissure (sulcus intermedins, s. 
 transversus) is situated about the centre, a little nearer the posterior 
 than the anterior edge. We notice in it the commencement of the 
 
300 
 
 BESCßimVE ANATOMY 
 
 excretory duel of the liver, or the hepatic canal (d. hepatic us), the com- 
 mencement of the arterial portion of the vena-porta and the hepatic 
 arteries. The hepatic canal is situated entirely forward, the vena- 
 portae between an anterior and a posterior series of branches of the 
 hepatic artery. Each of these three vessels divides into a right and a 
 left branch ; from the hepatic artery are commonly formed two, which 
 are entirely distinct, a right and a left. 
 
 § 2208. The left longitudinal fissure ( fossa longiludinulis sinistra), 
 which separates the right from the left lobe, extends from the anterior 
 to the posterior edge. The left extremity of the vena-portae divides 
 these into two halves, an. anterior, longer and deeper, and a posterior, 
 smaller and more superficial. 
 
 The anterior half ( fovea pro vena umbiiicali, s. lig. terete) is the 
 groove for the umbilical vein or the round ligament of the liver. 
 
 Gunz has asserted, contrary to most anatomists, that this anterior 
 half is most generally changed into a real canal, as in almost all ani- 
 mals, by one or more bands of the substance of the liver, which extend 
 like a bridge from the lower face of the great lobe, to that of the small, 
 and are sometimes also replaced by a simple prolongation of the peri- 
 toneal capsule of the gland. 
 
 The posterior half of the left longitudinal fissure, which is more su- 
 perficial than the anterior, especially toward the left lobe, is the fossa 
 for the venous canal {fossa pro duc lu venoso), which is there directed 
 from before backward, from below upward, and near its termination a 
 little from left to right. 
 
 It is continuous posteriorly with the fissure of the ascending vena- 
 cava. 
 
 We rarely find it intimately united with the venous canal by a 
 layer of the substance of the liver, which is then very thin. 
 
 § 2209. The right longitudinal fissure ( fossa longiludinalis dexlra) 
 is much more superficial, and its anterior part, separated from the pos- 
 terior by the vena-porta, differs much from this latter in form and in 
 importance. 
 
 The anterior is planer and is not covered by the peritoneum ; it re- 
 ceives the gall-bladder [ fossa pro vosiculd jelled). This depression is 
 most generally indicated forward by a greater or a less groove, and 
 sometimes it communicates near its anterior extremity with the upper 
 face of the liver by an opening. 
 
 The posterior is directed from below upward, and is continuous with 
 the posterior edge ; it is termed the fossa of the vcna-cava {fossa venae 
 cavœ), because it receives the upper part of the ascending vena-cava. 
 It blends posteriorly in the blunt edge of the liver with the fissure of 
 the venous canal. It is rarely wholly or partially changed into a canal 
 by a band of the substance of the liver. 
 
 About twenty small hepatic veins proceed from this fossa from below 
 upward, in pairs side by side, and empty into the ascending vena-cava ; 
 but from its upper part arise two large venous trunks, a right and a 
 left, which terminate in the same manner. 
 
OF THE DIGESTIVE SYSTEM. 
 
 301 
 
 Thus the vena-cava follows, in the arrangement of its branches, the 
 same law as the other vessels of the liver, and although the latter is a 
 simple organ, it seems composed of two halves, a right and a left. 
 
 Its vascular fissures are separated from each other on the lower 
 face by the posterior middle lobe ; they however blend together pos- 
 teriorly. 
 
 § 2210. The portion of the lower face of the liver, situated between 
 the two longitudinal fissures, is divided by the portal eminence into two 
 halves, an anterior and a posterior. 
 
 The anterior, which is deeper, is situated between the depressions 
 of the gall-bladder and the umbilical vein on one side, and the portal 
 eminence and the anterior edge on the other, and has been called from 
 its form the square lobe (Z. quadratus). 
 
 The posterior is smaller, more elongated, narrower, but more promi- 
 nent, because situated on a narrower base, is found between the porta, 
 the fissure of the ascending vena-cava, that of the venous canal, and 
 the posterior edge. It is termed the lobe of Spigel ( lobulus Spigelii, 
 s. caudatus). 
 
 § 2211. The right portion of the lower face of the great lobe is the 
 most extensive and thickest, and is uniformly convex or concave. 
 
 § 2212. The left lobe, which is much smaller and thinner, gra- 
 dually terminates in a blunt extremity. Its upper and its lower faces 
 are smooth and united. 
 
 Beside the fissures we have described, we not unfrequently find, 
 particularly in the right lobe, several which vary in size and are not 
 constant •, these are analogous to the division of the liver into many 
 lobes in the mammalia. 
 
 d. attachments. 
 
 § 2213. The liver is enveloped by the peritoneum, except the right 
 part of its posterior edge and the portion of its lower face covered by 
 the gall-bladder. This membrane is reflected on it backward by its 
 blunt edge, and forward by the portal eminence or the suspensory liga- 
 ment. There is no other envelop between it and the tissue of the 
 gland in most of its extent ; we however find an intermediate layer of 
 cellular tissue at the posterior part of the upper face near the edge. 
 
 § 2214. The liver is kept in place by several folds of peritoneum, 
 namely : 
 
 1st. By the coronary ligament, at its posterior edge. 
 
 2d. By the right and left triangular ligaments, which form its right 
 and left extremities, to the lower face of the diaphragm. 
 
 3d. By the suspensory ligament, which is attached to the lower face 
 of the diaphragm and to the linea alba. 
 
 The small epiploon unites it to the small curve of the stomach. 
 
 A short cellular tissue also unites it very loosely to the right kidney, 
 which it receives in a depression of the lower face of its right lobe. 
 
 VOL. III. 
 
 39 
 
302 
 
 DESCRIPTIVE ANATOM V. 
 
 E. COLOR, SPECIFIC GRAVITY, AND CONSISTENCE. 
 
 § 2215. The color of the liver is brownish red in young persons and 
 those in the prime of life. It becomes darkish and blacker in old age. 
 Its specific gravity is about as 15 : 10. 
 
 Its substance is firm, but brittle. Thus the liver is one of the organs 
 most frequently ruptured, from a mechanical cause acting on the pa- 
 rietes of the abdomen when the external parts are uninjured. 
 
 F. TEXTURE. 
 
 § 2216. The parenchyma of the liver is not absolutely homoge- 
 neous. In fact we do not find, as in the other glands and the ence- 
 phalon, the two substances of which it is composed separated from 
 each, so that one is placed internally and the other externally. But 
 whatever point we examine, these two substances, which are every 
 where arranged alternately, are easily distinguished. At first view 
 they seem to form undulated bands about half à line thick ; but when 
 examined more attentively we perceive that the yellow forms a co- 
 herent mass in all parts of the gland, that it there produces numerous 
 elevations and depressions, although interrupted in many parts, and 
 consequently represents a very complicated net-work. In the spaces, 
 which are about a line in diameter, and which are polygons, we find 
 a dark substance which does not form a coherent whole like the pre- 
 ceding, and which is softer but less transparent - than it. 
 
 Ferrein had already well distinguished these two substances. (I) 
 Haller(2) and Gunz(3) also mention its discovery. Autenrieth,(4) 
 Bichat, (5) Cloquet, (6) and Mappes,(7) have also mentioned this struc- 
 ture, which we have always thought was easily seen ; hence we con- 
 sider as erroneous the opinion(8) that they are arranged arbitrarily. 
 Physiologists, however, differ in regard to their uses. Ferrein terms 
 the deep colored substance the medullary , and the bright colored sub- 
 stance the cortical ; while Autenrieth and Mappes have applied these 
 terms in opposite senses. The views of these last two writers seem 
 to us to be more just than those of the others regarding the difference 
 in the consistence and the transparency of the two substances, in re- 
 spect to their color, or finally their arrangement in regard to conti- 
 nuity, since in all these respects the bright substance is more similar 
 
 (1) Mhn. de Paris , 1735, hist. 51. 
 
 (2) Bibl. anat., vol. ii., p. 253. 
 
 (3) De hepate, p. 28. 
 
 (4) lieber die Rindensubstanz der Leber; in Reil, Archiv, für die Physiolosric, 
 vol. vii., 1817, p. 299-308. 
 
 (5) Anat. dcscript., vol. v., p. 93. 
 
 (6) Traité d'anat., vol. ii., p. 1032, 1033. 
 
 (7) Loc. cit., p. 6. 
 
 (8) Porta), Anal, prat ., 1804, vol. v., p. 278. 
 
OF THE DIGESTIVE SYSTEM. 
 
 303 
 
 to the bright substance of the encephalon, the spinal marrow, and the 
 kidneys ; and the dark substance to the cortical substance of these 
 latter. 
 
 When the yellow medullary substance is examined attentively, it 
 seems formed of small points or grains. 
 
 We may term the small masses composed of medullary and of cor- 
 tical substance the lobules (acini), although they are more blended 
 than in the other glands, and are not separated by spaces filled only 
 with cellular tissue ; so that the structure of the liver is consequently 
 much less lobular than that of the salivary glands. 
 
 From the consistence and hardness of the substance of the liver, the 
 orifices of the vessels which are intimately united with it remain ga- 
 ping when it is cut. 
 
 § 2217. The liver is formed by the ramifications of the biliary ducts, 
 of the vena-portae, of the hepatic artery and the hepatic veins, and by 
 lymphatic vessels and nerves, united by mucous tissue. It is, how- 
 ever, essentially formed by the biliary vessels and the mucous tissue 
 which surrounds them. 
 
 § 2218. The vessels of the liver are not all distributed exactly in 
 the same manner. They vary in their connections with each other, 
 and with the substance of the organ. 
 
 The hepatic artery, the vena-portæ, and the biliary ducts are enve- 
 loped in their whole course through the substance of the liver by a 
 common cellular sheath, a prolongation of the capsule of Glisson. 
 Hence they are not in direct contact with the substance of the gland, 
 like the ramifications of the hepatic artery, around which the capsule 
 does not exist, and they are more solid and more resisting than the 
 latter. 
 
 The hepatic artery seems to be intended for the nourishment prin- 
 cipally of the tissue of the liver ; for according to Glisson’s observa- 
 tions/!) which have since been proved correct by Bianchi,(2) Wal- 
 ter, (3) and Mappes,(4) it is distributed on the other vessels, giving rise 
 there to a very complex net-work. The finest ramifications, however, 
 enter the vena-portæ. (5) 
 
 Its branches are fewer and straighter than those of the latter. (6) 
 When injected it is generally entirely filled, but sometimes this is true 
 only of the vena-portæ. (7) 
 
 § 2219. The vena-portæ forms by far the largest part of the vascu- 
 lar substance of the liver. It ramifies very frequently, and evidently 
 
 (1) L. i., c. xxix., De arteriœ hepatis distributions, 
 
 (2) hoc. cit., pt. i., cap. viii., § 5. 
 
 (3) Loc. cit., p. 96. 
 
 (4 ) ' Loc. cit., p. 13. 
 
 (5) Walter, p. 96,99. 
 
 (6) Id., p. 95, 96. 
 
304 
 
 descriptive anatomy. 
 
 like a disk, although one of the two branches is much larger than the 
 other.(l) 
 
 It terminates in two modes ; several branches, some of which are 
 very large and even a line in diameter, anastomose with the corre- 
 sponding twigs of the hepatic veins, (2) and hence the facility with 
 which the vena-portæ is injected through these latter, or the hepatic 
 veins through the vena-portæ. (3) Other and more minute branches 
 are more particularly connected with the origins of the biliary ducts ; 
 but their connections are less intimate than those we have mentioned, 
 since by injecting the vena-portæ we can never fill the biliary canals 
 alone, but the injection always passes into the other vessels, particu- 
 larly into the hepatic veins. (4) Its most minute twigs do not enter 
 into the medullary substance of the liver, but are distributed in the 
 cortical substance, and have no direct or proximate connection with 
 the first.(5) 
 
 § 2220. The biliary canals differ from the other vessels of the liver, 
 as their twigs are larger. Only the large branches unite in the man- 
 ner of a disk. The union of the small twigs is less regular, and seve- 
 ral proceed from the same point. Their parietes are much firmer than 
 those, of the veins. The muciparous depressions upon their inner 
 face on the outer half of the liver do not exist except in the largest 
 branches, and entirely disappear in the most minute, which are per- 
 fectly smooth. When they are injected the injection generally pene- 
 trates into no other kind of vessel, or when this happens the lympha- 
 tics, (6) and next the branches of the vena-portæ are most perfectly 
 and frequently filled. 
 
 The roots of the biliary canals seem to arise on the limit between 
 the. medullary and the cortical substance, although they do not dis- 
 tinctly pass through the former.(7) They never terminate on the sur- 
 face of the liver, and even when they are superficial, they penetrate 
 within the gland. 
 
 2221. The twigs of the hepatic vein are also fewer and larger than 
 those of the vena-portæ and the hepatic artery. They do not contribute 
 as much as the vena-portæ, to form the substance of the liver, (8) 
 although their less degree of development is only apparent, since their 
 twigs are so small, that they are more easily destroyed than the other 
 hepatic vessels. When injected, the fluid scarcely passes, excepting 
 into the vena-portæ. (9) Their direction is generally transverse, while 
 that of the other hepatic vessels is oblique from below upward, and 
 almost perpendicular, so that they cross these latter. Their final twigs 
 
 (1) Mappes, p. 13. 
 
 (2) Berlin, in the Mém. dc Paris , 1765. — Walter, p. 94, 95. 
 
 (3) Walter, p. 63. — Mappes, p. 23. 
 
 (4) Id., p. 64, 65. — Mappes, p. 22. 
 
 (5) Mappes, p. 11-13. 
 
 (6) Walter, p. 70. — Mappes, p. 24. 
 
 (7) Mappes, p. i. 
 
 (8) Walter, loc. at. 
 
 (9) Glisson, p. 285. 
 
OF THE DIGESTIVE SYSTEM. 
 
 305 
 
 are more intimately connected with then: medullary substance than 
 those of the other hepatic vessels, and it is more or less easy to trace 
 them into this substance, which depends partly on their not being sur- 
 rounded like these latter by the cellular capsule. 
 
 § 2222. The lymphatics of the liver are intimately connected with 
 the biliary ducts, and then cavity directly communicates with them, or 
 at least the substance between them is extremely thin, soft, and easily 
 destroyed. Those of the different regions of the liver do not anasto- 
 mose together, for the injection of one branch fills only the portion of the 
 organ to which this branch is distributed. 
 
 B. EXCRETORY PORTION OF THE BILIARY SYSTEM. 
 
 § 2223. The excretory portion of the biliary system includes the 
 proper excretory duct of the liver, and a cul-de-sac of this canal termed 
 the gall-bladder ( cystis , s. vesicula fellea, cholecystis) . 
 
 A. EXCRETORY DUCT. 
 
 § 2224. The excretory duct, of which we have already described the 
 portion within the liver, is formed by two membranes, one external, 
 solid, and cellular, the other internal, thicker, and smooth presenting 
 numerous and very compact depressions. We distinguish in it three 
 portions, the hepatic canal, the cystic canal, and the ductus choledochus. 
 
 The hepatic canal ( d . hepaticus ), or the first portion of the excretory 
 duct, arises in the fissure of the vena-portæ generally by two branches, 
 one on the right, which is smaller, and comes from the anterior part of 
 the great lobe of the liver, the other on the left, which is larger, and 
 arises from the posterior part of this lobe, and from the left lobe. These 
 two branches anastomose at an acute angle before leaving the fissure 
 of the vena-portæ. The canal formed by their union is from one and a 
 half to two inches long, and nearly two lines broad in the normal state ; 
 it is directed from above downward, and from right to left, and divides 
 to give rise to the cystic canal and the ductus choledochus, which 
 make a part of it. 
 
 The cystic canal ( cl . cysticus ) is directed at an acute angle forward, 
 downward, and to the right. It is narrower, and usually a little 
 longer than the hepatic, and enlarges to form the gall-bladder. 
 
 B. GALL-BLADDER. 
 
 § 2225. The gall-bladder is situated in a special depression of the 
 lower face of the liver. It is usually pear-shaped. The extremity, 
 near its orifice, termed the neck (cervix), is the narrowest part ; it is 
 broadest in its centre. Its anterior extremity terminates in a cul-de-sac, 
 and is called the base ( fundus ) ; it commonly extends a little beyond 
 the anterior edge of the liver. •The gall-bladder generally adheres in- 
 
soc 
 
 DESCRIPTIVE ANATOMY. 
 
 timately by its upper part, to the lower face of the liver, but sometimes 
 also it is loosely united with it by a fold of the peritoneum. The peri- 
 toneum covers it more or less perfectly, according as it presents one or 
 the other of these two arrangements. 
 
 We find below the peritoneum a dense cellular tissue, in which pro- 
 ceed the large vascular trunks, and which is called the vascular or ner- 
 vous tunic. The external face of the second tunic presents some fibres 
 which are generally whitish, proceed in different directions, sometimes 
 very analogous to those of the muscular coat of the intestinal canal, and 
 which cannot be considered as forming a distinct layer. 
 
 The cellular tunic covers the internal or mucous membrane, the in- 
 ner face of which presents folds which represent a reticular tissue, 
 formed of irregular pentagons, which do not disappear even when the 
 gall bladder is in its greatest possible state of distension. Some very 
 small openings, which are observed on this face, lead to simple glands 
 which are commonly invisible. Only ramifications of veins are distri- 
 buted on the surface of the folds. 
 
 The cystic canal and the neck of the gall-bladder are contracted by 
 about a dozen transverse folds, which are real valves, and arise from 
 the internal and cellular tunics. Most of these folds have their loose 
 edge turned toward the cavity of the gall-bladder, so as to form between 
 them and the wall of the canal, a depression which has the same di- 
 rection. 
 
 These folds gradually enlarge from the hepatic canal toward the 
 neck of the gall-bladder. They are attached to each other, especially 
 the largest, by intermediate, longitudinal, oblique, elevations which are 
 less prominent. 
 
 § 2226. The ductus choledoclms , or the lower portion of the excre- 
 tory canal of the liver, is the continuation of the hepatic and the cystic 
 ducts. It is a little broader than these two canals, but it is more 
 similar to the hepatic in structure and diameter, and may be con- 
 sidered the direct continuation of it, for it has the same direction, and 
 there exists, at least very frequently, along the opening of the cystic 
 canal, a small elevation between it and these two passages. 
 
 This canal is generally about four inches long ; its lower extremity 
 goes to the posterior wall of the duodenum, and opens at its central 
 portion. Its diameter is generally the same until it opens into the in- 
 testine, but it contracts much in gliding between the muscular and cel- 
 lular tunics of the latter, and finally terminates in an orifice which is 
 narrower than the rest of its course. 
 
 § 2227. When we cut the duodenum, we observe in the posterior 
 wall, the opening of the ductus choledochus, in the form of an oblong 
 tubercle, about four lines in length, and presenting at its lower extre- 
 mity an opening directed obliquely from above downward ; this open- 
 ing is generally situated three inches below the commencement of the 
 intestine, and is formed by the mucous and cellular membranes of the 
 latter and the ductus choledochus, which are uninterruptedly continu- 
 ous with each other. 
 
OF THE DIGESTIVE SYSTEM. 
 
 307 
 
 The lower part of this orifice does not belong to the ductus choie» 
 dochus alone, but it is common to the pancreatic canal. 
 
 § 2228. The most evident function of the liver, is the very important 
 one to secrete bile, a green, very bitter alkaline liquid, which is indis- 
 pensibly necessary to digestion ; its physical qualities vary much in 
 more than one respect. The bile is generally distinguished into cystic 
 and hepatic ; the first is thicker, darker, more bitter, and consequently 
 more concentrated than the second ; which differences depend on the 
 gall-bladder, and not on the different origin of these two fluids, although 
 Malpighi(l) and Galeati(2) have adopted this last opinion, or at least 
 in part. 
 
 It is very probable, that putting out of view this difference of con- 
 centration, the bile has not always the same chemical composition. 
 
 It always contains a considerable quantity, and generally about 
 eleven-twelfths of water. The rest is composed, according to Thenard, 
 of albumen and of resin, of each about an equal quantity, which form 
 almost the whole of it ; a small quantity of insoluble yellow substance, 
 of a still smaller quantity of soluble substance, finally, some traces of 
 soda, of the phosphate, the sulphate, and the hydrochlorate of soda ; of 
 the phosphate of lime, and of the oxide of iron, all of which are dis- 
 solved in the water except the yellow substance, which is insoluble. (3) 
 The resin admitted by Thenard and his successors, is produced, ac- 
 cording to Berzelius, (4) by the action of acids on a peculiar substance, 
 similar to albumen. This chemist considers bile composed in 1000 
 parts : of water 907.4 ; of a peculiar substance 80.0 ; of mucus 3.00 ; 
 of soda and common salts 9.6. None of these constituent parts con- 
 tain azote ; this is curious, on account of the frequent change of bile 
 into a fatty body, and on account of the analogy of the meconium with 
 vegetable substances. 
 
 Thenard asserts that picromel, a peculiar substance of a sweet and 
 bitter taste, which commonly occurs in the bile of most mammalia, 
 does not exist in that of man, but it has been found there by Che- 
 valier.^) 
 
 Probably the bile is formed entirely, or in great part, at the expense 
 of the venous blood of the vena-portæ, and the hepatic artery only 
 serves to nourish the liver. 
 
 The principal arguments in favor of this opinion, are : 
 
 1st. The distribution of the hepatic artery in the vascular mem- 
 branes. 
 
 2d. The existence even of the system of the vena-portæ. 
 
 3d. The great analogy between the venous blood and the bile, and 
 between it and the arterial blood. 
 
 . (1) De liene, c. vi. 
 
 (2) Com. Bonon., vol. i. ib. vol. ii. p. i. 
 
 (3) Mem. de la soc. (PArcueil, vol. i. 
 
 (4) Med. ckir. trails., vol. iii. 
 
 (5) Annales de chimie et de physique, vol. ix. 
 
30S 
 
 DESCRIPTIVE ANATOMY. 
 
 4th. The relation between the caliber of the hepatic vein and the 
 size of the liver, without regard to the abundance of the biliary secre- 
 tion, while this latter circumstance is always attended with a greater 
 development of the vena-portæ. 
 
 The arguments adduced against this theory, are : 
 
 1st. The absence of the system of the vena-portæ in the invertebral 
 animals. 
 
 2d. The cases where the vena-portæ opens into the vena-cava, and 
 the hepatic artery is unusually large. 
 
 3d. The correspondence between the caliber of the excretory duct 
 of the liver and that of the hepatic artery, and the disproportion be- 
 tween that of the hepatic canal and that of the vena-portæ. 
 
 These arguments do not refute those on the other side. We have 
 reasons for thinking that the arterial blood of the invertebral animals 
 is perhaps more proper for the secretion of bile than that of the verte - 
 brated animals. Possibly, also, the arterial blood of the latter was 
 more appropriate for this use in the anomaly on which the second ar- 
 gument rests, than generally, because the biliary secretion then did 
 not contribute to render the blood of the vena-portæ more analogous to 
 that which circulates in the arteries. Farther, all the known cases of 
 this anomaly have been observed in children, the bile being less bitter 
 and less in quantity than usual. As to the third objection, the hepatic 
 artery compared with the arteries of the other secretory organs, seems 
 too small to admit that it serves for secretion and nutrition. 
 
 Some physiologists, regarding the size of the liver, its constant ex- 
 istence, and the frequency of its diseases, have been led to believe that 
 it fulfills in the economy another function from that of secreting bile ; 
 but this other function is not proved. Theuses of the bile .are not confined 
 to digestion, but it is connected with the whole vital action ; in this re- 
 spect, the secretion which forms it, prevents an excess of hydrogen and 
 carbon in the body, as is indicated by its increase when the respiratory 
 function diminishes in the animal series, when it does not exist as in 
 the fetus, or when it is deranged as in certain diseases. (1) 
 
 The purpose of the circulation of the vena-portæ, however, may also 
 be to attenuate, to assimilate foreign substances brought by the venous 
 system into the intestinal canal, and thus diminish the injurious in- 
 fluence they might exercise on the body. 
 
 C. DIFFERENCES DEPENDING ON DEVELOPMENT. 
 
 2229. The differences depending on the development of the liver(2) 
 relate to its volume, situation, form, and texture. 
 
 1st. The liver is very large during the first week of gestation, and 
 we may say from the first moment of its appearance, that it is propor- 
 
 (1) Meckel, Abhandlungen , 1806. 
 
 (2) Walter, loc. cit., sect. i. — A. Portal, Observations sur la situation des viscères du 
 bas-ventre chez les enfans, et sur le déplacement qu’ils éprouvent dans un âge plus 
 
OF THE DIGESTIVE SYSTEM. 
 
 309 
 
 tionally much larger the younger the fetus is. Thus, in the fetus of 
 three weeks, its weight is one half that of the rest of the body,(l) and 
 even in the full grown fetus it is to the latter as 1 : 18, or as 1 : 20, 
 while the relation is as 1 : 35-36 in the adult. But the great propor- 
 tional size of the liver diminishes at the end of the first half of gestation, 
 because, after this period, the gland increases more slowly. It, how- 
 ever, continues to grow till birth ; but afterward the absolute weight 
 and size diminish until the end of the first year, for we have found in 
 five new born children, that the liver was one quarter heavier than in 
 five other children from eight to ten months old. 
 
 2d. The liver at first occupies a much greater space the younger 
 the fetus is ; even at the third or fourth month of gestation, it nearly 
 fills the cavity of the abdomen, descends to the crest of the ileum, and 
 covers the other viscera. This difference, however, partly depends 
 upon its being situated more perpendicularly at first, so that then, that 
 face which is afterwards superior, looks forward, and that which is to 
 be inferior, backward. 
 
 3d. Its formation is at first as much more symmetrical as is its situ- 
 ation, and it's left lobe differs less in size from the right lobe, and the 
 limit between these two parts corresponds more to the median line. 
 The absolute diminution mentioned above, takes place almost entirely 
 at the expense of the left lobe, for while during this period, the right 
 lobe preserves the size it had at birth, and often even increases a little; 
 the left diminishes in every direction, so that in a child of a year old, it 
 is hardly half as large as in a new born child ■ the lobe of Spigel, on 
 the contrary, is more developed. The liver is at first more rounded, 
 and its lower face is more convex than it is afterwards. 
 
 4th. Its tissue is softer, more homogeneous, more brittle, and more 
 vascular in the earlier periods of life than subsequently, where the ves- 
 sels diminish in size, and many of them disappear. We, however, 
 very readily distinguish the two substances in the full grown fetus. 
 
 5th. Its coloris at first a bright grayish brown ; it does not become a 
 deep red until after the first half of gestation ; its tint brightens shortly 
 after birth, and its tissue then changes also a little in appearance. 
 
 § 2230. The gall-bladder isatfirst entirely concealed in the substance 
 of the liver, is proportionally very long, narrow, filiform, a little en- 
 larged at its lower extremity, and empty. Its cavity cannot be 
 seen except by the aid of the microscope. Its inner membrane is 
 smooth until the sixth month of gestation ; broad, irregular elevations 
 are then developed in it, between which are narrow depressions, similar 
 to superficial grooves. These grooves gradually become deeper, and 
 also more numerous, and many fissures are developed on the surface 
 
 avance; in the Mémoires de Paris, 1771. — Id., Observations sur la situation du foie 
 dans l’etat naturel, arec des remarques sur la manière de connaitre, par le tact , plu- 
 sieurs de ses maladies ; in the Mém. de Paris, 1773. — J. S. Schumann, Dehepatis 
 inembryone magnitudinis causis ejusdcmquefundionc cum infœlutum inhomine 
 nato, Breslau, 1817. 
 
 (1) Walter, loc. cit., p. 45 
 Vol. iff. 40 
 
310 
 
 DESCRIPTIVE ANATOMY. 
 
 of the elevations ; hence, regular and narrow cellules are formed, which 
 are separated by .thin intermediate septa. 
 
 Notwithstanding its primitive narrowness, the gall-bladder is never 
 deficient at any period, according to our observations, as one would be 
 led to believe from some cases where its total absence has been assert- 
 ed. Its situation also in regard to the other biliary organs, is always 
 the same- ~ consequently it never arises by a kind of granulation, deve- 
 loped from the extremity of the biliary passage, but it arises in the 
 groove at the lower part of the liver, which is destined particularly for it, 
 and which is at first proportionally much deeper than in the adult. 
 We have never known it to communicate with the liver at first by 
 one or more 6peciul canals, while we have seen it manifestly terminate 
 in a cul-de-sac. 
 
 D. ABNORMAL STATE. 
 
 § 2231. The liver is one of the organs most(l) frequently abnormal 
 in more than one respect, but principally in its texture, which undoubt- 
 edly depends on the numerous organic elements which compose it 
 
 A. LIVER. 
 
 § 2232. The deficiency of the liver has hitherto been observed only- 
 in some acephalous monsters ; in these it is the rule, which has but few 
 exceptions, that the liver is always very small. 
 
 This organ sometimes preserves the same situation as in the fetus, 
 which depends on the imperfect development of the anterior face of the 
 abdomen. In this case it is sometimes situated externally, forming 
 either alone or with the other viscera, an umbilical hernia, in which it is 
 wholly or but partially contained. It exists more rarely in the cavity 
 of the thorax, on account of the imperfect development of the dia- 
 phragm. Sometimes, in these two cases, especially the first, the her- 
 niary part, forms a prolongation, which is attached to the peduncle , 
 this may give rise to the opinion that two livers exist. Sometimes, 
 also, when no similar mechanical cause exists, the liver is divided by 
 more or less deep grooves, into a greater or less number of distinct 
 lobes. 
 
 Sometimes an anomaly of the liver exists, similar to the latter in ex- 
 ternal appearance, but differing much from it in form and origin. It 
 consists in fractures of this organ, which are frequent on account of its 
 fragility, even when the external parts are uninjured from externa! 
 
 (1) Portal, Observations sur la nature et le traitement des maladies de Joie, Paris, 
 181 3. — Farre, The morbid anatomy of the liver , London, 1812*1815. — J. Thomas, A 
 treatise on the diseases oj the liver and digestive organs , London, 1820.— J. Johnston, 
 A treatise on derangement of the liver, London, 1820. — J. Faithorn, Facts and, obser- 
 vations on liver complaints and bilious disorders in general, Philadelphia, 1820. 
 
OF THE DIGESTIVE SYSTEM. 
 
 311 
 
 causes, acting not only on the region of the body in which it is situa- 
 ted, but also upon remote parts. 
 
 It is rare that the liver is abnormally small from a primitive devia- 
 tion of formation, but it often diminishes in the course of time, particu- 
 larly in advanced life, and finally becomes unusually hard and firm ; 
 this state is termed scirrhus , although this term is not perfectly con- 
 venient.- 
 
 Hypertrophy (1) of the liver is one of its most common affections ; it 
 supervenes at all periods of life, but most frequently in advanced age : 
 it is generally attended with a greater or less alteration of texture, and 
 particularly with induration , even when it does not depend solely on 
 new formations within the gland. 
 
 Induration of the liver, however, is not always attended by its hy- 
 pertrophy, although the contrary is generally admitted, since the latter 
 is sometimes attended with softening. Hypertrophy of the liver fre- 
 quently attends chronic general diseases, especially rachitis, scrofula, 
 and dropsy. In this case the gland is usually harder than in health : 
 but in scrofula, on the contrary, where we find hypertrophy at least as 
 frequently, its tissue is softer than in the normal state. The enlarge- 
 ment, of the liver, which usually attends pulmonary affections, is evi- 
 dently, at least in most cases, an effort of nature to restore health. 
 
 Induration of the liver is the most frequent alteration of texture, and 
 it often exists with or without enlargement. Softening of the liver is 
 much more rare, and exists sometimes with, and sometimes without 
 atrophy of the gland. (2) 
 
 The new formations in the liver are rarely repetitions of the normal 
 tissues : the most common anomaly is the change into fat, which exists 
 in several different degrees, usually affects the whole organ, and is ob- 
 served in the idle and luxurious. 
 
 Accidental ossification is generally developed on the edge of the 
 liver, below the peritoneal coat. Probably it is only a change of 
 another accidental formation, for instance, of one of those serous or 
 fibroserous cysts, often developed in the liver, where they form hy- 
 datids. 
 
 The liver is not unfrequently the seat of entirely new formations, 
 generally termed tubercles (tuber a) .(3) These tumors are rarely in- 
 closed in a cyst, and are rounded. They are generally whitish, sel- 
 dom red or brown. They vary in size from three to four inches. They 
 are frequently very numerous, being developed in the centre of the 
 liver, which is otherwise healthy. Like most new formations, they are 
 
 (1) V. Murat, Sur l’hypertrophie du foie ; in the Bull, de la soc. mod. d'emuL, 
 September, 1821. 
 
 (2) Portal, p. 117. 
 
 (3) V. Murad Des moyens de distinguer entre elles les diverses affections du foie, 
 désignées sous les noms de tubercules scrofuleux, d'hydatides, de squirrhe, d'hydro- 
 pisie enkystée, généralement confondues sous le nom d' obstructions ; in the Bull, de 
 la soc, méd. d' émut-, September, 1821. 
 
312 
 
 DESCRIPTIVE ANATOMY, 
 
 generally albuminous.(l) Those, however, which have a brownish 
 tint, appear from some recent experiments, to be more analogous with 
 gelatine. (2) The diseases they resemble are principally scrofula or 
 fungous hæmatodes. 
 
 AH the anomalies in the mass, size, and consistence of the liver 
 hitherto mentioned, all the accidental formations mentioned in this 
 gland, supervene principally after the immoderate use of arderlt spirits. 
 As they render the liver unfit for the secretion of bile, or prevent the 
 excretion of that which it forms, they frequently occasion jaundice. 
 This affection depends on a deposition of bile in a greater or less num- 
 ber of organs and fluids, particularly in the skin. It may also be de- 
 termined by the adjacent organs, and sometimes we discover no altera- 
 tion to which it can be attributed. 
 
 From the important functions of the liver, and also the intimate con- 
 nection between it and the mind, this organ varies more or less in all 
 general chronic and in all mental affections. 
 
 Entozoaries are developed in this gland more rarely. ' The animals 
 most commonly found there are hydatids, which occur in the liver more 
 frequently than in any other organ ; they are extraordinarily large 
 and numerous, and form very rapidly ; they are generally developed 
 in one point, rarely in several, and most commonly in the right lobe. 
 They are commonly separated from the healthy substance of the organ 
 by cysts, usually formed by several layers. They not unfrequently 
 destroy the liver to a great extent, and quitting the place where they 
 are formed, generally proceed outward, most commonly by entering 
 into the intestinal canal, more rarely into the chest and lungs, some- 
 times even directly through an opening in the common integuments. 
 
 Biliary concretions are more rare in the liver ; probably they al- 
 ways form in the biliary passages, whence they afterwards pass into 
 the substance of the gland. 
 
 B. BILIARY PASSAGES. 
 
 § 2233. Sometimes, but rarely, a part of the biliary passages, par- 
 ticularly the gall-bladder, is deficient(3) from a primitive deviation of 
 formation, although this anomaly does not necessarily exercise an in- 
 jurious influence on the health, which is less astonishing, since, accor 
 ding to the experiments of Herlin, the gall-bladder may be extirpated 
 in cats without inconvenience, and it is normally absent in many 
 animals. On the contrary, the entire absence of the biliary passages(4) 
 is always attended with the most fatal results. 
 
 (1) Portal, p. 95, Des obstructions albumineuses du foie. 
 
 (2) Portal, p. 98, Des obstructions gélatineuses dufoie. 
 
 (3) Ollivier, Note sur V atrophie de la vésicule biliare ; in the Archiv, gév . de méd., 
 yol. v., p. 196. 
 
 (4) Home, Phil, frans., 1813, pt. ii-, p. 146-158, 
 
OF THE DIGESTIVE SYSTEM. 
 
 313 
 
 We rarely also meet in the biliary passages deviations of formation 
 in regard to the quality, such as the existence of hepato cystic ducts 
 (d. hepato-cystici ), going directly from the lower face of the liver into 
 the gall-bladder, the slow union of the two roots of the hepatic canal, 
 the opening of one or more branches into the cystic canal, or even into 
 the gall-bladder, the insertion of the ductus choledochus in a point 
 different from the intestinal canal, or even in the stomach. 
 
 Of all the biliary passages, the gall-bladder most frequently presents 
 anomalies of this kind, since when it is divided by a contraction into 
 two cavities, placed successively in a longitudinal direction, or, as is 
 more rare, when a longitudinal septum divides it into two parts adapted 
 one to the other. The enlargement and the contraction of the biliary 
 passages generally depends on mechanical causes, among which we 
 must place first the biliary calculi contained within them, next, as is 
 more rare, the engorgement of the lymphatic glands, which compress 
 it from without inward.(l) The gall-bladder may be contracted 
 or dilated by the calculi within it. The contraction and the total obli- 
 teration of its cavity occur when a few or small calculi prevent by their 
 situation the bile from entering it. On the contrary, numerous or large 
 calculi, either alone or together with the bile, often dilate the gall- 
 bladder considerably when they are so situated as not to prevent en- 
 tirely the entrance or departure of the bile, or when they exist in the 
 ductus choledochus. Sometimes the gall-bladder is enormously dis- 
 tended, simply by an increased secretion of bile, without any mechanical 
 obstruction ; the membranes of this latter are then generally thin, 
 while in the opposite state they are very thick. Sometimes the calculi 
 are separated by perfect septa. 
 
 New formations rarely occur in the gall-bladder ; we must mention 
 as such, however, the osseous plates sometimes developed on the 
 outer face of the mucous membrane, and the hairs inserted on its inner 
 face. 
 
 ( 1 ) Andral ( Observations sur l’oblitération des canaux biliaires; in the Archiv, 
 gen. de méd., vol. vi., p. 16 ) admits four principal causes of perfect or imperfect, 
 transient or permanent obliteration of the biliary passages ; these are the obstruc- 
 tion of their cavity by a foreign body, a compression upon their parietes by mem- 
 branous folds and by tumors of different kinds, a spasmodic contraction independent 
 of all inflammation, and an inflammation followed by the engorgement of the mu- 
 cous membrane and its thickening. He remarks that the first two causes are fre- 
 quent, that in most cases the third has rather been supposed than demonstrated, and 
 that physicians have not yet attended to the fourth. The latter, however, seems to 
 be, if not always, at least very frequently, a consequent of a gastro-intestinal inflam- 
 mation; it is not unusual, and we have every reason to think that it always exists 
 in thé cases where the nervous pathology led one to suppose the third. Like all in- 
 flammations, that of the biliary passages, whether acute or chronic, is attended with 
 the thickening of the parietes of the canal, which is finally changed into a ligamen- 
 tous cord. F. x. 
 
314 
 
 DESCRIPTIVE ANATOMY 
 
 C, BILE. 
 
 § 2234. The bile is often abnormal in its physical and chemical 
 qualities, although we cannot always discover a certain connection 
 between its anomalies and the state of the liver. It however seems 
 less bitter when this organ is changed into fat. 
 
 The most striking anomaly is that resulting from the presence of 
 biliary calculi.(l) 
 
 These concretions, which are found in aged persons, or in those who 
 lead a sedentary life, differ from each other in situation, composition, 
 •color, number, size, texture, form, and consistence. 
 
 1st. Situation. The biliary calculi generally occur in the gall-blad- 
 der, so that they seem to be developed in this organ. They have 
 been found also in the biliary passages, in the substance of the liver, 
 although proportionally very rarely. Sometimes also they are situated 
 in the hepatic or cystic canal, or in the ductus choledoch us, but they 
 finally fall into the gall-bladder. Not unfrequently they leave the 
 ductus choledochus and pass into the intestinal canal. 
 
 The rarest case is where they occur out of the cavity of the bili- 
 ary passages in the substance of the liver, or in the membranes of the 
 gall-bladder. The former may be formed in the place where they 
 occur ; but the second are doubtless primitively developed in the cavity 
 of the gall-bladder, and afterwards glide between its membranes, and 
 are then inclosed by the closing of the opening which at first existed, 
 although it is admitted they are formed in the place even where they 
 are observed ; and this fact has even been cited to prove that the bile 
 is partially secreted by the glands of the gall-bladder. (2) 
 
 The justice of our etiology is demonstrated by the fact, that calculi 
 are sometimes found in the depressions of the gall-bladder, which case 
 is evidently intermediate between that where they are entirely loose in 
 the cavity, and where they are situated on the outside of it and en- 
 circled in the membranes. 
 
 2d. Chemical composition. The chemicafcomposition of the biliary 
 calculi generally causes all those properties of which we have yet to 
 speak. They are composed principally of two different substances ; 
 one more or less dark in color and brownish, and the other white ; 
 the latter is termed cholesterine. The bile contains none of it in the 
 normal state. (3) The other is the yellow coloring substance of this 
 
 (1) Vicq-d’Azyr, in the Mém. de la soc. de mid., 1779.- — Fourcroy, Sur les calculs 
 des animaux ; in t lie Annales du Muséum, vol. i. — S. T. Sœmmerring-, De concre- 
 mentis biliariis, Frankfort, 1793.— Mosovius, Diss. de calculorum animalium origine 
 et naturâ, Berlin, 1812. 
 
 (2) D. G. Galeati, De calculxs in cysti fcllcâ et mira ejus tunicas repertis ; in the 
 Comm. Bonon., vol. i., p. 354. — Ici., De cystis fclleœ duclibus, same journal, vol. i., 
 pt. ii., p. 331. 
 
 (3) Chevrcul has detected it in the bile of man and several animals ( Note sur la 
 
 présence de la cholestérine dans la bile de l’homme ; in the Jourrt. de physiol, cxvér., 
 vol. iv., p. 267). F. T. 
 
or THE DIGESTIVE SYSTEM. 
 
 315 
 
 fluid. The cholesterine probably arises from the change of a peculiar 
 substance which exists in the bile. 
 
 The biliary calculi also contain a little of bile, which is easily sepa- 
 rated from it by water. 
 
 We rarely find carbonate of lime on then surface.(l) 
 
 3d. Color. These concretions are more or less colored from the 
 brighest yellow to the deepest dark brown, because they generally 
 contain the substances mentioned above. Those only which are 
 formed of cholesterine are entirely white, and they are very un- 
 common. Farther, the tint varies in the different parts of a biliary 
 calculus. 
 
 4th. Number. It varies from one to several hundreds. The calculi 
 formed of pure cholesterine are usually single, or at least very few. 
 
 5th. Volume. It varies no less than the number, and usually hi an 
 inverse ratio. The calculi of pure cholesterine are generally larger than 
 the compound concretions. Not unfrequently one of them fills the 
 gall-bladder, and even distends it. 
 
 6th. Form. The biliary calculi are generally more or less round ; 
 those of pure cholesterine are more oblong. Their form is modified 
 also by their number, since the friction between them renders their 
 surface smooth. Hence why those of cholesterine are generally 
 more corrugated than the others ; but these concretions rarely pre- 
 sent sharp points. 
 
 7th. Their texture varies. 
 
 a. The biliary calculi are generally full and solid ; we, however, 
 have one which is hollow. 
 
 b. They are formed of several superimposed and differently co- 
 lored layers. 
 
 c. These layers are sometimes, though rarely, composed of one of 
 the two substances mentioned above. In the contrary case they are 
 all colored, and differ only in their shade of color. We not unfre- 
 quently find externally an entirely white layer. 
 
 d. The fight colored layers have generally more oi less evidently 
 a radiated and fibrous texture. It is often easy to see that they are 
 formed of very oblong pyramids slightly connected with each other, 
 the summits of which converge towards the centre. This form seems 
 to depend on the cholesterine, for it is never more apparent than in the 
 calculi formed by this fatty body, and it decreases inversely with the 
 color. 
 
 e. Consistence. Biliary calculi generally are neither very hard nor 
 solid. They are much softer and more brittle than the urinary con- 
 cretions. Sometimes, however, they are considerably hard. Those 
 of pure cholesterine are generally harder than the others, being even 
 very firm and solid ; but they are frequently also very soft, while 
 others which are more deeply colored are considerably hard. 
 
 (1) London mod. repository . , vol. iv., p. 469, 
 
316 
 
 DESCRIPTIVE ANATOMY. 
 
 II. PANCREAS. 
 
 § 2235. The pancreas( 1 ) is the largest of the salivary glands. Its 
 weight and size are three or four times those of the parotid gland, as 
 it is six inches long and one thick, and weighs from four to six ounces. 
 It is oblong, and is situated transversely at the upper part of the abdo- 
 minal cavity, before its posterior wall, in front of the first and second 
 dorsal vertebra, behind the stomach. Its left extremity generally 
 touches the spleen and the left kidney. It passes before the aorta, and 
 its right extremity is situated between the upper and lower folds of the 
 duodenum. 
 
 It is included between the two layers of the transverse mesocolon, 
 which slightly adheres to its upper part, and does not cover it poste- 
 riorly: 
 
 Its figure is that of a hammer, since it enlarges at its right extremity, 
 from whence proceeds an inferior prolongation, which embraces the 
 duodenum posteriorly, and on the left, and even a little forward. The 
 lower prolongation is called the /read, and the transverse larger portion 
 the tail. 
 
 § 2236. The pancreas is attached to the adjacent parts by a very 
 loose cellular tissue, and enveloped by a thick layer of the same ; it 
 has no special capsule. We also distinguish through the cellular en- 
 velop, the lobes which unite to form it. 
 
 These lobes can be divided into extremely minute lobules, attached 
 by a very loose cellular tissue. 
 
 The pancreas is yellowish brown, and rather firm in its texture. 
 
 § 2237. A considerable excretory duct passes entirely through this 
 organ ; it is white and solid, and is called the pancreatic canal (ductus 
 pancreaticus) ,(l ) or the canal of Wirsung (ductus TVirsungianus). 
 This canal arises at its posterior extremity by the union of several 
 branches, which anastomose at an acute angle. In its course it re- 
 ceives at a right angle, both above and below, a considerable number 
 of other branches, which may be easily followed by smaller granula- 
 tions, so that it gradually increases in volume, and finally becomes a 
 line and a half in diameter. Just before quitting the gland, it also re- 
 ceives one or more very large twigs, which arise from the head, and 
 which also open separately into the duodenum. 
 
 This canal is not visible on the surface of the gland, which must be 
 cut across in order to see it. 
 
 (1) Brunner, Exp. nova circa pancreas , Amsterdam, 1638. — Graaf, Dc succo pan- 
 creaiico, Leyden, 1664. — Johrenius, Dc affect, hypoehondriacis , Rinteln, 1678.—.). 
 M. Hoffmann, Dc panercale, Altdorf, 1706.— J. D. Santorini, Tabula: scptcmdccim, 
 tab. xiii. 
 
 (2) J. G. Wirsung', Figura ductus cujusdam, cum multiplicibus suis ramulis ■ 
 novitcr injiancrcatc, in diversia corporibus humanis observati, Padua, 1643. 
 
OP THE DIGESTIVE SYSTEM. 
 
 317 
 
 It generally opens into the duodenum, three or four inches below 
 the pylorus, but sometimes much lower down, and even ten inches 
 from it. 
 
 In the place where it communicates with the duodenum, it unites 
 externally with the ductus choledochus, but the two cavities remain 
 perfectly distinct, even when proceeding side by side through the mem- 
 branes of the intestine. They open side by side near the pancreatic 
 duct, a little to the left of the choledochus, at the base of a small cavity 
 about two lines long, the membrane of which has all the characters of 
 the inner tunic of the duodenum, so that we cannot properly consider 
 them as having a common orifice. 
 
 Near its orifice the excretory duct of the pancreas enlarges more or 
 less, but contracts at its opening, although there is no fold similar to a 
 valve in this or in any other part. The appearance of a valve at its 
 opening depends only on the septum between it and that of the ductus 
 choledochus. 
 
 § 2238. The pancreas, like all the salivary glands, and most of the 
 glandular organs, is more developed in the early periods of life than 
 subsequently. 
 
 We have observed that its excretory duct very constantly presents 
 a remarkable difference, as it is at first double, that is, beside the 
 permanent valve, there is then a second, which opens separately into 
 the duodenum.(l) 
 
 § 2239. The congenital anomalies of this gland extend principally 
 to the arrangement of its excretory duct, which sometimes seems 
 double ; this state must be considered as a permanence of that in the 
 fetus. (2) 
 
 The most remarkable consecutive anomalies are induration and hy- 
 pertrophy. We more rarely find in its excretory duct, calculi, (3) 
 composed of phosphate of lime and of an animal substance. 
 
 III. SPLEEN. 
 
 A. PERFECT STATE. 
 
 § 2240. The spleen ( splen , lien)( 4) is situated in the left hypochon- 
 drium, between the great cul-de-sac of the stomach, the lumbar portion 
 
 (1) Meckel, Abhandlungen, p. 331, 353, 366, 380. 
 
 (2) Tiedemann, Sur les différences que le canal excreteur du pancreas presente 
 dans l'homme et dans les mammifères ; in the Journ. compl. des sc. méd., vol. iv. p. 
 370. 
 
 (3) Baillie has figured a remarkable case of it. ( Engravings , fasc. v. tab. vii.) 
 
 (4) F. Schuyl, Dénatura etusulienis, Leyden, 1664. — Malpighi, I)e liene ; in De 
 structura viscerum. — C. Drelincourt, Dc licnosis, Leyden, 1693. — G. Stukcley, The 
 spleen , its description , uses , and diseases, London, 1723. — J. G. Duvernoi, De liene ; 
 in the Comm. Petrop., vol. vi. p. 156. — S. T. Quellmalz, De liene, Leipsic, 1748. — C. 
 L. Rolof , De fabrica et functions lienis, Frankfort, 1750. — Lasson e, Histoire anatir 
 mique de la rale ; in the Mém. de Paris, 1754. — Werlhof, De splenis usu, Wolfenbuttel, 
 1761. — J. F. Lobstein, De liene , Strasburg, 1774. — J, P, P. Assolant, Recherches sur 
 
 Vol. HI. 41 
 
31S 
 
 DESCRIPTIVE ANATOMY. 
 
 of the diaphragm, the commencement of the descending colon, and the 
 left renal capsule, which it covers anteriorly. Its form is elliptical ; its 
 posterior or external face is convex ; the anterior or internal is con- 
 cave, and divided by a longitudinal groove called the fissure of the 
 spleen ( hylus lienalis), into two halves, an anterior, which is the larger, 
 and a posterior. Its upper extremity is a little thicker than the lower ; 
 a fold of the peritoneum unites it to the diaphragm, the stomach, and 
 the descending colon. 
 
 It varies much in size, not only in different individuals, but also in 
 the same individual at different periods, and inconstantly. In general 
 we may say, that in the adult it is about four inches long, three broad, 
 and a little less than one thick. 
 
 Its weight varies as much as its size. Its mean weight is eight 
 ounces, so that in the adult it is to that of the whole body as I : 210. 
 But the volume and the weight of this organ are not necessarily in 
 an inverse ratio with the distension of the stomach, as has been 
 asserted. (1) Its specific gravity, compared with that of distilled water, 
 is as 1.200 : 1000. 
 
 It is of a brighter or darker red. 
 
 The consistence of the spleen is slight ; it is also very soft. 
 
 § 2241. At first view the spleen seems formed entirely of blood-ves- 
 sels, of which the arteries come from the cœliac trunk and the veins 
 rest directly on the surface of the artery, and are proportionally larger 
 than in any other part of the body ; they empty into the vena-portae, 
 and carry there a very dark blood. The substance of the organ is sur- 
 rounded by a very firm sero-fibrous membrane. The external layer 
 is serous and comes from the peritoneum, with which it is continuous 
 by two prolongations mentioned above. 
 
 The fibrous layer belongs properly to the spleen, but it can be se- 
 parated from the serous membrane only to a slight extent in the fis- 
 sure. 
 
 Numerous layers and very minute solid fibres proceed from it, which 
 interlace in many different ways, and enter the space circumscribed by 
 the capsule, leaving between them irregular spaces, in which the 
 splenic vessels are distributed. 
 
 These productions form, properly speaking, the base of the tissue of 
 the spleen. 
 
 Beside these fibres, other hollow canals proceed from the inner mem- 
 brane of the spleen to its fissure ; these closely envelop the vessels, 
 and unite with them. The first filaments are attached to the outer 
 
 la rate, Paris, 1801.— A. Morcschi,->SW vero eprimario usu della milza, Milan, 1803. 
 — E. Home, On the structure and use of the spleen ; in the Phil, trans., 1808. — C. F. 
 Heusinger, Ueberd.cn Bäu und Verrichtung der Milz , Thionvillc, 1817.— F. Gell- 
 haus, Inaugural Abhandlung über den Nutzent der Milz, 'Wurzburg, 1817.— G. M. 
 Felici, Osservazioni fisiologiche sopra lefunzioni della milza, Milan, 1818. — I. Deel- 
 linger, Betrachtungen über die Milz ; in the Deutsches Archiv für d.ie Physiologie, 
 vol. vi. p. 155.— Jæckel, Etwas über die Verrichtung der Milz ; same journal, vol. vi. 
 pi. 581.— Hodgkin, Sur les fonctions de la rate; in the Journ. com.pl. des sc. méd., vol. 
 xiv. p. 89. — Home, in the Phil. Irans., 1821, p. 25. 
 
 (1) Assolant, loc. cit., p. 129-133. 
 
OF THE DIGESTIVE SYSTEM. 
 
 319 
 
 face of these canals in the same manner as to the inner face of the 
 fibrous capsule. 
 
 The splenic arteries give off in their course numerous branches, 
 which divide into very minute ramuscules, arranged like the bristles of 
 a brush, but they do not anastomose together. On the contrary, the 
 veins which surround these arterial fasciculi, frequently anastomose 
 with each other, and with the adjacent veins. There are, however, 
 no great communications between the arteries or the veins of the dif- 
 ferent regions of the spleen. Those between the veins and arteries are 
 very large, as may easily be seen by the aid of a microscope, or by the 
 facility with which injections pass from the arteries into the veins. 
 
 Besides the blood-vessels, the spleen also possesses numerous lym- 
 phatics. Its nerves come from the splenic plexus, and are very small. 
 They are scarcely one twelfth as large as the arteries they surround, 
 and we cannot trace them far within the organ. Beside these consti- 
 tuent parts, which several anatomists assert are the only ones, 
 the spleen also contains, according to the more correct observations of 
 others, particularly Malpighi, Hewson, Dupuytren, Home, Heusin- 
 ger, and Meckel, very many rounded, whitish, and very probably 
 hollow, or at least veiy soft corpuscles, which differ much in respect 
 to size and situation ; their size varies from one sixth of a line to one 
 line, and they are sometimes near, and sometimes rather distant 
 apart. « 
 
 These corpuseles are very intimately connected wtth the rest of the 
 tissue of the spleen, and receive many blood-vessels; according to 
 Home’s observations, confirmed by those of Heusinger and our own, 
 they swell much in animals when they drink. 
 
 Malpighi considers them as glands. Ruysch and several other ana- 
 tomists have denied their existence, and have asserted, but wrongly, 
 that they are only simple fasciculi of vessels. 
 
 Although neither these corpuscles, nor the spleen, have excretory 
 ducts, they very probably contribute much to the changes of the blood 
 in passing through this organ, and assist in forming the gastric juice, 
 but particularly the bile. 
 
 The substance of a reddish brown, easily separated by washing and 
 pressure, should be regarded not as a constituent part of the spleen, 
 but as the blood changed by this organ. 
 
 The cellules heretofore admitted in the spleen, were very probably 
 produced by the destruction of a part of the vessels, and of the internal 
 fibrous tissue, by injections made with too much force, whence were 
 formed spaces which are afterwards distended by inflation. 
 
 § 2242. As the spleen has no excretory duct, its functions are very 
 obscure, and the more so, as it has frequently been extirpated without 
 producing any constant or very great derangement in any function. 
 Even at present, after so many experiments infinitely varied, after so 
 many observations and reflections, we can only hazard conjectures on 
 this subject. We may, however, conclude from facts hitherto known, 
 
320 
 
 DESCRIPTIVE ANATOMY. 
 
 that the spleen is intimately connected with the functions of the liver 
 and stomach, and acts in concert with these two organs. 
 
 That it assists in the functions of the liver, is proved by the fact, 
 that all the blood which passes through its tissue, is carried to this 
 organ by the trunk of the vena -portée. Hence, we may conjecture, 
 and very probably, that the blood is changed within it, and rendered 
 more proper for the secretion of bile, which conjecture is not contra- 
 dicted by chemical experiments, from whence it has been concluded, 
 that the blood of the splenic veins does not differ from that in the other 
 veins. Possibly, also, the spleen contributes mechanically to increase 
 the secretion of bile, since, during abstinence, a greater or less quantity 
 of blood collects there, which is afterwards expelled by the pressure of 
 the stomach when filled with food, and then goes toward the liver. 
 But as the blood is not merely circulated in the spleen, but there under- 
 goes some change, it follows, that the relation is not mechanical only, 
 but also chemical. 
 
 The spleen receives less blood at the commencement of digestion, 
 because the stomach, which is then full, prevents the blood from flow- 
 ing freely into it ; but in proportion as the contents of the stomach pass 
 out from it, the blood flows more easily to the spleen, and the function 
 of this latter, in regard to the . liver, becomes more active. Probably 
 also the spleen concurs in the accessory function attributed above to 
 the liver, that of neutralizing and assimilating foreign substances in- 
 troduced into the body. Hence we must consider it as a viscus which 
 performs, in regard to the vascular s 3 r stem, particularly to the liver, 
 the same part as the conglobate glands towards the lymphatic system. 
 It is more analogous to these glands than to the liver, as it has no 
 excretory duct. The liver then appears as an organ composed of a 
 conglomerate and a conglobate gland in the vascular system. 
 
 The action of the spleen may also relate to that of the stomach in 
 several different respects : 
 
 1st. In a dynamical respect, since the two organs seem to be op- 
 posed to each other, and the soft and blackish spleen may be consi- 
 dered, from its substance and the change of the blood which passes 
 through it, as contributing particularly to produce hydrogen, while 
 the stomach is an organ which, from the nature of its secreted fluid, 
 tends particularly to produce oxygen. 
 
 2d. In a mechanical respect, as the spleen attracts the blood to it 
 when digestion is not guing on, while it receives less when this viscus 
 is full, so that the blood flows in greater quantity toward the latter, 
 that is, precisely at the period when most necessary to the secretion 
 of the gastric juice. 
 
 The function of the spleen seems also to be to receive promptly at 
 least a part of the liquids introduced into the stomach, although this 
 function does not belong exclusively to it, since after it has been extir- 
 pated the liquids disappear as quickly as before, and the substances 
 contained in this viscus reappear in certain fluids. 
 
OF THE DIGESTIVE SYSTEM, 
 
 321 
 
 B. DIFFERENCES DEPENDING ON DEVELOPMENT. 
 
 § 2243. At first the spleen does not exist. It begins to appear dis- 
 tinctly during the second month of gestation. 
 
 It is at first infinitely smaller in proportion to the bod} 7 , and parti- 
 cularly to the liver, than it is subsequently, although it wrinkles and 
 also wastes in old age. 
 
 The whitish corpuscles are proportionally larger and more visible 
 during the latter periods of fetal existence and in infancy than during 
 the successive periods. 
 
 All these peculiarities are very important, as they support the eighth 
 law established in our introduction. In fact the spleen does not exist 
 in the mollusca which have a liver ; it becomes proportionally smaller 
 and smaller as we descend from the mammalia toward the lower 
 classes of the animal kingdom ; and in most mammalia, as also in 
 several other animals, the corpuscles are regularly larger in proportion 
 than in man. 
 
 c. abnormal state. 
 
 <5 2244. Among the anomalies of the spleen we must distinguish 
 particularly some deviations of formation,(l) which deserve to be no- 
 ticed. 
 
 This organ is very rarely deficient from a primitive deviation of forma- 
 tion in a subject where the formation is otherwise normal, while it is 
 generally absent in cases of acephalia vera. 
 
 A deviation of formation almost peculiar to the spleen, or at least 
 observed in it more frequently than in any other organ, is its division 
 into several spleens termed accessory ( licnculi , s. lienes accessorii). 
 These accessory bodies are always situated on the inner face, and 
 generally toward the lower extremity of the spleen. 
 
 They are usually, but not always, rounded, and vary in number 
 from one to twenty-three. The latter number, however, has been ob- 
 served only once, and we rarely find more than one supernumerary 
 spleen. 
 
 The great number of these accessory spleens is usually attended 
 with other deviations of formation. This occurred in a subject who 
 had twenty-three. (2) In another case, where there were seven, all 
 the organs of vegetative life were at the same time inverted. (3) In a 
 
 (1) C. S. Heusinger, Mémoire sur les monstruosités de la rate produites par le 
 défaut de développement de ce viscère ; in the Journ. compl. des sc. méd., vol, x., 
 
 p. 216 . 
 
 (2) Otto, Handbuch der pathologischen Anatomie , p. 302. 
 
 (3) Heusinger, loc. cit. t p. 62. 
 
322 
 
 DESCRIPTIVE ANATOMY. 
 
 third, where there were four, the foramen ovale of the heart was open 
 to some extent.(l) 
 
 The accessory spleens vary much in size. 
 
 The existence of a great number of fissures which are frequently 
 very deep on the anterior edge of the spleen, particularly toward its 
 lower extremity, or of a more or less distinct transverse fissure, which 
 passes over its whole external face, form a remarkable intermediate 
 degree between this anomaly and the normal state. 
 
 Among the accidental deviations of formation, one consists in an 
 enlargement of the spleen, usually attended with induration, which 
 commonly arises from the metastasis of a general disease. (2) 
 
 We not unfrequently find the spleen unusually hard withour en- 
 largement or very soft. The latter exists particularly in diseases 
 attended with great debility. 
 
 New formations are rarely developed in the spleen. The tubercles 
 sometimes seen in it are probably white corpuscles somewhat enlarged. 
 Perhaps we should consider a special formation a solid uneven yel- 
 lowish white mass which is frequently developed in the spleen. It, 
 however, seems to be very similar to fungus liæmatodes. 
 
 The capsule of the spleen frequently ossifies, particularly in ad- 
 vanced age, to such an extent even that when the osseous substance 
 has acquired a certain thickness in proportion to which the organ 
 always wastes, we are led to think that the spleen itself is changed 
 into bone. 
 
 ARTICLE FIFTH. 
 
 VESSELS AND NERVES OF THE ABDOMINAL PORTION OF THE 
 DIGESTIVE ORGANS. 
 
 § 2245. The vessels of the most important and the largest part of 
 the digestive organs mostly arise from three trunks, the cceliac, and 
 the superior and inferior mesenteric arteries, which come directly from 
 the abdominal aorta, and anastomose very frequently together. The 
 lower extremity of the rectum also receives some branches from the 
 hypogastric artery. 
 
 The veins, if we except those of the lower part of the rectum which 
 empty into the iliac veins, unite and form the vena-portae, so that all 
 the blood that returns from these organs passes through the liver be- 
 fore going to the heart, and from thence into the lungs. 
 
 (1) Baillie, Phil. Irans., vol. lxxviii., p. 350. 
 
 (2) C. F. Heusinger, Ueber dir, Entzündung und Vergrosscrung der Milz, 
 Eisenach, 1820. — S. Grotlanelli, Ad acuta: et ceronica: splenüidis h.istoriam animad- 
 versioncs, Florence, 1821. — C. 11. Schmid, Cummcnlatiu de palhulogiû lienis, Got- 
 tingen, 1816. 
 
OF THE ORGANS OF VOICE. 
 
 323 
 
 The nerves come principally from the great sympathetic nerve. 
 Those of the stomach, however, arise chiefly from the pne.umo-gastric 
 nerve, and those of the rectum from the sacral pairs. 
 
 CHAPTER II. 
 
 ORGANS OF VOICE AND RESPIRATION. 
 
 § 2246. In the preceding chapter on the systems we described the 
 digestive organs which belong to vegetative life ; these appear earliest 
 in animals, or in the fetuses of animals, perform at first the functions 
 of all the rest, and are the type on which these latter are formed, which 
 are, however, less perfect and much less complex. We now proceed 
 to describe the respiratory organs, in which the nutritious fluid formed 
 in the first is in general perfected. 
 
 The vocal apparatus is so connected with the organs of respiration 
 that it occupies the summit of the canal by which these latter commu- 
 nicate with the air by the cavities of the nose and mouth, and it is in 
 fact only a development of the upper extremity of this canal. It is 
 then most convenient to begin with it. 
 
 ARTICLE FIRST. 
 
 ORGANS OF VOICE. 
 
 § 2247. The organs of voice(l) are composed principally of the 
 larynx, in which the voice is formed, although it is modified in differ- 
 ent modes when passing through the cavities of the nose and mouth, 
 which are situated before it. 
 
 I. LARYNX GENERALLY IN THE PERFECT STATE. 
 
 § 224S. The larynx is an oblong, quadrangular cavity, formed of 
 several cartilages, of ligaments which unite them, of muscles which 
 
 (1) Galen, Vocalium instrumentorum disscctio: in the Opp. omn. — Fabricius of 
 Aquapendente, De visione, voce, etauditu: Id., De laryngé vocis instrumenta: in the 
 Opp. omn.^—3. Casserio, De vocis auditusqvc organis , Ferrare, 1600. — D. Santorini, 
 De laryngé : in the Obs. anat., c. vi. — A. F. Walther, De laryngé et voce , Leipsic, 
 1740.— R. A. Vogel, De laryngé humano et rocis formatione, Erfurt, 1747.— J. G. 
 Runge, De voce ejusque organis, Leyden, 1753. — Hérissant, Recherches sur les or- 
 ganes de la voix des quadrupèdes et de celle des oiseaux : in the Mêvti. de Daris , 
 1753.— J. M. Busch, De mec/ianismo organi vocis hujusque functione, Groningen, 
 1 770. — Vicq-d’Azyr, De la structure des organes qui servent à la formation de la 
 voix, considérée dans l'homme et dans les différentes classes d’animaux : in the 
 Mém. de Paris, 1779, p. 178-206.— J, WolfT, Diss. de organo vocis mammalium, 
 Berlin, 1812. 
 
324 
 
 DESCRIPTIVE ANATOMY. 
 
 move them, and of a mucous membrane which covers them in every 
 part, after which it is continuous upward with the buccal membrane, 
 below with that of the trachea. This cavity gradually contracts a 
 little from above downward. It is situated at the upper and anterior 
 part of the neck, below and behind the lower jaw, between the trachea 
 and the cavities of the nose and mouth, of which it is the direct conti- 
 nuation. 
 
 A. CARTILAGES OF THE LARYNX. 
 
 § 2249. There are nine cartilages which form the base of the 
 larynx, three of which are unmated and six exist in pairs. The pairs 
 are situated on the sides ; the unmated are divided by the median line 
 into two equal halves, a right and a left. 
 
 The unmated cartilages are the largest, and principally form the 
 whole larynx. They are the thyroid and cricoid cartilages, and the 
 epiglottis. The pairs are the arytenoid , the rounded , or the tubercles 
 of Santorini , and the cuneiform cartilages. 
 
 I. THYROID CARTILAGE. 
 
 § 2250. The thyroid cartilage (C. thyroidca ), the largest of the car- 
 tilages of the larynx, forms its upper and anterior part, produces at the 
 upper part of the neck, a prominence called Adam's apple. It is an ob- 
 long quadrilateral plate, more broad than high, and composed of two 
 lateral halves, which unite forward on the median line, where the angle 
 they form is more acute in the male than in the female. Hence this 
 layer is very convex forward and very concave backward, where it is 
 open. 
 
 Its upper edge is very convex ; it however presents in its centre a 
 deep groove, so that the cartilage is lower in this place. 
 
 Its lower edge is very convex : it is formed on each side of two 
 superficial grooves, separated by a median prominence. 
 
 The posterior edges are loose ; they extend upward and downward 
 into two elongated horns, which are rounded and turned backward, 
 and which are distinguished into upper and lower. The upper horns 
 are longer and thinner than the lower. 
 
 We observe on the outer face of the cartilage at the base of the 
 upper horn a considerable triangular prominence, whence arises an 
 oblique line which descends from behind forward to the lower edge, 
 and which separates the posterior sixth of each half of this external 
 face of the five anterior sixths. 
 
OF THE ORGANS OF VOICE. 
 
 325 
 
 II. CRICOID CARTILAGES. 
 
 § 2251. The cricoid cartilage (C. cricoidea, s. annularis ), which 
 forms the lower part and a portion of the posterior part of the larynx, is 
 circular, as its name indicates, and about three times higher posteriorly 
 than anteriorly. It is convex forward, and on the sides are depres- 
 sions which render the surface corrugated, and on its upper edge is a 
 sharp prominence which inclines outward. 
 
 The posterior part is irregularly quadrilateral and broader below 
 than above. Its anterior face is uniformly concave ; the posterior is 
 loose and very prominent in the centre, especially below. 
 
 We there observe a depression on each side, and it presents a plane 
 articular facet where it unites with the side. 
 
 Its upper edge also enlarges on each side into a plane articular facet 
 which is inclined from above downward. 
 
 III. ARYTENOID CARTILAGES. 
 
 § 2252. The arytenoid , triangular , or pyramidal cartilages (C. ary- 
 tœnoideœ , s. triquelrœ , s. pyramidales ) have an elongated triangular 
 form. Their anterior face is convex and uneven, and divided by a 
 transverse prominence into a superior and an inferior depression. 
 
 The posterior has about the same extent as the anterior, and is 
 concave. The internal is much smaller than the other two, and is 
 slightly convex. 
 
 These two cartilages are fitted by their concave base to the sides of 
 the upper articular facets of the cricoid cartilage (§ 2251). 
 
 IV. ROUND CARTILAGES. 
 
 § 2253. On the summit of each arytenoid cartilage is a much 
 smaller, and also triangular cartilage, termed the tubercle of Santorini, 
 or the round or horny cartilage (corniculum, s. capilulum Santorinia- 
 nwn),(l) the convex face of which looks forward, and the internal 
 backward. Its lower face is concave, rests on the convex summit of 
 the preceding, and is articulated with it by a loose capsular ligament, 
 some fibrous ligaments of which add to its solidity. 
 
 V. CUNEIFORM CARTILAGES. 
 
 § 2254. The cuneiform cartilages (C. cunéiformes ) are slightly 
 curved on themselves. Their bases are turned upward, and their sum- 
 mits downward. They are situated in the centre of the membranous 
 expansion extended between the arytenoid cartilages and the epiglottis. 
 
 VOL III. 
 
 (1) Loc. cit., p. 97. 
 42 
 
326 
 
 DESCIUETIVE ANATOMY. 
 
 VI. EPIGLOTTIS. 
 
 § 2255. The epiglottis ( epiglottis , s. ligula ), a very soft cartilage, is 
 nearly rhomboidal ; its lower part is pointed, and terminates by a su- 
 perficial groove, and is situated directly above the groove of tlie upper 
 edge of the thyroid cartilage. Its length exceeds its breadth, and it is 
 much thinner from before backward than in any other direction, except 
 at its centre. It presents numerous openings, through which pene- 
 trate small muciparous glands, which open on these two faces. Its 
 elasticity, and the ligaments to be described, cause it generally to he 
 perpendicular, and to rise towards the isthmus of the fauces : but the 
 weight of the substances which pass on it, and the action of special 
 muscles, depress it, so that it covers the entrance of the larynx. 
 
 The epiglottis prevents the entrance of foreign bodies, especially 
 the food and drink, from the cavity of the nose, and particularly the 
 mouth, into the larynx. Although pathological observations, in regard 
 to the absence of this cartilage,(l) and experiments, where deglutition 
 has not been impeded by removing the epiglottis, when the nerves and 
 muscles of the glottis were preserved, while it was very difficult when 
 these nerves were divided, the epiglottis remaining entire ;(2) although 
 all these facts(3) prove that the closing of the glottis also partially con- 
 tributes to prevent the food from falling into the larynx, it does not fol- 
 low that the epiglottis does not fulfill the function attributed to it by 
 every physiologist since the time of Aristotle. This function, in regard 
 to which we quote a lively, but perfectly correct remark of Casscrio,(4) 
 has been doubted by Magendie, whose opinion has been contested by 
 Mayer, from observations carefully made upon himself.(5) 
 
 (1) Targioni Tozzetti, Prima raccolta di osservazioni, Florence, 1752.— Magendie, 
 Précis de physiologie , vol. ii. p. 63. 
 
 (2) Magendie, Mémoire sur l'usage de l'épiglotte dans la déglutition, Paris, 1813. 
 
 (3) C. T. F. Reichel ( Diss . de usu epiglottidis, Berlin, 1816) has observed, con- 
 
 trary to Magendie’s assertion, that removig the epiglottis always rendered deglu- 
 tition difficult in those animals where it wa3 removed. On this subject, Rudolphi 
 mentions the case of a man who died of laryngeal phthisis, in whom the epiglot- 
 tis was destroyed so that but a small portion of its base remained. This man 
 found it very difficult to swallow: he was obliged to mix drinks with his food 
 to form akind of pulp, which was introduced into the stomach with difficulty. G. 
 Sachse relates several cases, which prove that deglutition is always very much im- 
 peded in laryngeal phthisis. (Beiträge zur genauem Kcnntniss und Unterschei- 
 dung der Kchlkopfs-und Lujtrührcnschwindsuchlcn, Hanover, 1821). Farther, 
 Rudolphi attributes to the epiglottis another use also : he thinks that this cartilage 
 serves also in those animals who breathe through the nostrils, the mouth being 
 closed, to favor the entrance of the air into the larynx, by presenting a more direct 
 way than through the cavity of the mouth. F. T. 
 
 (4) Loc. cit., De epiglottide, c. xvii., 'Palis structura , talc officium, ut stupidus 
 ille, vecorsque did mereatur, quern non corum consideratio, allonilum quasi, in ad- 
 mirationem Dei rapiat. 
 
 (5) Ueberdic Function, des Kehldeckels, in the Salzburger Zeitung, 1814, vol. iii. 
 p. 156. 
 
OF THE ORSANS OF VOICE, 
 
 327 
 
 H. LIGAMENTS OF THE LARYNX. 
 
 § 2256. The cartilages of the larynx are united with each other, 
 and with the hyoid bone and trachea, by capsules, fibrous ligaments, 
 and compact Cellular tissue. 
 
 L SPECIAL LIGAMENTS. 
 
 A. BETWEEN THE THYROID AND CRICOID CARTILAGES. 
 
 § 2257. The thyroid and cricoid cartilages are united by three liga- 
 ments, a central or pyramidal, and two lateral. 
 
 a. Middle crico-tbyroid ligament. 
 
 § 2258. The middle crico-thyroid ox pyramidal ligament (L. conoi- 
 deum , s. thyreo-cricoideum medium ), is short, fibrous, strong, and trian- 
 gular. Its base looks downward, and its blunt summit upward. It 
 fills the space between the centre of the lower edge of the thyroid car- 
 tilage, and that of the upper edge of the cricoid cartilage. 
 
 It prevents the cricoid and thyroid cartilages from separating from 
 each other too far upward and downward. 
 
 b. Lateral tbyro-cricoid ligament. 
 
 § 2259. The lateral thyro-cricoid ligament (L. thyreo-cricoideum 
 laterale ) is loose, composed of fibres, which are oblique from above 
 downward, and situated between the lower horn of the thyroid carti- 
 lage and the lower articular facet of the cricoid. 
 
 Its uses are the same as those of the preceding. It serves, however, 
 also to confine the motions of the two cartilages forward and backward. 
 
 B. LIGAMENTS BETWEEN THE THYROID CARTILAGES AND HYOID BONE. 
 
 a. Middle thyro-hyoid ligament. 
 
 § 2260. The middle thyro-hyoid ligament ( L . thyreo-hyoideum me- 
 dium) is a broad layer of compact cellular tissue, which descends from 
 the posterior edge of the body of the hyoid bone, to the middle groove 
 of the upper edge of the thyroid cartilage. 
 
 b. Lateral thyro-hyoid ligament. 
 
 § 2261. The lateral thyro-hyoid \igo.ment (L. thyreo-hyoideum late- 
 rale) is oblong, rounded, and formed of longitudinal fibres. It extends 
 
32S 
 
 DESCRIPTIVE ANATOMY. 
 
 from the summit of the upper horn of the thyroid cartilage, to the ex- 
 tremity of the great horn of the hyoid bone. At about its centre, but 
 generally nearer the upper than the lower edge, it contains a small 
 rounded and oblong cartilage, or bone (C. tritica), which, in fact, be- 
 longs to the class of the cartilages or bones of the tendons. 
 
 C. LIGAMENT BETWEEN THE CRICOID AND ARYTENOID CARTILAGES. 
 
 § 2262. Each arytenoid cartilage is united by its lower face to the 
 upper articular facet of the cricoid cartilage, by a loose synovial cap- 
 sule, strengthened at intervals by ligamentous fibres. 
 
 D. LIGAMENT BETWEEN THE ARYTENOID AND ROUND CARTILAGES. 
 
 § 2263. These two cartilages are united by a very loose, and often 
 slightly apparent capsule, on the surface of which pass ligamentous 
 fibres. • 
 
 I 
 
 E LIGAMENTS OF THE EPIGLOTTIS. 
 
 a. Epiglotli-byoid ligament. 
 
 § 2264. The epiglottis is united to the upper edge of the middle 
 hyoid bone by a compact cellular tissue, termed the epiglotti-hyoid 
 ligament (L. epiglotti-hyoideum) . 
 
 b. Thyro-epiglottid ligament. 
 
 § 2265. The thijro-epiglottid ligament (L. ihyreo-epiglottideum ) is 
 strong and fibrous. It extends from the lower extremity of the epi- 
 glottis to the groove in the upper edge of the thyroid cartilage. 
 
 F. LIGAMENTS BETWEEN THE THYROID AND ARYTENOID CARTILAGES. 
 
 § 2266. We find on each side, between the arytenoid and thyroid 
 cartilages, one above the other, two ligaments, directed from behind 
 forward, from above downward, and from without inward, which are 
 situated some lines from each other, and are termed the thyro-arytenoid 
 ligaments (L. thyreo-cinjlenuidea). 
 
 a. Inferior thyro-arytenoid ligament. 
 
 § 2267. The inferior thyro-arytenoid ligament (L. thyreo-arytenoi- 
 deum inferius ), is much larger than the upper, and is composed of very 
 distinct fibres. It extends from the upper and prominent end of the 
 anterior edge of the inner face of the arytenoid cartilage, to the lower 
 
OF THE ORGANS OF VOICE. 
 
 329 
 
 part of the posterior face of the thyroid cartilage, and is attached in 
 this place, directly at the side of its mate, above the groove of the 
 lower edge. 
 
 These two ligaments are generally more developed in the male than 
 in the female, and are termed the vocal cords, or ligaments of the glot- 
 tis ( L . vocalia , s. glottidis ), and the fissure between them is termed 
 the glottis (glottis, s. rima glotlidis). 
 
 b. Superior tliyro-arytenoid ligaments. 
 
 § 2268. The superior thyro-arytenoid ligaments (L. thyreo-arytenoi- 
 deora superior um, s. vcntricula laryngis) are situated farther outward 
 and upward, between the centre of the anterior face of the arytenoid car 
 tilage, and the angle of the thyroid cartilage. Those of the two sides 
 are more remote from each other, are looser and much less evidently 
 fibrous than the two preceding. They are distinguished only because 
 the mucous membrane of the larynx is reflected outward, and forms a 
 depression between them and these latter. 
 
 C. MUCOUS MEMBRANE AND GLANDS OF THE LARYNX. 
 
 § 2269. The larynx is covered internally by a reddish and smooth 
 mucous membrane, which is uninterruptedly continuous above with that 
 of the cavity of the mouth, and below with that of the trachea. The 
 outer face of this membrane contains muciparous glands, which vary 
 in size, and are united in bundles. One of these glands, the a7'ytenoid 
 (G. arytenoidea), is situated before the arytenoid cartilage. Another 
 is larger, imbedded in the midst of fat, and is termed the epiglottid 
 gland ( G. epiglottidea ) ; it occupies the space between the epiglottis, the 
 tongue, and the hyoid bone. It opens by from twenty to thirty excre- 
 tory passages, which pass through the epiglottis, and the origins of 
 which are easily seen on the inner face of the mucous membrane and 
 the epiglottis. 
 
 § 2270. The mucous membrane forms on each side a considerable de- 
 pression, termed the ventricle of the larynx ( ventriculus laryngis). This 
 depression is situated between the superior and inferior thyro-arytenoid 
 ligaments ; it is at most but one line deep; and two broad. It extends 
 then much farther from before backward, than in any other direction, 
 It is covered below by a considerable number of muciparous glands. 
 
 D. MUSCLES OF THE LARYNX. 
 
 § 2271 . The muscles of the larynx are divided into those which 
 move the whole apparatus, and those which move some of its carti- 
 lages. 
 
330 
 
 DESCRIPTIVE ANATOMY. 
 
 I. GENERAL MUSCLES OF THE LARYNX. 
 
 § 2272. The general muscles of the larynx are the sterno-thyroideus 
 and the hyo-thyroideus. 
 
 a. Sterno-thyroideus. 
 
 § 2273. The sterno-thyroideus muscle (M. bronchitis ), is thin, ob- 
 long, and considerably contracted from below upward. It arises from 
 the posterior face of the handle of the sternum, and the inner part of 
 the posterior face of the cartilage of the first rib, ascends directly before 
 the trachea, covered by the sterno-hyoideus muscle, and is attached 
 by an oblique edge, formed of very short tendinous fibres, to the oblique 
 line of the thyroid cartilage. It is generally blended at its outer part 
 with the thyro-hyoideus muscle, and it is cleft in a greater or less 
 extent. 
 
 Its external face generally presents, some distance from its lower ex- 
 tremity, a transverse or oblique tendinous intersection. 
 
 Sometimes there are two of these muscles placed one above the 
 other.(l) It depresses the larynx, by acting on the thyroid cartilage. 
 Its union with the following muscle causes it to depress the hyoid 
 bone. . 
 
 b. llyo-tLiyrokleus. 
 
 § 2274. The hyo-thyroideus muscle has an oblong square form : it 
 gradually contracts from below upward, and at the same time becomes 
 thicker in the same direction. It arises from the oblique line of the 
 thyroid cartilage, directly above the upper edge of the preceding, and 
 ascends along the outer part of the lateral face of the thyroid cartilage, 
 to arrive at the great horn of the hyoid bone, and is attached to the 
 anterior part of the lower face. 
 
 It raises the thyroid cartilage and the larynx, when the hyoid bone 
 is fixed, and depresses it when the latter is not fixed, so that it con- 
 tributes by the first of these two actions, to produce acute sounds, and 
 by the second to deglutition. 
 
 II. SPECIAL MUSCLES OF THE LARYNX. 
 
 § 2275. The special muscles of the larynx are those which dilate 
 and contract the glottis. 
 
 A. MUSCLES WHICH DILATE THE GLOTTIS. 
 
 a. Crico-thyroideus. 
 
 § 2275. The crico-thyroideus muscle (M. crico-thyroideus, s. dila- 
 tator glottidis anterior ), is very small, and nearly rhomboidal, and its 
 
 (1) Gunz, Ohs. anat., in the Mém. prés, a Vac. des sc., vol. i. p. 286. 
 
or THE ORGANS OF VOICE. 
 
 331 
 
 figure is a slightly inequilateral square. It is covered by the sterno- 
 thyroideus muscle, and is situated between the lateral faces of the thy- 
 roid and the lower edge of the cricoid cartilage. It arises from the 
 lower edge and the lateral face of this latter. Its fibres are directed 
 obliquely from below upward, and from before backward, and are often 
 divided into two distinct fasciculi, an anterior and a posterior. It is 
 attached by a short tendon to the lower edge, and the inferior horn of 
 the thyroid cartilage. 
 
 It is used to draw the sides of the thyroid cartilage downward and 
 outward, so that it enlarges the glottis. 
 
 6. Crico-arytenoideus. 
 
 § 2277. The crico -ary tenoideus muscle (AI. crico-arytcnoides, s. dila- 
 tator glotlidis posticus ), is rhomboidal, and fills most of the posterior 
 face of the cricoid cartilage. It arises from its whole extent, ascends 
 from within outward, and is attached by a short tendon to the outer 
 edge of the arytenoid cartilage. 
 
 It draws this cartilage outward, turns it a little on its axis, and thus 
 dilates the glottis, especially at its posterior part. 
 
 B. MUSCLES WHICH DILATE THE GLOTTIS. 
 
 a. Crico-arytenoideus lateralis. 
 
 § 2278. The crico-arytenoideus l at trails muscle is small, and of an 
 elongated triangular form. It extends obliquely from before backward, 
 and from below upward, from the posterior part of the upper edge of 
 the lateral portion of the cricoid cartilage, to the lower part of the outer 
 face of the arytenoid cartilage. 
 
 b. Arytenoides obliquus et transversus. 
 
 § 2279. The arytenoides obliquus and transversus muscles being 
 united very intimately, should be considered as forming a single mus- 
 cle, the different layers of which do not follow the same direction. 
 
 The oblique fibres form the two posterior and weaker layers. They 
 arise from the lower part of the outer edge of the arytenoid cartilage, 
 above the insertion of the crico-arytenoideus muscle, ascend obliquely 
 towards the opposite side, and becoming broader and thinner, are 
 attached to the outer edge of the arytenoid cartilage of the op- 
 posite side. 
 
 The fibres which come from the left arytenoid cartilage, usually 
 cover those arising from the cartilage of the other side. 
 
 The transverse fibres are partly covered by the preceding, and are 
 attached by their two edges to the posterior face and the external edge 
 of the two arytenoid cartilages. 
 
332 
 
 DESCRIPTIVE ANATOMY. 
 
 All these fibres bring together forcibly, the two arytenoid cartilages, 
 and thus contract 'the glottis, especially at its posterior part, in a 
 transverse direction. 
 
 c. Thyro-arytenoideus. 
 
 § 2280. The thyro-arytenoideus muscle (AI. thyro-arytenoideus) is 
 very elongated ; it arises from the centre of the inner face of the thy- 
 roid cartilage, from the pyramidal ligament, sometimes also from the 
 lower part of the epiglottis, goes backward and a little upward, and is 
 inserted at the lower part of the outer edge of the arytenoid cartilage, 
 directly above the upper extremity of the crico-arytenoideus lateralis 
 muscle, with which it is blended. 
 
 Sometimes we observe, still higher, another and smaller synonymous 
 muscle. 
 
 These two muscles draw the arytenoid cartilage forward, and thus 
 contract the glottis from before backward. They diminish the extent 
 of the glottis more than any other muscle. The fibres which go to 
 the epiglottis, are inserted in this cartilage. 
 
 cl. Thyro-epiglotticus. 
 
 § 2281. The thyro-epiglotticus, or the depressor cpigloilidis muscle, 
 arises from the centre of the inner face of the thyroid cartilage, and is 
 inserted on the lateral edge and the lower part of the epiglottis. 
 
 There is sometimes a smaller one, which arises farther inward and 
 upward. 
 
 These two muscles depress the epiglottis. 
 
 F. NERVES OF THE LARYNX. 
 
 § 2282. The nerves of the larynx arise from the pneumo-gastric 
 nerve, and are the superior laryngeal and the inferior laryngeal or re- 
 current nerve. Both are distributed in the mucous membrane and in 
 the muscles.(l) 
 
 (1) Magendie (Physiologie, vol. i., p. 206) and Cloquet (Traité d' anatomic, vol. ii., 
 p. 622) think the first of these nerves goes wholly or nearly so to the crico-thyroidei 
 posticus and laterales muscles, and also to the thyro-arytenoideus. Hence, whether 
 the different muscles contract or dilate the glottis, they receive all their filaments 
 from one of these two nerves, and completely dividing or tying them, enfeebles the 
 voice, which is entirely lost when both are divided. Kudolphi ( Physiologie , vol. ii., 
 p. 376) remarks that this description is incorrect, and that we must adopt that of 
 Andcrsch and Scemmcrring, whose neurology is followed by Meckel. In fact, the 
 superior laryngeal nerve anastomoses by some twigs with the recurrent nerve within 
 the larynx ; the two nerves send twigs also to the muscles which contract and dilate 
 the glottis, and the recurrent nerve sends some to the crico-thyroideus muscle. An- 
 dersch (Tract, de nervis hum. corp. aliquibus, p. i., Koningsberg, 1797, p. 60) men- 
 tions a case where the two nerves did not anastomose in the larynx, but expressly 
 
OF THE ORGANS OF VOICE. 
 
 333 
 
 G. FUNCTIONS OF THE LARYNX. 
 
 § 2283. The mucous membrane of the larynx is extremely suscep- 
 tible, on account of the great number of nerves which it receives, par- 
 ticularly in the region of the glottis. This sensibility prevents foreign 
 bodies from entering the trachea, where they would inevitably cause 
 suffocation. It is curious that it is so developed only at the upper 
 paît of the air-passages, and that the mucous membrane of the trachea 
 does not possess it. 
 
 The vitality of the larynx is manifested principally by its motions, 
 which are of two kinds. In fact ; 
 
 1st. They extend to the whole system, or are confined to some of 
 its component parts. 
 
 2d. They move in several different cases, and are connected with 
 several functions. 
 
 The general motions of the larynx vary its relations with the adja- 
 cent parts, according as it is drawn upward, downward, forward, or 
 backward. The partial motions change the mutual relations of its 
 constituent parts, and vary particularly the form and extent of the 
 glottis. 
 
 The whole larynx moves in speaking and deglutition. 
 
 During deglutition, the larynx is drawn forward and upward, as we 
 have already explained, which prevents the food from entering it. 
 
 In speaking, the larynx rises in acute sounds, both to raise the thy- 
 roid from the cricoid cartilage, and thus to contract the glottis, and at 
 the same time to tense its ligaments, so as to lengthen and contract the 
 trachea. In low tones, on the contrary, it is depressed to produce op- 
 posite changes. 
 
 The partial motions are connected with deglutition, respiration, and 
 speaking. 
 
 In fact, in deglutition, the glottis is so contracted by the action of its 
 constrictor muscles, that, even were the epiglottis absent, the food 
 would not necessarily and constantly fall into the air passages. 
 
 In respiration, the glottis is dilated during inspiration, and contracted 
 in expiration ; these changes constantly occur, even when the voice 
 
 states that this is not the common' arrangement. When it may be as true that it is 
 not, says Rudolphi, that the constrictor muscles and those which dilate the glottis 
 receive distinct branches from the par vagum, what must we conclude ? One nerve 
 causes the contractions in muscles which contract and those which dilate the glottis j 
 it is then unimportant which these museles receive. But the fact that the same 
 muscle receives twigs from the upper and from the lower nerve is very important, 
 since the action may take place in one direction when a ligature or section prevents 
 it in the opposite, and it is still more so as the pneumo-gasti ic nerve anastomoses- 
 above and below with the great sympathetic nerve, and above with the glosso-pha- 
 ryngeal, the accessory, and the hypogastric nerves, so that the inner nerves of the 
 larynx certainly come from several different sources. F. T. 
 
 VOL. III. 
 
 43 
 
334 
 
 DESCRIPTIVE ANATOMY. 
 
 cannot be formed, on account of an opening in the Irachea.(l) Far- 
 ther, this is not surprising, since they coincide with analogous changes 
 which supervene simultaneously in the trachea, of which the larynx 
 must be considered the upper enlarged and more developed part. 
 
 From Legallois’ experiments the closing of the glottis is the cause 
 of rapid death in suffocation, which occurs in certain cases from di- 
 viding the pneumo-gastric nerve or the laryngeal branch, particularly 
 in youth, as in such states the glottis always appears very much con- 
 tracted.^) 
 
 The fact is correct, but the mode of explaining it by the paralysis of 
 the arytenoidei muscles is only partially true. The contraction and 
 even the closing of the glottis from Ihe paralysis of the muscles to 
 which the recurrent nerve is distributed, seems to depend rather on the 
 predominance of the muscles, the nerves of which are unaltered, and 
 therefore caused only in part by the paralysis. 
 
 In fact in animals of a certain age, in which the operation is less 
 dangerous on account of the size of the glottis, this opening is almost 
 entirely closed after dividing the two recurrent nerves, while it is closed 
 but imperfectly when the superior laryngeal nerves are cut, and the 
 power of forming it is lost after separating all the nerves of the la- 
 rynx.(3) 
 
 The special motions of the larynx are very remarkable in forming 
 the voice. 
 
 At each tone the glottis contracts, and the more the louder the tone 
 is. (4) The contraction occurs particularly from one side to ihe other ; 
 sometimes also from before backward, and often in every direction at 
 once. 
 
 § 2284. The larynx is the organ of the voice. This is proved : 
 
 1st. By the loss of voice, without any derangement in the respira- 
 tion, when the trachea presents an opening through which the air 
 enters and emerges in inspiration and expiration. 
 
 2d. By the diminution or the total loss of voice when some parts of 
 the larynx, as the vocal cords have been destroyed, or the arytenoid 
 or cricoid cartilages, or the laryngeal nerves are divided. 
 
 3d. By the differences in the voice, dependent on those in the ar- 
 rangement of the parts of the larynx. 
 
 The voice is formed in the glottis, since the power of producing it is 
 lost when the crico-thyroid ligaments are divided, and the removal of 
 the upper half of the arytenoid cartilages and the longitudinal section 
 
 (1) Bichat, Anat. descript., 1802, vol. ii., p. 405. — Legallois, Exp. sur !c principe de 
 la rie, Paris, 1812, p. 198. — L. Mende, Lieber die Bewegung der Stimmritze beim 
 Athemholen, eine neue Entdeckung ; mit beygefügten Bemerkungen über den. 
 Nutzen und die Verrichtung des Kehldeckels , Gripswald, 1816. 
 
 (2) Leg'allois, p. 197. 
 
 (3) Magendie, Sur l’épiglotte, p. 4. 
 
 (4) Ferrein (M ém. de Paris, 1741, p. 559) has already opposed the opinion hitherto 
 existing, viz. that the contrary is true. Bichat has followed in the same track (Anat. 
 dcscr., vol. ii., p. 408). 
 
©F THE ORGANS OF VOICE. 
 
 335 
 
 of the thyroid cartilage produces the same effect, which is always ob- 
 served iu the contraction of the glottis in crying, as the destruction of 
 the upper ligaments has no effect on the voice, and as these ligaments 
 likewise are always too far from each other to contract the glottis(l) 
 transversely. 
 
 § 2285. We have now to determine how the voice is formed in this 
 place. Some suppose it is owing to the vibrations of the air, as in a 
 wind-instrument. (2) Others assert that it is produced by the vocal 
 cords, as in a stringed instrument.(3) Finally, several have combined 
 these two theories. (4) 
 
 The first has been supported : 
 
 1st. By the analogy of the air-tube with a wind instrument, in 
 which the formation of the different sounds is produced by modifying 
 the diameter of the opening. 
 
 2d. By the comparison with the lips, where the same conditions 
 occur. 
 
 3d. By different experiments proving : 
 
 a. That the tension or relaxation of the vocal cords has no effect on 
 the acute or grave character of the sound, inasmuch as the glottis is 
 dilated or contracted by them. 
 
 b. That when one of the vocal cords is tense and the other relaxed, 
 they do not produce two different sounds, but one sound, the acuteness 
 of which is proportional to the breadth of the glottis. 
 
 c. That the tone does not change when we touch the vocal cords. 
 
 d. That the contraction of the glottis is sufficient to render the tone 
 more acute, and its dilatation to depress it, although the tension of the 
 vocal cords does not change, and independent too of their form. 
 
 e. That the sound is independent of the force with which the air 
 leaves the lung. 
 
 f. That no tones are formed when the glottis is very much dilated, 
 and the vocal cords are very tense, and the air is forcibly expelled from 
 the lung.(5) 
 
 (1) E. Grasinow lias asserted (Russiche Jahrbücher, vol. ii., pt. i., p. 125-143) that 
 the voice is formed in the trachea. Burdach has refuted this absurd opinion (same 
 journal, p. 153-160). 
 
 (2) Fabricius of Aquapendente, De laryngé, p. ii., c. iv. Vocis opifcx, causa seu 
 organum inquiritur. — C. F. S. Liscovius, Diss. sistens theoriam vocis, Leipsic, 1814, 
 p. 28-37. 
 
 (3) Ferrein, De la formation de la voix dans Vhomme ; in the Mém. de Paris. 1 741, 
 p. 545. 
 
 (4) Galien, De vsu partium, vol. vii., p. 10. — Casserio, De laryngé, book ii., ch. 
 xiv., De glottide. — Dodart, Mém. sur les causes de la voix de l'homme et de ses diffé- 
 rens tons ; in the Mém. de Paris, 1700, p. 308. — Id., Supplémens aux mémoires sur 
 la voix et sur les tons; same journal, 1706, p. 169 and 500; 1707, p. 83. — Dodart, 
 however, attributes most influence to the vibrations of the air ; it is then difficult to 
 understand why modern physiologists, even neglecting Fabricius of Aquapendente, 
 should maintain that Ferrein’s opinion was the only one admitted, ana present the 
 theory a3 new, and more so because Ferrein directly opposes the hypothesis of 
 Dodart. 
 
 (5) Liscovius, he. cit., p. 29-34. 
 
33G 
 
 descriptive anatomy. 
 
 The second theory is supported : 
 
 1st. By the analogy of the vocal cords with stringed instruments^ 1) 
 
 2d. By experiments which have proved that the extent to which the 
 larynx was open had absolutely no effect, on the acute or grave charac- 
 ter of the sound,(2) while, on the contrary, the tone became acute as 
 the vocal cords were carried outward and extended by the air leaving 
 the lung, and was lower when the ligaments were compressed ; that it 
 is modified in the same manner when these ligaments are fixed on se- 
 veral points ; that the different tones are produced when the degree of 
 tension of the ligaments varied ; finally, that similar phenomena occur 
 when the ligaments of the larynx are entirely detached, except at 
 their tw 1 2 3 4 5 6 7 * 9 o extremities,(3) 
 
 Hence, the degree of openness of the larynx would not cause a dif- 
 ference in the sounds, but only in the volume of the voice. (4) 
 
 Very probably the third opinion is most correct, although the experi- 
 ments first mentioned prove, that the vibrations of the vocal cords con- 
 tribute less to produce the voice than those of the air passing through 
 the glottis ; they occur simultaneously, without being necessarily con- 
 nected with speaking, and the more as the larynx and trachea vibrate 
 very evidently when the air is blown in with force, although the voice 
 js not necessarily produced. (5) 
 
 The acuteness of the voice in the female corresponds very well with 
 the narrowness of the glottis, but not with the greater softness of the 
 vocal cords. 
 
 § 2286. But although the voice forms in the larynx, panicularly in 
 the glottis, the parts, however, before this opening, the epiglottis, the 
 cavity of the month, and the nasal fossæ, also assist to form it. 
 
 Doubtless the principal function of the epiglottis is to close the la- 
 rynx during deglutition, but very probably also it contributes to produce 
 the voice. 
 
 In fact Haller has refused to it, contrary to the opinion of Tam 
 \ - ry,(6) and Santorini, (7) all agency in phonation, not because it exists 
 before the fetus possesses a voice, (8) but because this latter is formed 
 in the larynx, consequently below the epiglottis, and because birds sing 
 although deprived of it. (9) 
 
 This view of the subject is supported by some experiments, which 
 demonstrate that the force of the voice does not change, although we 
 cut transversely between the larynx and the hyoid bone, draw the 
 
 (1) Ferrein, p. 566, 560. 
 
 (2) 14., p. 559. 
 
 (3) Fer roin, loc. cil. — Porta], Exp. sur la voix ! in bis Mémoires , vol. ii., p. 308. 
 
 (4) Ferroin, p. 558. 
 
 (5) Liscovius, p. 34. 
 
 (6) Nor. anal., Ulin, 1694, p. 408. 
 
 (7) De laryngé, § 10. 
 
 (9) Mayer, loc. cil,, p. 185, 186. 
 
 (9) Epiglottis cquidem nihil facial ad vocem.cum ea (rox) nat.a sit el perfecta 
 qua m primvm aer ex glottidis rima prodiit el absque epiglotlide arcs suaviseime 
 fçijiant (El phys., ). i x ., pt. i., § v., p. 572). 
 
OF THE ORGANS OF VOICE, 
 
 337 
 
 epiglottis outward, and thus place the glottis directly opposite the 
 external wound : that the removal of the top of this cartilage has no 
 influence on the voice generally,(l) and that its depression, its eleva- 
 tion, and even its entire removal, have no effect on the character of the 
 sounds.(2) 
 
 But these facts only demonstrate that the epiglottis is not absolutely 
 necessary to phonation. Farther, the argument drawn from birds 
 proves nothing, since their voice is formed in a lower larynx, and in 
 them the epiglottis may be replaced by the whole trachea and by the 
 superior glottis. 
 
 Finally, several observations and experiments, made with great care, 
 admit the conjecture that the epiglottis alone, or together with the soft 
 palate, contributes materially to the changes in the volume, tone, and 
 modulation of the voice, (3) since its situation, direction, and form ex- 
 perience changes like those remarked in this respect in the voice, and 
 we have no authority for admitting that these phenomena result from 
 other changes which occur in the larynx, an opinion probably pro- 
 fessed by Ferrein,(4) since the new organ of voice he maintains can 
 hardly be the soft palate.(5) 
 
 In regard to the cavities of the nose and mouth we may remark, 
 that the power and clearness of the voice are increased by its being 
 retained in these two cavities, as is easily seen from the difference 
 when the nose is stopped, or the pituitary membrane is swelled. 
 
 Farther, the different inflexions of the voice, which are termed let- 
 ters ,(6) are produced both by the larynx and the different parts of the 
 oral cavity. 
 
 The vowels are formed principally in the canal included between the 
 tongue and the palate. Their differences depend almost entirely on 
 those in the diameter of this canal, caused by the motions of the 
 tongue. 
 
 On the contrary, the epiglottis and the different parts of the mouth, 
 especially the lips and the soft palate, have great effect on the forma- 
 tion of the consonants. 
 
 II. SEXUAL DIFERENCES IN THE LARYNX. 
 
 § 2287. The larynx is one of the organs which presents most mani- 
 festly the differences of sex. That of the female is usually one third 
 and sometimes one half smaller than that of the male ; all its con- 
 stituent cartilages are much thinner : the thyroid cartilage also is even 
 flatter, because its two lateral halves unite at a less acute angle. 
 
 (1) Bichat, Anat. descript., vol. ii., p. 402, 404. 
 
 (2) Liscovius, p. 34. 
 
 (3) Mag-endie, Physiol., vol. i., p. 221. — Mayer, toe. cit. — Mende, loc. cit. 
 
 (4) JSur la formation de la voix ; in the Mem. de Paris, 1741, p. 574. 
 
 (5) Haller, loc. cit., p. 455. 
 
 (6) Kempelen, Mechanismus der menschlichen Sprache, nebst der Beschreibung 
 seiner sprecaenden Maschine , Vienna, 1791. 
 
338 
 
 DESCRIPTIVE ANATOMY. 
 
 Hence why the larynx in the male forms at the upper part of the neck 
 a prominence which is not visible in the female. From the same 
 cause also the groove in the upper edge is much more superficial in 
 this latter than in the male. 
 
 The glottis in the female is much smaller than in the male, and the 
 vocal cords are shorter. 
 
 III. DIFFERENCES IN THE LARYNX DEPENDENT ON AGE. 
 
 § 2288. The sexual differences we are about to mention do not ap- 
 pear until puberty : until then the larynx has precisely the same form 
 in the two sexes, and consequently the voice is nearly the same in 
 both. In eunuchs it is small as in females.(l) 
 
 This organ developes itself much more slowly than other organs, 
 and not proportionally with them : it seems less regular in respect to 
 its periods, so that the larynx is sometimes smaller in some children 
 than in others who are younger, although the growth of the others 
 corresponds perfectly to their age. 
 
 The larynx, especially the glottis, generally continues small for a 
 long time ; thus it differs but slightly in a child of three and one of 
 twelve years of age. But the difference is suddenly so great at the 
 period of puberty, that in the course of a year thè glottis doubles in 
 breadth and length. (2) 
 
 IV. ABNORMAL STATE OF THE LARYNX. 
 
 A. DEVIATIONS IN FORMATION. 
 
 § 2289. The whole larynx or some of its parts rarely present pri- 
 mitive deviations of formation. 
 
 We, however, must mention here its unusual littleness, which de- 
 pends on the permanence of its primitive formation, and which coexists 
 with the destruction or imperfect development of the testicles, (3) the 
 absence of the epiglottis, (4) the division of this cartilage, (5) the ab- 
 sence of the upper horns of the thyroid cartilage, (6) of the cricoid and 
 the arytenoid cartilages, (7) which is very curious as it establishes 
 an uncommon, resemblance between the larynx and the trachea : the 
 
 (1) Dupuytren, Hull, de la hoc. phil, , vol. ii., p. 195. 
 
 (2) Richerand, Recherches sur la grandeur de la glotte et sur l’état de la tunique 
 vaginale dans l'enfance ; in the Mém. de la soc. méd. d’émul. , vol. iii. p. 326. 
 
 (3) Dupuytren, Bull, de la soc. phil., vol. ii., p. 195. — Meckel, Handbuch der patho- 
 logischen Anatomie, vol. i., p. 485. 
 
 (4) Targioni Tozzelti, Prima raccolta, Florence, 1752. 
 
 (5) Meckel, loc. cit. 
 
 (G) Sandifort, Exerc. anat., 1. ii., ch. vii., p. G4. 
 
 (7) Roederer, De fceluparalylico ; in tlic Comm, soc. Gott., vol. iv., p. 136. 
 
OF THE ORGANS OF VOICE. 
 
 339 
 
 obliquity and curve of the epiglottis ;( 1 ) the imperfect division of the 
 larynx by a cord which is directed from above downward.(2) 
 
 The consecutive deviations of formation, (3) especially those depend- 
 ent on mechanical injury, are much more common than the primitive. 
 We must distinguish among them wounds in the larynx made by a 
 cutting instrument in suicide. Wounds of the epiglottis are generally 
 considered as fatal ; we however have one case before us, where this 
 cartilage was entirely divided longitudinally, and also cut transversely 
 in its right half ; but death did not ensue. This case is curious also 
 as it proves what we stated above, that the epiglottis is not absolutely 
 necessary to close the glottis. 
 
 Wounds of the larynx are very frequently fatal, from their conse- 
 quent irritation and inflammation, on account of its great sensibility. 
 
 Sometimes death occurs at the end of a certain time, being caused 
 by the abundant granulations which completely obstruct the glottis, 
 and which are formed in consequence of a wound which suppurates. (4) 
 
 The arytenoid cartilage is partially separated by a cutting instru- 
 ment, and thus hanging in the glottis, may cause death by suffo- 
 cation, like any other foreign body. (5) 
 
 The cartilages of the larynx are not necessarily fractured in persons 
 who die by hanging, although they are sometimes broken.(6) 
 
 B. ALTERATIONS IN TEXTURE. (7) 
 
 § 2290. The mucous membrane of the larynx either alone or with 
 that of other parts, particularly the cavity of the mouth and that of 
 the trachea, is often inflamed. Sometimes there is effusion, apd an 
 accidental membrane is formed, which more or less completely closes 
 the glottis, and the patient is suffocated. 
 
 In phthisis laryngea also ulcers often exist which destroy it in 
 a greater or less extent, and cause abnormal adhesions between it and 
 the pharynx. This state also may cause suffocation in more than 
 one way. But the swelling alone of the inflamed parts, without any 
 effusion or ulceration, may be fatal. (8) 
 
 (1) Atti di Siena, vol. iii., p. 232. 
 
 (2) Meckel, Handbuch der pathologischen Anatomie, vol. ii., pt. ii ., p. 140. The 
 case cited by Otto (Path, anat., p. 223), of a larynx divided into three, does not refer 
 to this, but to the trachea, which presented three branches instead of two (Sandifort, 
 Exerc. ac., p. 65). 
 
 (3) G. Beil, Cases of diseases and wounds of the larynx ; in his Surgical observa- 
 tions, London, 1817, p. 1. 
 
 (4) Bell, loc. cit., p. 44. 
 
 (5) Ibid. 
 
 (6) Morgagni cites one case of rupture of the cricoid cartilage (Ep. anat. med., 
 vol. xix., p. 13). 
 
 (7) Bell, loc. cit, — Howship, On the affections of the larynx ; in the Practical obser- 
 vations in surgery, London, 1816, p. 14. 
 
 (8) ; Howship, loc. cit., p. 153. 
 
340 
 
 DESCRIPTIVE ANATOMY. 
 
 The cartilages of the larynx are more subject than any others to 
 ossify, and consequently to be affected with all the diseases peculiar 
 to the bones. 
 
 Among the new formations cysts are not unfrequent in this organ, 
 although much less common than the preceding anomalies. Some- 
 times they belong to the class of hydatids ; there is more or less danger 
 of suffocation from them by closing the glottis. 
 
 C. FOREIGN BODIES. 
 
 § 2291. As substances which pass into the stomach from the upper 
 part of the alimentary canal must necessarily pass over the epiglottis, 
 foreign bodies not unfrequently enter this organ, and thence pass into 
 the trachea. This happens particularly when we talk while eating, 
 as then the glottis is not closed. These foreign bodies soon occasion 
 death by suffocation. A case however has been mentioned where a 
 ducat continued two years in the larynx,(l) and another where a piece 
 of a nut-shell as large as a finger-nail remained there seven years. (2) 
 
 ARTICLE SECOND. 
 
 ORGANS OF RESPIRATION. 
 
 I. NORMAL STATE. 
 
 A. LUNGS. 
 
 i. PERFECT STATE IN GENERAL. 
 
 § 2292. The organs of respiration ( systenia respiralorium)(3) are 
 the lungs, which communicate with the external air by the trachea. 
 Beside the prolongations of the trachea, they are formed by the pulmo- 
 nary arteries and veins, by lymphatic vessels, nerves, and cellular tis- 
 sue between these two parts, and a serous envelop, the pleura. 
 
 (9) Hoechstetter, Obs. mcd., dec. vi., c. x. 
 
 (1) Tulp, Obs. -tried., 1. ii., c. vii. 
 
 (1) RI. Malpighi, De pulmonibus epistol. I. et II. ad A. Borellum, Bologna, 1661. 
 — Th. Bartholin, De pulmonum substantiel et motu distribe. Ace. M. Malpigkii de 
 pulm. obs. anat., Leyden, 1672. — Helvétius, Observations sur le poumon de L’homme ; 
 in the Alim, de Paris , 1718. — Wildrik, De f abrita pulmonum, Franekcr, 1761. — 
 Wohlfahrt, De bronchiis vasisque bronchialibus, Halle, 174.8. — Hildebrandt, De pul- 
 monibus, Gottingen, 1786. — Reisseissen, De pulmonum, structura, Strasburg-, -1803. 
 — Scemmerring’ and Rcisseissen, lieber die idtruclur die Verrichtung und den Ge- 
 brauch der Lungen, Berlin, 1808. 
 
OP THE RESPIRATORY SYSTEM. 
 
 341 
 
 A. FORM. 
 
 § 2294. The lungs ( pulmones ) have the form of an irregular cone, the 
 base of which looks downward and the summit upward. Their concave 
 base rests on the diaphragm ; their very convex external face is turned 
 towards the ribs ; the internal, which looks toward the heart, is corn 
 cave. 
 
 The anterior edge is blunt, the posterior is sharp. 
 
 Each lung is divided into two triangular lobes, an upper, smaller, a 
 lower, larger, by a deep groove which extends obliquely from above 
 downward and from behind forward, and which passes entirely through 
 it. Between these two lobes the right lung also presents a third, 
 much smaller, which is situated forward, and contracts much from before 
 backward. The left lung differs from that of the right side, as its 
 lower edge presents a groove in which the lower part of the heart is 
 situated. 
 
 Beside this difference in the form, the right lung is a little larger and 
 lower but broader than the left, and this in return is a little more elon- 
 gated. 
 
 Considered as a whole, the lung is divided into three, five, or six 
 lobes, irregular in form and volume, in the spaces of which proceed 
 the blood-vessels and the lymphatics, but the surface of which is not 
 uneven, or but slightly so. 
 
 § 2295. The posterior edge of each lung is cleft in most of its 
 length, and thus presents a depression, the upper half of which re- 
 ceives the bronchiæ, the blood-vessels, and the nerves, while the liga- 
 ments of the organ are attached to the inferior. 
 
 The pulmonary artery is situated first entirely on the summit 
 before the bronchia, and sends in this place a considerable branch 
 to the lung ; but it is soon directed backward, and passes behind the 
 bronchia. 
 
 The pulmonary veins are found entirely forward and downward, 
 excepting the smallest and lowest branches, which proceed behind the 
 lowest ramifications of the bronchiæ. 
 
 B. SITUATION AND ATTACHMENTS. 
 
 § 2296. The lungs are situated on the two sides of the heart. Each 
 is inclosed in a special serous sac termed the pleura, with the parietes 
 of which they are in perfect contact in every part, but do not adhere, 
 except at the part where this membrane is reflected to cover their ex- 
 ternal face. 
 
 Their upper extremity passes a little beyond the first rib. 
 
 VOL. III. 
 
 44 
 
842 
 
 DESCRIPTIVE ANATOMY. 
 
 C. COLOR. 
 
 The color of the lungs when a person is in good health, is grayish 
 red, more or less spotted with black. 
 
 D. TEXTURE. 
 
 § 2297. Among the different parts mentioned as composing the 
 lung, the trachea is the base of the others, and also the most impor- 
 tant, as the air passes through it to enter and emerge from the lung. 
 
 a. Trachea. 
 
 § 2298. The trachea ( tracheia ct arteria aspera ) is a canal about 
 four inches long and nine lines broad, which begins at the fifth cervi- 
 cal vertebra, below the larynx, and is covered only by some muscles, 
 particularly the sterno-hyoideus and the sterno-thyroideus. It is situ- 
 ated exactly on the median line, passes directly before the esophagus, 
 and descends directly into the chest, between the large vessels of the 
 head. Thence it gradually inclines toward the right side, so that its 
 left portion corresponds to the centre of the vertebral column, and di- 
 vides at an obtuse angle behind the arch of the aorta, about opposite the 
 third dorsal vertebra, into two lateral branches, termed bronchi or bron- 
 chiez. The right bronchia is generally eight lines broad, one inch 
 long, and the left is about half an inch broad, and two long. The di- 
 rection of this latter is more perpendicular than that of the other : it is 
 situated between the descending vena cava and the azygos vein. The 
 left turns below the arch of the aorta, and goes forward. 
 
 Each bronchia is covered with the pleura, proceeds obliquely from 
 above downward, and from without inward, toward its corresponding 
 lung, and on arriving there, divides into a superior and an inferior bron- 
 chia, each of which proceeds to a lobe. The lower branch of the right 
 bronchia also soon subdivides into two twigs, a superior, which is 
 smaller, and an inferior, which is larger, for the middle and the in- 
 ferior lobe. 
 
 "These canals ramify extensively within the lung, and represent a 
 tree, terminated in every part of the surface of the organ in culs-de-sac, 
 along which are distributed all the other component parts of the lung. 
 The final ramifications, which are the most minute, and terminate in a 
 cul-de-sae, are termed the pulmonary cellules ( cellulce pulmonares). 
 
 § 2299. The trachea is formed by very different parts, viz. by 
 fibrous tissue, cartilages, muscular fibres, and a mucous membrane. 
 
 a. Fibrous tissue. 
 
 § 2300. The fibrous tissue is composed of longitudinal fasciculi, 
 which do not form a continuous membrane, but leave between them nu- 
 
OF THE RESPIRATORY SYSTEM. 
 
 343 
 
 merous oblong spaces. It constitutes the outer face of the trachea, and 
 adheres intimately to the subjacent mucous membrane. Its vessels 
 are more numerous than those in the other fibrous organs, and thus it 
 resembles the fibrous tunic of the arteries. 
 
 From the great elasticity of this tissue, the trachea contracts to its 
 former dimensions, after being distended longitudinally. 
 
 b. Cartilage. 
 
 § 2301. The fibrous tissue of the trachea and of its ramifications, 
 inclose pieces of cartilage, placed successively from above downward, 
 on the two faces of which it passes, and adheres intimately. It, how- 
 ever, does not cover directly the. surface of these cartilages, which are 
 entirely developed by a special perichondrium. 
 
 The form, dimensions, and situation of these cartilages, vary in dif- 
 ferent parts of the trachea, and in its ramifications. 
 
 In the trachea they form imperfect rings, open at their posterior part, 
 which surround the anterior and lateral parts of the passage. These 
 rings are about two lines high, half a line thick, and an inch and a half 
 long. They circumscribe about the two thirds of the trachea when 
 in its greatest state of distension, and more than three fourths of its 
 circumference when it is collapsed. 
 
 The number of its cartilages varies from sixteen to twenty. 
 
 Their form is more regular and more constant at the centre of the 
 trachea than at its upper and lower extremities. In most of this canal, 
 they generally form rings of equal extent, and of about the same 
 height. 
 
 The first, on the contrary, is much higher than the others, and higher 
 at its anterior than at its posterior part. This arrangement establishes 
 rather a remarkable correspondence from before backward, between it 
 and the cricoid cartilage, in which there is an opposite arrangement. 
 
 This ring, also, is most generally united at its posterior extremity 
 with the second whence results an undoubted analogy with the type of 
 the formation of the larynx. 
 
 Sometimes there is a similar adhesion between the third and the 
 fourth ring, either on both sides, or more commonly on one only. 
 
 The lower rings, on the contrary, frequently present on one or both 
 sides, a greater or less fissure, that is, one which sometimes extends to 
 their lower extremity, and sometimes stops short of it. Frequently, 
 but not always, we then remark on the opposite side, a small segment 
 of an imperfect circle, which corresponds to one of the two halves 
 formed by the division, or a ring cleft on the other side, which in some 
 measure makes up for the want of symmetry. But we as commonly 
 find there a common and perfect ring, or one which is partly divided 
 in the same manner and on the same side. 
 
 The rings of the loose portion of the bronchiæ are generally similar 
 to the final cartilaginous rings of the trachea. 
 
344 
 
 DESCRIPTIVE ANATOMY. 
 
 There are generally but eight in the right bronchia, while there are 
 eleven or twelve in the left. As they approach the lungs, they be- 
 come more irregular, and are divided or blended with the rings ad- 
 jacent. 
 
 The number of the cartilages suddenly diminishes very much within 
 the lungs, so that the ramifications of the bronchiæ become more mem- 
 branous there. But, at the same time, these cartilages lose their re- 
 gular form : they cease to represent rings, and resemble layers which 
 are irregularly quadrilateral, triangular, &c. Besides, we find them 
 in all parts of the trachea. 
 
 They become smaller and rarer, in proportion to the gradual con- 
 traction of the ramifications of the bronchiæ. The last which are per- 
 ceptible have a rounded form. 
 
 We find none in those ramifications about one third of a line in 
 diameter, or at least they are extremely small, and scarcely percep- 
 tible. 
 
 Finally, the last ramifications of the bronchiæ are simply membra- 
 nous, and some lines below the surface of the lung, we find no trace of 
 cartilage, 
 
 c. Muscular fibres. 
 
 § 2302. The posterior part of the trachea is formed by a muscular 
 membrane, (1) which is about half a line thick when it is contracted. 
 This membrane is composed only of transverse fibres, which are at- 
 tached to the cartilaginous rings, and to the fibrous tissue between 
 them, so as to cover the inner face of these rings, and of this tissue 
 about from one to two lines. 
 
 Within the lung, where the cartilages are arranged irregularly, and 
 distributed on the whole extent of the bronchial tree, these muscular 
 fibres surround also the whole trachea. They increase inversely as 
 the cartilages, and they can be traced farther than these latter. 
 
 d. Mucous membrane. 
 
 § 2303. The fibrous tissue and the muscular tissue of the trachea 
 are covered in their whole extent by a thin mucous membrane, which 
 forms a continuous sac, and adheres intimately to the adjacent parts. 
 
 Its posterior face presents in the whole extent of the trachea, muci- 
 parous glands, arranged compactly, which are more numerous and 
 larger at the lower part of the trachea, where it bifurcates, and in the 
 portion of the bronchiæ and of the lungs. They are very near in these 
 different parts, and they are frequently as large as a bean. 
 
 They form a continuous layer, situated mostly behind the muscular 
 membrane, between the fibres of which their very short excretory pas- 
 
 (1) Eberhard, DLss. de musculis bronchialibus corumque in statu sano vel morboso 
 actione , Marburg, 1817. 
 
OF THE RESPIRATORY SYSTEM. 
 
 345 
 
 sages penetrate. This layer extends uniformly on the portion of the 
 trachea formed by muscular fibres, while the glands are principally 
 collected between the cartilaginous rings, so that after removing 
 these latter, we easily perceive the place they occupy by the spaces in 
 the glandular layer. 
 
 We must distinguish from these muciparous glands, the bronchial 
 lymphatic glands ( G . bronchiales), which are found in the same 
 places. 
 
 § 2304. The mucous membrane is the last part visible among those 
 which contribute to form the trachea and its ramifications, although 
 reason and observation unite to demonstrate that its irritability extends 
 beyond the points where its muscular texture disappears. 
 
 The most minute ramifications of the trachea, which are formed by 
 a homogeneous substance, terminate in a cul-de-sac, and are not con- 
 tinuous, as Helvetius asserts, with the cellular tissue which unites the 
 different organic parts of the lung. The trachea forms a hollow tree, 
 the twigs of which communicate by the branches, and the lattemLof 
 the trunks resulting from their union, but not by means of mucous iija 
 sue existing between these ramifications. This fact is established by 
 numerous dissections and experiments. 
 
 The minutest twigs of the bronchial tree, when filled with air or any 
 other fluid, present the same form and the same limits, either when ex- 
 amined with the naked eye, or with a microscope. If we fill a bron- 
 chia with air or any other fluid, so as to inject, for instance, a whole 
 lobe, and one of the secondary twigs is afterwards tied, the part of the 
 lung in which this latter is distributed remains swelled and distended, 
 while that where the bronchial twig is not tied soon collapses. 
 
 b. Blood-vessels of the lung's. 
 
 § 2305. The blood-vessels of the lungs are of two kinds. Most of 
 the organ is formed by the pulmonary arteries and veins, the first of 
 which carry venous blood, while the veins carry back to the left half 
 of the heart this fluid, which has been changed by the action of the air 
 into arterial blood, in the limit between the two systems. 
 
 The trunks of these vessels enter and emerge from the lungs at the 
 same point. 
 
 Even within the organ the pulmonary veins are nearer the bronchiæ 
 than the arteries are. 
 
 § 2306. The second order of blood-vessels includes the bronchial 
 arteries and veins ( vasa bronchialia), which are connected with the 
 nutrition of the lungs. We have already mentioned their origin. These 
 vessels are distributed in the substance of the lung, along the ramifica- 
 tions of the bronchiæ, rest on their surfaces, and surround them with 
 numerous plexuses. After supplying the muscular and the fibrous tis- 
 sue, they penetrate to the mucous membrane, into which they send 
 numerous ramuscules to the membranes of the pulmonary vessels, to 
 
346 
 
 DESCRIPTIVE ANATOMY. 
 
 the nerves of the lungs, and form a very minute and complex tissue on 
 the surface of all these parts, below the pleura. 
 
 It is very curious that the anastomoses occur, not only in this vas- 
 cular net-work, but also between the considerable branches and twigs 
 of the pulmonary and bronchial vessels. 
 
 The bronchial veins even mostly empty into the pulmonary. Those 
 of the roots of the lungs alone White in small trunks, which empty into 
 the azygos vein, or the descending vena-cava, or into the subordinate 
 twigs of the system of the veins of the body. 
 
 It follows then, from this arrangement : 
 
 1st. That even in the normal state the vascular systems of black 
 and red blood communicate extensively in the substance of the lung. 
 
 2d. That analogous communications which appear in other parts as 
 abnormal, as the termination of the coronary veins of the heart in the 
 left ventricle, the insertion of one or more pulmonary veins into the 
 ticna-cava, the origin of a great pulmonary artery from the descending 
 aofhi, &c., are only a more marked development of this type. 
 
 3d. That in the cases where the pulmonary artery was obliterated 
 or very narrow, and the subjects lived a long time, these anastomoses 
 were probably large enough to carry the blood in the pulmonary ar- 
 teries. In fact, the bronchial vessels were found very much dilated in 
 a case of this kind.(l) 
 
 c. Lymphatic glands and vessels. 
 
 § 2307. We have already made known the most important facts in 
 regard to the distribution of the lymphatic vessels in the substance of the 
 lung, and of the lymphatic glands which exist along the ramifications 
 of the trachea. 
 
 d. Nerves. 
 
 § 2308. The nerves of the lungs arise from the pneumogastric 
 nerve. They are very small in proportion, but very numerous, and 
 they can be traced far on the ramifications of the bronchiæ. They are 
 divided into two orders. Some are distributed in the bronchial tree, 
 others in the pulmonary vessels. The first penetrate to the muscular 
 and mucous membranes, the second surround the vessels and pene- 
 trate either into the substance of the great trunks, or into the capillaries. 
 Some extend even to the pleura. 
 
 e. Pleura. 
 
 § 2309. The pleura is a serous membrane, the outer portion of 
 which, termed the costal pleura ( pleura coslalis), covers the inner face 
 
 (1) Jacobson, in the Deutsches Archiv für die Physiologie , vol. ii.p, 134, 
 
OP THE RESPIRATORY SYSTEM. 34Î 
 
 of the pectoral cavity, while the internal or reflected layer, termed the 
 pulmonary pleura (pleura pulmonalis), covers the external face of the 
 lung. 
 
 It adheres to the parietes of the chest less than to the surface of the 
 lung : it however can be easily detached from this latter organ. 
 
 It is composed of a right and a left sac ( sacci pleurœ ), which are 
 separate and entirely distinct. 
 
 The internal parietes of the external sac are not attached to the 
 parietes of the pectoral cavity, but are turned towards each other, and 
 form a septum which is directed from above downward, and from before 
 backward, which divides the chest into a right and a left half. 
 
 These two internal parietes, however, do not touch. They are sepa- 
 rated in the centre, and in most of the septum they form, by the heart : 
 backward, by the aorta, the esophagus, the azygos vein, and the tho- 
 racic canal ; forward by the thymus gland and the great vascular 
 trunks. They are united in all these parts by very loose cellular tissue ; 
 and are most remote from each other in their centre. That portion of 
 the septum situated before and behind the heart, is termed the anterior 
 and posterior mediastinum ( mediastinum anterius et posterius). 
 
 The anterior mediastinum descends between the heart and the 
 middle anterior part of the thoracic cavity. Its direction is not perpen- 
 dicular, but oblique from left to right. Besides, it does not correspond 
 perfectly to the median line, but is thrown a little to the left, for the an- 
 terior edge of the right layer is attached to the left edge of the sternum, 
 and that of the left layer to the cartilage of the left ribs ; thence the 
 mediastinum descends on the anterior face of the pericardium. 
 
 The posterior mediastinum is more perpendicular than the anterior, 
 and is situated between ’the anterior face of the vertebral column and 
 the base of the heart. 
 
 The external layer of the pleura of each side, is reflected on itself, 
 between the two mediastina, to pass on the lower and upper faces of 
 the lungs. For this purpose, it contracts around the pulmonary vessels 
 and the bronchiæ, and descends from the centre of the posterior edge 
 towards the lung. Upward, forward, and backward, it contracts sud- 
 denly, and from all parts towards this point ; but we observe below, on 
 each side, a considerable triangular prolongation, terminated by a lower 
 semicircular edge, which begins at the diaphragm, and is attached to 
 the posterior edge of the lower lobe of the lung. This prolongation is 
 termed the right and left ligament of the lung ( l . pulmonis dextrum et 
 sinistrum). That of the left side is much larger than that of the right. 
 
 The pulmonary pleura covers the whole surface of the lung, even 
 its lobes, but does not penetrate between these lobes, which are sepa- 
 rated from each other only by cellular tissue. 
 
348 
 
 DESCRIPTIVE ANATOMY. 
 
 f. Weight of the lung. 
 
 a. Absolute weight. 
 
 § 2310. The sound lung of an adult male, with all the blood and 
 the air it contains, weighs about four pounds. When removed from 
 the body, the pressure of the external air, which had been prevented 
 from acting on it, expels a considerable portion of this fluid which re- 
 mained in it after the last expiration. 
 
 Its weight then is to that of the whole body about as 1 : 35. 
 
 b. Specific gravity. 
 
 § 2311. Considered in itself, the substance of the lung is heavier 
 than water, for the lungs of a child which has never breathed sink in 
 this fluid. But when respiration has commenced the specific weight 
 of the organ is less than that of water, as the air which enters there is 
 not entirely expelled during expiration. We cannot even press it out 
 from a section of the lung : for then, after rupturing the ramifications 
 of the bronchiæ, it extends in the cellular tissue, so that at the end 
 of the experiment the substance of the lung is still lighter than the 
 water, although a little heavier than it was before.(l) 
 
 g. Capacity. 
 
 § 2312. The capacity of the lung is not the same in all periods of 
 life. It varies much, according as the organ is distended at the end 
 of inspiration ( inspiratio ), or in that of contraction, at the end of expi- 
 ration ( expiratio ). 
 
 The estimates given by authors vary, which may arise from a real 
 difference in the capacity of the lung and the nature of the modes 
 employed to estimate it. 
 
 In the first respect there are very great individual differences, which 
 are mostly congenital, but which may be accidental, as when the lungs 
 are but slightly used, for instance, in students. 
 
 The capacity of the lung is determined by adding the quantity of 
 air expelled during expiration with that which remains there after 
 this act is completed. This calculation may be made in several dif- 
 ferent ways. 
 
 Three processes can be used to determine the quantity of air which 
 enters the lung at each inspiration : 
 
 1st. We may measure the enlargement of the lung in inspiration, 
 and the contraction after expiration. 
 
 (1) Allen and Pepys, Second pager on respiration ; in the Phil, trans., 1809, p. 4L 
 
OF THE RESPIRATORY SYSTEM. 
 
 349 
 
 2d. We estimate the changes which supervene during inspiration 
 and expiration in a fluid in which the individual is situated. 
 
 3d. We measure the quantity of the air inspired and expired, by 
 inspiring from a vase which has been measured, and expiring into 
 another, the capacity of which is also known, or by the last proof 
 alone.(l) 
 
 At present the estimates of the quantity inhaled and expelled at 
 each respiration varies much, from three to forty cubic inches. In 
 fact, Abildgaard estimates it at three inches ;(2) Wurzer(3) and La- 
 metherie,(4) at eight or ten ; Keutsch,(5) between six and twelve ; 
 Abernetby,(6) Lavoisier, Seguin, (7) and Davy, (8) at thirteen ; Bo- 
 relli(9) and Goodwyn,(10) at fourteen; Kite, (11) Allen, and Pe- 
 pys,(12) at seventeen or eighteen ; Herholdt,(13) between twenty-five 
 and twenty-nine ; Cavallo,(14) Jurin,(15) Sauvages, (16) Hales, (17) 
 Hal'er,(18) Chaptal,(19) Bell,(20) Fontana, (21) Menzies,(22) and 
 Richerand,(23) between thirty and forty cubic inches. 
 
 In estimating the quantity of air remaining in the lung after expira- 
 tion, the following circumstances are attended to : 
 
 1st. After expiration, as long as the chest remains closed and the 
 lungs are not removed, these organs contain more air than when sepa- 
 rated from the body, because they collapse after opening the chest, and 
 thus expel the air they contain. 
 
 2d. It is very difficult to expel the air which remains in the lung, 
 and it can never be completely removed by the greatest possible 
 pressure.. 
 
 (1) Jurin, in Haller, El. phys ., 1. viii., s. iii. 
 
 (2) Neue Versuche über das Athmen und den Nutzen desselben ; in the Nordisches 
 Archiv, für Natur -und Arzneywissenchaft , vol. i., pt. i., p. 2. — Abildgaard however 
 asserts in another place (ibid., pt. ii., p. 206), that from two to seven, and sometimes 
 even fifteen cubic inches enter. 
 
 (3) Gunther, Darstellung , p. 28. 
 
 (4) Journ. de physique, vol. xlvi., p. 108. 
 
 (5) De act. gaz cxygenii per pulm. resp., Copenhagen, 1800. 
 
 (6) Essays, London, 1793, vol ii., p. 144. 
 
 (7) Mémoire sur la respiration, &c. 
 
 (8) Researches concerning nitrous oxyd , London, 1800, p. 433. 
 
 (9) De motu animalium, p. ii., prop. 81. 
 
 (10) Recherches expérimentales sur les effets que produisent sur les animaux vivons 
 la submersion, la strangulation, &c., Paris, 1798. 
 
 (11) lieber Wiederherstellung scheinbar todter Menschen , p. 19. 
 
 (12) Loc. cit. 
 
 (13) Nordischés Archiv., vol. i., pt. ii., p, 207. 
 
 (14) lieber Anwendung der Gasarten. 
 
 (15) Dies. phys. math., London, 1732, diss. iv. ; in Haller, De part, corp. hum. fab., 
 vol. vi., p. 325. 
 
 (16) In Haller, El. phys., vol. iii., p. 234. 
 
 (17) Statical essays, vol. i., p. 238. 
 
 (18) El. phys., vol. iii., loc. cit. 
 
 (19) Chemie; in Bostock, Heber das Athmen, p. 189. 
 
 (20) Anatomy, vol. ii., p. 193. 
 
 (21) Phil. Irans., 1799, p. 349. 
 
 (22) De respiratione, Edinburgh, 1790. 
 
 (23) Physiologie, vol. i., p. 374. 
 
 Vol. III. 45 
 
350 
 
 DESCRIPTIVE ANATOMY 
 
 Several methods have been proposed to estimate the quantity of air 
 which remains in the lungs after expiration. 
 
 1st. After fixing the diaphragm as firmly as possible, the abdomen 
 is tied and the lungs collapsed, by making an incision in the parietes 
 of the chest, we fill the space between these paiietes and the organ 
 with water, which it is asserted should be equal in quantity to that 
 of the air expelled from the lung by the pressure of the liquid, and 
 also that of the external air introduced into the chest through the 
 parietes. 
 
 2d. On opening the lung the air is received from it in a bladder 
 adapted to the trachea, and it is measured ;(1) the lung is then im- 
 mersed in water, the specific gravity of which is about equal to that 
 of distilled water, while its absolute wmight is known : the quantity 
 displaced is weighed, and w'e determine the cubic quantity of air it 
 still includes. 
 
 From these two methods we may conclude the quantity of air re- 
 maining in the lung of an adult after a con plete expiration to be about 
 one hundred and ten cubic inches. In fact, Gcodwyn has introduced 
 from ninety to one hundred and twenty cubic inches of water in the 
 space between the chest and the lung. 
 
 In Allen and Pepys’ experiments, the quantity of air first collected 
 was 31.580 cubic inches: the lungs, which weighed four pounds, 
 and which from their weight occupied as much space as an equal 
 quantity of water, displaced six pounds of the liquid, so that there still 
 remained within them a quantity of air equal to an ounce of water, 
 that is, 59.554 cubic inches. The total of these two sums gives a 
 little more than ninety-one cubic inches, as the quantity of air remain- 
 ing in the lung after expiration ; but we may admit it as about one 
 hundred and ten, on account of the pressure of the water on the mass 
 of the lung, and the higher temperature during life. 
 
 If we add to these one hundred and ten cubic inches of air remaining 
 in the lung after a common expiration, about thirty inches which leave 
 the organ at each common expiration of a healthy adult, (2) we shall 
 have one hundred and forty-five inches as the capacity of the lungs 
 in common inspiration, so that the difference of capacity between 
 the state of dilatation and collapse of the organ is about thirty-five 
 inches. 
 
 But this difference increases very much when the respiration being 
 deeper, the lung is unusually dilated and collapsed, because more air 
 enters and leaves the lung at each time. 
 
 (1) Cline, in Allen and Pepys, loc. cit. 
 
 (2) We take this as the mean number : it seems to us that a lower estimate should 
 be ascribed to an unusual smallness in the lung 1 2 , or to careless calculation, and that a 
 greater estimate depends upon an unusual development of the chest, or on a very 
 (leep respiration. Farther, we ought to mention that the air is dilated one sixth by 
 the heat of the body. 
 
OF THE RE3PIRATORV STSTEM. 
 
 251 
 
 Thus Seguin(l) inhaled in a very deep respiration one hundred and 
 thirty inches of air, which would expand by the heat of the body to 
 one hundred and fifty, so that then the capacity of the lung was equal 
 to two hundred and sixty cubic inches. Kite estimates the capacity 
 at three hundred cubic inches. 
 
 On the other hand, Jurin expired two hundred and twenty cubic 
 inches, (2) and Herholdt, 208.(3) If we admit here that these expira- 
 tions took place after a full inspiration, we ought to reduce the capa- 
 city of the 'lung to fifty-two and even to forty cubic inches, which 
 estimate perfectly agrees with that formed by Davy by another 
 method.(4) 
 
 In contrasting the estimates of Seguin and Jurin, and disregarding 
 the diminution of the volume of the air expired, we find a difference of 
 two hundred and twenty between the greatest dilatation and the 
 greatest relaxation of the lung, that is, this latter state is to the 
 other as 1 : 6.5. 
 
 h. Force of the lung’. 
 
 § 2313. The lung is not very sensible. Its transverse and its lon- 
 gitudinal muscular fibres, which are similar in their nature to muscles, 
 give it the power of contracting, which, judging from experiments, (5) 
 is exerted whenever its external or internal surface is stimulated, and 
 which without stimulation(6) executes the motions which cannot be at- 
 tributed to those of the parietes of the thorax, since they are simultane- 
 ous with these latter, and are observed when the parietes of the thorax 
 are destroyed. (7) Consequently the air-passages contract actively 
 during expiration ;(8) but all these phenomena, adduced to prove that 
 the lungs possess a power of extension which allow them to dilate 
 actively in inspiration, can be satisfactorily explained in another 
 manner. (9) 
 
 (1) Observations générales sur la respiration et sur la chaleur animale ; in the 
 Journ. de physique. 1790, p. 467. 
 
 (2) In Haller, loc. cit., p. 326. 
 
 (3) Loc. cit., p. 41. 
 
 (4) Loc. cit., p. 409. 
 
 (5) Varnier, in the Mém. de la soc. roy. de.med., ann. 1779. 
 
 (6) Rudolphi, Ueber das Athemholen ; in his Anat. phys. Abhandlungen , p. 111. — 
 Flormann, ibid., p. 110. 
 
 (7) Bremond, Expériences sur la respiration ; in the Mém. de Paris, 1739, p. 455. 
 — This author however adduces as proofs several phenomena which are by no means 
 conclusive. 
 
 (8) J. Carson, Mémoire sur l'élasticité des poumons ; in the Arch. gen. de méd., 
 vol. ii., p. 134. 
 
 (9) J. D. Herholdt, Ueber die chirurgische Behandlungen der Brustvrunden, 
 veranlasst durch neue Versuche über den Mechanismus des Athemholens ; in the 
 Nordisches Archiv., vol. ii., pt. i., p. 44-60. 
 
352 
 
 DESCRIPTIVE ANATOMY. 
 
 ». Function of the lung. 
 
 § 2314. The function of the lung is respiration, which consists es- 
 sentially in the change of venous into arterial blood by the expulsion 
 of carbon and the absorption of oxygen. The atmospheric air enters 
 into the organ during inspiration, and emerges from it loaded with 
 carbonic acid during expiration ; this change of the blood, and the cold 
 produced by the evaporation of the water exhaled, are the most im- 
 portant functions of the lungs ; but the variations in its capacity also 
 affect the circulation, for the blood circulates more rapidly from the 
 right half of the heart into the pulmonary artery during inspiration, 
 and from the pulmonary veins into the left portion of the heart during 
 expiration. 
 
 II. SEXUAL DIFFERENCES. 
 
 § 2315. The lungs of the male are larger than those of the female, 
 and the latter are more oblong than those of the male. 
 
 III. DIFFERENCES DEPENDENT ON DEVELOPMENT. 
 
 § 2316. The lung presents considerable periodical differences^ 1) in 
 respect to its existence, situation, texture, color, contents, volume, and 
 finally its absolute and relative weight. 
 
 1st. Existence. The lung is one of the last organs to appear. It 
 begins to be distinctly seen about the end of the second month of preg- 
 nancy. 
 
 2d. Situation. From the greater proportional volume of the heart 
 and its slight development, the lung is situated much more posteriorly 
 before than after birth, so that sometimes it is not seen at all on opening 
 the cavity of the thorax ; consequently it covers the pericardium, and 
 generally does not. entirely fill the sac of the pleura, and hence does 
 not touch the parietes of the chest. 
 
 3d. Texture. At the third month of pregnancy we begin to distin- 
 guish the cartilaginous tissue in the air-passages of the lungs. The 
 lobules are at first united by a looser cellular tissue than that com- 
 
 (1) Meckel, Mémoire sur le développement du cœur et des poumons dans les mam- 
 mifères ; in the Journ. compl. dessc. m éd., vol. i., p. 259. — Consult also on the differ- 
 ence in the lung- of the child before and after respiration, G. J. Schmitt, \eve Ver- 
 suche und Erfahrungen über die Plocquetsche und hydrostatische Lungenprobe , 
 Vienna, 1806. — A. Lccieux, Considérations medico-légales sur l'infanticide , Paris, 
 1011. — Magendie, Sur la structure du poumon de l'homme , sur les modif cations 
 qu'éprouve celle structure dans les divers âges , et sur la première origine de la 
 phthisie pulmonaire ; in the Journ. de physiol, expérim., vol. i., p. 78. — Fleischmann, 
 Sur la formation de la trachée-artère ; in the Journ. compl. du diet, des sc. méd., 
 vol. xvi., p. 141. — Id., De chondrogenesi asperiœ arterice et de situ oesophagi abnormi 
 nonnulla, Erlangen, 1820. 
 
OF THE RESPIRATORY SYSTEM 
 
 353 
 
 monly seen, and they are also formed of small subordinate lobes, so 
 that here, as in other parts, as the muscles, the homogeneous mass is 
 at first divided into its great subdivisions, but afterward into the 
 smaller parts. 
 
 4th. Color. The color of the lung is at first reddish white in the 
 fetus, and is whiter the younger the fetus is. This organ gradually be- 
 comes of a deeper red, in proportion as it is better supplied with bleed. 
 After birth this tint is bright from respiration, and also becomes 
 deeper. At twenty years the lung is gray, mottled with blue and 
 black spots, and from this time its color becomes still darker, so that 
 in advanced life it is more or less generally black or bluish black. 
 
 5th. Contents. The trachea and its ramifications contain after birth 
 only air, and a small quantity of aqueous vapor and mucus. But this 
 is not true of the fetus, where it is filled with the fluid of the amnion. 
 By the laws of hydraulics, when the fetus swims in this fluid it enters 
 the trachea, without any respiratory motion on the part of the fetus. 
 It usually escapes after birth, and when it does not escape at this time, 
 which is rare, it may suffocate the child.(l) 
 
 6th. Volume. The lung is at first much smaller ; it occupies much 
 less space than the heart, and . is easily blended with the very dilated 
 auricles of this latter. 
 
 It does not acquire its normal proportional size till puberty. 
 
 7th. Weight. The absolute weight of the lung presents very re- 
 markable periodical differences, which depend on the organ remaining 
 inactive until after biith. In the fetus its specific gravity is greater 
 than that of water, in which it sinks ; but when respiration has once 
 commenced, as it is never free from the air which has entered in it, its 
 specific gravity is less than that of the water, and it floats. 
 
 § 2317. Most of the differences mentioned, especially those in regard 
 to situation, volume, color, and specific gravity, appear more or less at 
 birth, and result from respiration. 
 
 The lung, becoming lighter from the effect of the air entering- it 
 and which never entirely leaves it, occupies also more space after^-es- 
 piration, and is situated more anteriorly, covers most of the pericar- 
 dium, and is in contact with the parietes of the chest. The deep red 
 color communicated to it by the venous blood before respiration 
 changes to a bright red when the new being breathes. 
 
 Finally the organ, which when collapsed received less blood, and 
 was consequently lighter, becomes heavier when after being distended 
 by respiration, it is more permeable to the blood. 
 
 Hence these differences have been thought sufficient to determine 
 whether an infant was born living or dead. But as the specific ora- 
 vity having diminished, the lung floats, which proof constitutes what is 
 
 (1) P. Scheel , Commentatio de liquoris amnii asperice arteriœfœtuum humanorvm 
 natura et usu ejusque in asphyxium neonatorum et medicinam forensem infiuxu 
 Copenhagen, 1799.— Herholdt, in Reil, Arch.iv.fur die Physiologie , vol. iii., p. 163 — 
 Id., in the Nordisches Archiv., vol. i, p. 212. 
 
354 
 
 DESCRIPTIVE ANATOMY. 
 
 termed the test hydrostatica ;(1) as also the afflux of the blood in- 
 creases the absolute weight of the organ, and its relative weight 
 compared to that of the body constitutes another kind of proof, termed 
 the test by the balance, (2) this principle has been laid down, that 
 when the lungs of a child swim in water, and a similar or analogous 
 proportion exists between the relative weight of the lungs and that of 
 the body, it is established that this child was born alive and that it 
 breathed. 
 
 Considered generally and absolutely, these conclusions are correct ; 
 but. great and important restrictions are necessary. 
 
 1st. The lungs may become lighter by respiration, and the child 
 not be born. 
 
 2d. The lungs may swim from some other cause than respiration. 
 
 3d. Respiration does not necessarily produce this change in them. 
 
 4th. The lungs sometimes have a greater absolute weight, although 
 respiration has not taken place. 
 
 5th. On the other hand, they may present after respiration a specific 
 gravity as great as that they possess, according to the general opinion, 
 before this act. 
 
 In fact : 
 
 1st. The infant sometimes breathes sufficiently during parturition 
 to render its lungs capable of swimming, although it may be still- 
 born. (3) 
 
 2d. The lungs may also swim from the fact that the air has been 
 pushed into them, through the mouth or nose, either while they con- 
 tinued in the thorax, or after their removal from this cavity. Putre- 
 faction also may give rise to the same result. 
 
 3d. Several experiments demonstrate that respiration does not ne- 
 cessarily cause in the lungs the above mentioned changes. Some 
 parts of a lung, or even an entire lung, have been seen which did not 
 swim in water, although the child has lived, breathed, and cried, not 
 only for several days, (4) but even for six weeks. We have seen in a 
 child six weeks old all the middle lobe of the right lung, and in ano- 
 ther four weeks old, great portions of the same lobe apparently healthy, 
 which were absolutely incapable of floating. 
 
 The left' lung is most frequently retarded in its development, which 
 peculiarity doubtless depends on the fact that the right bronchia is 
 much shorter and broader than the left, so that usually, even in chil- 
 dren who died soon after birth, the right lung floated, while the left 
 floated very imperfectly, or not at all.(5) 
 
 (1) F. Alberg-, De docimasiâ 'pulmonum hydrostatica , Halle, 1791. 
 
 (2) G. G. Plocquct, Comm. med. in processus criminates super homicidio, infanti- 
 cidio et embryoctonia, Strasburg-, 1787. 
 
 (3) Schmitt (loc. eit.. p. 150-176) has reported examples of this. 
 
 (4) Kaltsclimied, De exp. pulm. infant, aq. injectis , ann. 1751. 
 
 (5) A. Portal. Mémoire dans lequel on démontre l’action du poumon sur l’aorte 
 pendant le temps de la respiration, et où Von prouve que, dans l’enfant qui vient de 
 
OF THE RESPIRATORY SYSTEM. 
 
 355 
 
 It is at least very rare that the contrary occurs. 
 
 a. The rarest case is when the cause of the sinking of the lung 
 depends on a morbid alteration in its texture, an effusion, an indura- 
 tion, for these are very unfrequent before birth, and even when they 
 occur to a great extent, the organ does not acquire a greater specific 
 gravity than that of water. 
 
 b. A more common cause is the presence of foreign bodies, espe- 
 cially mucus, and the fluid of the amnion in the trachea, or the feeble- 
 ness of the fetus, all which circumstances render the dilatation of the 
 lung imperfect. 
 
 c. We must remark also that this change in the specific gravity 
 supervenes gradually, and when the respiration takes place with the 
 requisite degree of strength, as in the beginning, and when the child 
 respires but feebly, it extends to some parts of the lung only, and 
 sometimes it is not produced at all by the first inspirations. 
 
 4th. Sometimes, although the child has not breathed, the lungs 
 have an absolute and consequently a relative weight, in proportion to 
 the body, as great as when the child has respired. There are some 
 cases where the relation between the weight of the lung and the body 
 is still greater, for instance, as 1 V 15A, to 29ff, to 33f, to 32^f, to 
 34 t 7 3 5 t ,( 1) although respiration did not take place. 
 
 This circumstance is still more curious, as the lungs contained also 
 more blood than usual. 
 
 5th. Observation likewise proves that the lungs of infants born alive 
 are sometimes proportionally lighter than those of still-born children 
 are, according to the preceding estimate, (2) as they are found in the 
 proportion of 1 : 77 T 9 T , to 77if, and to 104. 
 
 II. ABNORMAL STATE. (3) 
 
 § 2318. Primitive deviations of formation. The lungs present pro- 
 portionally but few anomalies resulting from a primitive deviation of 
 formation ; they however sometimes manifest them in respect to quan- 
 tity and quality. 
 
 1st. The congenital anomalies in regard to quantity are generally : 
 
 a. Deviations of formation from an arrested development. Here 
 are arranged particularly : 
 
 a. The absence of the trachea, of a lung, or of the two lungs; this 
 last anomaly usually attends acephalia vera ; the second is more rare, 
 
 naître, le poumon droit respire avant le gauche ; in the Mém. de Paris, 1765. — Some 
 writers have attributed this discovery to Petit, but wrongly : he mentions only 
 one case (Mém. de Paris, 1753), and does not point out the real cause of the pheno- 
 menon. 
 
 (1) Schmitt, loc. cit., p. 139. 
 
 (2) Id., ibid. 
 
 (3) Van den Bosch, Commentatio exhibons analomiam systematic respirations in - 
 servientis pathologicam, Harlem, 1801. 
 
356 
 
 DESCRIPTIVE ANATOMY. 
 
 and also occurs in subjects whose formation is otherwise normal, and 
 resembles the normal singleness of the lung in several serpents. The 
 absence of the trachea is less common than that of the lungs ; when 
 it occurs the lung is situated next to the larynx, as also in several 
 reptiles. 
 
 b. Narrowness and closing of the trachea, which has been observed 
 when the skull was deficient.(l) 
 
 c. The smallness of one or of the two lungs. The first anomaly is 
 generally produced mechanically by an external obstacle, particularly 
 the presence of the abdominal viscera in the cavity of the thorax in a 
 subject affected with diaphragmatic hernia. The second, which is 
 generally connected with narrowness of the thoracic cavity, depends 
 on a primitive dynamic anomaly of the formative power, and some- 
 times occurs in individuals otherwise well formed, and sometimes is 
 attended with other deviations in formation, arising from suspended 
 development. 
 
 d. We ought also to mention here the exposure of the lungs or 
 trachea sometimes observed, since it depends upon the formation of the 
 parietes of the thorax being arrested at one of the early periods 
 through which it successively passes. 
 
 b. The great size of a lung, attended generally by the deficiency of 
 the other, results from an excessive action in the formative power. 
 
 2d. Congenital deviations in form relative to the quality are : 
 
 a. The abnormal division, which is indicated in the lungs by the 
 presence of an unusual number of lobes, or by the deeper separation of 
 those always existing, and in the trachea by its division into three 
 branches. This last anomaly, judging from facts hitherto collected, 
 occurs only on the right side, and is curious as a repetition of the pecu- 
 liar structure of the ruminantia and the cetaceous animals. 
 
 b. An opposite anomaly occurs when the lungs are not divided into 
 lobes as usual, or when this division is not clearty indicated. 
 
 c. Lateral inversion is where the right lung has but two lobes and 
 the left three. This anomaly commonly occurs only when there is a 
 genera! lateral inversion. 
 
 Consecutive deviations of formation. The pure consecutive accidental 
 deviations of formation are particularly wounds, which often suddenly 
 cause death, on account of the considerable caliber of the vessels, but 
 sometimes death occurs from the dangerous inflammation and suppu- 
 ration of such important organs ; but they are not necessarily nor 
 always fatal. 
 
 We must mention here the abnormal communication with the other 
 cavities, which sometimes occurs when the parietes are destroyed ; 
 the most remarkable is that which occurs in aneurism of the aorta. (2) 
 
 (1) Otto, Monst. sex. disq., p. 10, 11. 
 
 (2) Richerand, Observations sur l'ouverture des anévrysmes de l'aorte dans la 
 trachée-artère et dans les bronches; in the Mém. de la soc. méd. d'emul., vol. iv , 
 p. 645. 
 
OF TIFE RESPIRATORY SYSTEM. 
 
 357 
 
 In this case, from the respective situation of the parts, the opening 
 usually corresponds to the lower part of the trachea, or to the left 
 bronchia. 
 
 § 2319. Alterations in texture. They are : 
 
 1st. Inflammation, generally termed pneumonia , bronchitis , and 
 pleuritis , according as the whole substance of the lung, the mucous 
 membrane of the trachea, or the pleura, is affected.(l) 
 
 The most usual consequences of pneumonia are : 
 a. Thickening and induration of the tissue of the lungs, from an 
 effusion often existing in a great degree, and then forming the state 
 termed hepatization ( hepatisatio)(2 ) The substance of the lung is 
 then generally homogeneous, friable, brittle, grayish white, much 
 thicker in texture, and sometimes - possesses a specific gravity greater 
 than that of water. 
 
 2d. Suppuration Pus usually burrows for itself a passage into the 
 bronchiæ. More rarely it is effused into the chest, constituting empyema, 
 or into the adjacent organs, as the pharynx or the aorta.(3) 
 
 Bronchitis terminates sometimes by suppuration, sometimes by the 
 formation of solid or hollow membranes, which fill this cavity and rarely 
 adhere to its inner face. Very probably, however, the development of 
 these accidental membranes is not always and necessarily preceded 
 by an inflammation of the trachea. (4) 
 
 The consequences of pleuritis are : 
 
 (1) C. Hastings, A treatise on inflammation of the mucous membrane of the lungs, 
 London, 1820. — T. Alcock, Observations on the inflammation of the mucous mem- 
 brane of the orga ns of respiration, London, 1820. 
 
 (2) Bricheteau, De l’ hépatisation pulmonaire ; in the Journ. compl. des sc. mid., 
 vol. ix., p. 106. 
 
 (3) V. Laennec, De V auscultation médiate, vol. i. — Andral, Clinique médicale, vol. 
 ii. — Louis, Observations relatives à la perforation du parenchyme du poumon ; in the 
 Archiv, gén. de mcd., vol. v.j p. 321. — Bouillaud, Nouvelles observations sur la gan- 
 grène des poumons ; in the Revue médicale, vol. iv., p. 375. 
 
 (4) This proposition cannot be admitted. It rests upon a fact mentioned first by 
 
 Bayle, and since enlarged upon by Andral, that sometimes in individuals af- 
 fected with chronic bronchitis, even with an expectoration of pus, the mucous mem- 
 brane is. hardly rosy or even perfectly white in its whole extent. But ought not we 
 then to admit that the tissue is discolored after death 1 Farther, it is remarkable 
 that the softening and ulcerations are much more rare in the mucous membrane of 
 the bronchiæ than in that of the intestine, and that the frequency of the ulcerations 
 decreases from above downward. The inflammation of this membrane frequently 
 terminates also in thickening, which causes the contraction of the bronchiæ. Hy- 
 pertrophy even sometimes extends more or less to the external fibrous and cartila- 
 ginous tissues. We must not confound the contraction of the bronchiæ, which re- 
 sults from it, with that which comes from the compression of these canals by a 
 tumor, among others by tumefied ganglions, which are rather common in children, 
 or by au aneurism of the aorta. Chronic inflammation results also in a dilatation of 
 the bronchiæ, to which Laennec first attracted attention, and which has-been studied 
 very carefully since by Andral, as have also the different alterations in the secretion 
 of the mucous membrane of the bronchiæ. Consult on this subject : Lacnnec, De 
 l' auscultation médiate, Paris, 1819, vol. i., p. 124. — Andral, Observations sur quelques 
 altérations organiques des bronches ; in the Archiv, gén. de méd., vol. iv., p. 514.— 
 Id., Clinique médicale, vol. ii., p. 1-85. — Bree, Recherches sur les désordres de la 
 respiration, Paris, 1819.— Desruelles, Traité théorique et pratique du croup, Paris, 
 1824. F. T. 
 
 Vol. III. 
 
 46 
 
358 
 
 DESCilJPTIVK ANATOMV. 
 
 a. Thickening, induration of this membrane. 
 
 b. Effusion of serum, which when not coagulable in a great de- 
 gree, causes hydrothorax, and which when coagulable produces the 
 mutual adhesions of the contiguous surfaces of the pleura.(l) 
 
 The principal new formations in the lungs are tubercles. 
 
 3d. The repetitions of the normal tissues in the respiratory organs 
 are rare. We must however refer to this the accidental membranes 
 developed after pleuritis, because they are repetitions of the cellular 
 tissue and the accidental ossifications(2) formed in the osseous tissue. 
 These ossifications frequently appear as thin elongated laminæ, si- 
 tuated on the outer face of the pleura. They are more rare on the 
 inner face of this membrane, in the form of rounded bodies, which at 
 first adhere, but are finally detached. The pretended change of the 
 pulmonary substance into cartilage is probably in most cases only an 
 induration resulting from effusion. Sometimes however cartilaginous 
 tissue is really developed accidentally in the lungs. 
 
 § 2320. Foreign bodies. These are : 
 
 1st. Entozoaries, particularly hydatids which form in the substance 
 or on the surface of the lung, and. the hamularia subcompressa which 
 exists in the trachea. 
 
 2d. Foreign substances accidentally introduced into the air-pas- 
 sages. 
 
 ARTICLE THIRD. 
 
 CAVITY OF THE THORAX. 
 
 § 2321. The thoracic cavity contains, besides the lungs and their 
 vessels, the heart, the commencement of the aorta, the trunks of the 
 ascending and descending venæ-cavæ, the azygos vein, the thoracic 
 canal, the esophagus, and the thoracic portion of the ganglionnary 
 nerve. We have mentioned previously the manner in which it is 
 formed like a cage. Its upper extremity is generally the narrowest 
 and its lower extremity the broadest part of the chest : at least it is~ 
 generally much broader at its base than at its summit. It is convex, 
 on the sides, flattened forward, larger from above downward, and 
 shorter from before backward than in any other direction, much longer 
 posteriorly than anteriorly, and provided below with a more or less 
 convex floor which is formed by the diaphragm. Posteriorly the 
 bodies of the dorsal vertebra imperfectly divide it into two halves. 
 
 (1) Laennec, loc. cit., vol. i. — Andral, loc. cit., vol. ii. — Id., Observations sur Vin- 
 flammation de la plèvre diaphragmatique ; in the Archiv, gin. de mid., vol. iii., 
 p. 246. 
 
 (2) Rallier, Note louchant un Iris grand nombre de pièces osseuses développées 
 dan s le tissu du poumon ; in the Archiv, gin. de méd., vol. v., p. 271. 
 
 t 
 
OF THE RESPIRATORY SYSTEM, 
 
 359 
 
 It is a little shorter on the right than on the left side, on account of 
 the prominence of the liver. 
 
 The inner face of its parietes is covered in nearly its whole extent by 
 the external layer of the pleura, which is there attached to it by a very 
 short cellular tissue. Of the organs it incloses, the lungs and the heart 
 are united to it by its surrounding serous membranes ; the others di- 
 rectly by cellular tissue. 
 
 The division into a right' and a left half, indicated by the bodies of 
 the vertebræ, is completed by the mediastinum, 
 
 I. MOTIONS OF THE CHEST, 
 
 § 2322. The chest is continually extended, enlarged, contracted ; 
 and the first state occurs in inspiration, and the second in expiration. 
 The motions of the chest which determine them, produce a simulta- 
 neous dilatation and contraction in the air passages. The lung, being 
 compressed when the chest collapses, expels the air within it, while it 
 enters through the mouth and nose, when, the chest dilating, the ob- 
 stacle from the collapsing of its parietes no longer exists. 
 
 The dilatation of the chest during inspiration, and its contraction in 
 expiration, occur in every direction. 
 
 The greatest change is that in height. It depends partly on the 
 depression of the diaphragm in inspiration, and its rising in expiration, 
 partly also on the raising of the ribs by the intercostales and scaleni 
 muscles. 
 
 The enlargement in the direction of the breadth, depends on the ribs 
 being drawn outward. 
 
 The parietes of the chest follow exactly the motions of the lungs 
 during respiration, and these two parts remain in contact, at least in 
 the regular state, during expiration or inspiration, so that they are 
 found in perfect contact after the strongest of all expirations, that which 
 occurs at death. 
 
 II. DIFFERENCES DEPENDENT ON SEX. 
 
 § 2323. The chest of the male is much larger than that of the fe- 
 male, as it is longer, broader, and deeper. Its capacity is also more 
 uniform, so that it is proportionally a little broader, rounder, and more 
 movable. The bodies of the dorsal vertebrae do not project as much, 
 
 III. DIFFERENCES DEPENDENT ON DEVELOPMENT. 
 
 § 2324. The chest is proportionally the smallest of the three 
 sphlanchnic cavities of the body during the early periods of existence, 
 which depends particularly on the slight development and the inac- 
 tivity of the lungs. 
 
360 
 
 DESC R5PTIVE ANATOMY. 
 
 It possesses in the same proportion a greater degree of elasticity, 
 because the costal cartilages are much longer in proportion to the ribs, 
 than during the successive periods.(l) 
 
 It does not begin to move until after birth, and when the new being 
 breathes for the fast time. 
 
 IV. ABNORMAL STATE. 
 
 § 2325. Sometimes the chest is only partially closed, from a primi- 
 tive deviation of formation. When this anomaly exists on the anterior 
 face or the sides, the internal organs are exposed ; when in the lower 
 wall, the abdominal and pectoral cavities abnormaly communicate, and 
 some of the thoracic viscera enter the cavity of the abdomen. 
 
 The same also may be caused later by wounds, ulcers, &c. A com- 
 mon congenital deviation of formation is the abnormal smallness of the 
 chest, which generally attends a corresponding defect in the develop- 
 ment of the lung, and a disposition to tuberculous phthisis. 
 
 The alterations in the texture of the chest are principally different 
 kinds of tumors, which occur in the mediastinum. These tumors some- 
 times become large, and compress the organs in the thoracic cavity so 
 much, that the subject dies from the suspension of the circulation or nu- 
 trition. (2) 
 
 ARTICLE FOURTH. 
 
 GLANDULAR ORGANS SITUATED NEAR THE ORGANS OF VOICE 
 AND RESPIRATION. 
 
 § 2326. We find near the organs of voice and respiration, two im- 
 perfect glands, (3) the thyroid and the thymus glands, which are simi- 
 lar, not only as they both present the general characters of glands of 
 their species, but also because they are situated directly on the median 
 line, behind the anterior face of the body, before the organs of respira- 
 tion, and because they even touch in the early periods of fetal existence. 
 
 These two glands possess numerous blood-vessels and lymphatics. 
 They have no excretory ducts, but contain in their spaces a fluid dif- 
 ferent from their substance, and which is very evident in the thymus 
 gland. The change of a considerable quantity of blood, which is pro- 
 
 (1) Compare the measures in regard to this. subject, in Lohstein, Sur la première 
 inspiration de Venfanl nouveau nc ; in the Journal de médecine , vol. xxxv. p. 311- 
 312. 
 
 "(2) Lænnec, Sur le rétrécissement de la poitrine à la suite de certaines pleurésies : 
 in his V Auscultation médiate, vol. i. p. 369. 
 
 (3) P. H. Bœcklen, De thyroideœ, Ihymi et glana lularum sùjnarenaliumfunctionî- 
 bus, Strasburg 1 * 3 , 1753. — J. F. Meckel, Lieber die Schilddrüse, Nebennieren und einige 
 ihnen verwandte Organe ; in his Abhandlungen aus der menschlichen und ver- 
 gleichenden Anatomie, Halle, 1816, p. 1-277. 
 
OF THE RESTIRATORY SYSTEM. 
 
 361 
 
 bably peculiarly modified, and the formation of their fluid, are the only 
 functions which can be assigned to them with certainty. We then 
 have reason to think their functions in the sanguineous system are 
 analogous to those of the lymphatic vessels, that is, they are organs 
 which contribute to perfect the formation of blood. This conjecture is 
 rendered probable from the fact, that the blood which passes through 
 their tissue, and the fluid which they prepare, soon enter the venous 
 blood near its entrance into the lung. 
 
 I. THYROID GLAND. 
 
 A. PERFECT STATE. 
 
 § 2327. The thyroid gland (G. thyroidea){ 1) is situated forward 
 and on the sides of the upper part of the trachea and pharynx. 
 
 It is composed of a centre, which is slightly contracted, thin, and 
 about four lines high, termed the isthmus , and of two lateral portions 
 or horns, which are directed from below upward, and terminate in a 
 point. 
 
 The central part is situated directly below the larynx, and before the 
 three or four upper rings of the trachea. The two horns extend below 
 to the sixth or seventh ring, and above to the lower horn of the thyroid 
 cartilage. 
 
 There is generally detached more or less from its centre, a median 
 horn, which is generally single, rarely double, termed by Lalouette the 
 pyramid. This horn is rarely perfectly cylindrical, and generally cor- 
 responds to the left side more than to the right, (2) which deserves to 
 be remarked on account of the greater development cf the hyoid bone, 
 generally occurring on the same side. It reascends before the 
 thyroid cartilage to the middle hyoid bone, and it terminates there, 
 gradually becoming thinner. This horn exists more frequently than 
 it is deficient. (3) We must then attribute to accident, or to careless 
 dissection, the assertions of authors to the contrary. (4) 
 
 § 232S. It is generally surrounded by a special and unmated muscle, 
 the levator gland, thyroideœ muscle, the upper extremity of which is 
 generally attached to the body of the hyoid bone ; sometimes it does 
 
 (1) P. Evertze, De glandulâ thyroideâ, Leyden, 1708. — Santorini, Obs. anat., ch. 
 vi-xvii.- — Duvernoy, Obs. anat., 2, 3, 4 ; in the Comm. Petrop., vol. vii. 1740, p. 216- 
 218. — Lauth, De glandula thyroideâ, Strasburg-, 1742.— Morgagni, Ep. anat., 
 Venice, 1763, vol. ix.'§ 30^10. — Uttini, De glandules thyroideœ usu : in the Comm. 
 Bonon., vol. vii. p. 15-23. — Lalouette, Recherches anatomiques sur la glande thy- 
 roïde ; in the Mem. prés., vol. i. 1750, p. 159-175. — Gunz, Obs. anat. I. sur la glande 
 thyroids, ibid., p. 283-284. — Schmidtmuller, Leber die Ausfuhrungsgange der 
 Schilddrüse, Landshut, 1804. — B. Hofrichter, Mémoire sur la thyroïde, in the Journ. 
 compl. des sc. méd., \ ol. x. p. 21. 
 
 (2) Duvernoy, loc. cil. — Lalouette, loc. cit., p. 163. — Morgagni, Ep. IX. a. 34. — 
 Schmidtmuller, loc. cit. 
 
 (3) We have most generally found it, and Morgagni (Ep. anat. x. a. 36) has ob- 
 served it to be absent only six times in a great many cadavers. 
 
 (4) Schmidtmuller, loc. cit., p. 29. 
 
362 
 
 DESCRIPTIVE ANATOMY. 
 
 not extend so high, and is inserted in the lower edge of the thyroid car- 
 tilage. In the latter case the middle horn is very slightly developed. 
 
 This muscle participates in the asymmetrical arrangement of the 
 middle horn of the thyroid gland, so that it generally belongs to the 
 left half of this latter, more than to its right portion : it however is not 
 always attached to the same side of the hyoid bone, or of the thyroid 
 cartilage, but sometimes passes obliquely before the trachea or the 
 larynx, to arrive at the opposite side. This arrangement, which ap- 
 parently renders it still less symmetrical, although it really tends to 
 re-establish the symmetry, occurs particularly when it is attached to 
 the thyroid cartilage, and is then inserted in its inner edge, on the out- 
 side of the crico-thyroideus muscle. 
 
 § 2329. Each of the lateral horns is generally two inches high, 
 while the height of the isthmus is only one inch. The entire breadth 
 of the gland is about eight inches ; that of each horn is nine lines. 
 The whole gland weighs about one ounce. 
 
 2330. The thyroid gland is of a dirty red color; its texture is firm 
 and solid, its surface is smooth. It has no proper capsule, and is sur- 
 rounded only by a condensed cellular tissue ; it is composed of large 
 and small rounded, irregular lobes, each enveloped by a cellular sheath, 
 between which the vessels are distributed. It normally contains no 
 cavity ; however, when we make an incision, either into the lobes or 
 between them, a fluid analogous to the serum of the blood, oozes in 
 great abundance from the wound. 
 
 § 2331. For a long time it has been disputed whether the thyroid 
 gland has excretory ducts 1 
 
 Several anatomists, as Vater, (1) Santorini, (2) Coschwitz,(3) and 
 Schmidtmuller,(4) have thought they saw one or more passages 
 which extended from the gland into the larynx or trachea. They have 
 attempted to consider the middle horn as an excretory canal, both from 
 its form and the openings in the larynx on a level with its upper extre- 
 mity. But the observations in support of this opinion are so trivial, 
 and the most distinguished anatomists who have made them, have 
 thought them of so little importance, that as yet we have reason to 
 consider, with Duvernoy, Morgagni, and others, the thyroid gland as 
 having no excretory passage, or none except the lymphatic vessels. 
 
 As the thyroid gland is proportionally much larger during the early 
 periods of life, and as particularly its middle horn is then much more 
 developed than in the adult, perhaps the excretory canal exists at this 
 period, and is obliterated as the development of the gland is arrested, 
 so that the imperfect development of the glands from a deviation in 
 formation, often results from the absence or obliteration of their ex- 
 cretory passages. 
 
 (1) Denov. duct, saliv. in lingua, humana; in Haller, Coll, diss ., vol. i. p. 63. 
 
 (2) Loc. cit., p. 115. 
 
 (3) Ductus salivai, novus plurib. observ. illustr Halle, 1729, p. 10. 
 
 (4) Loc. cit., p. 45-51. 
 
OF THE RESPIRATORY SYSTEM. 
 
 363 
 
 B. DIFFERENCES RELATIVE TO SEX. 
 
 § 2332. The thyroid gland is more developed in the female than in 
 the male, which constitutes a very remarkable sexual difference. 
 
 C. DIFFERENCES DEPENDENT ON DEVELOPMENT. 
 
 § 2333. The thyroid gland is at first formed of two separate glands, 
 one of which is much larger proportionally than it is when the body is 
 entirely developed, softer, more vascular, and consequently redder. Its 
 middle horn, particularly, is much larger than it is subsequently. 
 
 D. ABNORMAL STATE. 
 
 § 2334. The thyroid gland is sometimes, but very rarely, as Mor- 
 gagni has remarked, (1) divided into two distinct and separate halves. 
 This anomaly is very remarkable on account of its relations with the 
 state of the organ in the early periods of fetal existence, and because it 
 occurs normally in most mammalia. An arrangement resembling it, 
 is the considerable narrowness of the central portion or of the isthmus. 
 Sometimes only a portion of a lobe is separated from the rest of the 
 gland. (2) 
 
 Rather a common deviation of formation, but which is most gene- 
 rally consecutive, and rarely congenital, is the enlargement of the thy- 
 roid gland, which constitutes goitre ( struma ) ; this is frequently enor- 
 mous, and is endemic in the narrow valleys of mountainous countries: 
 The goitre, however, by no means always depends simply on an in- 
 crease in the size of the thyroid gland : it is frequently only a conse- 
 quence of the development of new formations in the tissue of this organ, 
 or at least presents a conplication of the two states. 
 
 Hypertrophy of the thyroid gland, when not endemic, is much more 
 frequent in females than in males. It appears particularly at puberty, (3) 
 gestation, parturition, and lying in. 
 
 The abnormal formations occurring in the thyroid gland, are princi- 
 pally repetitions of normal organic elements, as serous cysts filled with 
 different fluids, also cartilages, fibro-cartilages, and bones : all these 
 formations frequently coexist. 
 
 § 2335. From what precedes, it follows, as we have already re- 
 marked, that in its situation and form, the thyroid gland is'a repetition, 
 in the upper half of the bodj», of the uterus and prostate gland. This 
 
 (1) Ep. IX. a. 30. 
 
 (2) Haller, El. physiol., vol. iii. p. 396. 
 
 (3) Journal de médecine de Sédillot, vol. lvii. p. 416. We there read the remark- 
 able case of a boy fourteen years old, in whom the thyroid gland was so much swelled, 
 without any external cause, as to produce suffocation. 
 
364 
 
 DESCRIPTIVE ANATOMY, 
 
 analogy seems to us more just, because we frequently remark the same 
 anomalies in both these parts at the same time in the same subject. 
 
 II. THYMUS GLAND. 
 
 A. NORMAL STATE. 
 
 § 2336. The thymus gland ( Gl . thymus , s. corpus thymianum)(\) 
 is an irregular square or quadrilateral body, the base of which looks 
 downward, and the summit upward, which occupies the upper and 
 anterior part of the anterior mediastinum, where it is situated directly 
 behind the sternum, before the base of the heart and the large vessels. 
 It as'cends also more or less out of the chest for about half an inch, and 
 extends on the anterior face of the neck, where it is covered by the 
 sterno-hyoidei and sterno-thyroidei muscles. 
 
 Its height and breadth much exceed its thickness. 
 
 Its length generally exceeds its breadth. Although it gradually 
 contracts towards its summit, it however generally presents a more or 
 less considerable prominence at its upper extremity. 
 
 § 2337. Its color is reddish white, and it is soft. 
 
 Its vessels, which are not very large, arise anteriorly, enter it from 
 above downward, from behind forward, and from before backward. 
 But each of its lobes has not a special trunk, and receives vessels from 
 several regions at once. 
 
 § 2338. Beside an external envelop, which is given to it by the an- 
 terior mediastinum, the thymus gland has still a less dense or less solid 
 proper cellular capsule, below which the fat collects here and there in 
 corpulent persons, but does not accumulate in any great quantity. 
 
 After removing this capsule, the thymus gland is itself divided into 
 a right and a left half. Its two lateral lobes are attached only by 
 very loose cellular tissue, and by the vessels which penetrate them, so 
 that it would be more correct to admit two thymus glands. 
 
 These two halves, which are also triangular, and the two internal 
 faces,- are situated one against another in their whole extent, are simi- 
 lar in form and volume, but are not exactly alike : one of them is some- 
 times about one tenth larger and heavier than the other. 
 
 The external envelop of the thymus gland will show that its surface 
 is not smooth and uniform, but divided into several larger and smaller 
 lobes, which are composed of smaller lobules, separated less deeply 
 from each other, between which the two external envelops do not 
 
 • ' 
 
 (1) G. E. Mctzg-er, Hist. anal. med. thy'mi, Tubingen, 1679. — G. H. Muller, De 
 glandula thymo, Leyden, 1705. — Verheyen, Dc tliymo, Leyden, 1706. — G. Bidloo, 
 Defens, exer de thymo , Leyden, 1707. — J. G. Duvernoy, in the Comm. Petrop., vol. 
 vii.— A. L. de Hugo, De glandidis et speciatim de thymo , Gottingen, 1746. — G. Hew- 
 son, Experimental inquiries , part iii. London, 1717. — Lucse, Anatomische Unter* 
 su/hungen der Thymus in Menschen und Thieren, Frankfort, 1811-12, 
 
OF THE RESPIRATORY SYSTEM. 
 
 365 
 
 penetrate more than between the two great lateral lobes, and which 
 are united only by a loose cellular tissue and by vessels. 
 
 § 2339. On cutting the thymus gland, there flows out spontaneously, 
 or by pressure, a fluid, differing from its own substance, more or less 
 abundant, thick and whitish, similar to that which exists in the ru- 
 minantia, between the fetal and maternal portions of the placenta. 
 
 Opinions differdn regard to the relations between this liquid and the 
 substance of the organ. With this question is connected another : Is 
 the thymus gland hollow % 
 
 Many anatomists assert there is no cavity in the gland, and this 
 fluid is consequently contained in its substance. Others think that the 
 lobules alone are really hollow. Finally, some admit a great cavity 
 the parietes of which are formed by the substance of the organ. 
 
 We maintain the latter opinion : for in examining very recent thy- 
 mus glands, we have several times observed either on cutting them 
 or slightly inflating them, a large cavity in each of the two lateral 
 lobes. This cavity is lined by a thin and smooth membrane. It com- 
 municates with those in the lobules, and contains a great quantity of 
 the fluid mentioned above. 
 
 Sometimes, however, this cavity is less apparent, so that very pos- 
 sibly the internal arrangement of the thymus gland is not always per- 
 fectly the same. Thus, in some cases, the lateral cavities are divided 
 into several compartments by intermediate septa. Sometimes, how- 
 ever, we find the arrangement maintained by the partisans of the 
 second opinion to be constant, and to which the preceding impercep- 
 tibly leads. 
 
 § 2340. The thymus gland does not continue to exist during life. 
 
 It is first seen in the third month of gestation. 
 
 It is at first proportionally smaller than at a more advanced period, 
 and its proportional size increases till the moment of birth. 
 
 In the full-grown fetus it weighs half an ounce, and sometimes a 
 drachm more when the child is vigorous and strong. 
 
 Its upper part appears first, and it enlarges from above downward. 
 
 Although it is not proportionally as large until the end of the first 
 year, and sometimes even till that of the second, it continues to grow 
 during all this period in the same proportion as in the full grown fetus. 
 
 But at this period it wastes, its vessels contract, and the fluid it se- 
 cretes diminishes. It disappears in a direction opposite to that in 
 which it was formed, that is from below upward. 
 
 At twelve years of age we find no trace of it, and it is then replaced 
 by fat. 
 
 From this we may conclude that it does not exist except for about 
 the fifth part of life, and that the energy of its function declines long 
 before it disappears. Its most flourishing period is -consequently very 
 different from that at which most other organs have attained their 
 greatest development. 
 
 VOL. III. 
 
 47 
 
3C6 
 
 DESCRIPTIVE ANATOMY. 
 
 § 2341. We have already mentioned in a general manner its func- 
 tions : several circumstances lead us to think it is very intimately con- 
 nected with respiration, and more or less replaces it. We may, how- 
 ever, easily reconcile the two conjectures, since from what we have 
 said above, the use of the thymus gland, is to prepare for the perfect 
 formation of the blood by respiration. 
 
 B. ABNORMAL STATE. 
 
 § 2342. The greatest anomaly of the thymus gland is its absence, 
 which is generally observed in acephalia vera. 
 
 Its smallness, when the organ is perfectly developed in respect to the 
 number of its parts, is commonly attended with a languid state in nu- 
 trition generally. We have sometimes seen this anomaly also in ace- 
 phalia falsa. 
 
 The thymus gland is rarely in this case divided into several, even as 
 many as five lobes.(l) 
 
 Its continuance at the degree of development which characterizes it 
 in the early periods of life, sometimes attends abnormal formations of 
 the heart, and those states of the lungs which prevent the perfect for- 
 mation of the blood. (2) This then supports our opinion advanced above 
 in regard to its functions. 
 
 As this organ disappears very early, alterations in its texture are 
 proportionally rare. We may, however, mention as such, different 
 kinds of tumors, although in many cases those mentioned by authors 
 are developed only in the place occupied by the thymus gland, and 
 after it has disappeared. 
 
 CHAPTER III. 
 
 OF THE URINARY SYSTEM AND RENAL CAPSULES, 
 ARTICLE FIRST. 
 
 URINARY SYSTEM. 
 
 A. PERFECT STATE. 
 
 § 2343. The urinary organs ( organa uropoetica)(3 ) are composed 
 of four parts destined, to secrete, carry, preserve, and excrete the urine, 
 
 (1) Meckel, Handbuch der pathologischen Anatomie, vol. i. p. 488. 
 
 (2) Meckel, Abhandlungen , p. 234. 
 
 (3) G. Bendt, Defabrica et usu viscerum uropoeticorum, Leyden, 1744. — J. Fan- 
 toni, De renibus et primum de succenturiatis, de ureteribus et vesica, Turin, 1745. — 
 A. Richerand, Mémoire sur V appareil urinaire ; in the Mém. de là soc. méd. d'émul. 
 vol. iv. p. 303. 
 
OF THE URINARY SYSTEM. 
 
 367 
 
 viz. the kidneys, the ureters , the bladder, and the urethra. The last 
 three organs may be opposed to the first. These are entirely excre- 
 tory organs, for they carry nothing which can be useful to the organ- 
 ism, remove from the body an excess of azote, which is the base of the 
 most essential constituent principle of the urine, the urea , and cor- 
 respond in form and situation in. the lower half of the body, to the re- 
 spiratory organs in the upper. 
 
 Ï. KIDNEYS.. 
 
 A. NUMBER AND SITUATION. 
 
 § 2344. The kidneys (renes),( 1) the most essential part of the uri- 
 nary apparatus, are double in the normal state, a right and a left ; they 
 are entirely distinct from each other, having no communication in sub- 
 stance, and connected in one system only by means of the bladder. 
 They are situated in the lumbar region, on the two sides of the verte- 
 bral column, behind the peritoneum, and are connected with the adja- 
 cent parts only by loose cellular tissue. 
 
 B. FORM. 
 
 § 2345. They have the form of a bean. Their anterior and pos- 
 terior faces are smooth. Their, external and internal edges are convex 
 in their upper and lower parts, but in their centres is a considerable 
 depression, termed the fissure of the kidney (hilus renalis). The kid- 
 ney is divided in this part for about half an inch, into an anterior and a 
 posterior half, between which pass the excretory duct and -the blood- 
 vessels. The blood-vessels are arranged so that the venous trunk is 
 situated before, and followed by that of the artery, behind which the 
 ureter commences. 
 
 The branches of the renal artery and vein intercross. 
 
 When the three vessels have arrived at the fissure of the kidney, 
 they divide near the inner edge of the gland into three principal 
 branches, which soon ramify. The blood-vessels then divide into two 
 series, an anterior and a posterior, which receive the vessels of the 
 pelvis. 
 
 (1) B. Eustachi, De renibus libellus, Venice, 1543. — J. Lœsel, Scrutinium renum, 
 Königsberg-, 1642.— M. Malpighi, De renibus, in ex. de viscerum structura. — L. 
 Bellini, De structura renum, Florence, 1662.— Bertin, Mémoire pour servir a l’ his- 
 toire des reins, in the Mémoires de Paris, 1745, p. 108. — A. Ferrein, Sur la structure 
 des viscères nommés glanduleux, et particuliérement sur celle des reins et du foie ; 
 in the Mém. de Paris, 1749, p. 709.— J. F. Droysçn, De renibus et capsulis renalibus, 
 Gottingen, 1752. — A. Schumlanski, De structura renum , Strasburg, 1788. — C..G. 
 Eysenhardt, De structura renum observaliones microscopicce, Berlin, 1818. — A. H. 
 C. Westrumb, Comment, phys. de phœnomenis quæ ad vins sic dictas lotii clandes- 
 tinas demonstrandas referentur, Gottingen, 1819.— Mappes, Quelques considéra- 
 tions sur la structure du rein et du foie ; in the Journ. compl. des sc. méd. vol. xii. 
 p. 223. 
 
363 
 
 DESCRIPTIVE ANATOMY. 
 
 All these vessels are united in the fissure of the kidney only by a 
 very loose cellular tissue and by fat. 
 
 Three particularly enter and emerge through the upper part of the 
 renal fissure, the lower part of which is occupied by the pelvis. 
 
 C. VOLUME AND WEIGHT. 
 
 § 2346. The proportional size of the kidneys varies. Generally 
 these organs are larger the .nearer the fetus is to its period of forma- 
 tion : they however present, even under this point of view, individual 
 differences, which are independent of the age, and which seem to re- 
 late to the size and energy of the other excretory organs. 
 
 Generally speaking, the two kidneys are equal in size : both, how- 
 ever, frequently vary extremely, although the side of the body has no 
 effect upon it. The ancients asserted that the right kidney is always 
 larger than the left, which is incorrect. 
 
 In the adult’ they are about four inches long and two broad. They 
 are about an inch thick at their inner part, but are thinner outward. 
 
 Each of them weighs between three or four ounces. 
 
 D. CONSISTENCE AND COLOR. 
 
 § 2347. The kidneys are much harder than the other glands, and 
 are firmer, more solid, and less easily torn. 
 
 They are generally reddish. 
 
 E. STRUCTURE. 
 
 § 2348. They are surrounded by a very loose cellular tissue, most 
 generally abundantly provided with fat, and termed the adipose mem- 
 brane. , or capsule of the kidney (mem. s. capsula renum adiposa ). 
 
 We find below this cellular mass a whitish membrane, reddish on 
 its two faces, the texture of which is not evidently fibrous, but which 
 is very solid, and resembles the fibrous membranes. This capsule en- 
 velops the entire kidney ; it only presents an opening corresponding to 
 the fissure, for the passage of the blood-vessels and the excretory duct, 
 and it adheres intimately in its whole extent to the substance organ, 
 
 F. TEXTURE. 
 
 § 2349. The kidneys are formed of two substances, which differ 
 much in color, situation, consistence, and texture. They are the corti- 
 cal or glandular substance ( substantia corticalis , s. glandtdosa ), and 
 the medullary , tubular , or fibrous substance ( s . medullaris , tubulosa, s. 
 fibrosa). 
 
 § 2350. The cortical surrounds the medullary substance in most of 
 its extent, and in every direction. It not only forms entirely the outer 
 
OF THE URINARY SYSTEM. 
 
 369 
 
 face of the kidney, but extends also to its inner face by several arched 
 prolongations, between which the medullary substance is situated. It 
 consequently forms a collection of cavities, united by a common base, 
 the culs-de-sac of which are turned outwaid. 
 
 Thus the cortical substance forms the external and colored part of 
 the kidney ; it is about two or three lines thick : its color is redder than 
 that of the medullary substance, and it is much less consistent. 
 
 It is composed principally of blood-vessels and glandular bodies, 
 which are the organs of the urinary passages. The urine is secreted 
 in it. 
 
 § 2351. The medullary substance is inclosed in the preceding, and is 
 composed of a mass of rounded, conical, or pyramidal bodies ( pyramides 
 malpighianœ ), the bases of which are turned outward, and the blunt 
 summits inward ; if we except the most internal part, which is only 
 some lines high and broad, and which constitutes the renal papilla 
 {papilla renales ), it is entirely enveloped by medullary substance. 
 
 It opens in this place into the commencement of the ureter or pelvis. 
 
 The summit of the renal papillæ usually, but not always, presents a 
 greater or less number of rounded openings, which although small, are 
 visible to the naked eye. The papillæ, which have a depression, pre- 
 sent openings only in this groove, while in those which terminate 
 simply in a point, the foramina are arranged around the summit. 
 
 The loose extremity of these papillæ is covered by thick envelops, 
 which is continuous with the inner membrane of the pelvis. 
 
 The number of these papillæ varies from seven to twenty. They 
 are distributed in three series, a middle, an anterior, and a posterior, all 
 of which are directed from above downward. Those of the inner series 
 are turned inward towards the median line of the body : those of the 
 anterior go backward, and those of the posterior forward, that is in a 
 direction opposite to the preceding. The superior go downward in 
 every direction. 
 
 Sometimes the papillæ, which are entirely distinct at their base, unite 
 and blend at their summit. 
 
 The medullary substance is less red and much harder than the cor- 
 tical. 
 
 It is composed of blood-vessels, but particularly of straight urinary 
 passages, with which the foramina of the papillæ communicate. 
 
 The urine is secreted in it, as when it is compressed, this fluid es- 
 capes from the excretory passages which form most of it, through the 
 foramina of the papillæ. 
 
 § 2552. From this description it follows that the kidneys are com- 
 posed of about fifteen segments, termed lobules (lobuli renales , s. ren- 
 culi ), each of which is formed in turn of medullary and of cortical sub- 
 stance, and the cortical envelops of which are continuous with each 
 other. 
 
 § 2353. The intimate structure of the kidneys is demonstrated by 
 maceration, injection, and the microscope. 
 
370 
 
 DESCRIPTIVE ANATOMY. 
 
 § 2354. The surface of the cortical substance is not smooth, but 
 seems formed by numerous irregular, rounded, quadrangular, penta- 
 gonal, or hexagonal spaces, arranged very compactly, which are not 
 half a line in diameter. These spaces are confined by small vessels, 
 which send branches within them : they consequently have a brighter 
 color than that of their edges, which are formed by these vessels. 
 
 We also find in every part in the cortical substance, rounded cor- 
 puscles, appearing to the naked eye as very small points. These cor- 
 puscles depend on the most minute ramifications of the blood-vessels, 
 particularly the arteries, andin connection with them they have the 
 form of a bunch of grapes. 
 
 • Some anatomists, especially Malpighi, Bertin, and Schumlansky, 
 consider them as special organs, different from the branches of the ves- 
 sels, as glands or bursts, on the parietes of which the vessels are dis- 
 tributed. Farther, authors are not agreed in respect to them, for Bertin 
 has described and figured -them much larger than those admitted by 
 Malpighi, while the observations of Schumlansky, from which those 
 pf Eysenhardt do not essentially differ, agree with the assertions of 
 Malpighi. Others, as Ruysch, consider these corpuscles not as glands, 
 but. as branches of vessels. 
 
 It is more probable that they are formed by the twigs of the arteries, 
 and by the roots of the excretory passages in the cortical substances, 
 united, by a mucous tissue, and that they are not hollow. In this man- 
 ner the two opinions may be reconciled. 
 
 The urine is undoubtedly formed, at least in great part, in these cor- 
 puscles. 
 
 They seem not to have a special envelop, and they are formed, at 
 least generally, by a single arterial twig. 
 
 They are not seen to communicate distinctly with the veins, al- 
 though the transition of them to the arteries is easity perceived. 
 
 § 2355. Besides these glandular corpuscles, the vascular ramifica- 
 tions to which we shall return hereafter, and finally the soft and whitish 
 tissue which unites all these parts, and to which Ferrein particularly 
 has called the attention of anatomists, the cortical substance also in- 
 cludes numerous small, white, and very tortuous canals, called the 
 cortical canals , or ducts of Ferrein ( C . corticales). These passages 
 frequently anastomose together, usually proceed separately, sometimes 
 unite in pairs, and circumscribe small and infinitely varied spaces. 
 They compose most of the cortical substance, and are very probably 
 the excretory canals of the corpuscles above mentioned. 
 
 These canals are tortuous in the cortical substance, but become 
 straight in the medullary substance.' When looked at attentively we 
 observe here and there that the change in direction regularly com- 
 mences rather high, some distance from the surface of the kidney, so 
 that the cylindrical prolongations of the medullary and the cortical 
 substance reciprocally penetrate in numerous points. 
 
 The cortical canals are single, and always have the same diameter 
 in the cortical substance ; but they gradually unite in the medullary 
 
OF THE URINARY SYSTEM. 
 
 371 
 
 substance in the form of angles acute at the base, into several trunks, 
 which generally are not much larger than they, and proceed side by 
 side toward the summit of the papillæ ; but according to some anato- 
 mists, particularly Ferrein and Eysenhardt, they do not extend to the 
 openings in these papillæ, but terminate before arriving there. The 
 same writers add that the openings of the papillæ only lead into small 
 culs-de-sac about one or two lines deep, which like them are much 
 broader than the canals of which we speak , and also fewer, there 
 being according to Ferrein, twenty in each papilla. 
 
 We have sometimes seen very distinctly some canals which ex- 
 tended entirely through the renal papillæ, so that we admit a direct 
 continuity between the urinary passages and the openings of the pa- 
 pillary eminences. We are more disposed to adopt this opinion, as it 
 is very easy to inflate the passages through the papillæ, since in large 
 animals even an injection passes from the artery into the whole pa- 
 pilla, and urine is pressed out from it in compressing the cortical sub- 
 stance. 
 
 § 2356. Each lobule of the kidneys then is composed of several 
 masses of canals, which are at first tortuous, then straight, arranged 
 very compactly, which have their base turned upward, their summit 
 downward, but represent the form of the whole, and are only more 
 elongated. 
 
 The right part of these canals, which is contained in the medullary 
 substance, has long been known, for it is mentioned by Berenger de 
 Carpi ; but it is described most correctly by Bellini : hence they are 
 termed the ducts of Bellini ( ductus , s. tubuli Belliuiani , s. renales). 
 
 Until the time of Ferrein these canals, which are visible to the naked 
 eye, were thought to be simple : but it follows from the researches of 
 this anatomist and those of Schumlansky, that each is a fasciculus of 
 several hundred passages, termed the pyramid of Ferrein. 
 
 Each tortuous canal is about one sixtieth of a line in diameter. The 
 total length of all these passages collectively is, according to Ferrein’s 
 estimate, more than sixty thousand feet. There are in each lobule 
 seven hundred pyramids, and hence as each kidney is composed of 
 fifteen lobules, there are about ten thousand pyramids. 
 
 According to Eysenhardt’s observations, each canal of the pyramids 
 of Ferrein is composed of about twenty smaller ducts.(l) 
 
 But there is certainly much incorrectness and latitude in these as- 
 sertions. 
 
 G. VESSELS. 
 
 § 2357. The two series of vessels, after being arranged in the fis- 
 sure of the kidney in the manner mentioned above, enter into the sub- 
 stance of the organ on a level with the base of the renal papillæ, and 
 
 (1) Eysenhardt, p 12. 
 
372 
 
 DESCRIPTIVE ANATOMY. 
 
 go from below upward in the prolongations sent inward by the cortical 
 substance. 
 
 Their branches describe arches turned towards one another, which 
 principally surround the bases of the pyramids of Ferrein or the dif- 
 ferent segments of the inner substance. Between these arches the 
 anastomoses are but few and small. Although they follow the divi- 
 sions of the medullary substance they are not distributed within it, but 
 almost exclusively in the cortical substance, first in the segments be- 
 tween the papillæ, then in the outer layer of the kidney. 
 
 Numerous small branches radiate from the convexity of the largest ; 
 these surround the base of each lobule, and ramify more and more to 
 give rise finally to glandular corpuscles. Many of these branches 
 penetrate to the external face of the kidney : others do not extend 
 so far. 
 
 The arteries and the veins reciprocally attend each other. Still, al- 
 though the direct communication between these two orders of vessels, 
 is admitted and is easily observed, we are as yet unable to discover 
 any between the most minute twigs of the veins and the glandular 
 corpuscles, while these latter adhere very intimately to the ramifica- 
 tions of the arteries, with which they represent, as we have already 
 mentioned, a bunch of grapes. 
 
 Numerous lymphatics arise from the kidneys, but these present no- 
 thing peculiar in the direction of their vessels. 
 
 • H. NERVES. 
 
 § 2358. The nerves of the kidney are proportionally very small ; 
 they arise from the renal plexus of the great sympathetic nerve, are 
 situated on the surface of the arteries, but do not penetrate deeply into 
 the organ. 
 
 II. URETER. 
 
 § 2359. The ureter(l) commences at the fissure of the kidney by 
 several rounded canals, the calices, which embrace the papillae, and 
 terminate suddenly or rather become thinner rapidly at their bases, and 
 are continuous with their external membrane. 
 
 The number of calices generally but not always equals that of the 
 papillæ. Sometimes a calix divided only into two compartments by a 
 slight .prominence embraces two papillæ, which are then .near each 
 other, a structure which leads to the union of two of these prolonga- 
 tions in one. 
 
 The others generally contract in two large trunks, a superior and 
 an inferior, which are termed the branches of the pelvis. The superior 
 
 (1) Pohl, Obs. de ureteribus, Leipsir, 1772. 
 
OF THE URINARY SYSTEM. 
 
 373 
 
 trunk is generally larger and composed of two branches. The two 
 trunks are united by a narrower intermediate canal, which descends 
 longitudinally. 
 
 The pelvis, which gradually terminates in a point from above down- 
 ward, on a level with the lower extremity of the fissure of the kidney, 
 is as small as the ureter. 
 
 The ureter is about two lines broad and a little tortuous ; it is sur- 
 rounded by a very loose cellular tissue, and descends on the psoas mus- 
 cle behind the posterior wall of the peritoneum. It crosses the spermatic 
 vessels situated before it and above the primitive iliac artery, to enter 
 into the pelvis : it then approaches that of the opposite side, being 
 about an inch and a half distant from it, and arrives at the lower and 
 posterior part of the bladder. After proceeding three or four lines be- 
 tween the fibres of its muscular tunic, forming a prominence directed 
 from above downward and from without inward, it opens by an orifice 
 which is slightly narrower, having the same direction, but no valve. 
 
 § 2360. The ureter is formed of two superimposed layers. The ex- 
 ternal is composed of a compact cellular tissue. It has a fibrous ap- 
 pearance, but no muscular fibres. The internal is a thin and smooth 
 mucous membrane, which is continuous above with that of the renal 
 papillæ, below with that of the bladder. 
 
 This canal has no valves. (1) 
 
 III. BLADDER. 
 
 § 2361. The bladdçr( 2) ( vesica urinaria ) is an elongated rounded 
 reservoir, the length of which exceeds its breadth and thickness ; it is 
 situated in the cavity of the pelvis, behind the symphysis pubis, on 
 the outside of the peritoneum, before the rectum in the male and 
 the vagina in the female, and is surrounded by a very loose cellular 
 tissue.(3) 
 
 (1) Coschwitz, De valvulis ureterum, Halle, 1723. 
 
 (2) J. Parsons, Description of the human urinary bladder and the parts belonging 
 to it, London, 1742. — A. P. Walter, Decolto vesicœ virilis , Leipsic, 1745.— J. Lieutaud, 
 Observ. anat. sur la structure de la vessie; in the Mém. de Paris, 1753. — J. Van 
 Beekhoven de Wind, Diss. de ureteribus et vesicà urinaria, Leyden, 1784. 
 
 (3) As the recto-vesical operation for stone, which becomes more advantageously 
 known every day, requires a very exact knowledge of the anatomical relations of 
 the bladder, we shall quote here the description of it by Sanson. (Des moyens de 
 parvenir à la vessie par le rectum, Paris, 1817, p. 15.) The base of the bladder is 
 extended from behind forward, from the recto-vesical layer of the peritoneum to the 
 origin of the urethra, is continuous on the sides with the lateral regions of the organ, 
 although there is no very distinct line of demarkation between them, and its dimen- 
 sions are nearly equal in every direction : it is united by firm adhesions to the ureters, 
 the vasa deferentia and the vesiculæ séminales, which passing through it obliquely 
 from behind forward and from without inward, thus divide It into three surfaces, 
 two of which are lateral, convex, broader anteriorly than posteriorly, situated on the 
 outside of the seminal vesicles, and correspond to an abundant and fatty cellular 
 tissue, which separates them from the levatores ani muscles, while the third, the 
 central, exists between the testicles, is triangular, having a base which looks back- 
 
 Vol. III. 48 
 
374 
 
 DESCRIPTIVE ANATOMY. 
 
 We distinguish in the bladder an upper and rounded part, termed 
 the base (fundus), a central part, the body, and an inferior part, the 
 neck ( cervix , s. collum vesicœ urinariœ). 
 
 We must regard it as an excessive common dilatation of the ureters, 
 which curves from below upward on leaving the lower extremity of 
 these two passages. 
 
 It is continuous at its lower extremity with the urethra, at the upper 
 with the urachus, a kind of ligament which proceeds towards the um- 
 bilicus along the anterior wall of the anterior face of the peritoneum, 
 gradually becoming thinner. 
 
 § 2362. The bladder is composed in its whole extent of three super- 
 imposed layers : but in the upper part of its posterior face there are 
 
 four. 
 
 The fourth layer is the most external, and covers the organ only in 
 the place mentioned ; it is the anterior part of the inferior wall of the 
 peritoneum. 
 
 This membrane, which adheres to the subjacent muscular tunic by 
 a very loose cellular tissue, is reflected from the bladder on the upper 
 part of the anterior face of the uterus. The rest and largest part of 
 the bladder is covered only by a very loose layer of cellular tissue, 
 which unites it to the adjacent organs. 
 
 ward, and corresponds to the peritoneum, and a summit turned forward, which 
 looks to the prostate gland and rests directly on the centre of the rectum, and follows 
 its curve exactly to the gland. It is there separated from it, and goes obliquely from 
 behind forward and a little from below upward to the neck of the bladder, where if 
 blends with the origin of the urethra, which may be regarded in some measure as 
 its continuation. 'I his latter, the origin of which is embraced by the prostate gland 
 and blended with the neck of the bladder, is not by any means so near the symphysis 
 pubis as has hitherto been believed, since, placed upon a line which would extend 
 from the lower part of this symphysis to the summit of the coccyx, it is about two 
 inches distant from it, first passes through the prostate gland, approaching the rec- 
 tum a little, then becoming loose goes directly towards the root of the penis, entering 
 it below the arch of the pubis, from which it is about fifteen lines distant ; at the 
 same time it is about fifteen lines distant from the intestine, with which it forms an 
 angle open towards the perineum. The skin of this region and the prolongation 
 of the sphincter downward, the urethra forward, and the last portion of the rectum 
 provided with this same spliincter posteriorly, form the three sides of a triangular 
 space filled by fatty cellular tissue, the base of which corresponds to the raphe, and at 
 the summit of which is the prostate gland. If, taking the cavity of the rectum for 
 a point of departure, we examine the parts before the intestine in the order in which 
 they appear, following the median line of the body, we find : 1st, on leaving the 
 central portion, and proceeding obliquely from behind forward and from below up- 
 ward, the anterior wall of this portion, a more or less dense layer of loose cellular 
 tissue containing a net-work of small veins, the lower wall of the bladder and its 
 cavity; 2d, on leaving the curve formed by the intestine below this region to go 
 towards the anus, and following a more horizontal direction : the anterior wall of the 
 rectum, a thin compact layer of cellular tissue, the prostate gland perforated by the 
 part of the urethra where we remark the crest of the urethra and the orifices of the 
 vasa deferentia ; 3d, finally, on leaving the lowest part of the intestine, and following 
 a horizontal line from before backward, the anterior wall of the rectum united to 
 the sphincter, the triangular space mentioned above, and entirely forward, the bulb 
 of the urethra and the posterior part of the bulbo-cayernosus muscle. In following 
 this direction, proceeding from any point whatever, we open no vessels, except the 
 capillary anastomoses which establish the communication between the two sides of 
 he vascular system. F. T. 
 
OF THE URINARY SYSTEM . 
 
 375 
 
 The texture of the muscular membrane is very complex : it may, 
 however, generally be reduced to two superimposed layers, which, 
 however, interlace at intervals. 
 
 The external layer, the strongest and most compact, is formed of 
 longitudinal fibres ; these fibres ascend from the lower extremity of 
 the anterior and posterior faces of the bladder toward the base of the 
 organ, where they partly anastomose with each other, and partly also 
 go from within outward. 
 
 The posterior external fibres are reflected from above downward 
 some lines below the urethra, go thence forward and upward, and are 
 then continuous, from without inward, with the anterior longitudi- 
 nal layer. 
 
 The lateral faces are mostly destitute of longitudinal fibres. 
 
 The internal layer is formed almost entirely of oblique fibres which 
 proceed in opposite directions, so that they frequently intercross and 
 interlace together. 
 
 The inferior are entirely transverse, and are more compact. They 
 form the sphincter of the bladder (JVf. sphincter vesicœ urinaria ). 
 
 The others are more remote from each other, and represent a net- 
 work, through the meshes of which we observe the inner membranes 
 when the bladder is distended. 
 
 Below this second layer we find in several parts, but principally 
 downward, some thinner muscular fibres arranged longitudinally, 
 which form in this place a third layer. 
 
 § 2363. Next to the muscular tunic come the vascular membrane, 
 which is very thin, and the mucous membrane. The latter is appa- 
 rently smooth, or at least its villosities are very minute. There are 
 generally no muciparous glands visible on its posterior face, except at 
 the neck of the bladder ; these glands, however, may sometimes be 
 seen when morbidly enlarged. 
 
 § 2364. The internal face of the bladder is smooth in nearly its 
 whole extent, except some inconstant prominences, which are often 
 produced by the internal muscular layer. 
 
 The posterior face of the neck, however, presents an eminence which 
 leaves the orifice of each ureter, is directed downward and inward, 
 unites below at an obtuse angle with that of the opposite side, on the 
 median line, and thus gives rise to an angle projecting downward, 
 termed the trigonus of the bladder or of Lieutaud. 
 
 This eminence is formed by some fasciculi of the internal muscular 
 fibres, which are more numerous in this part, the upper extremities of 
 which are attached around the orifices of the ureters, and which in 
 contracting extend and consequently enlarge these orifices, and thus 
 facilitate the flow of urine into the bladder.(l) 
 
 • (1) C. Bell, Account of the muscles of the ureters and their effects in the irritable 
 state of the bladder ; in the Med. chir. Irans., vol. iii., p. 171-191. 
 
376 
 
 DESCRIPTIVE ANATOMY. 
 
 IV. URACHUS. 
 
 § 2365. The urachus (1) is an elongated, very thin cord, which is 
 entirely enveloped by the peritoneum ; it gradually becomes thin from 
 below upward, is attached directly to the anterior wall of the abdomi- 
 nal cavity, and goes from the base of the bladder towards the umbi- 
 licus, but frequently does not extend as high. Its fibres are more or 
 less distinctly continuous with those of the muscular membrane of the 
 bladder. 
 
 Its texture is very differently stated by anatomists. Their descrip- 
 tions vary, particularly as some admit that it is hollow in the adult, 
 while others deny it. 
 
 Walter asserts it is hollow ;(2) Noreen, Senac,(3) and Portal, on 
 the contrary, think it is full and solid. 
 
 The latter writers assert that this cord is composed, beside its peri- 
 toneal tunic, of four layers, intimately united at its upper part, that is, 
 in most of its extent ; they separate near the summit of the bladder, 
 and in passing under its muscular membrane, go, two on the sides, 
 the other two on the anterior and posterior faces of the bladder to 
 its neck. They add that these two layers unite with each other 
 and with the peritoneal coat more intimately as age advances. 
 
 Walter, on the contrary, states the urachus to be formed externally 
 by longitudinal and then by circular fibres, and after that by the vas- 
 cular and muscular membranes of the bladder. We may introduce 
 into it for some inches a sound and mercury, but it terminates at 
 the side of the umbilicus in a cul-de-sac, and often contains a reddish 
 fluid. 
 
 From our observations it follows that generally the urachus is com- 
 pletely obliterated when the body is perfectly developed, and often 
 even long before this period, and thus it is then changed into a per- 
 fectly homogeneous cord, although we have often seen the arrange- 
 ment mentioned by Walter. 
 
 Finally, Noreen and Portal themselves mention several instances of 
 this structure, which Noreen has figured very exactly. 
 
 (1) J. C. Peyer, Observât, circa urachum, Leyden, 1721. — J. Noreen, De mutatione 
 luminum in vasis hominis nascentis , in specie de uracho, Gottingen, 1749. — P. A. 
 Bœhmer, De uracho in adulto homine aperto , cum cjusd. anat. ovi hum., Halle, 1765. 
 — A. Portal, Sur la structure et sur l'usage de Vouraque dans l'homme ; in the Mém. 
 de Paris, 1769, p. 19. 
 
 (2) Obs. anat., Berlin, 1775, p. 19. 
 
 (3) Essais de physique ; in Portai, Mém. sur phis, maladies, vol. i. 
 
OF THE URINARY SYSTEM. 
 
 377 
 
 V. URETHRA. 
 
 § 2366. The urethra, { 1) the termination of the urinary system, is a 
 canal narrow in proportion to the bladder, which is continuous by its 
 inner extremity, the vesical orifice, with the neck of the bladder, and by 
 its outer extremity, the cutaneous orifice, with the common integu- 
 ments. It is composed in both sexes of a mucous membrane covered 
 with a loose and spungy cellular tissue, and a very complex vascular 
 net-work. It is much shorter in the female than in the male, being 
 about two inches long in the former and eight in the latter. The 
 urethra in the female, on the contrary, is much broader than in the 
 male. 
 
 In both sexes this canal is situated below the organs of pleasure, 
 that is, in the female below the clitoris, and in the male below the 
 corpus cavernosum of the penis, which latter it contributes to form. 
 
 From the different length of these parts it does not open at the same 
 place in the two sexes. In fact in females its external orifice is situated 
 directly before the entrance of the vagina, and between the external 
 labia ; in males at the anterior extremity of the penis. As in the male 
 it is also the excretory canal of the semen, it will be more convenient 
 to describe its texture when treating of the genital organs. 
 
 B. FUNCTIONS OF THE URINARY ORGANS. 
 
 § 2367. The function of the urinary organs is to secrete and to 
 excrete the urine {urina, lotium). 
 
 The physical qualities of this liquid are its yellowness, tenuity, 
 transparence, slight viscosity, and particularly its peculiar odor. 
 
 The urine is composed of numerous constituent parts, which vary 
 more in their proportions than number and nature, at different periods, 
 than in any other animal liquid. 
 
 One of the principal characters of its chemical composition consists 
 in the great quantity of water it contains, which forms at least nine 
 tenths of it. 
 
 The substances which in the normal state are always or most ge- 
 nerally dissolved in the water, are : 
 
 1st. Urea, which of all the animal substances possesses the most 
 azote, as it contains thirty-two per cent, according to Fourcroy and 
 Vauquelin ; forty-three per cent, according to Berard ; and even forty- 
 
 (1) A. Moreschi, Commentarium de urethrce corporis glandisque structura , Milan, 
 1817.— Amussat, Remarques sur l’urèthre de l'homme et de la femme ; in the Archiv, 
 gên. de méd., vol. iv., p. 31 and 547. — E. Home, Mém. sur la structure de l’urèthre, 
 d’après les observations microscopiques ; same journal, vol. ii., p. 140. — T. Ducamp, 
 Traité des rétentions d’urine, Paris, 1822, p. 1. 
 
378 
 
 DESCRIPTIVE ANATOMY. 
 
 six per cent, according to Prout, while there is only about twenty per 
 cent, in the fibrine. 
 
 2d. An animal substance insoluble in alcohol. 
 
 3d. Several acids, the uric(l) and the lactic. 
 
 4th. Several salts, viz. the lactate of ammonia, sulphate of potash, 
 sulphate of soda, phosphate of soda, hydrochlorate of ammonia, and 
 the earthy phosphates, with some fluate of lime. 
 
 5th. A little of silex. (2) 
 
 Besides these substances, which enter regularly into the urine, we 
 sometimes recognize by our senses several constituent principles of the 
 body introduced into the system in different modes. Thus, for in- 
 stance, rhubarb colors it a deep yellow, and asparagus communicates 
 to it a disagreeble odor. 
 
 Although these substances also occur in greater or less quantity in 
 the other excretory fluids, especially in those exhaled by the lungs 
 and the skin, and in the matters expelled directly from the intestinal 
 canal, they nevertheless occur more frequently in the urine, so that 
 the urinary system seems to be the principal excretory organ of those 
 materials which cannot be assimilated. It necessarily exercises a pe- 
 culiar attraction for these substances, in order to remove them from the 
 blood and fulfil its function. 
 
 This system is also the principal agent of purifying it in the morbid 
 state : thus the urine is more or less modified in all diseases generally. 
 
 § 2368. But the urine constantly presents differences also in regard 
 to the greater or less length of time which has elapsed between its 
 emission and taking food or drink. Upon this is founded the distinc- 
 tion between the urine of ihe drink, and the urine of digestion or of 
 the blood. But it must be admitted that these differences are very 
 slight. 
 
 The urine of the drink, which is voided directly after a meal, is very 
 watery and limpid. The urine of digestion, voided some hours after 
 eating, during the digestive process, is more colored, less watery, more 
 odorous, and usually presents the smell and taste of some of the articles 
 of food. Finally, that which is passed when digestion is finished, the 
 proper and perfect urine, is more highly colored, and less in quantity : 
 it has not the characters of the ingesta, but on the contrary, presents 
 the characteristic smell and taste of the urine. 
 
 From comparative experiments, the urine of the food contains only 
 one thirteenth of urea, one sixteenth of uric acid, and one fourth of the 
 salts found in the urine of digestion or of the blood. 
 
 <5 2469. For a long time the question has been discussed, and it is 
 not yet settled, whether the constituent materials of the urine are 
 
 (1) It seems probable, from Prout’s experiments, that pure uric acid does not exist 
 
 in the urine, but it is combined with ammonia. Lactic acid is then the only cause 
 of the acidity of the urine in the normal state. k T. 
 
 (2) Berzelius, Annales de chimie, vol. lxxxix., p. 22. 
 
OF THE URINARY SYSTEM. 
 
 379 
 
 carried to the urinary system only by the vascular system, or whether 
 they do not proceed there directly by a shorter route, and consequently, 
 whether there are not secret urinary passages ( vice urinaria clandes- 
 tina). 
 
 The arguments in favor of the existence of these passages, are :(1) 
 
 1st. The rapidity with which fluids, especially cold water, are 
 expelled with the urine, and particularly the great quantity of fluids 
 evacuated in a short time through this passage, whether these liquids 
 have been introduced into the intestinal canal, or injected into the cavity 
 of the abdomen. 
 
 2d. The passage of several substances through the urine unchanged, 
 instances of which we mentioned above. 
 
 3d. The presence in the urine or in the lymphatic vessels between 
 the mesentery and the urinary system, of these substances, or of other 
 materials formed even in the body, as the saccharine matter in diabetes, 
 although the blood contains no trace of them. 
 
 4th. The presence of urine in the bladder, although the kidneys 
 have been destroyed, the ureters tied, and even when the kidneys did 
 not exist, or at least they did not communicate with the ureters. 
 
 5th. The presence in the bladder of solid bodies introduced into the 
 body by swallowing or any other mode. 
 
 6th. The very active sympathy between the bladder and the 
 stomach. 
 
 The manner in which the substances contained in the urine can ar- 
 rive at the urinary system without passing through the vessels, has 
 been explained in several different ways. 
 
 1st. Some think there are no visible channels, but that the phenomena 
 depend simply on transudation through the adjacent parts, particularly 
 from the intestinal canal into the bladder, through the medium of the 
 mucous tissue. (2) 
 
 2d. Others admit a retrograde motion in the lymphatic vessels and 
 urinary system, and even support their opinion by those cases where 
 the valves of these vessels have an opposite direction, and are turned 
 from the heart. 
 
 3d. Finally, some admit special canals, situated between the sto- 
 mach and the urinary apparatus. 
 
 § 2370. But it is easy to refute all these arguments and the man- 
 ner in which they are explained. (3) 
 
 (1) C. G. Kratzenstein, Theoria ßuxus diabetici ejusque sanandi methodus , 
 Halle, 1746. — Darwin, Zoonomie, vol. i. — -Wollaston, in the Phil, trans. 1811. — Tre- 
 viranus, Biologie , vol. iv. p. 513-521. — Morichini, in the Mem. della soc. Hal., vol. 
 xvii.-Tiedemann and Grnelin, Recherches sur la route que prennent diverses substan- 
 ces pour passer de l'estomac el du, canal intestinal dans le sang, sur la fonction de la 
 rate et sur les voies cachées de l'urine , Paris, 1821. 
 
 (2) Treviranus, Biologie , vol. iv. p. 513-521. 
 
 (3) P. J. Hartmenn, Super urinæ diâpedes quœstiones, Utrecht, 1776. — G. G. 
 Erhardt, De secrelione lotiiunica et svfjicientc, Erfort, 1799. — J. Jacopi, Esame della 
 doclrina di Darwin sulmoio rclrogrado dciliquidincivasi Zûi/att'd, Pavia, 1804. 
 
330 
 
 DESCRIPTIVE ANATOMY. 
 
 Nothing can be concluded from the last two arguments, for the sym- 
 pathy between the stomach and the urinary system does not depend 
 on mechanical connections between them, and solid bodies penetrate 
 through unusual channels formed by these bodies from the compres- 
 sion they exercise. 
 
 In order to refute the fourth argument, it is sufficient to remark that 
 we do not in fact find urine in the bladder when the kidneys have been 
 entirely destroyed, that a portion of the kidney still remains where 
 they seem to have been entirely destroyed, that no urine collects in the 
 bladder after tying the ureters, if the bladder be entirely emptied ; and 
 finally, that the cases of a noncommunication between the ureters and 
 the kidneys are very doubtful. 
 
 To the third argument we may answer, that at least all the imme- 
 diate principles of the animal substances do not exist in the blood ; 
 those found there do not exactly resemble those in the body, since the 
 same substances occur in other parts of the body, from whence it is 
 not proved that they pass into the urinary system : that very possibly 
 the substances proved to exist in the urine, might have disappeared from 
 the blood or were concealed in some mode : that these substances have 
 not been looked for in the arterial, but in the venous blood : finally, 
 that according to Magendie, we may prove the existence of one of 
 these substances, the hydrocyanate of potass, in the urine, in any 
 quantity however small, while after mixing it with the blood, even out 
 of the body, we cannot detect it, even when in great quantity, by 
 chemical reagents. 
 
 Besides the simultaneous existence of several substances, as rhubarb, 
 has been proved in the serum ofithe blood and the urine.(l) 
 
 Treviranus asserts(2) that this phenomenon proves nothing, as the 
 serum of the blood contained less rhubarb than the urine. But it is 
 easy to refute this objection, as the rhubarb is distributed through the 
 whole mass of the serum, and could only be removed from it by the 
 urinary system. 
 
 The lymphatic vessels, situated near the mesentery, may either 
 have sent these substances into the urinary system, and have accident- 
 ally imparted to them a retrograde motion, contrary to that which the 
 fluids generally follow, although we have no right to conclude that 
 foreign substances always enter the urinary system through this chan- 
 nel, nor even by admitting the retrogade motion, that they were intro- 
 duced by it. 
 
 The facts alledged in support of the second argument, do not con- 
 tribute in manner to the explanation given of them. The formation 
 and the want of decomposition in certain substances would not be ex- 
 plained more easily by this theory : for even admitting this channel, 
 which is not much shorter, they are no less subject to the organic 
 action : but Davy’s observations prove, that under the influence of 
 
 (1) Home, in the Phil. Irans., 1808. 
 
 (2) Biologic , vol. iv. p. 520. 
 
or THE URINARY SYSTEM. 
 
 381 
 
 electricity, bodies may be separated contrary to the laws of chemical 
 affinity, and earned far by the fluids, without combining with other 
 substances which these fluids contain, and which have great affinity 
 for them. 
 
 Finally, in regard to the first argument, the rapidity with which 
 drinks and certain substances pass into the urinary system, is not in 
 fact as great as has been asserted, and may be easily explained by the 
 short distance they proceed, even admitting that they are carried there 
 by the blood. 
 
 If we find rhubarb in the urine in seventeen minutes, if it disap- 
 pears from this liquid at the end of some hours, if it colors the excre- 
 ment after six or seven hours, and is then found again in the urine, 
 this fact does not prove as Treviranus asserts/ 1) that the rhubarb 
 first found, has arrived at the urinary system by a shorter route than 
 that afterward observed. 
 
 The rhubarb which appears first in the urine, has undoubtedly 
 passed from the stomach, to the inner and absorbing face of which it 
 was presented, without being decomposed into the sanguineous system, 
 and seventeen minutes is not too. short for the latter to come to the 
 urinary system. The action of the rhubarb on the inner face of the 
 stomach and intestinal canal, gradually causes the mucous membrane 
 of these organs to a greater secretion, which surrounds them on every 
 part and diminishes absorption. When this excessive action abates, 
 the rhubarb is again absorbed. But there is another cause to which 
 we must probably attribute the disappearance of the rhubarb in the 
 urine during a certain length of time, viz. that the action of the kid- 
 neys is l.ess energetic, while that of the alimentary canal is increased. 
 
 § 2371. In regard to the passages, we may say : 
 
 1st. The opinion that the cellular tissue serves as a conductor, is 
 very improbable, first, because the application of phenomena observed 
 in the inferior animals, to the theory of those which occur in the su- 
 perior animals, leads only to uncertain results, since by admitting this 
 supposition, it is difficult to explain why the passage takes place 
 through the kidneys. 
 
 2d. The retrograde motion in the lymphatic vessels is very impro- 
 bable, at least in the normal state, on account of the existence of valves. 
 The cases where it is asserted the valves were found arranged con- 
 trary to what they are generally, are only exceptions, or at least are 
 not sufficiently proved. Farther, this arrangement could not be gene- 
 ral, since then there could be no absorption from the bladder. It is not 
 proved that these valves are arranged in one manner in certain lym- 
 phatics, and an opposite manner in others. 
 
 3d. The special canals have never been proved by authentic obser- 
 vations, and the passages considered as such, were evidently acciden- 
 tal and morbid formations. 
 
 (1) Biologie , vol. iv. p. 519. 
 
 Voi. III. 
 
 49 
 
382 
 
 DESCRIPTIVE ANATOMY". 
 
 4th. Finally, another circumstance prevents its admission, viz., that 
 we have never found between the digestive canal and the urinary pas- 
 sages, any substance in these two systems not contanied in the san- 
 guineous system, and even when this phenomenon occurs, it can al- 
 ways be explained by saying that the substances in this place, especi- 
 ally in the lymphatic vessels, have come there from the urinary 
 system. 
 
 C. SEXUAL DIFFERENCES. 
 
 § 2372. The urinary system, except the bladder and the urethra, 
 presents no considerable differences relative to sex. 
 
 The bladder is rounder, broader, and generally larger in the female 
 than in the male, where it is more elongated. 
 
 The urethra of the female is broader and shorter than that of the 
 male, representing in fact only its commencement. 
 
 D. DIFFERENCES DEPENDENT ON DEVELOPMENT. 
 
 § 2373. This system changes much during life, in form, texture, 
 proportional size, and situation. 
 
 I. KIDNEYS. 
 
 § 2374. 1st. The kidneys are much larger proportionally the younger 
 the fetus is : in the full-grown fetus their weight is to that of the whole 
 body as 1 : 80, while the proportion in the adult is as 1 : 240. 
 
 2d. In respect to form they are more elongated, and the pelvis is 
 nearer the anterior face, so that the renal fissure is less developed. 
 Their surface is not smooth ; they do not form a coherent and homo- 
 geneous mass, but are composed of several lobules, which are at first 
 distinct, but are united so as to produce the larger lobes, which are very 
 evident in the adult, where, however, they are not separated. At this 
 period of life, in fact, they are attached only by a very loose cellular 
 tissue, so that they are easily insulated, and their bases are even 
 marked on the surface of the kidney by considerable depressions. 
 
 3d. The medullary substance is more abundant in proportion to the 
 cortical substance, than in the adult, at least in the full grown fetus. 
 The fasciculi of the urinary passages, or the pyramids of Ferrein, are 
 separated from one another more easily, and like all parts of the body, 
 are evidently composed of globules, which are not seen in the adult ; 
 on the contrary, the passages are more difficult to be distinguished. 
 Here then, also, as in the muscles and the lungs, the large parts are 
 formed before the small. 
 
OF THE URINARY SYSTEM. 
 
 283 
 
 II. URETERS. 
 
 § 2375. The ureters are also broader, proportionally, than when the 
 subject is perfectly developed. 
 
 III. BLADDER. 
 
 § 2376. From the narrowness of the pelvis, the bladder is not con- 
 tained in this cavity ; it is then situated much higher than in the adult, 
 so that the urethra is proportionally very much longer. 
 
 It is much smaller before than after birth. 
 
 Its form is more elongated. This circumstance and its smallness, 
 cause it to appear as a simple filament, and it seems to be only a slight 
 dilatation of the urachus. 
 
 IV. URACHUS. 
 
 § 2377. The urachus is much larger the younger the person is ; it 
 gradually diminishes, until in the course of life it often entirely disap- 
 pears. 
 
 It is at first hollow, and according to our observations, it retains this 
 character in the full-grown fetus. At this period we can distinguish 
 in it all the constituent membranes of the bladder with which its cavity 
 communicates. This cavity is at first much larger proportionally, the 
 younger the fetus is. In the full-grown fetus, and still more at the 
 periods preceding birth, we can follow the urachus a greater or less 
 distance, but always several inches beyond the opening of the umbili- 
 cus, sometimes even the whole extent of the cord. Analogj r with ani- 
 mals, and several observations upon man, authorize us to think that it 
 passes at first entirely through the umbilical cord, and dilates between 
 the envelops of the fetus, to give origin to a membranous vesicle, the 
 allantosi , to which we shall return when describing the human ovum. 
 This cord is certainly hollow, for even in the full-grown fetus we have 
 injected it with mercury through the bladder, and the injection extended 
 more or less in the umbilical cord. Our observations on this subject 
 agree with those of Rcederer(l) and Noreen.(2) 
 
 Several of the ancient anatomists, and even Trew, among the mo- 
 derns, (3) have admitted that the urachus is full and solid in the fetus, 
 as it normally is in the adult. This erroneous opinion depends 
 upon a great inflexion in the canal near its lower extremity ; hence, 
 when the bladder is distended, the muscular fibres are so adapted to 
 its sides, that the opening by which they communicate is closed. 
 
 (1) De fœtuperfecto , Halle, 1759. 
 
 (2) hoc. cit., p. 13. 
 
 (3) De cliff, inter, hom. natum et nascendum, p. 104. 
 
3S4 
 
 DESCRIPTIVE ANATOMY. 
 
 ARTICLE SECOND. 
 
 URINARY SYSTEM IN THE ABNORMAL STATE. 
 
 § 2378. The urinary system is one of those anomalies which occur 
 most frequently,(l) particularly as respects those of formation, for the 
 most striking differences it presents, relate to the form, situation, and 
 size of its different component parts, and also to its vessels. Besides, 
 its cavity not unfrequently includes foreign bodies, which depend par- 
 ticularly on alterations in the chemical composition of the urine. 
 
 DEVIATIONS OF FORMATION. 
 
 A. KIDNEYS. 
 
 § 2379. The primitive deviations of formation in the kidneys, (2) 
 which depend more or less evidently on a suspension of development, (3) 
 are : 
 
 1st. The absence of one or both of them. 
 
 2d. Smallness , in which case when this anomaly occurs on one side 
 only it is frequently, but not always, made up by the greater size of 
 the kidney of the other side. 
 
 3d. The greater or less difference in the size of the two kidneys. 
 
 4th. The great size of these two organs. 
 
 5th. Their union in one only. This anomaly differs much in degree 
 and quality. 
 
 The differences in respect to quality principally affect their situation. 
 Sometimes there is no trace indicating that a kidney has ever existed 
 in the place where it is not found ; the single kidney occupies the 
 usual place, follows the normal direction, and we discover that it is 
 formed by the union of the two, not only because it is larger than in 
 the normal state, but also because it is contracted at its centre, from 
 the excess in the number of its vessels, its fissure, pelvis, and ureter. 
 Sometimes the two halves of the single kidney are situated each in 
 the usual place. 
 
 As to the differences in degree, the two kidneys are generally united 
 only at their lower part and to a greater or less extent, so that they 
 
 (1) Baillie, Engravings, London, 812, fasc. vi-viii. — C. Bell, Engravings from 
 specimens of morbid parts, preserved in the authors collection selected from the divi- 
 sion inscribed urethra , vesica, renés , morbosa et lœsa, &c. London, 1813. — J. How- 
 ship, Practical observations on the diseases of the urinary organs , particularly those 
 of the bladder , prostate, gland, and urethra, London, 1816. 
 
 (2) O. Heer, De renum morbis, Halle, 1790. 
 
 (3) See in respect to these deviations of formation, our Handbuch der patholo- 
 gischen Anatomie, vol. i. p. 610. 
 
OF THE URINARY SYSTEM. 
 
 385 
 
 form a semicircular mass, which is concave upward and convex down- 
 ward. The union extends more rarely to their whole height, in which 
 case they are changed into a rounded or square mass. 
 
 6th. They are more oblong than usual. 
 
 7th. The situation of the pelvis on the anterior face. These two 
 anomalies generally attend enlargement, but they sometimes occur 
 also although there is no mark of hypertrophy. 
 
 8th. The lobular structure, which sometimes gives rise to several 
 separate kidneys. 
 
 Their low situation, so that sometimes we find the two kidneys in 
 the pelvis. 
 
 § 2380. Several of these anomalies are developed also during life 
 only, as is true of abnormal enlargement and diminution. Not unfre- 
 quently, in fact, the kidneys enlarge sometimes to an enormous extent, 
 although they change their texture, or on the contrary they disappear 
 and are almost entirely effaced. 
 
 In the latter case sometimes they diminish much in volume, but 
 their mass continues solid, or they even preserve their size or enlarge, 
 but their substance is almost wholly destroyed, and they are changed 
 into a sac with thin parietes. Wasting of the first kind supervenes 
 after a disease of the organ ; but not so with the second, which often 
 depends on an obstacle to the escape of the urine which exists below 
 îhe kidneys. 
 
 B. URETERS. 
 
 § 2381. The deviations in the' form of the ureter are particularly 
 worthy of notice. 
 
 Their congenital anomalies are : 
 
 1st. Their absence. 
 
 2d. Their imperforation in one or several points, from an obstacle. 
 
 3d. Their plurality , occurring from the want of union of the branches 
 of the pelvis ; this exists in different degrees.(l) 
 
 The most common consecutive- deviation of formation is their ab- 
 normal dilatation or distension from an obstacle to the course of the 
 urine situated in the ureter, or in another portion of the urinary system, 
 or even out of it. Obstacles of the first kind are calculi and contrac- 
 tions ; those of the second are the engorgement of the glands of the 
 pelvis, the swelling of the internal genital organs, the adhesions of 
 these parts either with each other or with the adjacent organs, &c. 
 
 Finally, the ureter is sometimes ruptured from excessive distension. 
 
 (1) Meckel, Handbuch der pathologischen Anatomie, vol. i., p. 715. 
 
386 
 
 DESCRIPTIVE ANATOMY. 
 
 C. BE ADDER. 
 
 § 2382. The primitive deviations iji the form of the bladder are : 
 
 1st. Its absence , attended or not with that of the rest of the urinary 
 system. 
 
 2d. Its smallness. 
 
 3d. Its fissure. This anomaly is not very rare, and is termed the 
 prolapsus of the bladder ( 1) ( prolapsus vcsicœ urinariœ inversa). Its 
 principal characters are : 
 
 At the lower extremity of the anterior face of the abdomen, above 
 the symphysis pubis, is a reddish, soft, rounded place, the edges of 
 which are continuous with the common integuments, and at the base 
 of which are two mammillary eminences directed one towards the 
 other, whence urine continually dribbles. It is the bladder in the form 
 not of a pouch but a layer, the anterior face of which is formed by its 
 mucous membrane. 
 
 Behind this membrane is the muscular tunic, covered at its upper 
 part by the peritoneum. The eminences are the orifices of the ureters 
 situated in the usual place, and which are not generally abnormal, 
 except from their great breadth. 
 
 The umbilicus is situated directly above the upper extremity of the 
 bladder, and consequently much lower than usual. 
 
 The urethra then most generally opens above the penis in the male, 
 and the clitoris in the female : it is more or less cleft, and more or less 
 imperfectly developed. Considered generally, the external genital 
 organs seem to have separated from each other to the right and left. 
 
 Excepting at most two cases as yet published, the symphysis pubis 
 is always more or less imperfectly closed, on which depends the appa- 
 rent shortness of the penis. 
 
 Duncan(2) asserts that this anomaly belongs particularly to males : 
 but the number of cases of its occurrence in females, mentioned by this 
 author, may be much enlarged. 
 
 4th. The bifurcation of the bladder, or its formation by several con- 
 nected sacs. (3) 
 
 5th. The continuance of the urachus to the umbilicus, through 
 which the urine then escapes. 
 
 § 2383. The following anomalies are, at least commonly, consecu- 
 tive or accidental. 
 
 1st. Excessive size. Here there is sometimes simple dilatation, and 
 sometimes an increase in mass and volume. This anomaly generally 
 depends on an obstacle to the course of the urine, situated at the lower 
 part of the bladder or in the urethra. 
 
 (1) Meckel, loc. cit. 
 
 (2) Edinb. med. and sur g. journal, 1806. 
 
 (3) J. A. Ehrlich, Chirurgische Beobachtungen, vol. ii., Leipsic, 1815, p. 123. 
 
or THE URINARY SYSTEM. 
 
 387 
 
 2d. The considerable development of the muscular tunic, which 
 sometimes occurs without dilatation, or even when the bladder is. 
 unusually small, which depends particularly on the presence of a 
 foreign body, as a calculus, in the bladder. 
 
 3d. Hernias of the inner membrane of the bladder through the mus- 
 cular tunic ( appendices , s. processus),(l) which are very rarely conge- 
 nital, and commonly arise from the same cause as the preceding. 
 
 4th. Ruptures of the bladder, which are generally caused by its 
 excessive distension. 
 
 5th. Displacements , hernias of the bladder. The bladder most ge- 
 nerally projects at the base, and gives rise to vaginal hernia when it 
 rests on the vagina, either because it has become very heavy, as in 
 the cases where it is filled by a calculus, or because it is depressed by 
 the contraction of the space it occupies, as in pregnancy. It then 
 causes a more or less perfect inversion of the vagina, after which it is 
 itself precipitated more or less, especially when the inversion is conge- 
 nital. 
 
 We also find the bladder in inguinal hernias, but much more 
 rarely.(2) 
 
 6th. When the bladder and vagina fall rapidly, there is sometimes 
 an inversion of the bladder. The urethra is necessarily more or less 
 torn, in order that this accident should supervene. 
 
 II. ALTERATIONS OF TEXTURE. 
 
 A. KIDNEYS. 
 
 § 2384. The two kidneys do not always possess the same consist- 
 ence. They are sometimes very flabby in persons affected with dia- 
 betes, in which case they frequently receive more blood than usual. 
 
 On the other hand they are sometimes unusually firm. 
 
 They are not unfrequently changed into fat. 
 
 Frequently also a great number of serous cysts are developed in 
 these glands in old persons ; these generally adhere, are filled with a 
 differently colored and generally a limpid serum, which sometimes en- 
 tirely destroys their substance. In some cases the kidney seems 
 formed primitively of similar cysts. (3) 
 
 Scrofulous(4) and spungy tumors occur more rarely in the kidneys, 
 
 (1) Brocke, De vesica urinaricc appendicibus , Strasburg-, 1754. — C. Bell, Surgical 
 observations , pt. iv., London, 1817. 
 
 (2) Meckel, Handbuch der pathologischen Anatomie , vol. ii., p. 424. 
 
 (3) O. Heer, De renum niorbis, Halle, 1790, (ab. i. 
 
 (4) Bajllie, Engravings, fase, iv., tab. viii. 
 
388 
 
 DESCRIPTIVE ANATOMY. 
 
 B. BLADDER. 
 
 § 2385. When the bladder enlarges, its membranes are also gene- 
 rally thickened by inflammation, become firmer, adhere more to each 
 other, or are destroyed in parts. 
 
 The muciparous glands of the inner membrane are often enlarged 
 in catarrh of the bladder. 
 
 Irregular, rounded, reddish tumors of various sizes are developed on 
 this membrane, principally at the lower part of the posterior wall of 
 the bladder ; these rest upon a narrower base, and have no determinate 
 texture. These tumors, called funguses of the bladder ( fongus vesicas 
 urinariœ), are observed principally in males, and at an advanced age. 
 
 III. FOREIGN BODIES. 
 
 § 2386. Of the foreign bodies most frequent in the urinary system, 
 and consequently in the ureters and bladder, entozoaries are rare, 
 and calculous concretions are very frequent. 
 
 A. ENTOZOARIES. 
 
 § 2387. The entozoaries in the urinary system are : 
 
 1st. Hydatids,(l) which occur particularly in the kidneys, and per- 
 haps are always primitively developed there. 
 
 2d. The strongylus gigas, which exists in the kidneys. 
 
 3d. Two other worms, as yet undetermined, which were voided 
 with the urine. (2) 
 
 B. CALCULI. 
 
 § 2388. The urinary calculiez) present several general and special 
 important characters. 
 
 (1) Baillie, loc. cit ., tab. vii-viii. 
 
 (2) Lawrence, Case of a woman who voided a large number of worms by the 
 urethra ; in the Med. chir. trans., vol. ii. 
 
 (3) Tenon, Sur la nature des calculs ; in the Mém. de Paris , 1765. — Scheele, Un- 
 tersuchung des Blasensteins ; in the Schwedische Abhandlungen , vol. xxxvii. — E. 
 Sandifort, De calculo renal. ; in the Obs. anat. pathol., 1777, vol. i., p. 6: De calculis 
 renum et vesicœ , ibid., vol. i v., p. 7 ; De lethali urinœ suppressions ex calculo urethrae 
 inserto, indeque natâ duplici hujus canalis rupturâ ; ibid., vol. iii., p. 3. — F. A. 
 Walter, Anatomisches Museum , th. i., Berlin, 1796. — Wollaston, On gouty and uri- 
 nary concretions ; in the Phil, trans., 1797. — Pearson, ibid., 1798. — Fourcroy, in the 
 Annales du Museum , vol. i. — Brande, in the Phil, trans., 1808. — Magendie, Re- 
 cherches sur la gravclle, Paris, 1818. — Prout, An inquiry into the nature and treat- 
 ment cfbiabetes, calculus , and other affections of the urinary organs, with notes and 
 additions, by S Colhoun, M. D., Philadelphia, 1826. — Marcet, Essai sur les affections 
 calculeuses, Paris, 1823. — F. A. G. Hoffmeister, De cakulis urinariis collectanea 
 quœdàm, Leipsic, 1821. 
 
OF THE URINARY SYSTEM. 
 
 389 
 
 § 2389. Their general characters relate to their situation, texture, 
 form, volume, number, mode of development, and effect on the organs 
 which contain them. 
 
 1st. Situation. It varies both in itself, and in its relations with the 
 urinary system. 
 
 a. Calculi occur in the cavity or in the paiietes of this system. 
 
 The calculous concretions in the first are much more common than 
 
 in the second. 
 
 Of the four parts in which they can be developed, the pelvis, the 
 ureter, the bladder, and the urethra, they occur most frequently in the 
 bladder, and most rarely in the urethra.(l) 
 
 The portion of the cavity of the urinary system which contains 
 them, particularly of the bladder, is not generally separated from the 
 rest by an abnormal septum. Sometimes, however, the calculi are 
 inclosed in a special sac, which communicates with the common ca- 
 vity by a narrow opening ; they are then termed encysted calculi. 
 
 This state is doubtless in most cases the source of the calculi exist- 
 ing in the parietes of the bladder. We must admit that the communi- 
 cation at first existing is finally obliterated ; it is impossible to suppose 
 that the concretions were formed except within the cavity of the 
 bladder. 
 
 b. Most generally, and even most always, the urinary calculi are 
 entirely loose ; but sometimes they are attached to the inner face of 
 the bladder by mucus or thickened and coagulated fibrine, which exists 
 between their prominences. (2) 
 
 2d. Texture. The urinary calculi are generally formed of superim- 
 posed layers, more or less distinct and more or less concentric. Their 
 centre also is usually formed by a nucleus, which most generally 
 consists of a small mass of uric acid, more rarely of a foreign body 
 accidentally introduced into the urinary apparatus, particularly the 
 bladder. 
 
 The different layers are generally, but not always, similar in their 
 chemical composition. They are always formed of at least two sub- 
 stances, one solid, the other softer and originally fluid, which unites 
 and connects the particles of the preceding. 
 
 3d. Form. The urinary calculi are more or less oblong and rounded, 
 and generally smooth and a little flattened. This character depends 
 in great part on the influence of the organ which contains them, the 
 bladder being round. The form of the renal calculi demonstrates par- 
 ticularly the great influence of the form of the organ on that of these 
 concretions. 
 
 (1) Ehrlich has described a very remarkable renal calculus. (Loc. cit., vol. ii., 
 p. 24.) 
 
 (2) Meckel, Handbuch der pathologischen Anatomie , vol. ii., pt. ii., p. 444. — How- 
 ship, loc. cit., p. 249, tab. iii., fig. 5. — Bell, Surgical observations , Loudon, 1818, pt. 
 iv., p. 444, tab. i. 
 
 VOL. III. 
 
 50 
 
390 
 
 DESCRIPTIVE ANATOMY. 
 
 4th. Volume. The size of the calculi varies from that of an almost 
 invisible grain to a diameter of several inches ; they are sometimes so 
 large that they completely fill the bladder, and even distend it. 
 
 5th. Number. Usually there is only one, or there are but few. 
 When many exist their chemical composition is generally, but not 
 always, the same. 
 
 6th. J\lode of development. We may mention, as a general rule, 
 that the formation of the calculi depends either on the abnormal state 
 of the urinary system, or on the presence of a foreign body accidentally 
 introduced into the bladder. 
 
 The abnormal state of the urinary system may vary in several dif- 
 ferent modes. The secretory portion is generally affected, so that an 
 alteration in the chemical composition of the urine is most generally 
 the cause of the formation of calculi. This accidental production de- 
 pends more rarely on an abnormal arrangement in the bladder, or the 
 excretory portion of the urinary system. It may, however, be caused 
 by a mechanical obstacle to the emission of the urine, especially by 
 sacs in the parietes of the bladder, by the hernia of the bladder, or by 
 strictures of the urethra. Calculi have even been developed between 
 the glans and the prepuce.(l) 
 
 7th. Influence on the urinary system. This influence varies. When- 
 ever they are developed, the urinary calculi, being foreign bodies, 
 cause more or less acute pains, the intensity and nature of which 
 depend on their form, situation, number, and size, independent of the 
 degree of sensibility of the patient. 
 
 The changes caused by them in the form of the urinary system are, 
 the distension of the membranous parts, particularly the ureters, the 
 thickening of the muscular portion, consequently of the bladder, which 
 often attends their enlargement, but still more frequently the contrac- 
 tion of its cavity, finally rupture, which is more rare, and which occurs 
 particularly in the urethra. 
 
 § 2390. The peculiar characters of the urinary calculi relate prin- 
 cipally and almost exclusively to their chemical composition. 
 
 Chemical analysis has discovered in them at this date uric acid, the 
 phosphate of lime, the ammoniaco-magnesian phosphate, the oxalate 
 of lime, and the cystic oxyd. There have been found also, but more 
 rarely, less constantly, and in less quantity, silex, carbonate of lime, 
 iron, and two other peculiar substances, the xanthic oxyd, and a fibri- 
 nous substance. Wollaston and Brande doubt the presence of urate 
 of ammonia, admitted by Fourcroy and Vauquelin, and consider this 
 salt as produced by the chemical analysis ; but we cannot conclude 
 positively from the arguments with which their opinion is supported 
 that it never occurs in common calculi. 
 
 (1) Walter, Obs. anat., Berlin, 1775, p. 74.— Penada, in Brera.— Meckel, Handbuch 
 der pathologischen Anatomie , vol. ii. ( pt. ii., p. 444. 
 
OF THE URINARY SYSTEM. 
 
 391 
 
 Sometimes these substances are distinct, and sometimes they com- 
 bine in a greater or less number to form a concretion, whence nume- 
 rous kinds of calculi are formed. 
 
 The simple calculi are : 
 
 1st. Those of uric acid, which are smooth, of a brownish red, 
 and generally composed of concentric layers. They are the most 
 common. 
 
 2d. Those of phosphate of lime, which are proportionally rare, are 
 white, and composed of layers easily separated. 
 
 3d. Those of oxalate of lime are round, generally rough and brown ; 
 sometimes they are smooth, and seem to form always in the kidneys. 
 
 4th. Those of the cystic oxyd, more property the renal oxyd, be- 
 cause this substance is very probably developed in the kidneys. These 
 calculi are yellowish and semitransparent. They have no lamellar 
 texture. 
 
 5th. Those of xanthic oxyd, which have been seen only once. 
 
 6th. Those of fibrinous matter, which also have been seen only 
 once. 
 
 The calculi composed of different substances which do not form as 
 many separate layers are : 
 
 1st. Those of the ammoniaco-magnesian phosphate, or the fusible 
 calculi (calculus fusibilis) of Wollaston and Marcet, the most common 
 next to those of the uric acid. They are white, and more friable than 
 those of the other species. The ammoniaco-magnesian phosphate 
 often predominates, although it. seldom or never forms it alone. The 
 calculi formed around the foreign bodies introduced into the bladder, 
 those developed in ischuria, or between the prepuce and the glans, 
 are most generally of this nature, because in this case the urine is 
 more or less decomposed. 
 
 2d. The more complex calculi are distinguished by their indetermi- 
 nate form, their color, their structure, which is not evidently in strata, 
 and their hardness. 
 
 Finally, among the compound calculi, there are some in which the 
 different layers are formed bjr as many distinct substances. The num- 
 ber of these substances varies from two to four : but there are gene- 
 rally but two, the uric acid, with a phosphate or oxalate of lime, with 
 sometimes another phosphate, or with silex. In a calculus formed by 
 four layers, Marcet has found, from the centre to the circumference, 
 cystic oxyd, phosphate of lime, oxalate of lime, and the ammoniaco- 
 magnesian-phosphate. 
 
392 
 
 DESCRIPTIVE ANATOMY. 
 
 ARTICLE THIRD. 
 
 RENAT, CAPSULES. 
 
 I. NORMAL STATE. 
 
 A. SITUATION. 
 
 § 2391. The renal capsules ( renes succenluriati , capsula , s. glan- 
 dula suprarenales , s. atrabiliares),( 1) are triangular bodies, very flat 
 from before backward, resting directly on the kidneys, to which they 
 are united by a short cellular tissue. They occupy their upper extre- 
 mity and the upper part of their internal edge. Like them, they are 
 situated on the outside of the peritoneum. 
 
 B. FORM AND VOLUME. 
 
 § 2392. We have mentioned the general form of the renal capsules. 
 They are more long than broad, that is, they extend farther from above 
 downward than from right to left. They are only about one line thick. 
 Their form differs on the two sides : that of the left side is a little higher 
 and narrower than that of the right : the left is from fifteen to seven- 
 teen lines long, and about three broad : the right is generally from 
 fourteen to fifteen lines long, and twelve or fourteen broad. 
 
 We remark on their external face the fissures through which the 
 blood-vessels enter and depart. The left capsule usually presents for- 
 ward a longitudinal fissure, while there are two on the right side, an 
 anterior and a posterior. 
 
 C. WEIGHT. 
 
 § 2393. Each renal capsule in the adult weighs about one drachm. 
 
 D. CONSISTENCE AND COLOR. 
 
 § 2394. These organs are quite firm but brittle. Their color is yel- 
 lowish brown externally, and a deep reddish brown internally. 
 
 (1) A. M. Valsalva, Diss. anat., III. — B. Morgagni, Epist. anat. XX. — Duver- 
 noy, Comm. Petrop., vol. ii. — Bœckler, De thyroid 'œ, ihymi et glandularum supra- 
 renaliumfunctionibus, Strasburg, 1753. -—J. C. Mayer, De glandulis suprarenalibus, 
 Frankfort, 1784. — Riegels, De usu glandularum superrenaliumnecnon de origine 
 adipis , Copenhagen, 1790. — F. F. Leonhardi, Diss. de glandulis suprarenalibus , 
 Dresden, 1810. — J. F. Meckel, Abhandlungen , p. 1-277. 
 
OF THF. URINARY SYSTEM. 
 
 393 
 
 E. TEXTURE. 
 
 § 2395. They are composed of two substances, one external, more 
 consistent and yellowish, the other interna], softer and of a deeper 
 brownish red. The first is evidently formed of perpendicular fibres, 
 which are directed from without inward. These two substances are 
 often intermixed, whence the capsule appears spotted externally. The 
 external is divided more or less easily into rounded lobes, which may 
 themselves be divided into lobules, and it is covered by a very thin se- 
 rous membrane, which intimately adheres to its surface. 
 
 According to several anatomists, the renal capsules contain a more 
 or less complex cavity. However, after much research, w r e are obliged 
 to adopt the opposite opinion ;(1) we think that there is normally no 
 cavity, that it does not form till after death, and that it results either 
 from the spontaneous decomposition of the inner substance, which is 
 not very consistent, or fiom this substance being destroyed by hand- 
 ling it. 
 
 The substance of the renal capsules, particularly the internal, is 
 very intimately and directly connected with the veins, for the liquids 
 and air injected into these vessels easily penetrate them, and the air 
 often forms in them a cavity, they are so soft. 
 
 § 2396. The renal capsules are imperfect glands, as they have no 
 excretory ducts. In fact, these ducts have been admitted by some 
 anatomists of note, as Bartholini,(2) Peyer,(3) Valsalva, (4) Ranby,(5) 
 Kulmus,(6) Heuermann, (7) and Bendt.(8) The capsules communi- 
 cate with the testicles, according to Bartholini, Peyer, Valsalva, and 
 Ranby : with the thoracic canal according to Kulmus, with the pelves 
 of the kidneys according to Heuermann and Bendt. But very careful 
 and numerous dissections have led us to the contrary opinion. The 
 absence of an excretory duct in these organs seems more probable, as 
 it accords with the researches of Morgagni. 
 
 II. DIFFERENCES PECULIAR TO THE RACES. 
 
 § 2397. Some writers have asserted that the renal capsules were 
 larger in negroes than in the Caucasian race, and that their medullary 
 substance was darker. (9) We have seen nothing of this in dissecting 
 
 a negro, although we had previously observed it in a negress.(lO) 
 
 (1) See our Abhandlungen, p. 17. 
 
 (2) Rhodii, Mantissa, p. 36. 
 
 (3) Obs. anat.; obs. 32. 
 
 (4) Diss. anat., 111. Morgagni, Ep. an. XX. 
 
 (5) Phil. Irans., p. 385. 
 
 (6) Brest. Samml. 1722, Feb. 
 
 (7) Physiologie, vol. iv. p. 97. 
 
 (8) Defabric, vise, uropcet., p. 17. 
 
 (9) Cassan, Observ. med.; in Hufeland, Annalen der franzœsiscken Arrneywis- 
 senschaft, vol. i. p. 475. 
 
 (10) Handbuch der pathologischen Anatomie, vol, i, p. 648. 
 
394 
 
 DESCRIPTIVE ANATOMY. 
 
 III. DIFFERENCES DEPENDENT ON DEVELOPMENT. 
 
 § 2398. The renal capsules are very easily distinguished in the 
 fetus of two months. 
 
 Their proportional size gradually diminishes on their first appear- 
 ance, and the same is true, at least frequently, of their absolute size 
 after birth. They become thinner and dryer, wrinkle, and even en- 
 tirely disappear in oldage.(l) At the end of the third month they 
 are a little larger and heavier than the kidneys : at four months they 
 are equal in size to these glands, but they are lighter, because their 
 tissue is looser. At the commencement of the sixth month they are 
 only half as large as the kidneys, but their weight is to that of these 
 latter as 2 : 5, since each capsule weighs ten grains, and each kidney 
 twenty-five. In the full-grown fetus the proportion is about as 1 : 3, 
 each capsule usually weighs a little more than four scruples, and each 
 kidney more than half an ounce. In the adult, on the contrary, the 
 relation is as 1 : 23, for the capsule weighs one drachm, and the kid- 
 ney three and a half ounces. 
 
 These organs are composed of lobes, which are at first more nume- 
 rous and more distinct than in the adult ; but they do not always con- 
 tain a cavity in the early periods of life. 
 
 IV. FUNCTION. 
 
 § 2399. It is very difficult to mention the function of the renal cap 
 suies, although their great size before birth indicates their importance. 
 
 We have every reason to think, that like the liver, the spleen, the 
 thyroid, and the thymus glands, they contribute directly to the perfect 
 formation of the blood. Their great size in the fetus, their free com- 
 munication with the venous system, and their nearness to the ascend- 
 ing vena-cava, are at least so many circumstances in favor of this con- 
 jecture. 
 
 Those observers who admit, an excretory duct to the genital organs, 
 necessarily connect the renal capsules directly with them. Other 
 facts, particularly their simultaneous, considerable development in seve- 
 ral orders of the mammalia had suggested the same idea to us, (2) be- 
 fore we knew that it belonged to another, but we could not describe 
 the mode in which the renal capsules and the genital organs co-ope- 
 rated. 
 
 We may also mention in support of this hypothesis, the coincidence 
 of anomalies in the renal capsules with those in the genital organs. 
 Thus, Vauquelin has found the capsules ossified in a cat, from which 
 the ovaries had been extirpated. (3) Lobstein has found that of the 
 left side tripled in size by a chalky mass in a man who had long been 
 
 (1) Bichat, Anal, descript, vol. v. p. 462. 
 
 (2) Abhandlungen , 1806, p. 164. 
 
 (3) Fourcroy, Médecine éclairéa, vol. i. p. 236 
 
Of THE URINARY SYSTEM. 
 
 395 
 
 affected with syphilis.(l) We have found these organs unusually 
 large in two individuals much addicted to venery,(2) and deformed in 
 a female shortly after parturition, in whom the uterus and one of the 
 ovaries also presented a similar formation. (3) Otto has seen them 
 twice the usual size, in one case where the genital organs were very 
 much developed. (4) 
 
 The great simultaneous development of these two orders of organs 
 in the fetus, the coincidence of their smallness, and even the simul- 
 taneousness of their absence with the development of the encephalon, 
 between which and the genital organs there is so striking a connection 
 in an opposite sense, are circumstances in favor of this hypothesis. 
 Another conjecture very similar to this, is to consider the renal cap- 
 sules as an imperfect rudiment of the genital organs, (5) although it 
 seems to us too doubtful to think, that if they were connected with the 
 kidneys more intimately, an excess of energy, a momentary excite- 
 ment alone would be necessary for this connection, acting like a real 
 copulation, should cause the renal capsules to produce a new being. 
 
 It seems to us less probable that the renal capsules have a mechani- 
 cal’or dynamical relation with the kidneys, because, that when these 
 latter are displaced, the capsules always preserve their normal situ- 
 ation, so that the two organs are then more or less distant. 
 
 Finally, it is still less probable that they contribute to produce the 
 fat. (6) 
 
 V. ABNORMAL STATE. 
 
 § 2400. The renal capsules are very rarely abnormal, (7) and inas- 
 much as their anomalies consist in alterations of texture, we may con- 
 jecture with great probability, that they depend on the premature ex- 
 tinction of the great power primitively possessed by the organ. 
 
 A very general primitive anomaly, is their extreme smallness, or 
 their entire deficiency, which attends the imperfect development of the 
 encephalon, and the upper half of the body generally. Only two or 
 three cases of this kind are known, where the renal capsules were 
 found of their usual size. Their imperfect development not only at- 
 tends alterations of the cerebrum, but the suspended development of 
 this viscus generally, particularly congenital hydrocephalus. 
 
 (1) Rapport sur les travaux anatomiques , Strasburg - , 1805. 
 
 (2) Abhandlungen, p. 185-186. 
 
 (3) Ibid., p. 159. 
 
 (4) Pathologisch-anatomische Beobachtungen, 1816, p. 139. 
 
 (5) L. C. Treviranus, Untersuchungen über wichtige Gegenstände der Naturwis- 
 senschaft und Medicin, Gottingen, 1803, p. 184. 
 
 (6) Riegels, loc. cit. 
 
 (7) Lauth, in Lobstein, loc. cit., p. 36. — Dupuytren, in Meckel, Abhandlungen, p. 
 141. Our observations perfectly agree with his. 
 
396 
 
 DESCRIPTIVE ANATOMY. 
 
 The number of the renal capsules soinetimes( 1) increases, an in- 
 teresting phenomenon, as it resembles one rather common in an adja- 
 cent organ, the spleen. 
 
 It is difficult to determine whether this state be only a simple divi- 
 sion, or whether we should consider it as a real increase in the sub- 
 stance of the renal capsules. Considered in the last point of view, it 
 would gradually lead to the hypertrophy of these organs, some cases 
 of which are known. (2) 
 
 This hypertrophy is rare : we may presume that it generally de- 
 pends on an alteration of texture, and it seems particularly coincident 
 with anomalies in the genital organs. 
 
 CHAPTER IV. 
 
 OF THE GENITAL SYSTEM. 
 
 § 2401. The organs of generation , the genital, parts ( partes , s. or- 
 gana sexualia, genitalia , s. generation's inserventia),(3 ) principally serve 
 to perpetuate the species, while the existence of the other systems is 
 directly connected only with that of the individual. They however are 
 directly connected with the organism of the individual, as is de- 
 monstrated by the consequences of their absence, whether primitive or 
 congenital, or consecutive and accidental, or produced by a determina- 
 tion of the will. The sexual character which is imprinted on the 
 whole organism, is most evident in them. Of all the organs then, 
 these differ the most in the tw T o sexes. A superficial examination 
 would lead to the conclusion, that the genital organs in the male are 
 entirely different from those of the female, and that they cannot be 
 compared. But if we compare them in any animal, or even in man, 
 we shall be satisfied that they have originally the same form, that 
 they correspond perfectly in respect to number, their essential peculiari- 
 ties in structure and function, that they differ only in size and situation, 
 and that consequently, the analogies between them are much greater 
 than the differences, and that they should be regarded as modifications 
 of one and the same primitive type. 
 
 It is convenient to add the history of the mammæ to that of the 
 genital system, since they contribute but slightly, or not at all, to the 
 organism of the individual, while in their quality of nutritious organs 
 of the infant, they exert a great influence on the preservation of the 
 species. Besides, they do not differ less in the two sexes than the 
 
 (1) Duvernoy, loc. cit.— Morgagni, Ep. XX. a. 43.— Otto, Seltne Beobachtungen, 
 vol. lxxxiv. 
 
 (2) Harder Apiar., obs. 61. 
 
 (3) F. Plazzoni, De partibus gcnerationi inservientibus, libri III, Padoue, 1521.— 
 W. Rolfink, Ordo et methodus generationi dicatarum partium per anatome n cognos- 
 cendi fabricant, Jena, 1664. — Id., De sexus utriusque partibus genitalibus specimen , 
 Leipsic, 1675.— Van Horne, Prodromus obscrvationum suaruni circa parles géni- 
 tales in utroque sexu, Leyden, 1668. 
 
OF THE GENITAL SYSTEM. 
 
 397 
 
 other organs of generation. It would be better then, instead of em- 
 ploying the expressions sexual parts and genital parts indiscriminately, 
 as is generally done, to confine the latter term to the organs which 
 produce the new being, that is, to the proper genital organs. 
 
 All these parts differ from most others, as their active state is pro- 
 portionally very slight, for it generally does not extend much beyond 
 the half of existence, during which it appears only at long intervals, 
 and requires also, in order to be brought into action, very general, 
 and often very great changes, both in the mode of vitality, and in the 
 structure of the organs. 
 
 ARTICLE FIRST. 
 
 GENITAL ORGANS IN THE NORMAL STATE. 
 
 I. PROPER GENITAL ORGANS. 
 
 § 2402. The proper genital organs occupy the lower part of the 
 trunk, and are situated within and on the surface of the pelvis. 
 
 Those of the male and female differ principally’' in this respect, that 
 the first are situated more externally’, and are arranged more longitu- 
 dinally, while the second are placed more internally. Those parts 
 which in the male are situated on the outside of the abdominal cavity, 
 exist in the female within the cavity of the pelvis, and even those 
 which occupy the cavity of the pelvis in the male, are pushed forward 
 so much that they are found directly below the common integuments. 
 Thus, while the external genital organs in the female, those seen 
 without opening the body, are much fewer and smaller than the in- 
 ternal, the opposite is true of the male ; but we shall demonstrate here- 
 after, that this difference also does not exist during the whole of fife. 
 
 § 2403. The best mode is to divide the genital organs, in the two 
 sexes, according to the functions of their different constituent parts ; 
 into the proper genital or formative organs ( organa generationis, s. 
 formantia ), and the organs of copulation ( organa copulationis) . 
 
 The formative organs in the man, are the testicles, with their excre- 
 tory ducts, the prostate gland, and the glands of Cowper : in the female 
 the ovaries wfith their excretory ducts, the Fallopian tubes, and the 
 uterus. 
 
 The organs of copulation are, in the male, the penis ; in the female, 
 the vagina and the vulva. 
 
 § 2404. In both sexes the genital organs are situated at the lowest 
 extremity of the trunk, consequently, directly opposite to the encepha- 
 lon. In both sexes they differ from the .other organs in the symmetri- 
 cal arrangement, then constituent parts existing in pairs, or in the 
 contrary case, being situated on the median line of the body’, which 
 divides them into two equal parts. 
 
 VOL. III. 
 
 51 
 
398 
 
 DESCRIPTIVE ANATOMT. 
 
 A. GENITAL ORGANS OF THE FEMALE. 
 
 § 2405. It is convenient to commence with the genital organs of 
 the female,(l) since the genital organs of the two sexes primarily as- 
 sume their form. 
 
 I. FORMATIVE ORGANS. 
 
 § 2406. The ovaries and the Fallopian lubes deserve to be ex- 
 amined first, on account of the period at which they appear, and their 
 importance. 
 
 A. OVARIES. 
 
 a. Form, situation, volume, and weight. 
 
 § 2407. The ovaries ( ovaria , s. testes muliebres)(2) are situated 
 at the upper part of the cavity of the pelvis, on the sides of the uterus, 
 to which they are attached only by the ligament of the ovary ( l . ovarii ), 
 a portion of the fold of the peritoneum, which attaches the uterus to 
 the pelvis, and is termed the round ligament. They are rounded and 
 oblong. Their anterior and posterior faces are convex. Their upper 
 edge is also convex and loose. The lower is straight or a little con- 
 cave, presenting a real vascular fissure ( hylus ). They rest by this 
 latter edge on the upper part of the broad ligament. They become 
 thinner towards their internal and external extremities, but particularly 
 toward the former. 
 
 Their surface is usually smooth in virgins, and generally uneven and 
 lacerated in aged females. When perfectly developed, they are about 
 an inch and a half long, about four or five lines high, and a little less 
 in thickness. They weigh about a drachm and a half 
 
 b. Structure. 
 
 § 2408. The ovaries are covered externally by the peritoneum, 
 below which is a very solid and very resisting white fibrous membrane 
 ( tunica albuginea). These two layers are inseparably united. The 
 internal is perforated at the lower edge of the gland by vessels which 
 pass through it, and are distributed in its tissue. 
 
 (1) R. de Graaf, De mulierum organis generationi inser vient ibus, Leyden, 1672. 
 J. Palfyn, Description anatomique des parties de la femme qui servent à la géné- 
 ration, Leyden, 1708.— D. Santorini, Obs. anat. cap. XI. De mulierum partibus pro- 
 creationi dalis . — J. G. Gunz, Observationes de utero et naturalibus fceminarum, 
 Leipsic, 1753. 
 
 (2) C. Bartholin, De ovariis mulierum et generationis historia, Rome, 1677. — 
 Fasch, De avaria malierum, Jena, 1681— Motz, De structura, usv, et morbU ovari- 
 orum, Jena, 1789. 
 
OF THE GENITAL SYSTEM. 
 
 399 
 
 When we cut the ovaries, their tissue appears brownish red, they 
 are very vascular, firm, and solid, and vesicles are situated within them. 
 
 § 2409. These vesicles(l) are termed the ovula of Graaf (vesiculoe, 
 s. ovula Gh'aafiana ), although they were known previously by Vesa- 
 lius(2) and Fallopius. (3) 
 
 In the normal state they are composed of a thin, smooth, and serous 
 membrane, which adheres intimately to the substance of the gland ; 
 they are entirely closed and filled with a clear and limpid fluid. They 
 vary in size, and they seem to be developed successively. The largest 
 are about three lines in diameter, they are more numerous on the edge 
 of the ovary than in the centre. In virgins their number varies from 
 eight to twenty. 
 
 B. FALLOPIAN 1 UBES. 
 
 §2410. The Fallopian tubes ( tubas Fallopiance, s. meatus semi- 
 narii)( 4) are the excretory ducts of the ovaries. They are situated 
 before and below these organs, then go from without inward toward 
 the upper edge of the uterus, passing through the upper end of the 
 broad ligament ( ala vespertilionum ), to which they are attached. 
 
 They are very tortuous, especially in their external portion, and 
 gradually enlarge, so that their diameter, which is only half a line on 
 the inside, becomes by degrees three and four lines. They open into 
 the abdomen ( ostium abdominale) by a mouth surrounded with a fim- 
 briated edge, called the morsus diaboli. This opening projects much 
 on the outside of the outer extremity of the ovary. The internal orifice 
 (ostium uterinum) opens in the angle formed by the union of the upper 
 edge of the uterus with its sides. There is no mark of valve or promi- 
 nence here. Each tube is about five inches long. 
 
 §2411. The tubes are covered by the peritoneum, which forms 
 their external tunic, and which is continuous with the inner membrane 
 on the edges of the abdominal orifice. 
 
 Below the peritoneal tunic is the middle membrane, in which we 
 cannot usually observe any fibres, but it is sometimes composed in 
 vigorous females of two muscular layers, which are formed, the ex- 
 ternal by longitudinal fibres, and the internal by circular fibres. (5) 
 
 The internal mucous membrane is smooth, and presents numerous 
 longitudinal folds. 
 
 II) Bartholin, De fœminarum oris, Leyden, 1684. 
 
 (2) De corporis humanifabricâ, lib. v. cap. xv. p. 459. 
 
 (3) Obs. anat.; in the Opp. omn. Venice, 1606, vol. i. p. 106. 
 
 (4) Bartholin, De tubis uteri , Leyden, 1684. 
 
 IB) Santorini, loc. cit. 
 
400 
 
 DESCRIPTIVE ANATOMY, 
 
 C. UTERUS. 
 
 § 2412. The uterus or matrix(l) is the largest of those parts which 
 unite to form the genital system in the female. 
 
 a. Form. 
 
 § 2413. It is pyriform, and much more extensive from above down- 
 ward than from right to left. Its thickness is much less than its 
 breadth. Its upper and largest part, which is termed the body , is tri- 
 angular. It gradually contracts toward the base. The lateral edges 
 are straight, the upper is very convex. 
 
 The upper part of the body is called the base ( fundus uteri). The 
 inferior, termed the neck ( collum , s. cervix uteri) is nearly cylindrical. 
 
 The anterior and posterior faces of the uterus are very convex, the 
 second more so than the first, so that particularly in the early periods 
 of life, we may admit two posterior lateral faces, which unite at an 
 obtuse angle on the median line. 
 
 The uterus represents a cavity closed at its upper part, always ex- 
 cepting the narrow orifices of the two Fallopian tubes, but open below 
 and continuous in this direction with the vagina. 
 
 § 2414. The parietes of this organ are very thick, firm and solid, 
 in the perfect state. The middle region of its body, its thickest portion, 
 
 (1) J. A. Pratis, Libri duo de uteris, Antwerp, 1524.— -L. Bonaccioli, De uteri 
 sections, Strasburg - , 1529. — M. A. Ulmus, Uterus muliebris, Bologna, 1601. — J. 
 Swammerdam, Miraculum naturce de uteri muliebris fabricâ, Leyden, 1672. — C. 
 Drelincourt, De utero, Leyden, 1682. — M. B. Valentini, De novâ matricis anatome, 
 Giessen, 1683. — G. Bartholin, De utero, Leyden, 1684. — A. Nuck, Adenographia 
 curiosaet uteri Jeminei anatome nova, Leyden, 1692. — F. Ruysch, 'J'ractatus de 
 musculo in fundo uteri observato, antea a nemine detecto, Amsterdam, 1726.— A. 
 Vater, De musculo novo uteri, Amsterdam, 1727. — J. J. Huber, Uteri muliebris par- 
 tiumque ad earn facientium preecipuarum iterata explicatio ; Halleri leones , fase. I. 
 — I. U. Buchwald, De musculo Ruyschii in fundo uteri, Copenhagen, 1741. — J. 
 Weitbrecht, De utero muliebri observationes ; in N. C. Petrop, vol. i. p. 337. — Sue, 
 Recherches sur la matrice ; in the Mém. pres., vol. v. — J. G. Rœderer, leones uteri 
 humani observationibus illustralœ, Gottingen, 1759. — T. Simson, Observations con- 
 cerning the placenta, the two cavities of the uterus , and Ruysch' s muscle in fundo 
 uteri ; in the Edinb. med. essays, vol. iv. n. 13. — J. G. Walter, Betrachtungen über 
 die Geburtstheile des weiblichen Geschlechtes, Berlin, 1776.— J. C. Loder, Demuscu- 
 losà uteri structuré, Jena, 1782. — J. G. Weisse, De structura uteri non musculosa 
 sed celluloso-vasculosa, Wirtemberg, 1784. — G. Azzoguidi, Observationes ad uteri 
 constructionem pertinentes, Leyden, 1788.— O. F. Rosenberger, De viribus partum 
 efficientibus generatim et de utero speciatim, ratione substantive musculosce et va- 
 sorum arteriosorum, Halle, 1791. — C. H. Ribke, Ueber die Structur der Gebärmut- 
 ter, Berlin, 1793. — G. C. Titius, De uteri structura ex ejusdem functionibus, Wir- 
 temberg, 1795. — J. F. Lobstein, Fragment d'anatomie physiologique sur l'organi- 
 sation de la matrice, Paris, 1803. — J. U. G. Joerg, Ueber das Gebarorgan des Mens- 
 chen und der tSàugthiere im schwängern und nicht schwängern Zustande , Leipsic, 
 1808. — C. Bell, On the muscularity of the uterus ; in the Med. chir. trans., vol. iv. 
 1813, p. 335. — J. B. Belloni, Memoria sopra la vera struttura deliutero, Rovigo, 1821. 
 — Mad. Boivin, Mémorial de l'art des accouchemens , Paris, 1824, p 57. 
 
OF THE GENITAL SYSTEM. 
 
 401 
 
 is half an inch thick. The body is a little thicker, but perhaps a little 
 softer than the neck. 
 
 The anterior and posterior parietes gradually grow thin on the out- 
 side, and the internal upward, so that their thickness diminishes from 
 four or five lines to one, and thus resembles that of the tubes, which 
 proceed some lines in the substance of the organ, following an oblique 
 direction from above downward, and from without inward. 
 
 The form of the cavity of the uterus generally corresponds with its 
 external figure, although it is extremely narrow in regard to the 
 thickness of the parietes, whence it follows, that its anterior and pos- 
 terior faces almost touch. Its mean breadth does not exceed four 
 lines. The three edges of the body are concave outward and convex 
 inward, while externally, only the upper edge of the uterus is convex 
 outward. The cavity of the neck is circumscribed by faces convex 
 outward, while its outer face is concave, as the organ is con 
 traded a little on its centre. The form of the cavity also differs from 
 that of the outer circumference, in this respect, that it extends above 
 on each side into a long horn, which gradually contracts, and at the 
 summit of which the Fallopian tube opens. 
 
 The cavity is narrowest in the neck, particularly on the limit be- 
 tween the neck and the body, where it contracts very much. It is 
 termed in this place the upper or internal orifice of the uterus ( ostium 
 uteri internum ). 
 
 Thence, the neck enlarges to about it's centre, and then again, con- 
 tracts. It terminates below in the upper extremity of the vagina, by 
 two sacs, an anterior and a posterior, the latter of which is usually 
 longer, but the anterior descends a little lower, and between which we 
 usually observe a transverse fissure, more rarely a smaller rounded 
 opening, termed the os tincæ , the external or vaginal orifice of the 
 uterus ( orificium uteri externum , os uterinum). The two sacs are 
 termed the lips (labia) of this orifice. 
 
 The inner face of the uterus is smooth in the body, but corrugated 
 in the neck, along the anterior and posterior parietes of which is a lon- 
 gitudinal prominence, which gradually diminishes from above down- 
 ward, the sides of which present oblique bands, which render it very 
 uneven. On the sides between the two prominences we observe also 
 numerous elevations, which intercross like a net-work. The lips of 
 the os tincæ are smooth, at least if we except lacerations, which are 
 always accidental, and occur rather frequently during parturition. 
 
 b. Volume. 
 
 § 2415. In virgins the uterus is about two inches long, nearly half 
 of which is formed by the neck. The greatest breadth of the body is 
 sixteen lines, and that of the neck from nine to ten. The lips of the 
 os tincæ are about ten lines broad, and the breadth of the external ori- 
 fice of the uterus is about six. 
 
402 
 
 DESCRIPTIVE ANATOMY. 
 
 The vaginal portion of the uterus is about six lines thick, and the 
 fissure is very narrow in this direction. 
 
 In females who have borne children the uterus commonly never 
 returns to its primitive dimensions, and the orifice of the os tincæ also 
 appears a little broader from before backward. 
 
 c. Weight. 
 
 § 2416. The well developed uterus of a virgin weighs between 
 seven and eight drachms ; but in a female who has borne children, 
 and in whom the uterus has contracted as much as possible, it often 
 weighs an ounce and a half. 
 
 d. Situation. 
 
 § 2417. The uterus is situated between the bladder and rectum. 
 Its upper half is placed in the cavity of the peritoneum, a fold of 
 which is intimately attached to its surface. 
 
 In the perfect state it. is situated entirely in the small pelvis, and its 
 base rises only to the level of the upper edge of the symphysis pubis. 
 This part is directed forward and upward: the os tincæ, on the con- 
 trary, downward and backward, so that the longitudinal diameter of 
 the axis of the organ corresponds nearly to the upper axis of the pelvis, 
 and it cuts the axis of the body backward and downward. 
 
 e. Attachments. 
 
 § 2418. The uterus is attached to the adjacent parts by several folds 
 of peritoneum,(l) which are continuous with the serous tunic of its 
 body, from whence they arise inward. 
 
 The largest are the lateral or broad ligaments (/. uteri lateralia, s. 
 lata). They pass from the lateral edges of the uterus, receive the ves- 
 sels of this organ between their anterior and posterior layers, go trans- 
 versely outward toward the circumference of the pelvis, divide this 
 cavity into two halves, an anterior and a posterior, the first of which 
 is smaller than the second, and are continuous with the lateral wall of 
 the peritoneum. 
 
 Beside these vessels, this fold of the peritoneum possesses more or 
 less distinct transverse muscular fibres, which leave the lateral edge 
 of the uterus and gradually terminate on the outside. (2) 
 
 (1) J. C. Schützer, De Jabricâ et morbis ligamentum uteri , Harderwyck, 1729. — 
 A. Petit, Description anatomique de deux ligamens de la -matrice nouvellement ob- 
 servés-, in the Mêm. de Paris, 1760.— A. Portai, Observ. sur la structure des parties 
 de la génération de la femme ; in the Mém. de Paris, 1770, p. 183. 
 
 (3) Sue, Recherches sur la matrice ; in the Mém. prés., vol. v., p. 248. 
 
or THE GENITAL SYSTEM. 
 
 403 
 
 Another fold, which is much smaller, elongated, and rounded, forms 
 on each side the posterior inferior ligament, or the semilunar fold of 
 Douglas (l. uteri inferius posterius, s. plica semilunaris Douglasii), 
 which extends from before backward from the lower part of the poste- 
 rior face of the uterus to the rectum. 
 
 This ligament also contains longitudinal muscular fibres.(l) 
 
 A third, which is still smaller, the inferior anterior ligament (l. uteri 
 inferius anterius ), one of which generally exists on each side, extends 
 from behind forward from the lower part of the anterior face of the 
 uterus to the bladder, embraces this latter, and frequently also pos- 
 sesses muscular fibres. 
 
 Finally we find on each side a very long and rounded ligament, 
 which leaves the upper part of the lateral edge of the uterus, directly 
 below and before .the inner extremity of the Fallopian tube; it is 
 termed the round ligament (/. uteri rotundum , s. teres). This ligament 
 is first situated between the two layers of the broad ligament, passes 
 behind the umbilical artery and before the hypogastric vessels, is di- 
 rected from below upward and from within outward directly behind 
 the peritoneum, towards the upper and external orifice of the inguinal 
 canal, is reflected in this place on the epigastric artery, then enters the 
 inguinal canal, proceeds from above downward, from without inward, 
 and from behind forward, emerges from the inguinal canal thiough the 
 inguinal ring, and terminates by dividing into several fasciculi in the 
 fat of the mons veneris, and in the upper part of the external labia. 
 
 It is composed principally of cellular tissue and vessels, but it pos- 
 sesses also some very distinct longitudinal muscular fibres, the upper 
 of which arise from the external layer of the fibres of the uterus, while 
 the lower come from the lower edge of the two internal broad muscles 
 of the abdomen, which are directed from below upward. 
 
 These ligaments keep the uterus in place. The muscular fibres of 
 the broad ligament serve also to approximate the Fallopian tubes to 
 the ovaries. 
 
 When the fibres of the broad and round ligaments of one side act 
 more forcibly than those of the opposite side, the uterus is carried tran- 
 siently or permanently into one half of the pelvis, an arrangement 
 which we have often observed, al’hough it depended on no mechanical 
 cause, and although the parts which serve to retain the uterus were 
 unaltered in their texture. 
 
 f. Texture. 
 
 § 2419. At first view the tissue of the uterus seems to be homoge- 
 neous ; we however distinguish in it when unimpregnated, several 
 layers superimposed from behind forward, which have a reddish yellow 
 color, and between which are whitish bands. 
 
 (1) Sue, ibid. 
 
404 
 
 DESCRIPTIVE ANATOMY. 
 
 The vessels of the uterus, which are very tortuous and frequently 
 anastomose together, proceed between these layers both on the ante- 
 rior and near the posterior face. 
 
 a. Fibres. 
 
 § 2420. There is perhaps in anatomy no subject on which opinions 
 are more divided than in respect to the fibres of the uterus, or, to state 
 the question more exactly, in regard to the existence of these fibres 
 generally, their nature, and their arrangement. 
 
 1st. Several anatomists, particularly Walter, Bcehrner, Blumenbach, 
 Azzoguidi, and Ribke, formally deny their existence, which is ad- 
 mitted, on the contrary, by Vesalius, Piccolomini, Malpighi, Morgagni, 
 Diemerbroek, Verheyen, Vieussens, Ruysch, Vater, Santorini, Buch- 
 wald, Weitbrecht, Monro, Noortwyk, Heister, Haller, Sue, Astruc, 
 Levret, Rœderer, Meckel, Hunter, Wrisberg, Loder, Mayer, Simeon, 
 Calza, Lobstein, and Bell. 
 
 Thus the second opinion, which we. also have adopted, is supported 
 by most authorities. 
 
 But the anatomists who admit their existence differ ; some consider 
 the fibrous texture of the uterus as constantly existing; while others, 
 who are more numerous, think that these fibres exist only in certain 
 conditions, as in gestation. 
 
 It is a fact that these fibres are at least very slightly apparent, ex- 
 cept in pregnancy. They however do not form only during this state, 
 but whenever the formative power of the uterus is exalted. Lobstein 
 has found them very apparent in a female where the uterus was much 
 distended by a steatomatous tumor, as it is generally in the seventh 
 month of pregnancy. He attributes this phenomenon to the distension 
 caused by the tumor ; but we have observed them more or less evi- 
 dently in the uterus of females where analogous tumors existed in the 
 uterus and ovaries, so that we think it more correct to admit that they 
 depend on a change of the proper vitality of the uterus. 
 
 2d. Most anatomists consider these fibres as muscular. In fact they 
 differ from the red fibres which form the voluntary muscles, as they 
 are less red, flat, and strongly united with each other ; but their mus- 
 cular nature is proved by their powerful contraction, either during 
 parturition to expel the fetus and the secundines, or afterward, to con- 
 tract the uterus and almost obliterate its cavity very rapidly. 
 
 In these twm characters they are very analogous to the involuntary 
 muscles. 
 
 This in fact is the manner in which the fibres of the uterus act, and 
 their substance presents in the different states of this organ the different 
 modifications observed in the muscular system of organic life, that is, 
 when the uterus is unimpregnated, they resemble the fibres of the ar- 
 teries, and during gestation, those of the other involuntary muscles, 
 except the heart. 
 
OF THE GENITAL SYSTEM. 
 
 405 
 
 The uterus of the female contains also a great proportion of fibrine. 
 
 Finally we may also mention the analogy with the mammalia, 
 where the uterus is evidently muscular at all periods of life, adding 
 however that by a very remarkable arrangement, the fibres in the 
 uterus of the female do not evidently possess this character, except 
 when the formative power of the organ is increased. 
 
 3d. The direction of the fibres is not described in the same manner 
 by all anatomists. Most of them, however, agree that they possess at 
 least two directions, a longitudinal and a transverse ; so that in this 
 respect also they resemble the muscles of organic life. 
 
 They are however more complex, since we find several layers pro- 
 ceeding in different directions, as the layers composed of fibres which 
 have the same direction proceed several times from within outward ; 
 and as finally the different layers frequently interlace together. 
 
 Some authors, particularly Malpighi and Monro(l) maintain that 
 the fibres are not arranged regularly. 
 
 Ruysch admits only a single, unmated, and circular muscle, situated 
 at the base of the uterus. Although several anatomists, as Vater, 
 Monro, and Simson agree with him, it is however certain that the 
 arrangement of the fibres of the uterus is not so simple. Farther the 
 description Ruysch has given of this muscle is not perfectly exact. 
 
 The following are the most general characters of the arrangement 
 of the muscular fibres of the uterus : 
 
 1st. There are two layers, an external and an internal, which are 
 separated by the vascular substance of the organ. 
 
 2d. The different planes and layers are interlaced so intimately that 
 it is difficult to separate them. 
 
 3d. The external layer is much thicker than the internal. 
 
 4th. The muscular substance is much thicker at the upper part of 
 the uterus, particularly in its base, than in the other regions. It does 
 not exist at all, or at least is very thin, in the neck. (2) 
 
 5th. Generally speaking the longitudinal fibres are much more 
 numerous than the others. The circular fibres, however, are more 
 developed at the base of the organ, while the longitudinal fibres are 
 larger near the lower orifice. 
 
 6th. The external plane is composed of longitudinal fibres, which 
 depart from the centre of the base, are distributed from above down- 
 ward on the anterior and posterior faces, follow an oblique and even 
 transverse direction, and disappear toward the neck. Some of these 
 fibres are irregular, others are continuous with the round ligaments. 
 
 7th. According to some authors, Rosenberger for instance, the ex- 
 ternal plane is composed only of longitudinal fibres ; there are however 
 below these fibres other transverse fibres which also go to the round 
 ligaments and to the Fallopian tubes. 
 
 (1) Dissection of a woman with child, with remarks on the gravid uterus ; in the 
 Edinb. phys. and Med. Essays, vol. i., p. 459 and 470. 
 
 (2) Beil, loc. cit., p. 342. 
 
 VOL. III. 
 
 52 
 
406 
 
 DESCRIPTIVE AH ATOM ï\ 
 
 8th. We also remark in this plane, oblique fibres which have very 
 different directions, and are tortuous ; these interrupt particularly the 
 longitudinal layers, and occur principally at the lower part of the 
 body. 
 
 9th. The oblique fibres do not exist in the neck, which however is 
 composed, at least frequently, of several superimposed layers of trans- 
 verse and longitudinal fibres. 
 
 10th. The inner plane, which is the thinnest, is formed of two 
 layers. The external is composed of two circular muscles, each si- 
 tuated round one of the orifices of the tubes ; they blend together on 
 the median line anteriorly and posteriorly, by the inner part of their 
 edge. Very probably one of these circular layers is the muscle of 
 Ruysch, who had considered the lateral wall of the uterus as the 
 upper, and had neglected the opening of the tube. 
 
 11th. Below this layer are longitudinal and oblique fibres, which 
 unite on each side anteriorly and posteriorly to form two elongated 
 triangles, the summits of which blend in the orifice of the tube. 
 
 12th. Below these fibres, and interlacing with them, are rather 
 transverse and indistinct fibres, seen particularly at the lower part of 
 the uterus.(l) 
 
 (1) Mad. Boivin describes the fibres of the uterus differently. She remarks that 
 after macerating the uterus for a few days, wo observe on each face six fibrous fasci- 
 culi, three on the right and three on the left of cacti wall, besides one which is ver- 
 tical, and which forms the median line. This last layer, which extends from the 
 circumference of the base to the base of the body, presents longitudinal fibres. Each 
 of the others seems to arise from the median line : 1st, at the centre of the base are 
 two fasciculi, one on each side, which extend transversely on the edge of the base to 
 the upper angles, where they fold in the form of tubes, which separate and extend to 
 form the tubes ; 2d, below this first layer of the anterior face, two other broader 
 layers, which occupy the upper half of the body, proceed horizontally on each side 
 from the median line, and a little before the angle of the tube, to unite to other layers 
 of fibres, and there form the origin of the round ligament ; 3d, at the lower third of 
 the median line two other layers of fibres are directed obliquely from below upward, 
 separating on the sides : one portion of this fasciculus unites to the band of fibres of 
 the round ligaments, and the other blends and interlaces with the transverse fibres 
 of the posterior regions of the organ. On the posterior wall of the uterus the ar- 
 rangement of the fibrous layers is nearly the same as in the anterior wall. The 
 middle layer is more prominent than that of the anterior face, and also presents lon- 
 gitudinal fibres. The fibrous layers of the upper region extend across, leaving the 
 median line, to the origin of the tubes and a little below, where they unite to go to 
 the ovaries, of which they form the ligament. Below is another layer, which reas- 
 cends obliquely and divides rather distant from their point of departure into two 
 portions : one superior and lateral, turns on the side, and goes to unite forward to 
 the round ligaments ; the other terminates in the form of a ring, and goes to the 
 base of the ovary. At the lower extremity of the median line in the external central 
 region of the neck arc two other fasciculi, which are composed of a portion of the 
 fibres of the median line of the neck, separate some lines from each other, are insu- 
 lated, and arc attached to the lateral edges of the middle region of the 3acrum, and 
 form the posterior ligaments. 
 
 These different fibrous layers change their direction during pregnancy. In pro- 
 portion as the body of the uterus elongates and enlarges, the layers of fibres of the 
 upper regions from transverse become oblique, their median extremities rise to- 
 wards the middle of the base, and their lateral extremities are depressed, in the same 
 proportion, to the lower third of the lateral edges of the organ, so that at the end of 
 gestation the fibrous layers of the upper and lateral regions have a radiated arrange- 
 
OF THE GENITAI. SYSTEM. 
 
 407 
 
 b. Internal surface. 
 
 § 2421. The inner surface of the uterus is covered by a reddish mu- 
 cous membrane, which is almost smooth, and presents only some very 
 small villosities, which are continuous above and on each side with 
 those of the tubes, and below with that of the vagina. 
 
 In the recent state this membrane adheres so intimately to the sub- 
 jacent fibrous substance that it is inseparable, although its structure 
 intimates distinctly that it belongs to the class of mucous membranes ; 
 but after macerating the uterus we can detach some folds of it by care 
 and precaution. 
 
 Its intimate union with the rest of the substance of the uterus has 
 caused its existence to be doubted by several anatomists.(l) 
 
 We find some muciparous glands only in the neck, particularly at 
 its lower part. Not unfrequently their orifice is obliterated, perhaps 
 from inflammation. They then form more or less numerous large 
 cysts filled with a limpid liquid, produced by the accumulation of their 
 habitual secretion. 
 
 These cysts are termed the ovula of JYaboth (ovula JYabothiana, s. 
 ovarium secundarium),(2 ) which have been very badly compared to 
 the ovula of Graaf. 
 
 iment, and may be compared to a head with Ions' hair, separated in all the extent of 
 the median line of the skull, smooth on each side of the forehead, and situated very 
 near and before each ear : this union in a single fasciculus of these superior fibrous 
 layers forms forward and on each side the broad ligaments. The layers of fibres of 
 the lowerVegion of the body have löst progressively the oblique direction assumed 
 by them at first, and become semicircular. These fibrous layers, which leave the 
 lower portion of the median line, unite on the sides and before the middle region of 
 the uterus to the broad ligaments, an inch below the union of the superior fasciculi. 
 The direction of the fibrous layers of the posterior wall is changed in nearly the 
 same manner as those of the anterior face. These layers, which are at first trans- 
 verse, are arranged obliquely from above downward, and turn on each side. One 
 portion is attached to the ovary, and then projects on the lateral face of the uterus, 
 and the other passes below these glands to unite forward to the anterior fasciculi 
 which form the round ligaments, whence it follows that not only the fibrous layers 
 of the anterior region of the uterus, but also a portion of the middle layers of the 
 posterior region, contribute to form these ligaments. The median layers, which are 
 arranged longitudinally, extend from the base to the origin of the internal orifice of 
 the neck, loose their vertical direction by separating progressively on the sides, and 
 appear at the end of gestation a kind of tissue of fibres, which intercross, and from 
 whence proceed the other layers of fibres which have been described ( Mémorial de 
 l'art des accouchemens , Paris, 1824). P. T. 
 
 (1) This is the opinion of Cbaussier and Ribes. Mad. Boivin says also she has 
 
 never seen this mucous membrane, and thinks that the inner face of the uterus is 
 formed only by the extremities of the exhalent vessels which open there. ( Mèmoria . 
 des accouchemens, p. 66.) This explanation is very vague, if not unintelligible. Ana- 
 logy does not admit us to doubt that the inner face of the uterus is covered by a 
 membrane. F. T. 
 
 (2) M. Naboth, De sterililate viutierum, Leipsic, 1707. 
 
408 
 
 DESCttlTTIVE ANATOMY 
 
 II. ORGANS OF COPULATION. 
 
 § 2422. The organs of copulation are composed, in the female, of 
 the vagina, the clitoris, the external labia, and the nymphæ ; the three 
 latter have been termed the external genital parts ( pudendum , s. 
 cunnus), in opposition to the others, termed the internal. 
 
 A. VAGINA. 
 
 a. Form and dimensions. 
 
 § 2423. The vagina is a membranous canal, with thin parietes, ge- 
 nerally about four inches long and one broad, and larger at its upper 
 than at its lower part ; it is directly continuous with the uterus. 
 
 Its upper extremity terminates in a cul-de-sac, called the base {fun- 
 dus vaginae ), and is continuous with the substance of the uterus, em- 
 bracing its lower or vaginal portion. 
 
 The other extremity is narrower, and is termed the entrance of the 
 vagina ( adilus vagina, ) : it opens externally where it is continuous 
 with the external labia. 
 
 b. Situation and direction. 
 
 § 2424. This canal is situated between the rectum, the bladder, and 
 the urethra, to which parts it is united by very loose cellular tissue. 
 It has not the same direction as the uterus, for it descends from behind 
 forward, so that its axis corresponds exactly to the lower axis of the 
 pelvis. 
 
 Farther, its posterior wall is slightly convex, and the anterior is 
 concave. 
 
 c. Texture. 
 
 § 2425. The vagina is formed of two layers, one external, very thin, 
 solid, and reddish white, which corresponds to the muscular and vas- 
 cular tunics, is continuous with the fibrous tissue of the uterus, and 
 gradually becomes more solid and vascular from without inward ; the 
 internal is reddish, and is firmly united to the preceding, from which 
 however it may be separated. 
 
 It is very much corrugated in a full grown female, and particularly 
 in virgins. 
 
 Among these folds we see, particularly on the anterior and posterior 
 faces, a series which is transverse and oblique, situated one above 
 another ( columna rugarum anterior et posterior), which are the conti- 
 
OF THE GENITAL SYSTEM. 
 
 409 
 
 nuation of those in the neck of the uterus, where they are termed the 
 arbor vitœ. 
 
 There are some muciparous glands at the upper part of the vagina. 
 
 B. HYMEN. 
 
 § 2426. The hymen {hymen, s. valvula vaginœ){ 1) is a semicircular 
 fold of the mucous membrane of the genital parts, formed of tw'o layers 
 united by cellular tissue ; it occupies the sides and the posterior part 
 of the entrance of the vagina, and leaves a greater or less space be- 
 tween its anterior concave edge and the anterior part of the vagina. 
 
 Not unfrequently this fold arises from all the edge of the canal. 
 Even then however the opening is generally situated forward and 
 rarely in the centre ; the hymen is rarely also thick, hard, solid, and 
 muscular. 
 
 This membrane separates the internal and the external genital or- 
 gans, and also the genital and the urinary systems, as we perceive 
 before it the orifice of the urethra, surrounded by small similar folds. 
 
 C. CLITORIS. 
 
 a. Clitoris in itself. • 
 
 § 2427. The clitoris ( clitoris , s. membrum muliebre , s. coles femina- 
 rum, s. nympha){2) is an oblong, rounded body, situated below the 
 symphysis pubis. It arises from the upper part of the inner face of the 
 ascending ramus of the ischium by two branches about an inch long, 
 which unite at an obtuse angle. 
 
 It terminates forward by a small elongated and rounded prominence, 
 called the glans of the clitoris ( G. clitoridis). This enlargement is 
 covered by a thin mucous membrane, and by a thick and soft epider- 
 mis, which is easily detached, and it is surrounded by a triangular fold 
 of skin which entirely envelops it. 
 
 This fold of skin, termed the prepuce of the clitoris ( prœputium cli- 
 toridis), which is closed above and open or cleft below, is thin, soft, 
 and moist on its two faces, but particularly on the internal. We re- 
 mark in it, especially where the prepuce is continuous with the skin 
 which surrounds the glans of the clitoris, a great number of sebaceous 
 glands. 
 
 (1) A. Vater, De hymene, Wittemberg, 1727. — J. J. Huber, De hymene et raginm 
 rugis, Leyden, 1742. — B. S. Albinus, De hymene ; in the Annot. acad., Leyden, 1758, 
 1. iv., x. — Goering, De hymene , Altdorf, 1765.— G. Tolberg, De. varietate hymenum, 
 Halle, 1791.— B. F. Osiander, Abhandlung über die Scheidenklappe ; in his Denkwür 
 digkeitenfür die Geburtshülfe, vol. ii., pt. i., p. 1. 
 
 (2) T. Tronchin, De nymphâ , Leyden, 1730. 
 
410 
 
 DESCRIPTIVE ANATOMY. 
 
 On a more attentive examination we remark that the glans is not a 
 continuation of the substance of the posterior part of the clitoris, but is 
 attached to it only by cellular tissue, vessels, and nerves, and that the 
 posterior part of the clitoris terminates by a concave surface destined 
 only to support it. 
 
 § 2428. The clitoris is composed of an external fibrous sheath, below 
 which is a spungy tissue formed by broad venous trunks, which fre- 
 quently anastomose. Thus these lateral parts are termed the cavernous 
 bodies ( C . cavernosa , s. spongiosa clitoridis ). 
 
 After the two branches by which it arises unite, we observe between 
 its two lateral halves a perpendicular fibrous septum, which separates 
 them imperfectly, and which is directly continuous with the external 
 envelop. 
 
 There is no trace of a septum in the glans, which is formed of a 
 similar but finer tissue. 
 
 By reason of this texture the clitoris is capable of enlarging very 
 much. 
 
 Its vessels and nerves proceed on its dorsal face, which are very 
 considerable ; they are numerous and enter, particularly the latter, into 
 the glans. 
 
 b. Igchio-cavernoaus muscle. 
 
 § 2429. The branches of the clitoris are covered at the lower part 
 of their edge and on each side by a muscle, which arises directly below 
 their lower extremity by short tendinous fibres ; these are attached to 
 the inner branch of the ascending ramus of the ischium, and extend 
 almost to their other extremity. This muscle is called the ischio-ca- 
 vernosus muscle (JM. ischio-cavernosus, s. director , s. depressor cli- 
 toridis) . 
 
 It depresses the clitoris, and may contribute to expel the blood which 
 collects in it during erection. 
 
 D. NYMPHJE, 
 
 § 2430. The small or internal labia , or the nymphœ ( L . pudendi 
 internez , s. minores , s. nymphœ), are two oblong, reddish, corrugated 
 folds, similar to the crest of a cock, and very much compressed from 
 right to left ; they are connected posteriorly, and their anterior extremi- 
 ties unite in the glans of the clitoris. The skin which covers them is very 
 delicate, soft, moist, destitute of hair, and similar, especially on its inner- 
 side, to a mucous membrane. 
 
 Their inner face is continuous with the vagina, and the external 
 with the external labia. 
 
 They are formed by a spungy tissue, called the cavernous body of 
 the nymphœ and glans ( corpus cavernosum nympharum et glandis), 
 
OF THE GENITAL SYSTEM. 
 
 411 
 
 which is finer than that of the clitoris, but is similar to that of the 
 glans, of which it is the direct continuation. 
 
 The two branches of the prepuce terminate near the anterior and 
 upper extremity of these folds, and are continuous on the outside with 
 them. 
 
 Hence it follows that the nymphæ divide at their anterior extremity 
 into two branches ; the internal, which is the smaller, enters into the 
 glans, and the external, or the larger, terminates in the prepuce, and 
 their spungy tissue unites with that of the glans. 
 
 The space between them is termed the vestibule ( vestibuhm ). 
 
 E. EXTERNAL LABIA. 
 
 § 2431. The great or external labia ( L . pudendi externa , s. magna ) 
 are considerable folds of skin, directed from before backward, which 
 envelop the other external genital parts. Their external fold is formed 
 by the skin : the internal by a very thin mucous membrane, which is 
 continuous with that of the nymphæ. 
 
 They unite anteriorly and posteriorly, thus forming the anterior and 
 posterior commissures. They are imperceptibly continuous forward 
 with the mons veneris. They are united posteriorly, on the inside 
 and above the posterior commissure, by a thin and transverse fold, 
 termed their frenum ( frenulum pudendi). 
 
 The space between the frenum and the posterior commissure is 
 termed the navicidar fossa {fossa navicularis). 
 
 T. MUCOUS CRYPTS OP THE EXTERNAL GENITAL PARTS. 
 
 § 2432. The external genital parts are provided with numerous 
 large mucous crypts ; they abound particularly around the orifice of 
 the urethra and the entrance of the vagina. The first have been 
 termed the prostate of Bartholini {prostata Bartholiniana).{\) 
 
 G. CONSTRICTOR VAGINÆ MUSCLE. 
 
 § 2433. The upper extremity of the external genital organs in the 
 female is surrounded on a level with the nymphæ by a thin, long, 
 round, and muscular layer, which blends posteriorly with the anterior 
 extremity of the sphincter ani externus muscle, and is attached forward 
 to the branches and the body of the clitoris. This is the constrictor 
 vaginae muscle (JVf. constrictor cunni). 
 
 This muscle powerfully contributes to contract the entrance of the 
 vagina. 
 
 (1) Bartholini, De ovariis, p. 21. 
 
412 
 
 DESCRIPTIVE ANATOMY. 
 
 III. VESSELS AND NERVES. 
 
 § 2434. The female genital organs receive their vessels from two 
 sources, principally from the spermatic arteries and the branches of 
 the hypogastiic arteries ; they are termed the uterine and vaginal ar- 
 teries, and the arteries of the clitoris, and they are distributed in the 
 parts of the same name. Some twigs of the internal pudic artery also 
 go into the external labia. 
 
 The synonymous veins carry the blood into the crural, the hypo- 
 gastric, and the renal veins. 
 
 The spermatic vessels form around the ovaries a very complex 
 plexus, called the pampiniform body ( plexus pampiniformis). They 
 anastomose in the substance of the uterus not only those of one side 
 with those of the other, but those of the upper part with those of the 
 lower. 
 
 The nerves of the internal genital parts(l) come from the ganglion- 
 nary nerve, and those of the external from the iliac plexus. 
 
 IV. PROPERTIES AND FUNCTIONS. 
 
 § 2435. As the external genital parts of the female receive a great 
 number of nerves, they possess an extreme sensibility, which does not 
 exist to the same degree in the internal. 
 
 The uterus by its muscular fibres possesses great powers of con- 
 tractility, which exist to a certain degree in the vagina also. (2) 
 
 The formation of the new being commences in the ovary. (3) 
 
 The following facts prove this proposition : 
 
 1st. When extirpated, sterility ensues, although all the other parts 
 remain perfect. 
 
 2d. Of all the parts of the genital system the first changes after a 
 productive copulation are observed in them. 
 
 3d. Fetuses have been found within them. 
 
 4th. They have also been found in the abdomen, without any trace 
 of injury in the parts, and with or without the closing of the tubes. 
 
 The tubes receive the product of conception which is developed in 
 the ovary, and carry it into the uterus. This is proved : 
 
 (1) F. Tiedemann, Tabules nervorum uteri, Heidelberg-, 1822. 
 
 (2) Lobstein, in the Journ. de médecine , vol. xxxvi., p. 143. 
 
 (â) Prévost and Dumas assert (Mémoire sur la génération dans les mammifères 
 et les premiers indices du développement de l’embryon ; in the Annales des sc. nat,, 
 vol. iii., p. 134) that fecundation does not take place in the ovary, because we never 
 find in the pouch covering this organ the spermatic animalculæ, which are consi- 
 dered the agents of fecundation; so that according to them the moment of fecun- 
 dation is much later than that of copulation, and the ovum is not impregnated until 
 arriving in the Fallopian tube or the uterus it comes in contact with the seminal 
 fluid. How can this theory be reconciled with ovarian pregnancy 7 F. T. 
 
OF THE GENITAL SYSTEM. 
 
 413 
 
 1st. By the fetuses found in the cavity of the abdomen. 
 
 2d. By those found within the tube, especially in the cases where 
 the external or internal orifice of this passage was obliterated. 
 
 3d. The uterus is the organ in which the new organism is deve- 
 loped. 
 
 This proposition is supported by the following arguments; 
 
 1st. The fetus is developed in the uterus, when no anomaly occurs. 
 
 2d. Even when the fetus is developed out of the uterus, the latter 
 undergoes the usual changes in its substance and its cavity. The 
 possibility of extra-uterine fetation, however, proves that it is not ab- 
 solutely necessary to form the new organism. 
 
 The vagina is only the conducting organ of the penis, the semen, 
 and the fetus. 
 
 The external parts are the exciting organs, the organs of pleasure, 
 as is proved by their increase of susceptibility before and during 
 coition. 
 
 This increase of susceptibility communicated to the internal geni- 
 tal organs and to the organism is attended with the degree of energy 
 or excitement necessary to produce the new being. 
 
 B. GENITAL ORGANS OF THE MALE. 
 
 ■ I. FORMATIVE ORGANS. 
 
 A. TESTICLES. 
 
 § 2436. The most important genital organs in the male are the 
 testicles ( didymi , s. testes , s. testiculi) ,(l) or the glands which secrete 
 the semen. 
 
 a. Form and situation. 
 
 § 2437. The testicles have an elongated, rounded, and an almost 
 oval form. They are situated at the lower part of the trunk, on the 
 sides and below the penis, in a special fold of the skin which is formed 
 like a sac, and is termed the scrotum. They communicate wfith the 
 parts of the genital apparatus situated within the abdomen, by the 
 spermatic cord ( funiculus speculations, s. testicularis). This cord is 
 formed by their excretory duct, their vessels and nerves, and the cre- 
 master muscle. 
 
 (1) R. de Graaf, De virorum organis generations inservientibus, Leyden, 1668. — 
 Leal Leali, De partibus confie ientibus in viro, Padua, 1686. — Santorini, De virorum 
 naturalibus ; in the Obs. anat ., cap. x. — J. G. Rœderer, De genitalibus virorum, 
 Gottingen, 1758. — J. Wilson, Lectures on the structure and physiology of the male 
 urinary and genital organs of the human body , London, 1821. 
 
 Vol. III. 53 
 
414 
 
 DESClUfTIVE ANATOMY. 
 
 b. Volume and weight. 
 
 § 2438. The testicle 'alone, that is its substance, when its envelops, 
 except the most internal, are removed, is generally an inch and a half 
 long, one broad, and about nine lines thick. 
 
 It usually weighs about four drachms. 
 
 c. Composition, 
 a. Membranes. 
 
 § 2439. The testicles are surrounded with several superimposed 
 layers, which vary in their nature, and are termed tunics. { 1) 
 
 1. Skin of the scrotum. 
 
 § 2440. The external layer is the skin of the scrotum, a fold of the 
 common integuments, which descends from the inguinal region, and 
 terminates between the roots of the penis and the perineum. This 
 fold, which is broader at its lower than at its upper part, differs from 
 the rest of the skin, as it is generally a little darker colored, since it 
 presents distinct hairs, and because there is no fat. 
 
 It presents also exactly on the median line a narrow sac, the direc- 
 tion of which is from before backward ; this is slightly prominent, and 
 is formed by numerous transverse folds arranged very compactly, and 
 is termed the raphe. Although apparently thicker at this part, the 
 scrotum is in fact thinner than in any other. 
 
 The epidermis of the scrotum is very solid and thick. 
 
 2. Dartos. 
 
 § 2441. Immediately under the skin we find the dartos ( tunica 
 carnea , s. dartos ), which is situated, in regard to the skin of the 
 scrotum, in the same manner as the adipose substance is in regard to 
 the common integuments, excepting, however, in men who are very 
 fleshy. 
 
 It is very vascular, and hence it is reddish, and more or less evi- 
 dently fibrous. As it is also very contractile, several anatomists, as 
 
 (1) J. E. Neubauer, De tunicis vaginalibus testis et funiculi spermatid dissertatio, 
 Giessen, 1767. — A. Monro, Remarks on the spermatic vessels and the scrotum , with 
 its contents ; in his Medical essays, vol. v., pt. i., p. 205-222. — J. Brugnone, De 
 testium in fœlu positu, eorum in scrotum descensu, tunicarum quibus continentur, 
 numéro et origine, Leyden, 1788. — P. A. Bondioli, Sul numéro delle tonache vagi- 
 nali del testicolo, Padua, 1780. — J. Tumiati, Richerche anatomische intorno alle 
 tonache dci testicoli, Venice, 1790. 
 
OF THE GENITAL 8YSTEM. 
 
 415 
 
 Winslow,(l) have considered it as muscular, and have compared it to 
 the subcutaneous muscles ; but accidental or designed emphysema, (2) 
 and the comparative results obtained by macerating it and the platis- 
 ma myoides muscle, show nothing but cellular tissue. (3) Probably, 
 however, it makes the transition from the mucous to the muscular tis- 
 sue, and there is between it and the other muscles, about the same rela- 
 tion as between it and the muscles of the superior and inferior animals, 
 in whom the fibrous structure is not very distinct, and is concealed in 
 some measure by the gelatine, an element of muscous tissuej which 
 envelops and conceals the fibrin instead of leaving it exposed, as in 
 the superior animals, where even it is not changed into this substance. 
 
 § 2442. The dartos forms tw'o distinct sacs, which are adapted to 
 each other on the median line, and give rise to the septum of the scro- 
 tum {septum scroti) which corresponds to the raphe. It consequently 
 separates the two testicles, not only in respect to position, but also, and 
 to a certain extent, in that of vitality, although they are not perfectly 
 distinct. Like the mucous tissue in general, it is more or less infiltrated 
 with serum. 
 
 3. Cremaster muscle. 
 
 § 2443. The cremaster muscle, the fleshy or erythroid tunic ( tunica 
 carnea, s. erythroides ), is situated below the dartos ; it arises from the 
 horizontal ramus of the pubis, and forms a third layer. This tunic is 
 formed by an external fasciculus, which descends from the lower edge 
 of the two internal broad abdominal muscles, and by an internal fasci- 
 culus, which is generally smaller, but is sometimes as large, and rarely 
 larger; this arises from the horizontal ramus of the pubis. It surrounds 
 the spermatic cord, and the internal tunics of the testicle, and is distri- 
 buted principally on the anterior face, even when it embraces all the 
 surface of the organ. Its fibres describe arches which are convex 
 downward, and separate more from each other the lower they de- 
 scend. 
 
 When there are muscular fibres on the whole surface of the organ, 
 the spermatic cord emerges through the inferior part of the obliquus 
 internus muscle, and not only below its inner edge. Sometimes the 
 internal fasciculus is really or apparently deficient ; the latter case is 
 most common. Sometimes in muscular persons, but very rarely, fas- 
 ciculi leave the cremaster muscle, and go with the spermatic cord into 
 the abdominal cavity.(4) 
 
 This muscle entirely surrounds the cord only at its upper part ; be- 
 low, its fibres separate. 
 
 (1) Traite du bas-ventre , § 499. 
 
 (2) Morgagni, Adv. anat., vol. iv. an. 1. 
 
 (3) Tumiati, p. 142. 
 
 (4) Brugnone, Observations sur les vésicules séminales ; in the Mémoires de Turin, 
 1786. p. 610.— Penchienati, ibid. 
 
41G 
 
 DESCRIPTIVE ANATOMY. 
 
 It is itself enveloped by a prolongation of the thick cellular sheath 
 ■which surrounds the obliquus abdominis externus muscle, and its 
 fibres, although separated are united by cellular tissue. This cellular 
 tissue and the cellular sheath which we have mentioned, blend to- 
 gether below, where they alone envelop the testicle, below which they 
 unite with a common vaginal tunic, to give rise to a short but solid 
 tubercle. 
 
 This muscle, which is more developed in animals than in man, raises 
 the testicle. 
 
 4. Common vaginal tunic of the testicles and spermatic cord. 
 
 § 2444. Next to the erjhhroid tunic is a layer of mucous tissue, 
 termed the common vaginal tunic of the testicle and spermatic cord 
 ( tunica vaginalis testis, et. funiculi spermatid communis ). This tunic 
 arises from the mucous tissue which surrounds the peritoneum, and 
 covers the whole cord and testicles : we may by inflating its lower ex- 
 tremity, pass air through the inguinal ring into the cellular layer 
 which covers the anterior and posterior faces of the peritoneum, and 
 even between the layers of the mesentery. 
 
 Prolongations proceed inward from the external edge of this layer, 
 and go toward the interior, where they unite together the vessels of 
 the spermatic cord and the vas deferens, but we do not find below it 
 the pretended proper vaginal tunic of the spermatic cord ( tunica vagi- 
 nalis funiculi spermatid propria ), which Neubeauer admits and which 
 he asserts has a distinct cavity, for if after carefully removing this 
 layer from its external surface, the vessels of the spermatic cord be in- 
 flated, this air penetrates into every part ; and farther, air injected into 
 it, also enters the vessels of the cord. Farther, the common vaginal 
 tunic cannot be considered at its upper part as a special, independent 
 and close serous cylinder, if we reflect, that on removing the cre- 
 master muscle which covers it, it ceases to be impermeable to the air, 
 and that it presents this character only so long as it is surrounded by 
 the muscle and its tendon. 
 
 We can at most admit an external layer, similar to the loose layer 
 of the serous membranes, and a reflected fold which surrounds and 
 unites the vessels of the spermatic cord. The first then will be termed 
 the common, and the second the special tunic of the cord. 
 
 But below, as far as it covers the proper vaginal tunic of the testicle, 
 thi 3 tunic is very firm, evidently fibrous, and adheres intimately to the 
 proper tunic of the gland, especially near its lower extremity. 
 
 It is also continuous on the outside in this part with the two tunics 
 which cover it externally. * 
 
OF THE GEKITAL SYSTEM. 
 
 417 
 
 6. Proper vaginal tunic of the testicle. 
 
 § 2445. We must distinguish from this layer the fifth envelop of 
 the testicle, th e proper vaginal tunic ( t . vaginalis testis propria), from 
 which it is perfectly separated. 
 
 T his tunic is a compound serous membrane. It usually has an oval 
 form, similar to that of the testicle ; it however is rather more extern 
 sive, so that its cavity is a third higher than - the gland, being two 
 inches and a half high. Sometimes a narrower prolongation, which 
 varies in length, leaves the anterior part of its surface, and penetrates 
 below into the common vaginal tunic, and the two cavities uninter- 
 ruptedly communicate. 
 
 We conclude from our dissections, that this prolongation is never 
 ■detached exactly from its summit, but always a little below it. 
 
 The special vaginal tunic receives in its cavity not only the testicle, 
 but also the whole epididymis and a portion of the spermatic cord. At 
 the place where it is reflected on itself, it receives directly these last 
 two parts in thé commencement of its internal and reflected fold. When 
 it has enveloped them, it passes on the upper and lower extremity of 
 the testicle, but covers the gland in its greatest portion, so that the 
 summit and the base of the epididymis are only covered by it in the 
 point by which they look toward the testicle. Thence it goes on the 
 whole circumference of the gland. It is by this fold that the spermatic 
 vessels pass to go to the testicle, and enter at its upper and posterior 
 edge. 
 
 The two layers which form this fold are slightly united by cellular 
 tissue, so that they are easily separated. It is not difficult to detach 
 the vaginal tunic from the epididymis ; but it is less easy to separate 
 it from the testicle, excepting for some lines near the posterior edge. 
 
 A portion of this membrane which covers the testicle, has been im- 
 properly termed by Tumiati,(l) the conjunctiva. It is usually called 
 the external layer of the tunica albuginea, a term still more incon- 
 venient. 
 
 6. Fibrous or albugineous tunic. 
 
 § 2446. The fibrous or albugineous membrane ( T. albuginea , ano- 
 nyma, fibrosa) is the last and the most internal tunic of the testicle. 
 It directly envelops the substance of the gland, and determines its form. 
 It is thick, solid, silvery, shining, and fibrous. In fact, it is a fibrous 
 membrane . 
 
 It forms a single cavity, and is perforated at its upper extremity for 
 the passage of the seminal ducts, and at the posterior edge for thjat of 
 the spermatic vessels. 
 
 (I) Loc. cit., p. 146. 
 
418 
 
 DESCRIPTIVE ANATOMY. 
 
 b. Substance of the testicle. 
 
 § 2447. On the inner side of the albugineous membrane, to which 
 it adheres in great part but slightly, is the substance of the testicle,(l) 
 a soft brownish yellow mass, divided by the blood-vessels of the tunic 
 into several lobules ( lobidi),{2 ) situated one above another. This sub- 
 stance is composed principally of very many minute canals, which 
 are single, and do not ramify and interlace with each other ; they are 
 termed the seminal canals ( canaliculi semmales, s, vascvla serpentina , 
 s. ductus seminiferi). Each lobule includes one of these canals. Their 
 circumvolutions, and they themselves, are united very loosely by a fine 
 cellular tissue, so that they may be easily detached. But it is much 
 more easy to prove by maceration, their very great number, which is 
 about three hundred. Each of them is about sixteen feet long and 
 broad. If attached to one another, they would consequently ex- 
 tend about five thousand feet. 
 
 § 2448. These canals unite near the upper extremity of the testicle, 
 into several larger canals, which pass through the albugineous tunic, 
 and soon produce about twenty others, which are still larger, called the 
 vasa efferentia. These latter are united in a single fasciculus by a 
 mucous tissue, wind around from below upward, and form the rounded 
 and enlarged head of the epididymis. 
 
 B. EPIDIDYMIS. 
 
 § 2449. The epididymis{ 3) is the commencement of the excretory 
 duct of the testicle. It begins at the upper extremity of this gland 
 by a thicker, enlarged, and rounded part, called the head , and de- 
 scends along its posterior and upper- edge. The fasciculi which form 
 the seminal passages, are still separated in the head of the epididymis, 
 although, according to our observations, this part seems to be perfora- 
 ted, even at its upper extremity, only by a simple and very tortuous 
 canal, into which the seminal passages severally open. 
 
 The thinnest and longest part of the epididymis, that termed its 
 tail ( cauda ), is a simple, but very tortuous canal ; it is at first very 
 narrow, but gradually enlarges very much, and becomes more tortu- 
 ous. It is but loosely attached to the proper vaginal tunic of the tes- 
 ticle by a fold of this membrane, and is reflected on itself from below 
 upward at its lower extremity, and is then called the ductus deferens. 
 
 It is about thirty feet long. 
 
 (1) A. Haller, De vasis seminalibus observationes, Gottingen, 1745. — A. Monro, 
 Description of the seminal vessels ; in the Edinb. essays phys. and literary, yo\. i. 
 xvi. — Id., De testibus et de semine in variis animalibus , Edinburg, 1755. — Id., Of 
 the seminal ducts ; in the Observations anatomic, and physiol, wherein Hunter’s 
 claim some discoveries is examined , Edinburg, 1753. — G. Prochaska, Beobach- 
 tungen über die Samengange ; in the Abhandl. der Jos. Akad., vol. i. p. 198-213. 
 
 (2) B. S. Albinus, De teste humano ; in the Ann. acad., 1. ii. c. xii. 
 
 (3) B. S. Albinus, Dc epididymo ; in the Ann. acad., 1. ii. c. vi. 
 
OF THE GENITAL SYSTEM- 
 
 419 
 
 C. DUCTUS DEFEHENS. 
 
 § 2450. The ductus deferens or vas deferens, ( 1) ascends along the 
 posterior and upper edge of the testicle, first in a straight line, then ob- 
 liquely from within outward. It is tortuous at its origin, but soon be- 
 comes straight, and joins the spermatic vessels, with which it is united 
 by cellular tissue, to give rise to the spermatic cord. It ascends di- 
 rectly to the inguinal ring ; but in this place its direction changes, and 
 it goes from below upward, and from within outward in the inguinal 
 canal, within which we observe the relation we have indicated, be- 
 tween the blood-vessels and the lymphatics, and the ductus de- 
 ferens. On leaving this canal it crosses the epigastric artery, and as- 
 cends directly before it, then turns behind it on the inside, and upward, 
 and thus comes into the abdominal cavity. Thence it leaves the sper- 
 matic vessels at a more or less acute angle, goes inward and down- 
 ward always on the outside of the peritoneum, which covers only its 
 posterior part, and descends into the small pelvis, converging very 
 much toward that of the opposite side. 
 
 § 2451. The ductus deferens is situated in the pelvis, on the pos- 
 terior face of the bladder. 
 
 It dilates and gradually thickens in its course. At its lowest part, 
 which suddenly dilates considerably, it becomes at the same time very 
 tortuous, less so, however, than at its origin, and gives rise on the out- 
 side upward and backward, to a great enlargement, to a kind of purse 
 or cul-de-sac, termed the seminal vesicle. 
 
 Two very different substances enter into its composition. The ex- 
 ternal, which is about half a line thick, is of a brownish yellow color, 
 very hard and solid. Very probably it is irritable, although fibres are 
 distinctly seen in it very rarely. Sometimes, however, we have ob- 
 served circular fibres which it was impossible to mistake.(2) 
 
 The inner substance is whitish, and easily separable from the pre- 
 ceding, with which it is united only by a loose cellular tissue. It is a 
 mucous membrane, a prolongation of that of the urethra. It is smooth 
 in most of its extent, but reticulated below for an inch or turn. 
 
 D. SEMINAL VESICLES. 
 
 § 2452. The seminal vesicles ( vésicules séminales, s. parastatœ)( 3) 
 are situated one on each side, on the outside of the corresponding 
 ductus deferens. They are also intimately adapted to the poste- 
 rior face of the bladder, and are covered posteriorly by the perito- 
 
 (1) B. S. Albinus, De vasis defer entib us, vesiculis seminalibus, emissariis quibus 
 ad urethram pertinent, ostiolis in capite gallmaginis ; in the Ann. acad., 1 . iv. c. iii. 
 p. 16. 
 
 (2) Leuwenhock (ep. xli) has seen also longitudinal fibres. 
 
 (3) Haller, Observationes dc vasis seminalibus , Gottingen, 1745. 
 
420 
 
 DESCRIPTIVE ANATOMY. 
 
 neum which adheres to them but slightly. Their breadth is, however, 
 slight in proportion to their length, for they are about two or three 
 lines broad, and four or five inches long; but they appear much shorter, 
 as they are very tortuous. 
 
 They are, however, not always simply tortuous or similar to a long 
 cul-de-sac, as Lealis, and since his time Caldani,(l) have asserted. In 
 fact, they more commonly ramify. 
 
 Their inner membrane presents numerous inequalities, which pro- 
 duce a kind of net-work with irregular meshes. There is also between 
 the largest folds, a considerable number of less prominent folds, which 
 also render their inner face still more uneven. This arrangement es- 
 tablishes a striking analogy between the seminal vesicles and the gall- 
 bladder. 
 
 § 2453. The lower, extremity of the seminal vesicle and of the duc- 
 tus deferens, opens into an extremely narrow duct some lines long, 
 termed the ejaculatory duct ( ductus ejaculatorius). This duct ap- 
 proaches from behind forward, and from below upward, that of the 
 other side, enters into the substance of the prostate gland, and opens 
 into the urethra, directly at the side of this latter, in the centre of the 
 verumonianum. 
 
 E. PBOSTATE GLAND. 
 
 § 2454. The prostate gland ( prostata ) is a triangular (2) body, 
 usually of the size and form of a chestnut ; is about an inch broad, one 
 high, and half an inch thick, and weighs about five drachms. 
 
 It is situated below and before the bladder, and surrounds the com- 
 mencement of the urethra posteriorly and on the sides. 
 
 It is whitish, hard, and solid, and it is surrounded by a fibrous and 
 resisting membrane. 
 
 It is composed of three tubes, two lateral and a central, which is 
 posterior and smaller. 
 
 The middle lobe is situated behind and between the two lateral lobes 
 and the ejaculatory ducts, and likewise between these latter and the 
 bladder ; it is rounded and smaller than the lateral ; its volume how- 
 ever varies. In the centre of its lower face is an oblong rounded emi- 
 nence, which terminates anteriorly in a narrow and elongated point. 
 This eminence has been termed from its form, the verumontanum 
 ( caput gallinaginis , s. verumontanum, s. colliculus seminalis). It pre- 
 sents at its centre one or two orifices of the ejaculatory ducts, and on 
 the sides a considerable number of orifices leading to the excretory 
 canals, -which are distributed in the substance of the glanfl. These 
 orifices give passage to a yellowish fluid, the fluid of the prostate , 
 which mingles with the semen at the time of emission. 
 
 (1) F. Caldani, Opusc. anut., Padoue, 1803, 
 
 (2) Home, On the prostrate gland. 
 
OF THE GENITAL SYSTEM. 
 
 421 
 
 The excretory ducts of the middle lobe pass immediately through 
 the membranes of the bladder, behind and on the outside of the veru- 
 montanum. 
 
 II. ORGANS OF COPULATION OR PENIS. 
 
 A. FORM AND SITUATION. 
 
 § 2455. The penis (penis, s. coles, s. priapus, s. membrum virile ) 
 is situated forward, and entirely on the outside of the pelvis, below the 
 symphysis pubis, between the thighs. Its form is nearly cylindrical. 
 The common excretory duct of the urine and semen, the urethra , 
 passes through it. 
 
 It is entirely surrounded by a prolongation of the skin, which in this 
 place is thin and destititute of hairs, and fat. External examination 
 shows even through the skin, that it suddenly enlarges at its anterior 
 extremity, where it presents a considerable prominence, and that it ter- 
 minates in a blunt point.(l) 
 
 a. Gians. 
 
 § 2456. This enlarged portion is the glans penis, (2) a rounded tri- 
 angular body, terminated posteriorly by a rounded sac, termed the 
 crown ( corona glandis ), which entirely surrounds it, and forward by a 
 longitudinal groove, the external orifice of the urethra. The contracted 
 portion, situated behind the glans, is its neck. 
 
 The glans is not exposed ; it is covered by three layers of skin. 
 
 b. Prepuce. 
 
 § 2457. The first two layers are united by cellular tissue, so that 
 the external is turned outward, and the internal inward. They form 
 th e prepuce (preputium). This fold is fitted to the glans, but is not 
 attached to it, so that it can be drawn backward and forward ; the first 
 motion exposes the glans, the second covers it. 
 
 The internal layer of the prepuce is soft, reddish, moist, and similar 
 to a mucous membrane. 
 
 In the centre, where the two layers are continuous with each other, 
 the prepuce presents apparently a rounded opening, which corresponds 
 
 (1) F. Ruysch, Responsio, &c. in the epist. xv. De vas. sanguineorum extremit., 
 &c. Iiisce accedunt nonnulla circa penem detecta. — B. S. Albinus, Dc Ruyschiano 
 involucro penis externo, et de tunica cellulosa penis ; in the Ann. acad., 1. ii. c. xi. — 
 F. Ruysch, De involucro penis externo, ibid. ]. ii. c. xiii. — L’Admiral, Iconpenis hu- 
 mani cera præparati, Amsterdam, 1741. — J. H. Thaut. Diss. de virgae virilis statu 
 sano el morboso, Wurzburg’, 1808. 
 
 (2) F. Ruysch, Glandis in pene vera structura noviter detecta ; in the Obs. med. 
 chir., cap. c. — B. S. Albinus, De integumentis glandis penis ; in the Annot. acad., 
 lib. iii. c. ix. 
 
 VOL. Ill, 
 
 54 
 
422 
 
 DESCRIPTIVE ANATOMY. 
 
 to the anterior oiifice of the glans, and which disappears when the pre- 
 puce is drawn entirely backward. The latter is corrugated trans- 
 versely in the same proportion. 
 
 The internal layer of the prepuce is reflected a second time behind 
 the glans, but here from behind forward, and covers this organ, inti- 
 mately adhering to its tissue. This adhesion is almost gradual on the 
 circumference of the glans. In fact the internal fold of the prepuce is 
 loose at its upper part, where it is attached but feebly to the penis ; 
 but near the centre of its lower part, it is tense, short, and intimately 
 united to the corresponding portion of the glans, and forms a short per- 
 pendicular fold. 
 
 This portion of the prepuce is termed the frenum of the glans ( fre- 
 nulum glandis): 
 
 All around the neck and posterior face of the crown, the most inter- 
 nal cutaneous fold of the glans presents numerous rounded depres- 
 sions, termed the glands of Tyson ( glandulœ Tysonianœ), which se- 
 crete a thick and whitish fluid. 
 
 This fluid ( smegma prœputii) has a disagreeable smell, and tends 
 very much to solidify. 
 
 3. SIZE or THE PENIS. 
 
 § 2458. When not erected, the penis is about three or four inches 
 long and one inch thick. 
 
 C. COMPOSITION. 
 
 § 2459. The penis is attached to the skin, which covers it only very 
 loosely. 
 
 It is composed of a thick and fibrous membrane, which determines 
 its form, and of a spongy tissue, principally formed by dilated veins, 
 which is then divided into three distinct bodies. The two upper and 
 lateral are termed the cavernous bodies of the penis ( corpora spongiosa, 
 s. cavernosa , s. nervosa penis), the inferior is termed the spungy body of 
 the urethra ( corpus spongiosum , s. cavernosum urethrae). 
 
 The cavernous bodies of the penis and urethra are generally de- 
 scribed as a collection of different cellules of the vessels ; but these 
 cellules are in fact only dilated veins, and the spungy bodies are com- 
 posed of a very complex net-work of arteries and veins, as Vesalius(l) 
 and Maipighi(2) had already stated generally in regard to the penis, 
 and Hunter, (3) of the spungy body of the urethra particularly. 
 
 (1) De corporis humani fabricà, lib. v. c. xiv. Corpora have... enata ad eumfere 
 modum, ac si cx innumcris arteriarum. venarumquefasculis quam tenuissimis, si - 
 uiulquc proximé implicatis, retia quœdam efformarentur, orbiculatim a nervea ilia 
 ■membrane aque substantia comprehcnsa. 
 
 (2) Diss. epist. varii argumenti ; in the Opp. omn., vol. ii. p. 221. Sinuum spe- 
 eiem in mammarum tubulis et in pane habemus ; in his nonnihil sanguinis reperi- 
 tur, ita ut videantur venarum diverticula , vel saltern ipsarum appendices. 
 
 (3) Hunter, Obs. on certain parts of the animal economy, p. 43. 
 
ÜF THE GENITAL SYSTEM. 
 
 423 
 
 This structure had been perfectly demonstrated in the penis of the 
 large animals, as the elephant and the horse, partly by Duvernoy,(l) 
 but particularly by Cuvier(2) and Tiedemann ;(3) in the penis of man 
 by Ribes.(4) Moreschi, and Panizza. 
 
 a. Cavernous bodies of the penis. 
 
 § 2460. The cavernous bodies of the penis form most of the member, 
 that is, its upper parts and its sides. They are more broad than high. 
 
 They alone have evidently a fibrous envelop, the fibres of which in- 
 terlace with each other, and are longitudinal. 
 
 They arise on each side by a branch about half an inch long, which 
 comes from the ascending ramus of the ischium ; the two branches 
 ascend to meet each other, and unite before the symphysis pubis, 
 where they are surrounded in their whole circumference by a common 
 envelop. 
 
 Although they appear simple externally, these bodies are however 
 imperfectly divided into two halves, a right and a left, by a perpendicu- 
 lar septum ( septum corporum cavernosorum ), which extends almost 
 fheir whole length, and is a prolongation of the external fibrous mem- 
 brane. This septum is formed of very long fibres, compressed from 
 right to left, which extend the whole heigth of the cavernous bodies, 
 and which, forming posteriorly an almost perfect septum, proceed 
 forward, growing thinner, and diminishing much in number so as 
 to leave between them greater or less spaces. The separation which 
 takes place between the two cavernous bodies at their posterior extre- 
 mity, then gradually disappears forward entirely. They however se- 
 parate still more at their anterior extremity, although apparently only 
 on the outside, since the external part of their circumference is much 
 longer than the internal, whence their anterior faces, surrounded by 
 the external tunic, unite from without inward at a re-entering angle. 
 
 b. Urethra. 
 
 § 2461 . The urethra( 5) proceeds along the lower face of the penis. 
 It begins in the prostate gland, where it is broad. In front of this point 
 
 (1) Conm. Petrop. a. ii. p. 400. Venarum ductus solummodo cribriformes, fara- 
 minibus undique pertusi ac reluti erosi, a cellulis œgre discriminandi extra capsu- 
 lam penis , venarum (s. brevium tubulorum verticalium) formam induenlia, in con 
 spectum veniunt. 
 
 (2) Anat. comparée, vol. iv. 
 
 (3) F. Tiedemann, Notice sur less corps caverneux de la verge du cheval , suivie 
 de quelques réfléxions sur le phénomène de l'érection ; in the Journ. compl. des. sc. 
 méd., vol. iv. p. 282. 
 
 (4) Exposé sommaire de quelques recherches anatomiques , physiologiques et patho- 
 logiques ; in the Mém. de la soc. méd d’emul., vol. vii. p. 605. 
 
 (5) A. Littré, Description de l' urètre de l'homme; in the Mém. de Pc, ris, 1700, — 
 J. P, Werne, Structura urethra- , Leyden, 1752. 
 
424 
 
 DESCRIPTIVE ANATOMY. 
 
 it contracts much for about an inch, so as to be only one or two lines 
 in diameter. This contracted portion is called the isthmus of the ure- 
 thra (isthmus urethrcc). It ascends a little obliquely from below up- 
 ward, and from behind forward, below the symphysis pubis, from which 
 it is about an inch distant, surrounded by a loose spungy tissue, like 
 the urethra in the female, which corresponds only to this portion of the 
 urethra in the male. The canal afterward enlarges very much, and 
 is then surrounded in the rest of its extent by the cavernous body of 
 the urethra, the size of which is generally in direct ratio to its diameter. 
 
 The cavernous body of the urethra is largest at the second promi- 
 nence, where it forms a considerable enlargement called the bulb oj 
 the urethra (bulbus urethrcc) . 
 
 On leaving this point the urethra contracts very much. Its diame- 
 ter continues about the same to the anterior extremity of the penis ; 
 but directly behind and within the glans it enlarges a third time to 
 form the navicular fossa ( fossa navicularis) . 
 
 The cavernous body of the urethra is enveloped only by a dense 
 cellular tissue, which is not fibrous. It is finer, and of a more delicate 
 tissue than that of the penis, and has no septum. It alone forms the 
 glans anteriorly. 
 
 Below this body is a thin and reddish mucous membrane, which is 
 united intimately with it, and has longitudinal folds. 
 
 This membrane presents numerous cavities arranged successively 
 as culs-de-sac in a single series, termed the glands of Littré. 
 
 These cavities are sometimes three lines deep. They are seen only 
 at the lower part of the circumference of the urethra, and their direc- 
 tion is such that their orifice looks forward and their cul-de-sac back- 
 ward^ 1) 
 
 (1) As Ducamp’s researches have reduced the treatment of strictures of the 
 urethra almost to mathematical accuracy, it is necessary to have a more extensive 
 knowledge of this canal than has been given by Meckel. This may be found in a 
 memoir of Amussat ( Remarques sur l'urètre de l’homme et de la femme ; in the 
 Archiv, gén. de mêd ., vol. iv., p. 31 and 347), who has ascertained a very important 
 practical fact, that even in young subjects the urethra is straight or nearly straight 
 when the rectum is empty, and the penis is directed from before backward. We 
 distinguish in it three portions : the prostatic portion, with thin parietes, which is 
 enveloped by the prostate gland ; it is about twelve or fifteen lines long; the mem- 
 branous portion, the parietes of which are a little thicker ; it is from nine to 
 twelve inches long ; and the spungy portion, which is from about six to seven inches 
 long. Most authors consider the whole canal as ten or twelve inches long ; but it 
 is only nine, and very frequently, at least sometimes, even less than eight, as has 
 been stated by P. Whately (An improved method of treating strictures in the urethra , 
 London, 1816, p. 68). We may then estimate its mean length as between eight and 
 nine inches, nine inches and six lines and seven inches and six lines being the two 
 extreme proportions observed by Whately in forty-eight different subjects. It is not 
 equally broad in every part. It follows, from Sir E. Home’s researches (Practical 
 observations on the treatment of strictures in the urethra , London, 1805, vol. i., p. 24), 
 that its diameter is four lines in most of its extent, and that its external orifice is at 
 least one line narrower, since it is only from two and a half to three lines in diame- 
 ter. Amussat has since proved that the urethra, when the parts which cover it are 
 removed and it is reduced almost to the mucous membrane, represents a cone, the 
 base of which is turned backward, and which is slightly prominent at its membra- 
 nous portion, contracts opposite the bulb to enlarge suddenly at the commencement 
 
OF THE GENITAL SYSTEM. 
 
 425 
 
 c. Cowper’s glands. 
 
 § 2462. Besides the testicles and the prostate gland, we also fre- 
 quently, but not always, find two or three other small, yellowish, 
 oblong, rounded, hard glands formed of several lobes enveloped by a 
 very dense aponeurotic sheath. These glands are about the size of 
 a large pea, are situated directly below the upper part and a little 
 before the prostate gland. 
 
 Their ducts are about an inch and a half long, go forward in the 
 bulb of the urethra, and open from below upward in the sides of this 
 canal by distinct orifices. 
 
 The two posterior lateral are termed the glands of Cowper. {V) The 
 anterior, which is unmated, is smaller and much less constant than 
 the other two ; it is termed the anterior prostate gland ( antiprostata .) 
 
 D. MUSCLES OF THE PERINEUM. 
 
 a. Special muscles of the penis. 
 
 § 2463. The penis has three muscles, one of which, the ischio-ca- 
 vernosus , belongs to the cavernous bodies of the penis, the second, the 
 bulbo-cavernosus , belongs to the spungy body of the urethra, while the 
 third, the constrictor urethrae muscle, moves the membranous portion 
 of this canal. All three are situated at the extremity of the penis. 
 
 a. Ischio-cavernosus. 
 
 § 2464. The ischio-cavernosus muscle, ischio-uretral , Ch. (JW. ischio- 
 cavernosus ■, s. erector penis), resembles that of the clitoris in its origin, 
 attachments, direction, and mode of action ; but it is much larger, and 
 sometimes arises by a second head from the sciatic tuberosity. 
 
 of the spungy portion, and diminishes imperceptibly to the meatus, so that there is 
 no enlargement in the place corresponding to the glans, that is, in the navicular 
 fossa. Amussat explains the appearance of an enlargement in thi3 latter point, by 
 saying that the tissue of the glans is less soft and the mucous membrane is attached 
 to it more intimately, so that in dividing the urethra, the two halves of the glans 
 remain firm and distinct, while the proper spungy tissue contracts and collapses, 
 being freed from the blood within it. That the navicular fossa is only apparent is 
 proved by extending transversely the spungy portion behind the glans, when it be- 
 comes as broad as that situated in the body. He has also given a very exact plate 
 of the urethra ( loc . cit., pi. iii., fig. 1 and 2). P. T. 
 
 (1) G. Cowper, Glandularum quarumdam nv.per detectarum descriptio, London, 
 1702. — L. Terranus, De glandulis universim et spedatim ad urethram virilem 
 novis, Leyden, 1729. — G. A. Haase, De glandulis Coicperi mucosis, Leipsic, 1803. 
 
426 
 
 DESCRIPTIVE ANATOMY. 
 
 b. Bulbo-cavernosus. 
 
 § 2465. The bulbo-cavernosus muscle, bulbo-uretral, Ch. (JM. acce- 
 lerator urinœ, s bulbo-cavernosus ), is thin, flat, and nearly rhomboidal. 
 It surrounds the bulb and the posterior part of the urethra. It arises 
 forward from the posterior part of the cavernous body of the penis, and 
 backward from the upper part of the lateral wall of the bulb of .the 
 urethra. It terminates anteriorly by a straight edge, which descends 
 from without inward and from before backward, and posteriorly by a 
 rounded edge. It is formed at its anterior part by very oblique fibres, 
 and at its posterior part by fibres which are nearly transverse. It 
 blends on the median line with that of the opposite side so intimately, 
 that frequently they are not separated by a median tendinous line. 
 
 c. Constrictor urethræ. 
 
 § 2466. The constrictor urethræ. muscle, pubo-uretral , Ch. (JM. 
 constrictor urethrae, s. pub o-urethr alls), ( 1) is elongated, quadrilateral, 
 and flattened from without inward. It arises by a short tendon a little 
 above the lower edge of the symphysis pubis, some lines below the 
 tendinous attachment of the bladder, directly at the side of the tendon 
 of that of the synonymous muscle, on the inner face of the symphysis. 
 Thence it descends enlarging, is first next that of the opposite side, 
 but removes from it on arriving at the membranous portion of the 
 urethra, to which it is attached, and below which it is blended with 
 its synonymous muscle, so that generally only a tendinous line, corre- 
 sponding to the median line, indicates their separation. 
 
 It usually blends at its anterior extremity with the posterior extre- 
 mity of the bulbo-cavernosus muscle. 
 
 It is frequently united at its lower part by some fibres to the levator 
 ani muscle ; but in the rest of its extent it is separated from it only 
 by veins, which arise from the prostate gland and the bladder, pro- 
 ceed from behind forward, and empty into the great dorsal vein of the 
 penis. 
 
 The two muscles form a ring around the membranous portion of 
 the urethra ; they compress it, and by their convulsive contractions 
 very much increase the difficulty of passing a sound through this por- 
 tion of the canal. 
 
 (1) Wilson, Description of two muscles surrounding the membranous part of the 
 urethra; in the Med. chir. trails, of London , vol. i., p. 175. 
 
or THE GENITAL SYSTEM. 
 
 427 
 
 b. Common muscles .of the genital parts, the rectum, and the urinary passages, 
 a. Transversi perinei. 
 
 § 2467. We usually find two muscles on each side, the transversi 
 perinei muscles, iscliiu perineal, Ch., which go inward from the ischium 
 and the pubis, and which are similar, as they are .both long. 
 
 § 2468. The posterior and inferior arises from the inner face of the 
 sciatic tuberosity, goes from without inward and from behind forward, 
 and blends particularly in the female with that of the opposite side 
 and with the anterior extremity of the sphincter ani externus muscle, 
 and slightly also with the posterior extremity of the bulbo-cavernosus 
 and the constrictor vaginae muscles. 
 
 In acting with its synonymous muscle it draws the anus a little 
 backward and compresses it from before backward, and thus favors 
 the expulsion of the feces. 
 
 § 2469. The anterior and superior arises from tlie inner face of the 
 lower part of the descending ramus of the pubis, where it is frequently 
 united intimately to the preceding, goes inward and a little forward, 
 blends again with the preceding, that of the opposite side, and the 
 sphincter ani externus muscle, and likewise with the bulbo-cavernosus 
 and the constrictor vaginæ muscles, farther forward than that we have 
 mentioned. 
 
 It acts like the posterior, but it also contributes to open in the male 
 the posterior part of the urethra, and in the female the vagina. 
 
 § 2470. The posterior transversus perinei muscle is frequently de- 
 ficient. In man the two muscles are much nearer each other and 
 much slighter than in the female. In the latter we sometimes find a 
 third, situated between the other two. 
 
 b. Levator ani. 
 
 § 2471. The levator ani muscle, sous-pubio-coccygien , Ch., is broad, 
 thin, and semicircular. It arises forward and upward from the lower 
 part of the symphysis pubis and the horizontal ramus of the pubis ; it 
 also comes from the inner face of the body of the ischium to the sciatic 
 spine, above and on the inside of the upper edge of the obturator in- 
 ternus muscle. Thence it goes inward, downward, and backward, so 
 that its anterior fibres are almost perpendicular and the posterior trans- 
 verse. 
 
 It passes behind the lower part of the rectum, and is attached by 
 short tendinous fibres to the lateral edge of the three lower pieces of 
 the coccyx by the posterior part of its inner edge, while by the ante- 
 rior it blends with that of the opposite side. 
 
428 
 
 rF.SCIUFTIVE ANATOMY. 
 
 It follows from this arrangement that the two muscles form a large 
 ring, which surrounds the lower extremity of the rectum posteriorly, 
 and which in the female is attached very intimately to the vagina be- 
 fore arriving at the rectum. 
 
 In the female the anterior part which arises from the symphysis 
 pubis is often separated from the rest. 
 
 This muscle raises the lower part of the rectum, contracts it, and 
 thus prevents the prolapsus of the intestine, also favors the expulsion 
 of the feces, carries' forward and upward the coccyx, which has been 
 pushed forward by the feces and excrements, and by the fetus in par- 
 turition, favors the expulsion of the urine and semen by compressing 
 the bladder and seminal vesicles, and finally prevents prolapsus of the 
 vagina in females. 
 
 III. VITAL PROPERTIES AND FUNCTIONS OF THE GENITAL ORGANS IN THE MALE. 
 
 § 2472. The testicles secrete the semen, and are the most important 
 part of the genital organs, since the action of this fluid on the body 
 of the female can alone cause the formation of a perfect new organism. 
 
 This is demonstrated by sterility occurring when these organs are 
 extirpated, are congenitally absent or diseased, although the other ge- 
 nital organs are formed normally. 
 
 The semen is a whitish and strong smelling liquid ; it is composed 
 in 1000 parts: of water 900, animal mucilage 60, phosphate of dime 
 30, soda 10.(1) 
 
 The 'testicles also perform an important part in the individual or- 
 ganism ; for when they do not exist, or when they have been removed, 
 the body and the mind vary more or less from the normal state, the 
 larynx and the voice are not developed, the beard does not grow, in 
 short the individual does not acquire the distinctive characters of his 
 sex. 
 
 The semen is carried from the testicles through the ductus deferens 
 into the seminal vesicles, where, like all the other fluids in their reser- 
 voirs, it continues a certain time, becomes perfect, and is concentrated 
 by the absorption of its aqueous portion, (2) and perhaps is somewhat 
 modified by mingling with a fluid secreted in the parietes of the ve- 
 sicles. 
 
 In fact, several distinguished anatomists, as Wharton, (3) Van 
 Horne, (4) Swammerdam, (5) and Hunter, (6) have rejected this gene- 
 
 (1) Yauquelin, Annales de chimie, vol. ix., p. 64. — Berzelius states ( Annales de 
 chimie, vol. lxxxviii., p. 115) that the semen is formed of a peculiar animal matter 
 and of all the salts of the blood. 
 
 (2) G. Eitner, Semen non resorhetur, Berlin, 1820. 
 
 (3) De vesiculis semin alibus ; in his Adenographia, cap. xxx., p. 208. 
 
 (4) Prodromus observationum suarum circa partes genitales in utroque sexu , 
 Leyden, 1668. 
 
 (5) Miraculum naturce, s. uteri muliebris natura, Leyden, 1672, p. 10. 
 
 (6) Observations on the glands situated between the rectum, and bladder, called 
 vésicules séminales ; in the Observations on certain parts of the animal economy, 
 
OF THE GENJTAL SYSTEM, 
 
 429 
 
 rally admitted opinion, and assert that the seminal vesicles do not re- 
 ceive the semen, but they only secrete a peculiar fluid supplied by the 
 testicles, and some of them, as Wharton, have considered it as the 
 proper semen. They adduce the following arguments : 
 
 1st. The seminal vesicles and the. ejaculatory ducts have no com- 
 mon excretory canal. (1) 
 
 2d. Their structure is glandular.(2) 
 
 3d. A liquid injected to the base of the seminal vesicle penetrates 
 into the ductus deferens. (3) 
 
 4th. Several animals, particularly fishes, have seminal vesicles, but 
 no testicles. (4) 
 
 5th. The fluid contained in the seminal vesicles differs from the 
 semen, both in man and animals ; it is much brighter and more liquid, 
 and has not the peculiar odor of semen. (5) 
 
 6th. The fluid which sometimes comes from the urethra, when vio- 
 lent efforts are made at stool, is very similar to that found in the 
 vesicles. (6) 
 
 7th. In males who have lost one testicle, (7) or in whom one of the 
 testicles does not communicate with its seminal vesicle, this latter and 
 even the lower part of the ductus deferens of the same side have been 
 found not contracted or empty, but, on the contrary, larger and fuller 
 than that of the opposite side. (8) 
 
 8th. When coition is interrupted, pain is felt in the testicle, and not 
 in the seminal vesicles.(9) 
 
 9th. The seminal vesicles are as full in aged men and those who 
 have long been indisposed, as in those who die suddenly, or as in 
 young men.(10) 
 
 10th. In several animals there is no communication between the 
 seminal vesicles and the vasa deferential 11) 
 
 11th. In many animals, particularly in guinea-pigs, the seminal 
 vesicles are filled with fluid after coition.(12) 
 
 12th. We find no traces of them in several animals. (13) 
 
 London, 1786, 1792, p. 31. — Chaptal, Mém. où Von se propose défaire voir que les 
 vésicules séminales ne servent pas de réservoir à la semence séparée des testicules ; in 
 the Journal de physique, 1787, p. 101. 
 
 (1) AVharton, p. 209. — Van Horne. 
 
 (2) Ibid. 
 
 (3) Swammerdam, loc. cit., p. 10. 
 
 (4) Idem, in Brugnone, Mém. de Turin , 1786, p. 619. 
 
 (5) Hunter, p. 32, 38, 39. 
 
 (6) Id., p. 33. 
 
 (7) Id., p. 33-36. 
 
 (8) Id., p. 37. 
 
 (9) Id., p. 37. 
 
 (10) Id., p. 37-38.! 
 
 (11) Id., p. 38. 
 
 (12) Id., p. 39. 
 
 (13) Id., p. 40. 
 
 Vol. III. 
 
 55 
 
430 
 
 DESCRIPTIVE ANATOMY. 
 
 § 2473. Many of these facts, however, are but slightly conclusive, 
 or are even incorrect, so that they may be easily refuted, and the old 
 opinion thus be maintained.(l) 
 
 1st. The seminal vesicles and the vasa deferentia communicate in 
 the manner mentioned above. 
 
 2d. The glandular structure of the vesicles only proves that they 
 secrete, and not that they receive semen. 
 
 3d. The facility with which liquids injected into them penetrate into 
 the ductus deferens proves exactly that with which the semen passes 
 from these latter within them. 
 
 4th. The organs of fishes said to be seminal vesicles are in fact tes- 
 ticles. 
 
 5th. The difference between the liquid in the vesicles and the semen 
 emitted, may depend on a mixture of their proper secretion with that 
 of the testicles. Farther the semen ejaculated is composed of the fluid 
 of the testicles united with that of the seminal vesicles, the prostate 
 gland, the glands of Cowper, and the mucous membrane of the 
 urethra. 
 
 6th. It does not follow from this that the liquid ejaculated has not 
 passed from the testicles into the seminal vesicles. Possibly, the fluid 
 expelled during efforts to go to stool, comes from the prostate gland 
 and even from other parts, as a similar thing occurs in dogs which 
 have no seminal vesicles. (2) 
 
 7th. Possibly this effect was accidental, which is more probable, 
 since the gall-bladder, when the bile is prevented by a calculus from 
 entering, is often distended to a great degree by the mucus which it 
 secretes. 
 
 8th. This opinion is often opposed, at least by experience. Farther 
 when this is not the case it would only prove that the venereal or- 
 gasm increases also the action of the testicles, and that the semen 
 emitted comes not only from the vesicles, but also from the glands 
 themselves. 
 
 9th. The assertion is not correct, and proves nothing. Even Hun- 
 ter admits that the seminal vesicles take part in the genital act, so that 
 their uniform depletion under different circumstances is not more sur- 
 prising, whether the fluid comes from the testicles, or is secreted by 
 the vesicles. 
 
 10th. The absence of the seminal vesicles in several animals, does 
 not prove that the semen is not introduced into the reservoirs when 
 they exist. Farther, a communication between the vesicles and the 
 vasa deferentia, really exists in several animals where it is not admit- 
 
 (1) De Graaf, Partium gcnitalium defensio, Leyden, 1673.— Needham, Croone, 
 and King-, in Birch, Hist, of the ray. society , vol. iii., p. 103. — Brugnohe, Observa- 
 tions anatomiques sur tes vésicules séminales tendantes à en confirmer l’usage ; in 
 the Mém. de Turin , 1786-1787. — Soemmerring, Anmerkungen über Hunter's Auf- 
 satz ; in Blumenbach, Medic. Bibi ., vol. iii., p. 87. 
 
 (2) Brugnone, loc. cit., p. 622. 
 
OF THE GENITAL SYSTEM. 
 
 431 
 
 t ed by Hunter, as the guinea-pig and the horse, while the pretended 
 seminal vesicles, which according to others do not communicate with 
 the excretory passages of the vesicles, are protsate glands. 
 
 1 1th. There is no proof that a portion of the contents of the seminal 
 vesicles does not escape during coition. 
 
 12th. It does not follow that the semen does not run at all in the 
 seminal vesicles in those animals which are provided with these reser- 
 voirs. 
 
 13th. In whatever position the body may be, the liquid injected 
 through the ductus deferens, arrives sooner into the vesicle than into 
 the ejaculatory passage.(l) 
 
 14th. The substances injected into the vesicle generally emerge 
 through the ejaculatory passage before arriving at the ductus deferens, 
 and frequently do not penetrate at all into the latter. (2) 
 
 15th. The air and sounds introduced through the orifice of the duc- 
 tus deferens, easily penetrate into the vesicle, but with difficulty into 
 the ejaculatory passage. Notwithstanding this refutation of Hunter’s 
 opinion, we cannot deny that the proper secretion of the seminal ve- 
 sicles seems to contribute powerfully to elaborate the semen. 
 
 § 2474. The semen comes into the urethra and directly into the 
 prostate gland, where it mingles with a more serous and yellowish 
 white fluid secreted by this gland, and which also contributes to per- 
 fect it.(3) 
 
 On leaving this point it is sent into the penis by the action princi- 
 pally of the bulbo-cavernosi muscles. 
 
 § 2475. The penis possesses in a great degree the power of enlarg- 
 ing and lengthening by the excitement of the venereal passion. It also 
 becomes hard and stiff, which depends undoubtedly on the dilatation 
 and tension of its fibrous envelop. 
 
 Its power of erection depends on the peculiar arrangement of its 
 vessels ; when erected it can enter into the vagina of the female; 
 it fills this canal more or less perfectly, and injects the semen into the 
 internal organs of generation, particularly the uterus. The erection 
 of the penis depends on the great excitement of the nervous action, 
 either in the whole system or in the nerves of the penis, which are pro- 
 portionally very large ; a greater quantity of blood is then carried into 
 it by the arteries, and is not resumed by the large and numerous veins of 
 the organ, as rapidly as it flows into it. It has been asserted that 
 the phenomenon of erection ought not be explained thus by the accu- 
 mulation of blood, (4) but this opinion is- completely refuted by the ex- 
 periments, (5) in which, on cutting the penis when erected, after 
 tying its base, the venous plexuses are found gorged with blood. 
 
 (1) De Graaf, loc. cit.— Brugnone, p. 620. 
 
 (2) Brugnone, loc. cit. 
 
 (3) Haller, El. phys., vol. viii. p. 454. — Brugnon e, loc. cit. 
 
 (4) Langguth, in Schumann, Devi imaginationis in feet um, Wittemberg, 1790. 
 
 (5) R. de Graaf, De virorum organis ; in Opp. omn ., p. 84. — Swammerdam, 
 Prodr. obs. de part, genit., p. 13 — Th. Roose, lieber das Anschwellungsvermogen 
 
432 
 
 DESCRIPTIVE ANATOMY. 
 
 § 2476. The first changes which cause the emission of semen, un- 
 doubtedly take place in the glans, since it possesses the most nerves, 
 and is the most sensible part, not only of the penis, but of the whole 
 genital system. The excitement of the nervous action in this part is 
 extended to the whole nervous system, particularly to the nerves of the 
 genital organs, quickens the secretion of the testicles, the seminal ve- 
 sicles, and the other glands, and causes convulsive motions in the 
 bulbo-cavernosi muscles, which compress the spermatic fluid when it 
 arrives at the posterior part of the urethra, and throw it by jets into 
 this canal, which is rendered straight by the erection of the penis. 
 
 II. MAMMAE. 
 
 § 2477. The mammcc{ 1) are the accessory parts of the genital sys- 
 tem, which in man and in all true mammalia, establish a natural rela- 
 tion between the organism of the mother and that of the child, by 
 means of the milk which they secrete, which continues during the 
 early periods of life. In birds, and perhaps also in some reptiles, there 
 exists a similar connection between the mother and the offspring, 
 which continues a longer or shorter period after the birth of the latter. 
 But in these animals it does not occur by a special organ, having the 
 power of secreting a peculiar nutritious fluid. It is only by a portion 
 of the intestinal canal, the crop ( ingluvies ), which undergoes about 
 this period a change analogous to that which occurs in the mammae, 
 but which, however, serves for the mother and the offspring. 
 
 I. NUMBER. 
 
 § 247S. The mammae are two in number ; they are glandular or- 
 gans, conglomerate glands. 
 
 Although regularly, they fulfill their function only in the female, 
 they occur also in the male, where they are much less developed ; the 
 mammae of the male, however, are sometimes as large, and their 
 secretion as abundant as those of the female. 
 
 des männlichen Gliedes im gesunden Zustande; in Physiologische Untersuchun- 
 gen i, Brunswick, 1796, p. 17. 
 
 (1) A. Nuch, Adenographia curiosa, Leyden, 1691, c. ii. — Mencelius, De struc- 
 tura mammarum, Leyden, 1720. — Guntz, De mammarum fabrica et lactis sccretione, 
 Leipsic, 1734. — Bcehmer, De ductibus- mammarum lactiferis , Halle, 1742. — Kcelpin, 
 De structura mammarum, Gripswald, 1764. — Crusius, De mammarum fabrica et 
 lactis secretione , Leipsic, 1785. — Covolo, De mammis ; in Santorini, Tabul, septemd., 
 p. 92-110. — Girard, De mammarum structura ; ibid., p. 110-116. — A. Joannides, De 
 mammarum physiologia, Halle, 1801. 
 
OF THE MAMMARY GLANDS. 
 
 433 
 
 II. SITUATION AND FORM. 
 
 § 2479. They are situated opposite to one another, one on each 
 side, on the anterior face of the chest, and the region which they oc- 
 cupy in the female is termed the mammary region ( regio mamma). 
 The glandular substance which forms their base, is surrounded by a 
 great quantity of fat, which gives them a semicircular form. Their 
 base, however, is not perfectly circular, but rather eliptical. 
 
 It extends particularly upward and outward, and often to the region 
 of the axilla ; it is more circular below and inward. It extends from 
 the third to the seventh rib, and covers most of the pectoralis major 
 muscle ; but not unfrequently the most external portion of its lower 
 edge covers also a portion of the serrât us magnus muscle. 
 
 The edge of the mammas is not smooth in every part, nor is its 
 thickness uniform. In those females w r ho have borne several chil- 
 dren, it presents inequalities, because the gland enlarges irregularly 
 outward, so that irregular prolongations leave its edge. 
 
 Nor is the circumference of the mammae smooth in every part. 
 
 It presents in every part analogous prolongations, differing in form, 
 size, and direction, which render its surface uneven, and leave between 
 them greater or less depressions. The lower and internal part of these 
 glands is much thicker than the upper and external. 
 
 A little below the centre of the mammæ, in its thickest portion, we 
 perceive a more or less prominent eminence, termed the nipple ( ma - 
 milia, papilla mamma), which is surrounded by a more colored circle, 
 and the level of which is often below that of the common integuments. 
 This circle, the skin of which is thinner and finer than that of the rest 
 of the nipple, is termed the areola ( areola mamma.) 
 
 III. TEXTURE. 
 
 § 2480. The texture of the mammæ is not the same in every part. 
 Almost all its substance is composed of small reddish white grains 
 (acini), which are distinguished very easily in females during the 
 period of lactation. These grains are about the size of a millet seed. 
 They are composed in turn of smaller vesicles, not rounded, but oblong, 
 which are grooved and ranged in rays. They are united by cellular 
 tissue and vessels. 
 
 These grains do not exist toward the centre, in the areola, where we 
 find only a fibrous and whitish substance, which is decomposed by 
 maceration, into a tissue of canals, which are united by cellular sub- 
 stance. 
 
 § 2481. These canals are the extremities of the milk-ducts (ductus 
 galactophori, s. lactiferi). The latter arise by as many small roots 
 as there are grains, and gradually unite in larger trunks, which finally 
 terminate in the centre of the nipple, behind the areola by conical, dila- 
 
434 
 
 DESCRIPTIVE ANATOMY. 
 
 tâtions or sinuses. Tiie excretory passages of the mammary gland 
 are larger than in any other conglomerate gland. The size of the 
 trunks varies according as they receive a greater or less number of 
 branches. Many are very small. The number of great branches 
 which finally unite to give rise to one trunk, varies from four’ to twelve. 
 The extent of the central sinus is also in direct ratio with the size of 
 the. trunks. Sometimes these dilatations are from two to three lines 
 broad ; but they are always short, compactly arranged at their internal 
 extremity, and a little separated at their external. The internal ex- 
 tremity of each suddenly contracts into a very small canal, which 
 passes in a straight line through the centre of the nipple to its summit, 
 contracts a little, rarely enlarges in some part of its extent, and finally 
 opens on the surface of the nipple by a very small orifice. All these 
 small canals, which are about the breadth of a finger long, are united 
 very intimately by mucous tissue. Only one canal comes from each 
 dilatation. 
 
 § 2482. The whole milk-passage,- which consequently includes the 
 carrying portion, the dilatation, and the excretory canal, is formed by 
 a soft, thin, and transparent membrane, similar to a mucous membrane. 
 
 These passages are not exposed in most of their course. The 
 trunks are often situated very deeply in the substance of the gland, 
 and those even which proceed at first on its surface, especially those 
 which come from the prolongations mentioned above, penetrate deeply. 
 
 They are formed by the successive union of branches and twigs, 
 which always diminish in caliber ; but they do not communicate by 
 anastomosing branches. Nuck(l) and Yerheyen(2) have in fact de- 
 scribed and figured very large anastomosing branches, situated in the 
 areola, directly at the base of the nipple, which go from one milk-pas- 
 sage to another, and thus form a ring ; but no other person has found 
 them, and we also have been unsuccessful, although we have carefully 
 sought for them several times. This anastomosing circle is not only 
 invisible, but also the injection pushed into one milk-passage never flows 
 into another, which would be the case if the anastomoses really existed. 
 The milk-passages are not provided with valves as several observers 
 have stated. Farther, the existence of these valves is refuted by the 
 facility with which injections enter through the nipple. Sometimes, 
 however, we observe fluids, particularly mercury, injected through an 
 opening in one milk-passage, return by another, but always under cir- 
 cumstances which prove the communication exists between the most 
 minute ramifications of the passages. Probably the anastomoses, like 
 the ducts themselves, do not dilate sufficiently to produce this result 
 until toward the end of pregnancy, and during the period of lactation. 
 But the researches of Meckel(3) on the mammae of females dying in 
 
 (1) Adenographia curiosa, Leyden, 1691, p. 1G. fig 1 2 3 . 2. 
 
 (2) An at. corp. hum. vol. i. tab. xviii. fig. 4. 
 
 (3) J. F. Meckel, Nova expérimenta el observât, de sinibus venarum, Berlin, 1772, 
 
 { 4, 5, 9. 
 
OF THE MAMMARY GLANDS. 
 
 435 
 
 parturition, demonstrate their existence as positively, as it refutes that 
 of the anastomoses admitted by Nuck and Veiheyen. We have also 
 obtained the same results under similar circumstances. 
 
 § 2483. Notwithstanding these small anastomoses, the mammas is 
 composed of as many distinct and separate glands as there are milk 
 passages. This is demonstrated by injecting each canal with differ- 
 ently colored fluids, for the injections blend in no part, and the different 
 glands can be detached and separated. 
 
 § 2484. The number of the milk-passages, consequent^ also that 
 of the conglomerate glands, varies even in the two mammæ of the same 
 female. The old anatomists have reduced the number too much, as 
 they estimated them only at six or seven ; Haller, Walter, Covolo, 
 and ourselves, have never found less than fifteen. Our dissections, 
 however, have convinced us that Walter was mistaken in saying that 
 there are never more than fifteen, sometimes we have found more than 
 twenty, as have also Haller and Covolo. Their greatest number is 
 twenty-four, according to Covolo. These that are situated highest, 
 and most on the outside, are, as Waiter justly remarks, very small 
 and very narrow, which agrees with the less degree of thickness of the 
 mammary gland at its upper part. 
 
 § 2485. Besides the orifices of these milk-passages on the summit 
 of the nipples, we find in the areola also, others which generally 
 occupy the extremities of the tubercles ; these are arranged irregu- 
 larly, and two or three of them sometimes unite in one. 
 
 Several anatomists have considered these tubercles as simple seba- 
 ceous glands. Bidloo and Morgagni have sometimes seen coming 
 from them a limpid liquid ; Morgagni, Winslow, and Covolo have also 
 seen them supply a more or less thick milk in females, during lacta- 
 tion, and the last phenomenon has been observed also in males- by 
 Morgagni. The quantity and the nature of the fluid coming from 
 them, depends on the length of time which has elapsed between the 
 repast and the time of nursing, so that several hours after the repast, 
 or when the child has not nursed for a longtime, the milk is abundant, 
 while in the opposite case, some drops of a brighter liquid slowly 
 dribble out. 
 
 These tubercles are entirely different from sebaceous glands. We 
 find numerous sebaceous glands on the areola and the nipple, and they 
 never rise above the surface like the tubercles, on which we often ob- 
 serve several. An attentive examination shows in several of these tu- 
 bercles, one, and sometimes even four small excretory ducts, leading to 
 small glands, which are precisely of the same nature as those we have 
 mentioned, but which, however, are smaller ; they are situated directly 
 under the skin of the areola, and are united with each other and with 
 the body of the gland, by cellular tissue. Sometimes, in fact, but 
 rarely, these small glands open into the portion of the integuments of 
 the mammæ, which directly covers the circumference of the areola. 
 They vary in number and size. There are generally from five to ten 
 tubercles. 
 
436 
 
 DESCRIPTIVE ANATOMY. 
 
 Thus the small glands and the tubercles in which their excretory 
 ducts terminate, are arranged in regard to the mammary gland, pre- 
 cisely in the same manner as the sublingual glands or the buccal and 
 the labial glands, are in regard to the parotid and the submaxillary, 
 and they cannot, at least in our opinion, be regarded as anomalies, as 
 Hildebrandt thinks them.(l) 
 
 § 2486. The mammary gland is situated in a more or less abundant 
 adipose tissue, which does not form a continuous layer as in every 
 other part, for it enters between the depressions which we have men- 
 tioned above, and even contrary to what occurs in the other glands, it 
 penetrates deeply into the substance of the organ, while there is none 
 at its base. We find no fat in the nipple nor behind the areola ; this 
 fat is more firm and yellowish than in most of the other regions of the 
 body. The mucous tissue which contains it, also penetrates into all 
 the spaces between the different glands. It condenses on the surface 
 of the organ in a special sheath, nearly similar to those which surround 
 the muscles. 
 
 Haller asserls(2) that he has frequently seen milk-passages arise 
 from the fat, which afterwards penetrated into it. Covolo and our- 
 selves have seen nothing like this. We have every reason to think 
 that Haller is mistaken, and that his error must be attributed to the 
 existence of the prolongations mentioned above. 
 
 § 2487. The vessels of the mammae arise from the external thoracic 
 vessels. Their nerves come from the third and fourth cervical, and 
 from the five or six superior dorsal nerves. 
 
 IV. FUNCTIONS. 
 
 § 2488. The function of the mammary gland is to secrete the milk. 
 In the normal state this secretion does not begin until toward the end 
 of gestation. Its history will be more in place after that of the pheno- 
 mena produced by coition. 
 
 ARTICLE SECOND. 
 
 PERIODICAL DIFFERENCES IN THE ORGANS OF GENERATION. 
 
 § 2489. Until the sixteenth week there is no trace of the genital 
 organs. When they appear they are formed precisely after the same 
 type in all fetuses ; their form, volume, and situation are the same, 
 and there is consequently no distinction of sex. The internal genital 
 organs are formed ; 
 
 (1) Lehrbuch der Anatomie des Menschen , vol. iii. p. 339. 
 
 (2) El. phys ., vol. vii., p. 8. 
 
OF THE GENITAL SYSTEM. 
 
 437 
 
 1st. Of two very elongated and narrow parts, oblique from without 
 inward und from above downward, situated very high out of the pelvis, 
 and which afterward become either the te'sticles or ovaries. 
 
 2d. Of two canals which are not much narrower, but which are 
 longer and thicker, proceed beyond them above, and descend on their 
 outer side. They produce either the tubes, or the epidydimi and the 
 excretory organs of the semen, and unite out of the pelvis in a common 
 median duct, which becomes either the uterus and vagina, or the 
 prostate gland, seminal vesicle, and posterior part of the urethra. 
 
 3d. Of a considerable triangular body, a little enlarged at its ante- 
 rior extremity, situated first at the- lower part of the anterior wall of 
 the abdomen, and which afterward hangs loosely forward. This body 
 is formed of two halves, separated by a fissure which proceeds along 
 its lower face ; it afterward forms the penis or clitoris. 
 
 4th. There is soon developed on each side of this last body a fold of 
 skin, which is directed from before backward. These two folds are 
 not united posteriorly. They change into the scrotum, or the ex- 
 ternal labia. 
 
 § 2490. Home,(l) Autenrieth,(2) and Ackermann(3) had already 
 admitted this primitive identity of the genital organs in all individuals, 
 although they indicated perhaps less exactly and precisely the cha- 
 racters of the primitive form, and the manner in which the differences 
 occur. 
 
 As all the fetuses at this period, which we have compared and they 
 are at least fifteen, present exactly the formation described, it is more 
 correct to consider, as is generally done, the raphe of the scrotum and 
 penis as a mark of the separation primitively existing, and which gra- 
 dually disappears by the closing of the fissure from behind forward, 
 than to regard it, with Autenrieth, as proving a tendency to this sepa- 
 ration which really occurs only in the female. Thus we have already 
 said for a long time, reasoning from the facts observed by us, that the 
 genital organs are formed after the same type, particularly after 
 that of the female. (4) 
 
 We . have already established from observation that their character 
 is still more similar to that of the female in all fetuses, (5) and Tiede- 
 mann has confirmed this result, describing very exactly several fetuses 
 very near the moment of then formation.(6) 
 
 (1) Phil, tram., 1790. 
 
 (2) Infantis androgyni hisloria, Jena, 1805, p. 53. 
 
 (3) Ueber die Verschiedenheit beider Geschlechter ; in Reil, Archiv, für die Phy- 
 siologie , vol. vii., p. 88. 
 
 (4) Abhandlungen aus der menschlichen und vergleichenden Anatomie , 1806, vol. 
 ii. We have there described six fetuses of this age. — Beytruge zur vergleichenden 
 Anatomie, 1808, vol. i., part i., no. 5. We have there described twelve fetuses of this 
 age. 
 
 (5) Beyträge zur vergleichenden Anatomie, vol. ii., pt. ii., p. 170, Leipsic, 1812. 
 
 (6) Anatomie der kopflosen Missgeburten, 1813, p. 80. 
 
 Vol. III. 56 
 
438 
 
 DESCRIPTIVE ANATOMY. 
 
 These phenomena are curious in two respects : 
 
 1st. There are generally no genital organs in most of the lower 
 animals, or at least those which exist correspond to the genital organs 
 of the female in those where there are two sexes, so that in this re- 
 spect also the same law prevails in the development of the fetus and 
 that of the aminal series. 
 
 2d. This explains also the greater frequency of female monstrosi- 
 ties. 
 
 Farther the great size of the clitoris, the -smallness of the uterus, 
 and perhaps also a real connection between the ovaries and the Fal- 
 lopian tubes : and secondly, the situation of the testicles in the abdo- 
 men, establish still longer between the two sexes a similarity which 
 afterward does not exist. 
 
 From the third month of pregnancy, however, the ovaries are al- 
 ways smaller than the testicles ; they are situated more horizontally, 
 and the penis differs from the clitoris, as the fissure has disappeared 
 from its surface. 
 
 1. GENITAL ORGANS OF THE FEMALE. 
 
 § 2491. The development of the genital organs of the female differs 
 particularly from that of the genital organs of the male, in the less 
 number of successive periods through which it passes. 
 
 I. OVARIES. 
 
 § 2492. At first the ovaries/ 1) proportionally speaking, and parti- 
 cularly in regard to the other genital organs, are much larger than 
 they are subsequently. They form for a long time most of these 
 organs, although when the difference of sex is more evident, they are 
 proportionally smaller than the testicles, and this difference even is 
 one of their principal distinctive characters. 
 
 At about the middle of the third month of fetal existence, and when 
 the embryo is two inches long, they are hardly a line and one quarter 
 in length, less than half a line high, and a little less than one third of a 
 line thick. In the full-grown fetus they weigh between five and ten 
 grains. They are situated almost horizontally far above the small 
 pelvis, but from their horizontal direction their upper or external ex- 
 tremities do not rise as high as the testicles in the male fetuses of the 
 same age, so that they are very far from touching the kidneys. 
 
 Their internal extremities, on the contrary, are so near each other 
 that only the rectum exists between them, which is at this time very 
 narrow, so that the intestine does not completely separate them. Their 
 
 (1) Roaenmullei-, De ovariis embryonen et fœtuwn, Leipsic, 1802. 
 
OF THE GENITAL SYSTEM. 
 
 439 
 
 form is very elongated, narrow, and prismatic ; ihey become rounded 
 only at puberty, and they are then thicker in proportion to their length. 
 Their capsule is very thin, not only in the full-grown fetus, but also 
 during all the early years of life. 
 
 Their tissue is more simple until the middle of the first year of exist- 
 ence. In this respect we have as yet been unable to discover any 
 trace of the vesicles of Graaf before the age of six months, when these 
 vesicles form, and they arè then proportionally very large. 
 
 In the latter half of the existence of the female the ovaries begin to 
 grow harder and to waste. They lose their smoothness, and their 
 surface appears more or less uneven, because the depressions observed 
 in it are changed into considerable cavities. 
 
 This effect depends principally on the disappearance of the paren- 
 chyma ; but the vesicles also change at the same time ; they diminish, 
 their membranes become thicker, and finally their cavity disappears, 
 and they are converted into yellowish or blackish, or often into fibro- 
 cartilaginous or osseous bodies. 
 
 The ovaries wasta so much in females advanced in life that they 
 sometimes disappear. entirely, and the place they occupy is indicated 
 only by the vessels. Frequently then they weigh only twenty grains. 
 
 § 2493. According to several writers, as, for instance, Malpighi, (1) 
 Vallisneri,(2) Santorini, (3) Bertrandi,(4) Brugnone,(5) and Buffon,(6) 
 the formation of the yellow bodies ( corpora lutea ) belongs also to the 
 history of the development of the ovaries, because they have been found 
 not only in virgins, but in the young females of animals. But it is 
 not well proved that these bodies have the same origin and the- same 
 use as the common yellow bodies ; and it is extremely probable that 
 their formation has been preceded by an increase in the activity of the 
 genital organs, arising from some cause. We think it more proper to 
 refer the examination of them to the chapter on the changes produced 
 in the genital parts by conception. 
 
 II. TUBES, UTERUS, AND VAGINA. 
 
 § 2494. The Fallopian tubes, the uterus, and the vagina, form at 
 first only a single canal, cleft at its upper part, which is uniformly 
 broad, and which extends uninterruptedly from the abdominal extre- 
 mity of the tubes to the external orifice of the vagina. 
 
 (1) Diss. ep. var, largum ; in the Opp. omv., Leyden, 1687, vol, ii., p. 223. 
 
 (2) Von der Erzeugung des Menschen und der Thiere , pt. ii. c. iii., p. 262, 319. 
 
 (3) Obs. anat., c. xi., p. 223. 
 
 (4) De glandules ovarii corporibus ; in the Mise. Taur., vol. i., p. 104. 
 
 (5) Dt ovarii eorumque corporibus lut eis ; in the Mim,, de Turin, 1790, p. 393. 
 
 (6) Hist, nat., vol. ii., p. 203. 
 
440 
 
 DESCRIPTIVE ANATOMY. 
 
 A. TUBES. 
 
 § 2495. The tubes are at first proportionally much thicker and 
 longer than they are subsequently. 
 
 They descend at first very obliquely from without inward on the 
 outside of the ovaries, to which they are directly united, but extend 
 much beyond their upper extremity. Until the third month they are 
 united at an acute angle at their lower and inner extremities in a small 
 and median perpendicular mass, which is at first very narrow, but 
 which gradually becomes a little wider, and represents the uterus. 
 They are not tortuous until the fourth month. (1) At five months 
 only they begin to exhibit curves, which are at first very indistinct, 
 and gradually enlarge, so that at eight months and at birth they are 
 more tortuous than in the adult : an arrangement which they preserve 
 also during the first years of life. They seem at first to terminate in 
 a cul-de-sac and by an enlargement. 
 
 Their abdominal extremity seems to open at the fourth month, but 
 the fimbriated ends are not developed till afterward. Their cavity is 
 always much larger proportionally the younger the fetus is, and it is 
 always found without difficulty whenever it is sought for. (2) 
 
 Bettveen the tubes and the ovaries in the fold of the peritoneum 
 extremely curious vessels(3) exist, not only in the embryo and the 
 fetus, but also during the first years of life ; these cannot be injected 
 through the tubes nor through the ovary, so that we cannot consider 
 them as establishing a communication between the cavity of the 
 former and the substance of the latter ; they are so similar in their 
 number, situation, and form, to the vasa deferentia of man, that we 
 must consider them at least as tending to the formation of these pas- 
 sages and the epidydimis. 
 
 The primitive form of the abdominal extremity of the tube, however, 
 allows us to conjecture, and with some probability, that they commu- 
 nicate first with the ovarjq but that the communication is probably 
 closed when the abdominal extremity of the tube opens, and conse- 
 quently when a new passage forms. 
 
 B. UTERUS. 
 
 § 2496. The uterus is at first, and usually even until the end of the 
 third month at least, much broader, and has two horns. " The horns 
 are as much longer and their angle of union is more acute the younger 
 
 (1) The general opinion then that the tubes are always tortuous in the fetus is 
 not exactly correct. Their primitive straightness is very important, on ac- 
 count of the analogy it establishes, first between them and the intestinal canal during 
 the early periods of existence, and also between them and the oviducts of several 
 animals. 
 
 (2) Hirschel and Roesslein have asserted the contrary, but they are wrong. 
 
 (3) Rosenmuller, loc. cit. 
 
OF THE GENITAL SYSTEM. 
 
 441 
 
 the fetus is. But when this angle entirely disappears, the uterus 
 seems to have two horns. At first it is equally broad in every part, 
 and perfectly smooth ; there is no prominence either on the outside or 
 on the inside which separates it from the vagina. It begins to enlarge 
 at its upper extremity about the end of the fourth month. This phe- 
 nomenon depends on the disappearance of the horns which existed at 
 first, and which are replaced by a single cavity. But this upper part 
 is much smaller the younger the fetus is, whence the neck is larger 
 than the body in the same proportion. 
 
 The body gradually increases, so that about the period of puberty 
 the uterus loses its almost cylindrical form, and becomes pyriform. 
 The length of the body is only one fourth of that of the whole organ 
 in the full-grown fetus ; it is only one third at thirteeen years old, and 
 does not form one half till after puberty. 
 
 At the same time transverse and slightly oblique wrinkles are deve- 
 loped on the anterior and the posterior faces ; these converge upwards 
 towards the orifices of the tubes, but are very compact at the lower 
 part where they begin to appear, and gradually extend over the whole 
 of the uterus. 
 
 There forms also imperceptibly on the two faces of the organ an 
 elongated eminence which passes through its whole length, and to- 
 ward which the wrinkles on each side converge from above down- 
 ward. These wrinkles enlarge very much. They render all the 
 inner face of the uterus very uneven, not only in the full-grown fetus, 
 but also during the early period of life. They however gradually dis- 
 appear in the body, and at the age of five years its inner face is en- 
 tirely smooth. 
 
 The external orifice of the uterus appears at first as a slightly per- 
 ceptible prominence of the organ in the vagina ; but this prominence 
 gradually increases, so that in the latter periods of fetal exist- 
 ence, the vaginal portion of the uterus is proportionally much larger 
 than subsequently. At seven and eight months less than in the full- 
 grown fetus, and during the first months after birth, all this portion of 
 the organ is very uneven, and also on its external face, presents longitu- 
 dinal wrinkles, terminated by sharp uneven edges, which are deeply 
 fissured, the grooves of which often occupy all the vaginal portion. 
 This prominence afterwards shortens, becomes smooth externally, 
 takes the form of a glove, and the uterine orifice then appears as a 
 simple and smooth transverse fissure. 
 
 . The parietes of the uterus are as much thinner in proportion to the 
 'cavity, the younger the fetus is. At first they are equally thick in 
 every part ; but at five months they become much thicker in the neck 
 than at the upper part. Gradually between the age of five and six 
 years, the thickness again becomes uniform in every part, and pre- 
 serves its character till puberty, at which time the body is much thicker 
 than the neck. 
 
 Thus the uterus does not assume till very late, its form and the nor- 
 mal thickness of its parietes ; but it acquires ils permanent length 
 
442 
 
 DESCRIPTIVE ANATOMr. 
 
 much sooner, at least in great part. It is even proportionally longer 
 at first, for instance in the full-grown fetus, than subsequently. 
 
 It is the body principally which grows in the adult, and the uterus 
 then assumes a triangular form. In females advanced in age, it be- 
 comes irregularly rounded, which does not depend on previous preg- 
 nancies, since the same changes are observed in old unmarried females. 
 At the same time it diminishes in those females who have lived in 
 celibacy. 
 
 The consistence and the color of the uterus in old age, resemble 
 those of infancy. At these two periods the organ is hard and white, 
 while in the prime of life it is soft and red. 
 
 In the fetus of three or four months, the uterus is situated almost 
 entirely out of the small pelvis, and it extends much beyond in the full- 
 grown fetus. After the age of fifteen years, it is entirely situated in 
 the pelvis, at the base of which it is found in old females. 
 
 In the fetus it is almost perpendicular, but its direction gradually 
 changes, so that its greatest diameter is directed almost exactly from 
 before backward. 
 
 § 2497. The functions of the uterus as well as its form, present con- 
 siderable periodical differences. 
 
 At the period of puberty, when the female has the power of concep- 
 tion, there is every month a discharge of blood and serum from the 
 genital organs, which continues some days, and is termed menstruation 
 ( menstruatio , s. menses ), from its occurring periodically. This discharge 
 disappears with the susceptibility for conception, usually between the 
 fortieth and the fiftieth year. It is not a character belonging exclu- 
 sively to women.(l) This discharge proceeds from the whole inner 
 face of the uterus. 
 
 The discharge usually continues some days, at most a week. 
 
 The quantity of blood may be estimated between six and eight 
 ounces. 
 
 Its color is dark, from which character alone it is very probably 
 venous, (2) which is not the general opinion. 
 
 This conjecture is strengthened by chemical analysis. In fact, 
 Lavagna(3) has found in it no fibrin. But Saissy and Mayer(4) have 
 proved that the venous blood contains less fibrin, and consequently less 
 azote than the arterial blood. 
 
 The uterus enlarges a little during menstruation ; its vessels dilate 
 and project like villosities on its inner surface. (5) 
 
 Menstruation essentially consists undoubtedly in an increase of 
 the vitality of the genital organs of the female, resembling inflamma- 
 tion, and of which hemorrhage is the crisis. This is demonstrated by 
 
 (1) Cuvier, Annales du Muséum, vol. ix. p. 118-130. — Kahleis, Remarques sur la 
 menstruation ; in the Journ. compl. des sc. méd., veil.' xviii. p. 252. 
 
 (2) J. F. Csiander, Diss. de fiuxu menstruo atque uteri prolapsu, Gottingen, 
 1808, cap. iii. 
 
 (3) In Brugnatelli, Giornale difisica, 1817, p. 397-416. 
 
 (4) Deutsches Archiv für die Physiologie, vol. iii. p. 534. 
 
 (5) Osiander, cap. i-ii. 
 
Ol’ THE GENITAL SYSTEM. 
 
 443 
 
 the irritation in' these organs before the period of menstruation, the 
 greater propensity of the female at that time for coition, and the greater 
 facility with which she conceives. 
 
 We may also consider it as an attempt to form a new organism. In 
 fact, the changes in the uterus at this period, resemble those observed 
 in it after conception. On the other hand, according to the observa- 
 tions of Denman, Brandis, and Joerg, the menstrual blood is not unfre- 
 quently attended with membranous productions, similar to the deci- 
 duous membrane which is developed when the female has conceived. 
 
 Finally, menstruation may carry off from the body generally, and 
 the genital organs particularly, probably not injurious substances, but 
 at least superfluous blood, for while the female is disposed to con- 
 ceive, the blood always collects in these organs from one menstruating 
 period to another, to form there a new organism, and during pregnancy 
 and lactation it is employed in other formations. 
 
 C. TAGÏNA, 
 
 § 2498. At first the vagina is not broader than the uterus, and is 
 entirely smooth like it. It begins to be uneven at about the same 
 time. First, at about the fifth month a longitudinal elevation appears 
 on each anterior and posterior face. This elevation afterwards presents 
 very many large transverse folds arranged very compactl} 7 . These 
 folds are united by others, which are oblique, and are distributed on the 
 whole circumference of the vagina, so as to render its surface much 
 more uneven and reticulated, as they themselves present numerous 
 fissures and folds. This is the appearance of the vagina at seven and 
 eight months. But the folds gradually dimmish ; they are less evident 
 in the full-grown fetus ; they afterwards gradually disappear, become 
 less prominent, more closely united, farther from each other, so that at 
 the period of puberty, even before coition, the vagina is much smoother, 
 and is only corrugated at its lower extremity on its anterior and pos- 
 terior faces, in the first more than in the second. 
 
 At first the vagina is always proportionally narrower than it is sub- 
 sequently. It is undoubtedly broadest in proportion, about the seventh 
 and eighth month. 
 
 It is always proportionally longer in the fetus than subsequently. 
 It is always more than two inches long in the fetus of eight months, 
 and in the child at birth, while in the adult female its length is seldom 
 more than four inches. This arrangement depends at least in part on 
 the higher situation of the uterus, but not entirely on this, as the 
 vagina is not narrower in the same proportion. 
 
 D. HYMEN. 
 
 § 2499. The vagina is much narrower at its lower part than in 
 other places. We discover no trace of the hymen before the middle of 
 gestation. At this time it begins to appear on each side in the form 
 
444 
 
 DESCRIPTIVE ANATOMY. 
 
 of a thin and narrow prominence, which is directed from behind for- 
 ward, so that a longitudinal fissure exists in the centre. This promi- 
 nence is at first directed downward, and is equally broad in every part; 
 but it gradually becomes broader backward, so as to form a semicircu- 
 lar fold, or rather a rounded and oblong septum, which presents an 
 opening at its anterior extremity. The hymen preserves this form 
 until it is destroyed. The inequalities of the vagina are also con- 
 tinuous in the fetus, on it, and on the orifice of the urethra, from 
 whence they descend on the clitoris, and the inner face of the internal 
 labia. 
 
 III. CLITORIS. 
 
 § 2500. When the sexual organs are once developed, the clitoris is 
 proportionally very large, and the more so the younger the fetus is. 
 
 At the commencement of the third month, when the latter is at most 
 but two inches long, its length is about one line, and it is half a line 
 thick. In fact, it soon loses these large proportions, but it remains 
 considerable during the whole of gestation, so that a slight, examina- 
 tion might easily deceive in regard to the sex of the child, which is 
 more probable, because the scrotum is then very small, and the testicles 
 are situated in the abdomen ; but the clitoris is always turned forward 
 and downward, and never looks toward the umbilicus.(l) 
 
 This organ presents a deep fissure on the whole of its lower face. 
 At three months we distinguish a longitudinal eminence on the centre 
 of this lower face. 
 
 The glans is not entirely exposed until the fourth month ; it forms a 
 rounded prominence, and is distinctly separated from the rest of the 
 clitoris. When this period has elapsed, the prepuce grows rapidly, 
 and entirely envelops it. The posterior part of the clitoris is composed 
 of the internal labia and the prepuce ; the internal labia are then very 
 much developed during the early periods ;(2) we cannot distinguish 
 them from the prepuce, with which they are directly continuous. As 
 the prepuce forms and extends on the glans, a line of demarkation 
 gradually forms between it and the internal labia, the edge of which 
 was at first straight, becomes rounded ; at the same time they evi- 
 dently divide at their anterior part, and on each side, into two branches, 
 the one small and internal, which goes to the glans, the other external, 
 going to the prepuce. Previously there was no trace of these two 
 branches. 
 
 Thus the clitoris and the labia form originally but one mass. 
 
 (1) Walter, Physiologie , vol. ii. p. 328. 
 
 (2) According- to Osiander ( Abhandlungen über die Scheidenldappe ; in the 
 Denkwürdigkeiten Jur die Heilkunde, vol. ii. p. 46), the nymphæ are very imper- 
 fect, and hardly perceptible at three and four months ; observation disproves this 
 assertion. The fact is, that the internal labia are not so large in proportion to the 
 very large clitoris, as they are afterward, but they are very large in respect to the 
 genital organs and the whole body, so that they cannot be mistaken for what they 
 really are not. 
 
OF THE GENITAL SYSTEM. 
 
 445 
 
 IV. EXTERNAL LABIA. 
 
 § 2501. The external labia are at first, at three months, small, 
 rounded, semicircular sacs, convex outward, much thicker anteriorly 
 than posteriorly, and nearer each other at their anterior than at their 
 posterior extremities, and separated forward by the large clitoris, which 
 projects much beyond them. They gradually enlarge, approach each 
 other, as the clitoris does not increase in the same proportion, become 
 more elevated and thinner, and thus their edge becomes sharper. 
 They never, however, cover the clitoris and the nymphæ entirely, 
 during the early periods of existence ; first, because these parts are al- 
 ways considerably large; second, because they themselves are but 
 slightly developed. 
 
 II. GENITAL ORGANS IN THE MALE. 
 
 § 2502. The genital organs in the male during their development, 
 pass through several periods, which are very important in a physiolo- 
 gical, pathological, and surgical point of view. The differences they 
 present, relate to their situation, form, and size. 
 
 I. TESTICLES. 
 
 § 2503. The testicles(l) deserve to be first considered, as they are 
 the most important parts, and appear first. 
 
 They form not in the scrotum, but in the abdomen, and particularly 
 in the peritoneal cavity, and has the same relation to it as have all the 
 other organs enveloped by this membrane. 
 
 About the middle of the third month their upper extremity still 
 touches the lower extremities of the kidneys. At this time they are 
 situated obliquely from above downward, and from without inward, 
 
 (1) Haller, De lierniis congenilis, programma ad dissertationem tSteding, Got- 
 tingen, 1749.' — Pott, Oïl ruptures, 1756, p. 13.— Camper, in Verhandetingen vanhet 
 Harlcmsche genootschap, 1761, vol. vi. part i. — J. Hunter and G. Hunter, Medical 
 commentaries , London, 1762, p. 1. p. 75. — Id., in Observations on certain parts of the 
 animal economy, vol. i. — Arnaud,, in Mémoires de chirurgie, vol. i. no. i. London, 
 1768. — Lobstein, De herniâ congenita, in qua intestinum in contactu testis est, 
 Strasburg, 1771.— J. F. Meckel, De morbo hernioso congenito singulari, Berlin, 
 1772. — Girardi, in Santorini, Septem, tab., . Parma, 1775, p. 184-202. — J. B. Palletta, 
 Nova gubernaculi testis Hunteriani et tunicœ vaginalis anatomica descriptio, Milan, 
 1777. — H. A. Wrisberg, Observationes anatomicoe de testiculorum ex abdomine in 
 scrotum descensu, Gottingen, 1779. — Vicq-d’Azyr, in Mém. de Paris, 1780, p. 494- 
 507. — -J. Brugnone, De testium in fcetu positu, dé eorum in scrotum descensu, de 
 tunicarum quibus hic continentur, numéro et origine, Turin, 1785. — Tumiati, loc. 
 cil., p. 541. — J. F. Lobstein, Recherches et observations anatomico-physiologiques 
 sur la position des testicules dans le bas-ventre du fœtus et leur descente dans le scro- 
 tum ; in Schweighæuser, Archives de V art des accouchemens, Strasburg, 1801, vol. 
 i. p. 269. — B. G. Seiler, Observationes nonnullœ de testiculorum ex abdomine in scro- 
 tum descensu et partium genitalium anomaliis, Leipsic, 1817. 
 
 Vol. III. 57 
 
446 
 
 DESCRIPTIVE ANATOMY. 
 
 fill the space between the kidney and the bladder, and consequently 
 occupy all the inner face of the ossa ilia. 
 
 They are very large, since in the fetus of this age, which is scarcely 
 more than two inches long, they are two lines in length and one line 
 thick. They are rounded and oblong, convex anteriorly and concave 
 posteriorly, and rest on a very broad fold of the peritoneum, which first 
 covers the epidydimis, then goes on the posterior and concave face of 
 the testicle, leaving between them a great space, arises from the pos- 
 terior face of this gland, but is by no means as high as that, and is 
 very similar to the epiploon. They adhere to this fold so slightly, that 
 their situation is easily changed, and particularly carried outward or 
 inward. The epidydimis rises no higher than the testicle, descends at 
 its side from before backward, and a little from within outward, and is 
 continuous at its'lower extremity with the vas deferens, which descends 
 into the small pelvis behind the peritoneum. At the place where this 
 continuation occurs, the whole mass, but the epidydimis and vas de- 
 ferens particularly, rest directly on a short, very fine, rounded cord, 
 which arises from a depression of the lower wall of the peritoneum, at 
 about-the centre of the crural arch, which is also covered by the peri- 
 toneal membrane, but less loosely than the testicle, because the fold is 
 shorter in the point which corresponds to it. This cord is infinitely 
 thinner than the testicle and the epidydimis. 
 
 It is the sheath (vagina) of Haller, the gubtrnaculum of Hunter, 
 the cylinder of Camper, the basis of Gerardi. 
 
 After this period the proportionally large size of the testicles rapidly 
 diminishes. 
 
 At four months, when the fetus is four inches long from the vertex 
 to the coccyx, their length is scarcely two lines and a half, and their 
 thickness at most but one line. The epidydimis is then larger in pro- 
 portion to the testicle, than before or afterward. The testicles are situ- 
 ated a little lower, but very little however, but are more remote from 
 the kidneys, being at least four lines from them, because the ossa ilia 
 are much larger. The vas deferens is then reflected a little from below 
 upward on leaving the lower extremity of the epidydimis, so that it de- 
 scribes an arch before descending into the pelvis. The gubernaculum 
 is much larger, and it arises from the region of the inguinal ring, al- 
 though the peritoneum is not perforated in this place ; but is only re- 
 flected on itself from below upward, and envelops a mucous mass to 
 which we must attribute the thickness and the more round form of 
 the gubernaculum. 
 
 At five months, the testicles are not longer than in the preceding 
 month, but they are about half a line thicker, so that they appear a 
 little rounder than they were then. They have not descended lower, 
 or at least but very little, and they are still more than a line distant 
 from the lower wall of the peritoneum. The gubernaculum, which is 
 then evidently triangular and the summit of which is much thinner 
 than the inguinal ring and goes downward, while its base looks up- 
 ward, ascends obliquely from within outward. It begins a little below 
 
OF THE GENITAL SYSTEM. 
 
 447 
 
 the inguinal ring, at the upper part of the scrotum, by some distinct 
 fibres, passes through the ring, then receives some fibres from the ob- 
 liquus internus and transversalis abdominis muscles, behind which it 
 passes, then ascends on the iliacus muscle, and rises directly to the 
 lower extremity of the epidydimis. At its lower part, between the in- 
 guinal ring and the place where it appears in the abdominal cavity, 
 we discover before it a prolongation of the peritoneum {processus peri- 
 tonei) which terminates in the ring in a cul-de-sac. This prolongation 
 also descends obliquely from without inward. Its upper orifice is much 
 broader than the lower, and than the gubernacuium which passes 
 through it. This last is filled with a soft and gelatinous mass ; it how- 
 ever contains no cavity. The epidydimis is evidently tortuous at its 
 lower part, and the vas deferens is slightly so at its origin. 
 
 At six months the testicles are still situated in the same place. At 
 this time they are only four lines long, and one and a half thick, so 
 that they are proportionally oblong, and almost straight. The epidy- 
 dimis rises a little above the surface of the glans, and like the vas de- 
 ferens, it is more distinctly curved than in the preceding month. The 
 same is true of the gubernacuium and the prolongation of the perito- 
 neum. Sometimes we may pass air into the lower part of the guber- 
 nacuium, and it is sufficient in certain cases to cut it across to perceive 
 that it is hollow. 
 
 Thus, there has hitherto existed a canal, terminated in a cul-de-sac, 
 a prolongation of the peritoneum, which descends from about the 
 centre of the lower tendon of the obliquus abdominis externus muscle, 
 between this muscle and the lower edge of the two broad internal ab- 
 dominal muscles, and behind which proceeds a prolongation of mucous 
 tissue, which is generally solid, and to which are added some fleshy 
 fibres from the two broad internal abdominal muscles. But the testicle 
 is still loose in the cavity of the peritoneum, where it rests on the upper 
 extremity of the gubernacuium. 
 
 At seven months we generally find it directly on the upper extre- 
 mity of the canal, or more or less within it, so that frequently it does 
 not project at all beyond -it, or only in a very small part of its upper 
 extremity. It is usually situated behind the lower edge of the obli- 
 quus abdominis extemus muscle. The prolongation of the peritoneum 
 then extends downward, to just above the inguinal ring. It seems 
 composed of two lajrnrs, the internal of which is thinner, and is con- 
 tinuous with the peritoneum, while the external is a mucous tissue, 
 and is continuous with the sheath of the obliquus abdominis externus 
 muscle, in which are distributed the fleshy fibres coming from the ob- 
 liquus internus abdominis and the transversalis muscles. The lower 
 part of the prolongation of the peritoneum is filled above by the lower 
 extremity of the epidydimis, and by the commencement of the vas de- 
 ferens ; these rest on a small mass of mucous substance, which 
 rises from the lower extremity of the prolongation of the peritoneum, 
 and they are united with it posteriorly by a fold, which is detached 
 from the posterior wall of this prolongation. 
 
448 
 
 DESCRIPTIVE ANATOMY. 
 
 At eight months, the testicle itself usually passes through the ingui- 
 nal ring, and gradually, until the end of the ninth month, arrives at the 
 bottom of the sacrum, so that its situation is normal about the period 
 of birth. The prolongation of the peritoneum is then considerably 
 elongated ; it is open its whole extent, excepting only its lower extre- 
 mity, which terminates in a cul-de-sac, and it communicates freely by 
 its upper with the proper peritoneal cavity. 
 
 After the testicle has descended entirely to the bottom of the peri- 
 toneal’prolongation and of the scrotum, its cavity still continues to com- 
 municate with that of the peritoneum for a greater or less length of 
 time, but not more than a few weeks when the development is perfectly 
 normal. But the canal of union gradually contracts at its centre, a 
 little nearer the top than the bottom, so that usually that portion of 
 the prolongation of the peritoneum which surrounds the testicle, begins 
 to be obliterated near the inguinal ring. The upper portion of the 
 canal from the inguinal ring to the centre of the crural arch, or to 
 the place where the vas deferens joins the spermatic vessels, remains 
 open for a considerable time ; but when the child is regularly deve- 
 loped, it is also obliterated during the first months after birth, so that 
 it is finally only indicated by a slight depression, which by no means 
 always exists. 
 
 The central portion of the canal of communication also is perfectly 
 obliterated as high as the upper extremity of the testicle, and entirely 
 disappears in most cases. At least we have rarely been able to see 
 any traces of it, although we have made the most careful examina- 
 tions on this subject. We cannot then agree with Brugnone and 
 Scarpa, that we always find in the adult a special cord, composed of 
 cellular tissue, termed by them the bridle {habenula), which they con- 
 sider as the remains of a canal of communication, and the cavity of 
 which they assert can always be demonstrated by maceration. 
 
 Thus the canal of union is first obliterated, and then disappears. 
 Adhesion in it results from its serous nature, and like its disappearance, 
 it is perhaps favored by the pressure of the testicle upon it. 
 
 § 2504. Farther, these changes in the situation of the testicles do 
 not occur at the same period, and uniformly on the two sides ; one 
 of the two organs usually comes into the scrotum long before the 
 other. 
 
 The anomalies in the progress of this phenomenon are as follow : 
 
 1st. The early descent of the testicles. This case is rare : Wris- 
 berg has found the testicles in the scrotum at four and five months, 
 and has also remarked that the canal of communication was then 
 obliterated.(l) 
 
 2d. A suspension of development, from whence several periods are 
 retarded, or even never supervene. This case is much more common 
 than the preceding. The greatest anomaly is where one testicle or 
 
 (1) Loder, Journal , vol. i., p.‘175. 
 
W THE GENITAL SYSTEM. 
 
 449 
 
 both remain in the abdomen or in the inguinal region, from whence 
 we may think one or both of these organs are deficient. 
 
 In this case the testicles are arranged in regard to their envelops 
 precisely in the same manner as in the fetus, as they are entirely ex- 
 posed, and are provided with a gubernaculum. The least anomaly 
 is where the peritoneal prolongation is imperfectly obliterated. When 
 this last anomaly exists in the greatest degree, the canal remains en- 
 tirely open, so that the testicle is inclosed in the same cavity as the 
 other abdominal viscera, although its position is otherwise changed. 
 When the anomaly is less, sometimes and most frequently, only the 
 upper part of the peritoneum is open, which extends between the in- 
 guinal ring and the obliquus abdominis internus muscle ; sometimes 
 and more rarely the lower part of the prolongation does not adhere, so 
 that not only the layer which surrounds the testicle, and which be- 
 comes the external layer of its proper vaginal tunic, forms an oblong 
 and rounded cavity, but also we see arise from the upper extremity of 
 this sac a canal varying in length, which marks the old canal of com- 
 munication ; sometimes finally and more unfrequently, the obliteration 
 occurs regularly at the two extremities of the canal of union, but the 
 central part of this latter continues in a greater or less extent. 
 
 We shall mention hereafter the diseases produced by these ano- 
 malies. 
 
 § 2505. The testicle differs considerably both in respect to situation 
 and its envelops, whether it is found in the abdominal cavity or in that 
 of the scrotum. 
 
 While it is situated in the abdomen, it is surrounded only by the 
 albugineous tunic and the portion of the peritoneum which passes on 
 this membrane. 
 
 The fold of the peritoneum, which is attached to the latter, is conti- 
 nuous with the posterior wall of the peritoneum, and at this period the 
 testicle, like the other abdominal viscera, is not inclosed in a proper 
 capsule, with which this serous fold is continuous, as are the lungs or 
 the heart. 
 
 The other envelops which cover it in the scrotum are developed at 
 the expense of the gubernaculum, and the prolongation of the perito- 
 neum. The peritoneum becomes the external and loose layer of the 
 proper vaginal tunic of the testicle, with which, when the testicle has 
 descended, the internal layer is continuous, precisely in the same man- 
 ner as it was previously connected with the external wall of the peri- 
 toneum. 
 
 The common vaginal tunic of the testicle and the spermatic cord is 
 formed from the cellular tissue within the gubernaculum. 
 
 At this period also the fibres coming from the two internal muscles 
 of the abdomen, which were at first ascending, go outward, and form 
 the cremaster muscle. The cellular tunic or the dartos already ex- 
 isted in the scrotum, and the testicle entered it on descending. 
 
 These changes depend principally on the fact that the gubernacu- 
 lum gradually turns, so that its internal face becomes external, and its 
 
450 
 
 DESCRIPTIVE ANATOMY. 
 
 upper extremity becomes the lower ; hence the epidydimis which is 
 attached to it, and with it the testicle, are necessarily drawn from 
 above downward. The prolongation of the peritoneum also emerges 
 in the same manner outward, and independent of this inversion, since 
 it already exists before the testicle descends, and it supervenes also in 
 hernias which are caused simply by the spontaneous prolapsus of the 
 peritoneum, without any other mechanical change. 
 
 The descent of the testicle is generally explained entirely in a me- 
 chanical manner, and attributed to the compression produced by the 
 motions of respiration upon the abdominal viscera,(l) or to the weight 
 of the testicle, (2) or to the greater flow of blood into its vessels, (3) or 
 finally to the contraction and inversion or to the reversion of the guber- 
 naculum. (4) 
 
 The first opinion is not correct, since when the formation is normal 
 the testicles usually descend in the scrotum long before birth, and they 
 are often found in the abdominal cavity long after parturition, when 
 the formation is abnormal. The second is refuted by the habitual 
 situation of the fetus, as the testicle would ascend against its specific 
 gravity. The third is inadmissible, because if true the testicles should 
 be situated as much lower the younger the fetus is, since then they 
 are proportionally the largest. 
 
 The contraction of the gubernaculum doubtless does not cause the 
 gliding of the testicle to the inguinal ring ; but it does not contribute 
 to its farther progress in the scrotum, for instead of favoring its motion 
 in this direction it would rather contribute to raise it. "We cannot, 
 however, deny that it assists very much to the displacement of the 
 organ, and this is proved positively by the great development of the 
 muscular fibres of the gubernaculum in those animals where the tes- 
 ticles possess alternate motions, whence they enter and leave the 
 cavity of the abdomen alternately. 
 
 If sometimes the testicles do not descend, although the gubernacu- 
 lum exists, we must not conclude that this latter takes no part in the 
 phenomenon, since other circumstances may prevent its action, or at 
 least may produce the effects it generally causes. Farther, its con- 
 traction is only one mode of causing the displacement of the testicle, 
 and the cause of this displacement is unknown to us. 
 
 § 2506. When man has passed the period of his virility, the tes- 
 ticles diminish a little, at least frequently ; but they rarely waste as 
 much as the ovaries, and the power' of impregnation continues longer 
 in the male than that of conception in the female. 
 
 The scrotum gradually relaxes more or less, so that the testicles 
 descend lower. 
 
 (1) Haller. 
 
 (2) Haller, Pott. 
 
 (3) Haller, Tumiati. 
 
 (4) Paletta, Vicq-d’Azyr, Bruguone. 
 
OF THE GENITAL SYSTEM. 
 
 451 
 
 § 2507. The secretion of semen commences about the same time 
 that menstruation does, but it usually continues a little longer. 
 
 II. PENIS. 
 
 § 2508. About the middle of the third month the glans is not yet 
 covered by the prepuce, and a deep groove separates it posteriorly 
 from the proper penis, which is larger than it. 
 
 Its anterior extremity is imperforate ; we only perceive a whitish 
 spot at the place where the urethra afterwards opens. But we always 
 observe at this period a longitudinal fissure, which sometimes exists 
 posteriorly on the small portion of the lower face of the glans and 
 which constantly occupies the anterior extremity of the lower face of 
 the penis situated directly next to it. 
 
 Thus the urethra does not extend as far forward as when the de- 
 velopment is completed, and farther its anterior part presents a fissure 
 below. This fissure, however, by no means extends to the posterior 
 extremity of the penis. 
 
 The scrotum is very small, is separated very distinctly from the 
 penis forward, and is entirely closed. 
 
 At four months, the appearance of the scrotum is not changed, but 
 the form of the penis is altered. The glans is a little larger propor- 
 tionally, is covered by the prepuce at its posterior and inferior part so 
 that only the lower part of its anterior side is exposed, and we remark 
 at the lower part of its anterior surface a longitudinal fissure, which is 
 the opening of the urethra. 
 
 Next comes a state directly opposite, which continues during the 
 whole of gestation. The prepuce is very much enlarged, covers the 
 whole glans, and presents only a very narrow opening ; it is adapted 
 so intimately to the surface of this part that it cannot be drawn back- 
 ward. 
 
 Thus in the normal state there is paraphymosis during the early 
 periods of fetal existence, and phymosis during those that succeed. 
 
 III. MAMMÆ. 
 
 § 2509. The mammæ are already apparent at the third month of 
 pregnancy, at which period the nipple is scarcely perceptible, but pre- 
 sents a very' broad opening. It is worthy of remark that they gene- 
 rally contain during the latter period of gestation, and in the fetus at 
 birth, a lactescent liquid, of which there is often a considerable quan- 
 tity. Until the period of puberty they present no marked differences 
 in the two sexes ; but at this time they enlarge more or less in the 
 female. 
 
452 
 
 DESCRIPTIVE ANATOMY. 
 
 They are more or less hard and solid. As age advances they di- 
 minish, which occurs sooner when their action has been exhausted by 
 frequent lactations. Even where their mass does not seem dimi- 
 nished, and they are even enlarged, the substance of the gland is, 
 however, replaced by fat. 
 
 ARTICLE THIRD. 
 
 DIFFERENCES IN THE GENITAL ORGANS PRESENTED BY DIF- 
 FERENT RACES. 
 
 § 2510. Beside the differences depending on the sexes and the pe- 
 riods of life, the genital organs present others which relate to the races 
 of the human species. 
 
 The most remarkable are those in the external genital organs of the 
 female and the mammæ. 
 
 The internal labia are very long in certain Ethiopian races, among 
 others that of the Boschismans, as we have already mentioned. 
 This is the origin of the apron of the Hottentots, which the recent 
 observations of Somerville and Cuvier have demonstrated not to be a 
 new organ. 
 
 The mammæ are also very much developed and very long in the 
 Hottentots, who can throw them over their shoulders. 
 
 We have already mentioned the great size of the penis in ne- 
 groes. 
 
 ARTICLE FOURTH. 
 
 COMPARISON OF THE MALE AND FEMALE GENITAL ORGANS. 
 
 § 2511. We have already mentioned several times that the genital 
 organs of the two sexes are formed primitively in the same model, and 
 that they should be considered only as modifications of the same fun- 
 damental type. 
 
 In fact it is easy to demonstrate that all the parts which unite to 
 form this system exist equally in both sexes, and differ only in size, 
 situation, and structure. • The analogy appears much greater the 
 younger the fetus is, and that it is founded on the nature of things is 
 proved by the fact that they are originally of the same sex. 
 
OF THE GENITAL SYSTEM, 
 
 453 
 
 The testicles Correspond perfectly to the ovaries in form and func- 
 tions, the vessels and nerves they receive, and even, at first, in situa- 
 tion. 
 
 The Fallopian tubes are evidently analogous to the vasa deferentia. 
 We however have reason to think they originally communicate with 
 the ovaries by straight canals, and by a kind of epidydimis similar to 
 that which exists in the male between the vas deferens and the tes- 
 ticle. 
 
 The seminal vesicles and the prostate gland undoubtedly corres- 
 pond to the uterus in respect to situation and connection, with the 
 vasa deferentia, and the Fallopian tubes ; the uterus however is larger 
 and more completely developed, and the orifices of the seminal canals 
 are more remote from each other. 
 
 The penis and clitoris are similar in essential respects as to situation 
 and structure. They differ only in their respective size, and because 
 the urethra does not extend under the clitoris. This difference how- 
 ever disappears, when we consider the imperfect development of the 
 clitoris is compensated by that of the vagina or nymphæ, which must 
 consequently be regarded as the penis and urethra of the male, the 
 two lateral halves of which are separated, and which are turned in- 
 ward instead of outward. 
 
 In this respect also the analogy is greater in the early periods, since 
 then the urethra does not extend to the anterior extremity of the penis. 
 
 We explain in the same manner the difference between the bulbo- 
 cavernosi and the constrictor vaginæ muscles. These two muscles 
 correspond ; the two halves of the second, however, are united only 
 on the median line. 
 
 The external labia represent the two halves of the scrotum, which 
 are separated. 
 
 The mammæ differ only in size, and this difference is almost nothing 
 before the period of puberty. 
 
 Thus the analogy of the genital organs of the female is found in 
 the other sex. The history of hermaphrodites will demonstrate that 
 the deviations of formation contribute still more to efface the differ- 
 ences between the two series of organs, and these anomalies 
 produce between them so great a resemblance, that it is often very 
 difficult to determine to what sex the individual really belongs. 
 
 VOL. Ill 
 
 58 
 
464 
 
 DESCRIPTIVE ANATOMY 
 
 ARTICLE FIFTH. 
 
 GENITAL ORGANS IN THE ABNORMAL STATE.(l) 
 
 3. GENERAL ANOMALIES 
 
 § 2512. The genital organs present some anomalies common to the 
 two sexes, and others peculiar to one only, a remark which applies also 
 to deviations of formation and alterations of texture. In this respect 
 we must remark, that the corresponding sections of the genital organs 
 usually participate in the same anomalies, or at least present those 
 which are very analogous. 
 
 We observe in both sexes : 
 
 1st. Suspensions of development and developments continuing after 
 the type of the fetus. Such are : 
 
 a. The entire or partial absence of the genital organs. The first 
 anomaly causes the total absence of sex, although the rest of the body 
 sometimes indicates clearly to what sex the individual would have be- 
 longed if the genital organs had been developed. 
 
 b. Abnormal smallness. 
 
 c. The abnormal continuance of a primitive formation. 
 
 These anomalies are not rare. 
 
 2d. Plurality, which is much less common. 
 
 3d. The too early development, although more common" than the 
 preceding anomaly, is however a rare phenomenon. 
 
 (I) Consult, 1st. On the diseases of the genital organs generally : Vercelloni, De 
 pudendorum morbis, Leyden, 1725. — 2d. On those of the organs of the female in par- 
 ticular : J. G. Walter, lieber die Geburtstlieile des weiblichen Geschlechts , Berlin, 
 1776. — Justi, Diss. cxhibens observationum sericm circa genitalia muliebria, Mar- 
 burg, 1798. — Thamm, Diss. de genitalium sexus sequioris varietatibus , Halle, 1799. 
 — 3d. On those of the external genital organs of the female : Louis, De partium ex- 
 ternarum generationi inservientium in mulicribus naturali , viiiosâ et morbosa dis- 
 positions, Baris, 1764. — 4th. On those of the ovaries ; Kruger, PatholOgia ovariorum 
 muliebrium, Gottingen, 1782. — Motz, De structura, usu et morbis ovariorum, Gies- 
 sen, 1789.— 5th. On those of the Fallopian tubes : Leonhardi, Quœdam de tubarüm 
 uterinarum morbis, Wittemberg, 1808. — 6th. On those of the matrix and of the va- 
 gina : A. Vater, De morbis uteri, Wittemberg, 1709. — Haller, De morbis uteri, Got- 
 tingen, 1753. — Schwarz, De uteri degeneraiione , Jena, 1792. — Clarke, Diseases of fe- 
 males, London, 1814. — 7th. On the anomalies of the hymen: G. Tolberg, De varie- 
 tate hymenum, Halle, 1791. — Osiander, loc. cit. — 8th. On the diseases of the genital 
 organs of the male in general: G. Wadd, Cases of diseased bladder and testicle , 
 London, 1815. — 9th. On those of the testicle : Henrel, Diss . de morbis scroti, Stras- 
 burg, 1723. — J. Warner, Account of the testicles and the diseases to which they are 
 liable, London, 1774.-10. On those of the prostate gland : E. Home, Observations prati- 
 ques et pathologiques sur le traitement des maladies de la glande prostate, Paris, 
 1820. — llth. On those of the penis : Brockhausen, De exeretionis vrince impedimen- 
 ts n vitiis membri virilis, Strasburg, 1781. — Thaut, De virgœ virilis statu sano et 
 morbosa , Wurzburg, 1808. — C. Bell, Engravings of specimens of morbid parts, Lon- 
 don, 1813. — J. Howship, Practical observations on the diseases of the urinary organs , 
 London, 1816. 
 
OF THE GENITAL SYSTEM. 
 
 455 
 
 4th. It is less rare to find tire characters of both sexes blended in the 
 same individual, one or several parts of whom are formed after the 
 type of one sex, and the rest of the body after that of the other sex. 
 This anomaly essentially constitutes hermaphrodism. 
 
 5th. Alterations in texture. They are seen most frequently, and are 
 most developed, in the genital organs. Not a single new formation 
 but has been seen in some part of the genital apparatus, which un- 
 doubtedly depends on the energy of the formative power being 
 greater in this than in any other of the organic systems 
 
 SI, SPECIAL ANOMALIES. 
 
 A. DEVIATIONS IN FORMATION. 
 
 I. HERMAPHRODISM. 
 
 § 2513. Hermaphrodism, (\ ) which constitutes the second class of 
 deviations of formation in regard to quality, is indicated in the formation 
 of the genital organs, of which alone we shall treat here, by the forma- 
 tion of one part of the sexual system, after a type contrary to that of 
 the rest or of the whole body, that is, with or without an increase in 
 the organs of generation. 
 
 The second case is infinitely more common than the first. 
 
 The genital organs of the male assume the characters of the female : 
 
 1st. By the continuance of the testicle in the abdomen, and gene- 
 rally by the imperfect disappearance of the primitive relations of lo- 
 cality. 
 
 2d. By the interruption of the vas deferens. 
 
 3d. By the higher situation, the increase in volume, and enlarge- 
 ment of the prostate gland, 
 
 4th. By the smallness of the penis. 
 
 5 th. By the different degrees of its imperforation. 
 
 6th. By the division of the scrotum, and the existence between the 
 penis and the anus of a canal similar to the vagina, varying in its di- 
 mensions, which leads to the prostate gland, and which is often at- 
 tended by one of the three preceding anomalies. 
 
 Tth.SBy the development of one or of the two mammae resembling 
 those of the female in respect to size and function. 
 
 The genital organs of the female assume the characters of the male : 
 
 1st. By the hernia of the ovaries through the inguinal ring. 
 
 (1) J. F. Meckel, Ueber die Zwitterbildungen ; in Reil, Archiv für die Physiolo- 
 gie, vol. xii. — Burdach, Die Metamorphose der Geschlechter, oder Entwichlung der 
 Bildungsstufen durch welche beide Geschlechter in eidander ubergehen ; in his 
 Analomische Xj ntersuchungen, part i. 1814. — All the works which have appeared be- 
 fore on the same subject are mentioned there. — Seiler, Observationes J nonnullœ de 
 tcsticulorum ex abdomine in scrotum descensu et partium genitalium anomalis , 
 Leipsic, 1787 . — J. Feiler, Ueber angeborne menschliche Missbildungen , im allge- 
 meinen , und Hermaphroditen insbesondere , Leipsic, 1820 . 
 
456 
 
 DESCRIPTIVE ANATOMY. 
 
 2d. Perhaps by the adhesion of the tubes with these glands. 
 
 3d. By the smallness and sloping situation of the uterus. 
 
 4th. By the narrowness and shortness of the vagina. 
 
 5th. By the enlargement of the clitoris and the extension of the 
 urethra to its surface. 
 
 6th. By the adhesion of the large and small labia. 
 
 7th. By the imperfect development of the mammae. 
 
 All these anomalies do not necessarily coexist in the same organ- 
 ism: but hermaphiodism, and the equivocal character of the sex 
 which depends on them, are more marked, the greater the number of 
 those existing. 
 
 Generally only one or some of the different parts of the genital ap- 
 paratus are constructed after different types, and the synonymous parts 
 of the two sides correspond. It is much more rare to find an herma- 
 phrodism so perfect that each of the two lateral faces present all the 
 characters of a different sex. 
 
 Finally the greatest degree of hermaphrodism consists in the deve- 
 lopment of some parts constructed after a sexual type contrary to that 
 of all the others. 
 
 But few authentic instances of this last and the preceding anomaly 
 are known, and they all differ in respect to quality and quantity. 
 
 All these varieties of hermaphrodism present more or less distinct 
 and perfect analogies with animals. 
 
 Hitherto, however, not a single instance of human hermaphrodism 
 is known where the two sexes were so completely united that it was 
 possible either alone or with other individuals to procreate both as a 
 male and female. 
 
 All imaginary reasonings, however, cannot demonstrate the impos- 
 sibility of such a formation, as it exists in many animals, as herma- 
 phrodites have been seen which were very nearly in this state, as 
 several phenomena seem even to prove that a perfect male organism 
 sometimes possesses the creative power, independent of the other sex, 
 and we cannot to a certain extent absolutely refuse this power to the 
 female. 
 
 II. DEVIATIONS IN FORMATION OF THE SPECIAL GENITAL ORGANS. 
 
 A. GENITAL ORGANS. 
 
 a. Ovaries and tubes. 
 
 § 2514. Among the primitive deviations of formation in the ovaries 
 and their excretory ducts, the Fallopian tubes, we remark the fol- 
 lowing, which arise mostly from suspended development : 
 
 1st. The absence of an ovary, or more rarely of the two, with or 
 without simultaneous absence of its tubes. 
 
OF THE GENITAL SYSTEM. 
 
 457 
 
 2d. Smallness. 
 
 3d. The absence of the vesicles of Graaf in the ovaries of barren 
 women. 
 
 4th. The closing of the abdominal extremity of the tubes. 
 
 This last state is frequently developed after inflammation ; it then 
 constitutes a consecutive deviation of formation. 
 
 Another anomaly, which is generally congenital, but more rare, 
 consists in the hernia of the ovaries and Fallopian tubes through the 
 inguinal ring, in which case they resemble the testicles. 
 
 b. Uterus. 
 
 § 2515. The primitive deviations in the formation of the uterus, 
 most of which consist in its suspended developmental) are : 
 
 1st. Its total or partial absence. In the latter case sometimes the 
 upper and sometimes the lower part is deficient. 
 
 2d. Its smallness, with thinness of its parietes. 
 
 3d. The continuance of its form at a primitive degree of deve- 
 lopment. 
 
 Here exist several degrees which essentially consist most frequently 
 in a division into two halves. (2) 
 
 When the anomaly exists in the greatest degree possible, the uterus 
 is divided at its upper part into two horns, and also divided into two 
 halves by a septum at its lower part. Next come two nearly equal 
 degrees : sometimes the body of the organ is extended into two horns, 
 and the neck is single ; sometimes the form of the uterus is normal 
 externally, but its cavity is divided into two halves at its lower part by 
 a septum. Next come two other degrees ; in one a groove more or 
 less deep at the bottom of the organ makes it appear imperfectly double 
 horned, in the other, it is single externally, while its body is divided 
 into two portions. 
 
 Finally, when the anomaly is as slight as possible, the form of the 
 uterus is only more elongated. 
 
 These different degrees in the anomaly present very remarkable 
 resemblances with the formations seen in animals, and with animals 
 situated as much lower in the scale as the deviation is greater. 
 
 Primitive deviations of formation consisting in an excess of the 
 formative power, are hardly known. The term double uterus (3) has 
 been wrongly applied to those which present several of the anomalies 
 mentioned by us. 
 
 The deviations in formation in respect to quality which relate to 
 form and situation, are rarely primitive. 
 
 (1) See our Handbuch der pathologischen Anatomie , vol. i. 
 
 (2) Thamm ( loc . cit.) has given a complete list of works published on this subject. 
 — F. J. Hunkelmœller, De vaginâ et utero duplici, Berlin, 1818. 
 
 (3) F. Tiedemann, Observation d’une grossesse chez une femme dont la matrice 
 était double ; in the Journ. compl. des sc. méd., vol. vi. p. 371. — Mad. Boivin, Mémo- 
 rial de l’art des accouchcmens , p. 85. 
 
458 
 
 DESCRIPTIVE ANATOMY 
 
 The uterus however is sometimes oblique, which state is generally 
 blended with its obliquity in respect to situation. (1) 
 
 The accidental deviations of formation are : 
 
 1st. Abnormal situation . The principal varieties of this anomaly are 
 the following : 
 
 a. The situation of the uterus cut of the median line , in which case 
 it generally rests against one of the sides of the pelvis. 
 
 b. Obliquity , in which its direction is from one side to the other. 
 This state, especially when the uterus is unimpregnated, generally 
 results from adhesions with the adjacent parts. 
 
 c. Retroversion ,(2) in which the longitudinal diameter of the uterus 
 corresponds to the antero-posterior diameter of the pelvis, so that its 
 base is directed downward and backward, and its vaginal orifice up- 
 ward and forward. This anomaly occurs particularly during the 
 fourth month of pregnancy. 
 
 d. Prolapsus, (3) where the uterus, most frequently from an inver- 
 sion of the vagina, descends more or less into the pelvis. When the 
 vagina is entirely inverted the uterus is depressed its whole extent, 
 and the lower orifice is situated at the lower extremity of the tumor 
 formed by it between the thighs. Usually also the neck is more or 
 less elongated, and the uterus adheres to the primitively external face 
 of the inverted vagina. 
 
 From the elongation of the neck, however, the body of this latter is 
 rarely situated on the outside of the sac of the vagina. In this de- 
 viation of formation the orifice of the uterus is rarely completely 
 effaced. (4) 
 
 Sometimes the uterus, even when it contains a fetus, forms a hernia. 
 
 2d. Abnormal form. One accidental anomaly in the formation of 
 the uterus connects it with the proper deviations of formation, as it is 
 attended with displacement of the organ. 
 
 This is inversion, (5) which consists essentially in the turning out- 
 ward of the inner face of the uterus. It appears in several degrees, 
 for sometimes only the base of the uterus approaches the orifice, and 
 sometimes it projects through this opening. The tumor it forms in 
 this latter case differs from prolapsus, as its lower part presents no 
 opening. This fact happens only when the cavity of the uterus is 
 considerably distended and its walls are proportionally thin, and the 
 organ is then compressed or drawn down by the base. Thus it is 
 observed in parturition, in uterine polypi, &c. 
 
 S Boer, Abhandlungen geburtschûlflichen Inhalts , vol. i. p. 1. 
 
 Cuyper, De relroversione uteri, Leyden, 1772. — Korscheck, De retroverso utero, 
 Halle, 1799. — One is figured in Hunter, De utero gravido , tab. xxvi. 
 
 (3) Bœhmer, De prolapsu et invcrsione uteri, Halle, 1745. — It is figured in Ruysch, 
 Obs. med. chir., obs. 2 and 8.— Baillie, Engr. fase. ix. fig. i. — Clarke, Diseases of 
 females , London, 1814, tab. i-v. 
 
 (41 Bedard and Cloquet, in the Bull, de lafac. de mcd., vol. v. 1816, p. 114. 
 
 (5) Van Sanden, De prolapsu uteri, Leipsic, 1723.— Saxtorph, Auszüge aus der 
 Abhandlungen der Copenh. Gelleschaft, Halle, 1785. — It is figured in Ruysch, Obs. 
 anat. chir. cent., obs. x.— Denman, introduction to the praciiec of midwifery, tab. 
 xii-xiv.— Baillie, Engravings, fasc. ix., fig. 2. 
 
OF THE GENITAL SYSTEM 
 
 459 
 
 Rupture is a deviation of formation of the uterus occurring under 
 similar circumstances, although it is rare, except in a state of preg- 
 nancy ; it occurs when parturition is opposed by any cause, and is 
 seen, particularly at the lower part of the organ, in a transverse direc- 
 tion. 
 
 The obliteration of the cavity of the uterus is generally partial, and 
 commonly occupies the lower part of the organ, to a greater or less 
 extent. 
 
 It is sometimes congenital, and may then constitute a primitive ano- 
 maly ; but it frequently supervenes after suppuration and ulceration. 
 
 c. Vagina. 
 
 § 2516. Sometimes the vagina is imperforate, or is even deficient, 
 and a loose cellular tissue exists in its place. This anomaly is most 
 generally primitive. Its least degree is the closing of the canal, or the 
 very great thinness and hardness of the hymen. 
 
 Sometimes the vagina is divided in a greater or less extent into two 
 halves by a longitudinal septum, directed from before backward, so 
 that when the division extends to its lower extremity even two hymens 
 exist. This anomaly may or may not be attended with an analogous 
 state of the uterus. 
 
 The vagina also presents primitive deviations of formation in respect 
 to length and breadth. In fact it is sometimes extremely narrow and 
 very short, which anomalies exist alone or together. 
 
 The most common consecutive deviation of formation is the imper- 
 fect^) or perfect retroversion of the vagina, attending the prolapsus of 
 the uterus. The bladder is then generally drawn downward, and very 
 frequently also we find calculi, which may sometimes produce the 
 disease, and sometimes have been produced by it.(2) 
 
 The vagina is sometimes ruptured in the same cases as the uterus, 
 but more rarely than it. 
 
 d. External labia. 
 
 § 2517. The external labia are sometimes deficient, from a primi- 
 tive deviation of formation, or adhere to each other on the median line. 
 These two anomalies result from the permanence of a primitive state 
 of formation. 
 
 They rarely contain the abdominal viscera which have escaped 
 through the inguinal ring, 
 
 (1) Kaudin, Mémoire sur les chutes- partielles du vagin; in the Journ. gén. de 
 méd., vol. lvi. 1816, p. 259. 
 
 (2) Ruysch, Obs. med. chir.. obs. i. — Paget ( Lond . med. andphys. Journ., vol. vi, 
 p. 391) mentions a stone weighing twenty-seven ounces, attended with several 
 smaller ones, found in a case of prolapsus of the bladder. 
 
460 
 
 DESCRIPTIVE ANATOMY. 
 
 Sometimes they enlarge very much, either suddenly, from the me- 
 tastasis of other diseases, particularly blenorrhea, or slowly and gra- 
 dually. 
 
 e. Internal labia. 
 
 § 2518. Sometimes also the nymphæ are deficient, or adhere. 
 These two states may be primitive or accidental, and developed after 
 an inflammation. In some cases they present an opposite anomaly, 
 and are double or even triple.(l) Their unusual enlargement is com- 
 monly consecutive or accidental. 
 
 f. Clitoris. 
 
 2519. The clitoris is sometimes unusually large, and then resem- 
 bles the penis in the male, particularly when the urethra extends 
 unusually far forward. Sometimes this part is enlarged in conse- 
 quence of syphilitic affections, and its texture is altered ; it then be- 
 comes harder, firmer, and irregular. 
 
 Its fissure is an anomaly interesting as analogous with animals. 
 
 B. GENITAL ORGANS IN THE MALE. 
 
 a. Testicles. 
 
 § 2520. The deviations in the formation of the testicles are : 
 
 1st. The absence of one of these two organs, which must be distin- 
 guished from its apparent absence, depending on the gland continuing 
 in the abdomen. 
 
 2d. Smallness. 
 
 3d. Permanence in their primitive situations. This anomaly pre- 
 sents a great many degrees, from the case where the testicle remains 
 below the kidney to that where the canal of communication, which 
 continu es^some time after leaving the abdomen, is imperfectly oblite- 
 rated. This last deviation of formation becomes the cause of conge- 
 nital inguinal hernia. 
 
 4th. The interruption of the vas deferens, its termination in a cul- 
 de-sac, the absence of the seminal vesicles. (2) 
 
 5th. The plurality of the testicles. This anomaly is very doubtful. 
 The seminal vesicles also are rarely more than two in number.(3) 
 
 The consecutive deviations of formation are : 
 
 1st. Abnormal enlargement. 
 
 2d. Atrophy. 
 
 (1) Neubauer, Dc Iriplici nympliarum ordine, Jena, 1774. 
 
 (2) See our Handbuch der pathologischen Anatomie, vol. L, p. 685. — H. Bosch* 
 Diss. sistens obscrvalioncm de vcsiculæ seminalis sinislræ dejectu , integris lestibus , 
 vase vero deferente sinislro clauso, Leyden, 1813. — Seiler haa published an excellent 
 account of the post-mortem examination of a person affected with cryplorchis. 
 
 (3) Meckel, Dc duplicitate monslrosa, in Hundbuch der pathologischen Anatomic, 
 vol. ii. p. 32. 
 
OF THE GENITAL SYSTEM. 
 
 461 
 
 These two states are most frequently attended with alterations of 
 texture. 
 
 b. Prostate gland. 
 
 § 2521. The prostate gland is particularly subject to enlargement, 
 which is sometimes attended with a change in its tissue. In this case 
 it is usually said to have become schirrous ; this assertion is true some- 
 times, but not always. Hypertrophy of the prostate gland often 
 depends on the development in its substance of fibrous or fibro-cartila- 
 ginous formations, which are also as commorÉtn its corresponding 
 organ, the uterus.(l) 
 
 The middle lobe of the prostate gland is often swelled abnormally ; 
 but this swelling does not always exist, which is contrary to Home’s 
 assertion. 
 
 c. Penis. 
 
 § 2522. The penis presents a great number of primitive deviations 
 of formation, which depend principally on a suspension of develop- 
 ment, or the permanence of a primitive form. They are : 
 
 1st. Absence. 
 
 2d. Smallness. 
 
 3d. Total or partial imperforation, which presents several differ- 
 ences, either in respect to the degree or the quality, from the closing 
 of the prepuce to the opening of the urethra in the perineum, which is 
 or is not attended with the abnormal smallness of the penis ; in this 
 case the lower part of the urethra, and consequently of the penis, are 
 in fact cleft on their lower face. (2) 
 
 4th. The narrowness of the prepuce, or phymosis, which is gene- 
 rally accidental. 
 
 5th. The fissure of the penis at its upper face, which is often at- 
 tended with that of the bladder, and which when existing alone makes 
 the transition from this latter anomaly to the normal formation. 
 
 6th. The complete division of the penis into two halves. This de- 
 viation of formation is much more rare than the preceding. (3) 
 
 On the other hand, sometimes the penis is more or less perfectly 
 double. 
 
 Perhaps we ought to consider as the first degree of this anomaly, 
 the entire separation of the urinary and seminal passages, which has 
 sometimes been observed. 
 
 (1) Dupuytren, Sur les calcules de la prostate; in the Bull, de lafac. de méd.. vol. 
 vii., p. 135. 
 
 (2) Sixtus, De dijßsione genitalium, Wurtzburg, 1813. 
 
 Ij3j Bamberger, De intussusceptione membrance urethrce internee, Wurtzburg, 
 
 Vol. III. 
 
 59 
 
462 
 
 descriptive anatomy. 
 
 When the organ is perfectly double, the two penises are situated 
 one at the side of or one above the other. This last anomaly presents 
 a remarkable analogy with the doubling of the tongue, the organ 
 which corresponds to the penis. The first might be regarded as a 
 greater development of the fissure of the penis. 
 
 The consecutive deviations of formation comprehend the unusual 
 enlargement of the penis, which commonly supervenes after the deve- 
 lopment of accidental formations. 
 
 The internal membrane of the urethra is rarely reversed.(l) 
 
 C. MAMMS. 
 
 <5 2523. The mammae are sometimes deficient on one side, or on 
 both. 
 
 Their unusual smallness in the female and their abnormal size in 
 the male constitute the first degree of hermaphrodism, especially when 
 in the second case they secrete milk. 
 
 Sometimes they are multiplied as in the mammalia. In the first 
 degree of this anomaly one mamma has two nipples : next we find 
 several mammae one above another, two and even three on each side, 
 or on one only.* 
 
 B. ALTERATIONS IN TEXTURE. 
 
 A. GENITAL ORGANS IN THE FEMALE. 
 
 § 2524. Of all the parts of the genital system, alterations of texture 
 exist most frequently in the ovaries ; here too the most different and 
 the most regular new formations appear. The increase in the size of 
 the ovaries must generally be attributed to the formation of these acci- 
 dental productions, although it is sometimes, especially at first, only 
 simple hypertrophy, either in the whole substance of the gland, or, as 
 is more frequent, of one of its constituent parts, the vesicles. The en- 
 largement of the ovary is often enormous, and to such an extent that 
 the organ has been found weighing fifty- five, (2) eighty -five, and even 
 one hundred and two pounds. (3) 
 
 (1 ) Stiebe], Männliches Hymen; in the Deutsches Archiv. Jüt die Physiologie, 
 vol. viii. p. 207. 
 
 * Sometimes the supernumerary mamma; exist in unusual parts of the body. Dr. 
 Roberts mentions a woman in whom a third mammae existed in the groin, with 
 which she suckled several children. 
 
 (2) Normand, Observation sur la transformation d’un ovaire ; in the Journ. gen. 
 de méd., vol. lvi., p. 145. — Valentin, ibid., vol. lviii., p. 218. _ 
 
 (3) Van den Bosch, in Voigtei, Handbuch der pathologischen Anatomie , vol. in. 
 p. 641. 
 
OF THE GENITAL SYSTEM. 
 
 463 
 
 The least abnormal formation of this kind is dropsy of the ovary. (1) 
 This state presents some differences. Sometimes, in fact, the liquid is 
 contained in one pouch, sometimes it fills several vesicles, of various 
 sizes. It also differs much not only in respect to quantity, -which is 
 often enormous, but also, and even sometimes in the different cysts of 
 the same ovary, in respect to color, consistence, &c. 
 
 The cysts generally adhere to the substance of the ovary ; but we 
 frequently also find them entirely loose and very numerous in the 
 cavity of this organ, where they seem to have been produced by an 
 effusion of serum. This morbid alteration depends sometimes on the 
 increase of the vesicles of Graaf, sometimes on a repetition of these 
 vesicles resembling the effects of generation, and consequently in a 
 formation of serous membranes. 
 
 Not unfrequently these serous membranes contain fat or adipocire. 
 
 Beside the serous membranes, accidental mucous membranes are 
 often developed in the ovaries ; these also have the form of cysts, con- 
 tain a more or less dense fluid, and belong to the class of atheromata 
 or melicerides. 
 
 Another alteration in texture of the ovary, which frequently is seen 
 alone or attended with the preceding, is the formation of fibrous, fibro- 
 cartilaginous, cartilaginous, or osseous substance, which is frequently 
 developed in very large rounded masses, and also increases the weight* 
 and size of the organ. To this we must refer, if not entirely at least 
 in great part, the formations described as steatoma, sarcoma, scihrrus, 
 osteo-sarcoma, and ossification of the ovary. 
 
 To these abnormal repetitions of normal tissues, which frequently 
 occur also ift the other parts of the body, but much less commonly 
 than in the ovaries, we must add another, which is almost if not en- 
 tirely peculiar to these glands. We mean the hairs and the teeth. (2) 
 The hairs are much more frequent than the teeth, and are developed 
 in the fat, and the teeth in the midst of cysts filled with a gelatinous 
 mass, so that here the normal type is perfect, both in respect to the 
 organ where the new formation occurs, as in that of the proportional 
 frequency of its appearance. 
 
 The nature of the organ in which these productions of bone, hair, 
 and teeth occur, and which is the workshop of generation, the period 
 of life at which they are most frequently developed, the fact that they 
 have often been preceded by coition, finally the numerous cases of 
 ovarian dropsy, have led many physiologists to consider them as the 
 remains of a fetus which is developed in the ovary. But this hypo- 
 
 (1) Fehr, De virgine , hydrope ovarii laborante, Strasburg-, 1762. — Huth, Casus 
 rirginis hydrope ovarii extinclce, Strasburg, 1768. — Murray, De hydrope ovarii , 
 Upsal, 1780. — Rossum, De hydrope ovariorum, Louvain, 1782. — Julia-Fontenelle, 
 Analyse de quelques substances contenues dans les ovaires dans certains états morr 
 bides ; in the Archiv, gén. de méd., vol. iv., p. 257. 
 
 (2) J. F. Meckel, Mémoire sur les poils et les dents qui se dévelloppent acciden- 
 tellement dans le corps ; iu the Journ. compl. du diet, des sc. méd., vol. iv. p, 122 
 and 217. 
 
464 
 
 DESCRIPTIVE ANATOMY. 
 
 thesis is absolutely inadmissible : for the total disparity often observed 
 in respect to number, form, and size, between these abnormal produc- 
 tions, and the remarkable fact that the hair, the bones, and the teeth 
 are the only parts found thus, while in extraordinary pregnancies all 
 the parts of the fetus are long preserved, prove also that the act of 
 generation, if necessary to produce them, has not at least given rise to 
 a perfect fetus, and is confined to developing the parts there found. 
 
 Although in many cases the development of these more perfect 
 formations, and also of all the other abnormal formations seen in the 
 Gvary, undoubtedly arises from a copulation not sufficient to give rise 
 to a normal organism, on account of the unhealthy state of one or 
 of both the parents, their advanced age, or any other cause which 
 weakens in them the power of generation : we cannot, however, admit 
 that the male is necessary to produce them, since they have been 
 found in very young girls, where the genital organs were perfectly 
 untouched, and they have occurred in other parts of the body not only 
 of the female but in the male. 
 
 If they are more common and more perfect in the ovary than in any 
 other of the organs, it is because the formative power is more energetic 
 in this gland. We must not conclude from this that the union of the 
 sexes must necessarily have preceded them, and still less are they the 
 remnant of an ovarian fetus. 
 
 The entirely abnormal alterations of texture are much more rare in 
 the ovary, probably for the same cause, and because from the greater 
 energy of the formative power, attempts to create new formations are 
 there more frequently successful. 
 
 An extremely rare alteration in respect to form, belonging exclu- 
 sively to the ovary, and the nature of which has not yet been exa- 
 mined, is a large arborescence, formed of several solid tubercles united 
 by filaments. This anomaly has been observed by Prochaska.(l) 
 
 Otto has seen an analogous production, which was not an inch in 
 size. (2) 
 
 We also have before us two instances, which are recent. In opening 
 the cadaver of a prostitute aged about thirty years, in whom were 
 traces of an inflammation of the ovary, we found the tubes adherent 
 and very thick, and farther the left ovary considerably enlarged, very 
 soft, and changed into numerous eminences of different figures. In 
 another cadaver of a woman forty years old, on the surface of the right 
 ovary were three cysts about four lines in diameter, the inner face of 
 which was very much folded, and presented similar circumvolutions. 
 The first case was very probably the formation described by Prochaska, 
 which perhaps might have appeared in the second, if the cysts had 
 been torn, and their inner face had vegetated. 
 
 § 2525. Alterations in the texture of the uterus are very frequent. 
 
 (1) Disquis. organism, anat. phys., § 58, tab. v. 
 
 (2) Handbuch der pathologischen Anatomie, p. 378, note 3. 
 
OF THE GENITAL SYSTEM. 
 
 465 
 
 Among the abnormal repetitions of normal tissues we may mention 
 principally the fibrous, fibro-cartilaginous, or osseous bodies, which 
 must be distinguished from schirrus, although they have frequently 
 been described as such, on account of their hardness. 
 
 These productions are rounded, sometimes distinct, sometimes united 
 in great numbers, and adhere but slightly to the substance of the 
 uterus. They generally appear on its external, but sometimes on its 
 internal face, and have a yellowish white tint, and an irregular or 
 more or less evidently fibrous structure. They commonly ossify in 
 some parts, although their volume has no effect on this phenomenon. 
 They then become sometimes extremely hard, so that they are cut 
 with difficulty. They are seen principally about the middle of life in 
 unmarried females who have not borne children. 
 
 Hairs and fat are formed more rarely under similar circumstances 
 in the substance of the uterus. 
 
 All these formations and even the teeth are sometimes developed 
 also on the inner face and in the cavity of the uterus. (1) 
 
 The circumstances in which they occur in the last two places allow 
 them to be considered as the imperfect products of generation. Those 
 in the substance of the uterus are most frequently developed without 
 the co-operation of the male, although they may be caused also by 
 copulation. In this respect they resemble the abnormal formations of 
 the ovary. It is very curious that the phenomena caused by them in 
 both organs sometimes resemble those of pregnancy. (2) 
 
 Not unfrequently even in these same circumstances other formations 
 are developed in the cavity of the uterus, which may be considered as 
 resulting from an ineffectual effort to produce a new organism, and 
 which resemble either the deciduous membrane, or, when they have 
 the form of thin vesicles filled with a serous fluid, the inner membranes 
 of the ovum. 
 
 The entirely abnormal alterations in the texture of the uterus are: 
 1st. Schirrous and cancerous formations. (3) This alteration does 
 not appear, like the fibrous bodies, in the form of distinct masses ; it is 
 formed by a change which generally commences at the lower part of 
 the organ, and which gradually extends to the whole of it. The parts 
 in which it is situated become at first hard, then swell more or less, 
 afterwards suppurate in the same order, and are thus gradually de- 
 stroyed ; abnormal openings are thus formed which communicate with 
 the cavity of the abdomen, the bladder, or the rectum, or with several 
 of these parts at once. Here as in all other cases of this change, the 
 lymphatic system is infected, and death is the necessary consequence, 
 
 <i) Sec our Handbuch der pathologischen Anatomie, vol. i. p. 525-542. 
 
 (2) Cochon-Dupuis, in the Mém. de Paris, 1698, p. 339.— A. Monro, Four cases of 
 the tumefied ovarium ; in the Med. essays of JEdinb., vol. vi., p. 278.— In two cases 
 pains supervened ; in the first at nine months, in the other at ten. 
 
 (3) Patrix, Traité sur le cancer de la matrice et sur les maladies des voies uri- 
 naires, Paris, 1820. 
 
466 
 
 DESCRIPTIVE ANATOMY. 
 
 All these characters distinguish them from the fibrous and osseous 
 productions.* 
 
 2d. Polypi are developed on the inner face of the uterus so fre- 
 quently that, in twenty cadavers, Portal has found them in thirteen. (1) 
 They are distinguished, according to the place where they exist, into 
 polypi of the base, of the body, and of the neck : and according to then- 
 degree of solidity into soft and hard. They vary much in respect to 
 number and volume. 
 
 The vagina usually participates in the schirrus of the uterus, at 
 least at its upper part. Polypi also are developed there, particularly 
 at its summit, but much more rarely than in the uterus. 
 
 Sometimes hairs grow on the inner face of the external labia. 
 
 B. GENITAL ORGANS OF THE MALE. 
 
 § 2526. The alterations in the texture of the testicles are princi- 
 pally : 
 
 1st. Induration, a consequence of inflammation. 
 
 2d. Dropsy of the vaginal tunic, termed hydrocele. This disease is 
 common. The liquid is commonly serous and limpid ; but sometimes 
 also instead of serum we find a solid and opaque substance, or when 
 this liquid is thicker and more viscous than usual, it contains shining 
 laminae very similar to the fatty substance of cholesterine, but which 
 differ from it, as their specific gravity is greater, and they dissolve more 
 readily in the alkalies. (2) 
 
 3d. Ossification, which is situated principally in the epididymis and 
 the vaginal tunic. We not unfrequently find in the albugineous mem- 
 brane rounded plates of bone and cartilage, which are finally detached, 
 and become loose in the cavity of the vaginal tunic. These produc- 
 tions are less common in the spermatic cord. 
 
 4th. Hairs are very rarely developed in them. 
 
 * Very recently the mollescence of the uterus has been made the subject of re- 
 search. In an article on this subject by Dr. Luroth, we make the following extract 
 in regard to this disease: 
 
 He states that mollescence of the uterus is more frequently partial than general ; 
 it more commonly occupies the internal surface and the cervix, though it occasion- 
 ally extends through the substance of the organ. The mollescence presents several 
 degrees, blending insensibly with each other. In the first, the parts are simply 
 softened or very flaccid, generally with serous or sero-sanguineous infiltration into 
 the nterstices. In the second degree, the structure of the uterus is still farther al- 
 tered. It will scarcely bear handling without reduction into a pultaceous mass. In 
 the third degree, the disorganization amounts almost to a liquefaction or reduction 
 of the viscus to an inorganic pulp. — (Am. Journ. of the Medical Sciences , for No- 
 vember, 1828.) 
 
 (1) Observations sur la structure des parties de la génération clans la femme ; in 
 the Mem. de Paris, 1770, p. 190. — C. Mayer, Diss. de polypis uteri, Berlin, 1820. 
 
 (2) Beclard and Cloquet, Deux observations d' hydrocèles rares ; in the Bull, de la 
 fac. de méd., vol. v. p. 38. 
 
OF THE ABDOMINAL CAVITY. 
 
 467 
 
 5th. The albuminous and tuberculous formations in the substance 
 of these glands are not rare. 
 
 6th. We find also schirrous formations, which change into cancer. 
 
 7th. Fungous formations. 
 
 8th. Cysts filled with a liquid similar to the serum of the blood. 
 
 Sometimes, but rarely, calculi form in the seminal vesicles,(l) or in 
 the prostate gland. (2) The latter at least are composed of phosphate 
 of lime. 
 
 The alterations in the texture of the penis are usually of syphilitic 
 origin, ulcers, warts, &c. 
 
 C. MAMMÆ. 
 
 § 2527. The mammæ of the male are subject to but few diseases. 
 The alteration most frequent in those of the female is schirrus. We 
 however designate by this term new formations, however much they 
 differ, for almost all can be developed either alone or with others, in 
 the tissue of the mammary gland.* 
 
 CHAPTER Y. 
 
 OF THE ABDOMINAL CAVITY. 
 
 ARTICLE FIRST. 
 
 ABDOMINAL CAVITY IN THE NORMAL STATE, 
 
 A. PERFECT STATE. 
 
 I. ABDOMINAL CAVITY IN GENERAL. 
 
 § 2528. After describing the digestive, the respiratory, the urinary, 
 and the genital systems, we proceed to the topography of the abdo- 
 minal cavity, (3) the general characters of which have already been 
 mentioned. (4) 
 
 (1) Hartmann, De calculis in vesicula seminali, Erfort, 1765, 
 
 (2) Pohl, De calculis in prostata invenlis, Leipsic, 1737. 
 
 * An abnormal formation in the mammæ which is not common is that of hyda- 
 tids, one case of which is detailed in the Am. Journ. of the Medical Sciences for No- 
 vember, 1825. 
 
 (3) Fantoni, De musculis abdominis, peritonceo, vasis ombilicalibus et omento, 
 Turin, 1745. 
 
 (4) Vol. i. p. 151. 
 
468 
 
 DESCRIPTIVE ANATOMY. 
 
 A. COMPOSITION. 
 
 § 2529. The upper wall is formed by the diaphragm ; the posterior , 
 in the centre, by the lumbar vertebra and the sacrum, on the sides by 
 the psoas magnus and the posterior part of the two broad internal 
 abdominal muscles : each side is constituted above by the middle por- 
 tion of these two muscles, and the posterior part of the obliquus ab- 
 dominis externus, below by the ossa ilia and the descending ramus of 
 the ischium, the anterior by the anterior part of the broad abdominal 
 muscles, the rectus, the pyramidalis, the linea alba, the pubis, and its 
 ascending ramus. The inferior by the muscles of the perineum. 
 
 The parts we have mentioned are covered on the inside directly or 
 indirectly by the peritoneum. 
 
 Hence the abdominal parietes are most solid in the posterior and in- 
 ferior parts. We mayjudge also from the description of the mùscles 
 which form them, that these also are enveloped in some parts more per- 
 fectly than in others. In the latter, the muscular layers are thinner 
 and more feeble, or the muscles and their tendons are here entirely or 
 in great part deficient. 
 
 B. FORM. 
 
 § 2530. Considered generally, the form of the cavity of the abdo- 
 men is oval. The umbilicus is situated at about the centre of its an- 
 terior face : the half above this cicatrix is a little larger and broader 
 than the lower. The anterior wall is the longest. The sides are very 
 short and almost straight. The posterior presents inequalities produced 
 by the projection of the lumbar vertebrae and the sacrum. It is con- 
 vex in the centre, at its upper part, and concave on the sides, particu- 
 larly below. The upper and lower faces are more or less concave. 
 
 c. DIMENSIONS. 
 
 § 2531. The abdominal cavity is much larger than the thoracic : it 
 is the most extensive of the three splanchnic cavities. 
 
 D. CHANGES IN FORM AND SIZE. 
 
 § 2532. As its parietes are formed mostly by muscles, it can vary 
 much in form and size. The most important change is that which 
 occurs regularly and constantly during respiration, and which depends 
 on the alternate contraction and relaxation of the diaphragm. The 
 action of the abdominal muscles also occasionally contract it more or 
 less, to expel the substances contained in the intestinal canal, the 
 uterus, and even in the bladder. The diaphragm and the other abdo- 
 
OF THE ARDOMINAL CAVITY. 
 
 469 
 
 minai muscles are generally antagonists. Their simultaneous action 
 exerted in straining,(l) produces the greatest possible contraction. 
 
 The abdominal cavity is unusually distended : 
 
 1st. By every thing which normally or abnormally increases the 
 mass or the volume of the parts it contains. 
 
 2d. By the direct accumulation within it of substances of every 
 kind, the origin of which varies infinitely. 
 
 In this case all the parts which form its parietes are generally uni- 
 formly distended. 
 
 § 2533. Besides the organs we have mentioned above, the abdomi- 
 nal cavity also contains the lower part of the aorta, the ascending vena- 
 cava, the commencement of the thoracic canal, the great iliac trunks, 
 the lower part of the ganglionnary nerve, and the lumbar and iliac 
 plexuses of the last spinal nerves. 
 
 All these parts are attached more or less by cellular tissue and in a 
 larger or smaller part of their parietes, especially with the posterior, less 
 to the superior, still less to the inferior, the anterior, and the lower re- 
 gion of the side ; the upper region of the selatter and of the anterior, 
 is entirely loose, except a small portion of the anterior, to which the 
 suspensory ligament of the liver is attached. 
 
 Even where there is no continuity between the containing parts and 
 those contained, the external faces of these latter are in direct contact 
 with the internal face of the abdominal parietes, so that these faces can 
 glide or play upon each other. 
 
 As to their situation, the parts contained in the abdominal cavity 
 differ principally in this respect, that most of them, viz. the upper region 
 of the genital system of the female, and the whole digestive apparatus 
 except the pancreas and the lower extremity of the rectum, are con- 
 tained in the peritoneum, while the others, especially the great vascu- 
 lar and nervous trunks, the urinary organs and the lower part of the 
 genital system, are situated out of this membrane. 
 
 II. PERITONEUM. 
 
 § 2534. The peritoneum, (2) the largest and the most complex se- 
 rous membrane in the body, has a fibro-serous structure in some parts. 
 It forms a sac, closed in every part except at the abdominal orifices of 
 
 (1) J. Cloquet, De l'influence des efforts sur les organes renfermés dans la cavité 
 thoracique, Paris, 1820. 
 
 (2) Wedel, De peritonœo, Jena, 1696.— J. Douglas, Description of the peritoneum 
 and ofthat part of the membrana cellular is which lies on its outside , with an account 
 of all the abdominal viscera, London, 1730. — C. G. Buttner, De peritonœo, Königs- 
 berg-, 1738. — F. G. Hewsing-, De peritonœo, Giessen, 1742. — H. A. Wrisberg, Deperi- 
 tonœo diverticulis, illisque imprimis, quee per ombilicum et lineam albam contingunt, 
 Gotting-en, 1780. — A. Vacca-Berlinghieri, Mémoire sur la structure du péritoine et 
 sur ses rapports avec les viscères abdominaux ; in the Mémoires de la soc. méd. 
 d'émul., vol. iii. p. 315. — C. J. M. Langenbeck, Commentarius de structura peri- 
 tonœi, testiculorum tunicis, eorumque ex abdomine in scrotum descensu, ad illustran- 
 dam herniarum indolem, Gottingen, 1817.. 
 
 Vol. III. " 60 
 
470 
 
 DESCRIPTIVE ANATOMY. 
 
 the two Fallopian tubes, where it is continuous with the mucous mem- 
 brane of these passages. It covers almost the whole cavity of the ab- 
 domen, except at the lowest part of the pelvis, and like all the serous 
 membranes, it covers in two different modes the parts on the surface of 
 which it passes. In fact, 1st, it envelops them all with its external 
 layer, which has the form of a sac, but does not touch them ; 2d, 
 Its inner layer is reflected in several places, and is fitted to the surface 
 of the parts, and forms their external envelop. 
 
 Several anatomists assert, that not only the parts enumerated above, 
 but also all those situated in the abdomen, are contained in the peri- 
 toneum, which divides into an external and an internal layer to em- 
 brace them. This opinion arises from another, that the condensed 
 cellular tissue on the outer face of the peritoneum, is a special fold of 
 this membrane. But we cannot admit it, since this layer is not serous; 
 it exists in every part ; it does not come from the division of the proper 
 serous fold of the peritoneum, but it is formed by the scalpel, particu- 
 larly when the parts are hardened by immersion in alcohol. 
 
 § 2535. Like all serous membranes, the peritoneum is highly ex- 
 tensible, so that it does not tear when suddenly or gradually extended 
 very much. Its solidity in the normal state depends upon this property. 
 
 It is not equally firm in every part. The external layer is generally 
 much stronger and thicker than the internal. It is strongest in the 
 lumbar region, and at its lower and anterior part, and is weakest at its 
 upper part. 
 
 As its connections with the abdominal parietes are generally slight, 
 it yields easily when drawn down, so that its situation and its relations 
 with the adjacent parts change in a greater or less extent, when the 
 testicles descend into the scrotum, or when a hernia exists, 
 
 A. EXTERNAL FOLD OF THE PERITONEUM. 
 
 § 253G. We may distinguish in the external fold of the peritoneum, 
 four parietes, an anterior, a superior, a posterior, and an inferior, the 
 external faces of which arc almost in every part united to the internal 
 face of the abdominal parietes. 
 
 A. ANTERIOR WALL. 
 
 § 2537. The anterior wall covers the posterior face of the linea 
 alba, the common anterior tendons of the broad muscles of the abdo- 
 men, and the anterior part of the fleshy portion of the transversalis 
 muscle. It is attached rather loosely to the linea alba, adheres inti- 
 mately to the anterior tendon, and is connected less firmly with the 
 fleshy portion of the transversalis muscle. It is serous only at its lower 
 part: but above it is covered on the outside by a very apparent layer of 
 transverse and strong fibres, entirely distinct from those of the tendons 
 
OF THE ABDOMINAL CAVITY. 
 
 471 
 
 of the transversalis abdominis muscle, and of the linea alba, and which 
 terminate near the umbilicus by a semicircular edge. 
 
 From the bladder to the umbilicus the urachus passes over its in- 
 ternal face, on the sides of which we observe the remains of the um- 
 bilical arteries, which separate below, are united in a single cord at 
 their upper part, penetrate from without inward, and thus produce on 
 the inside the prominences which have been called prolongations of 
 the peritoneum [processus peritonei). 
 
 On the inner face of the anterior wall we remark the suspensory 
 ligament of the liver (L. hepatis Suspensorium) which descends from 
 right to left to the umbilicus. It is a considerable triangular fold, ex- 
 panded like a fan, the posterior edge of which is attached from before 
 backward to the upper face. of the liver, where it separates the right 
 from the left lobe, and in the lower and loose edge of which we distin- 
 guish the round ligament of the liver (L. hepatis teres), which extends 
 from the umbilicus to the liver. 
 
 B. SUPEHIOB WALL. 
 
 § 2538. The posterior wall covers the lower face of the diaphragm, 
 to which it is loosely attached. 
 
 Near the posterior edge of the muscle the peritoneum is reflected to 
 the right on the liver, and not only covers the whole of this viscus, but 
 also when it comes to the fissure of the vena-portæ, where it forms as it 
 were a sheath, the fasciculus formed by the union of the hepatic artery, 
 the vena-portæ and the biliary passages, goes on the upper part of the 
 duodenum, to be continuous there with the small epiploon, the great 
 epiploon, and the transverse mesocolon. 
 
 The very short fold between the blunt edge of the liver and the up- 
 per wall of the peritoneum, is termed the coronary ligament of the liver 
 (L. hepatis coronarium). 
 
 From the right side, between the union of the posterior edge of the 
 liver with the anterior, and the limit of the posterior, superior, and an- 
 terior walls of the peritoneum, we perceive a larger fold, which is the 
 right triangular ligament of the liver (L. hepatis trianguläre dex- 
 trum ). 
 
 A similar but much larger fold extends from the posterior edge of 
 the small lobe of the liver, and from its summit, to the posterior wall of 
 the peritoneum ; it is the left triangular ligament of the liver ( L. he- 
 patis trianguläre sinistrum ), which is continuous forward with the su- 
 perior ligament of the organ. 
 
 In the place where the esophagus passes through the peritoneum, 
 in proceeding through the esophageal fissure of the ^diaphragm, this 
 membrane covers it in every part, and also in the upper part of the 
 stomach. The folds which result from them are termed the right and 
 left phrenico- gastric ligaments (L. phrenico-gastricum, dextrum , and 
 sinistrum). The first is continuous with the small epiploon, and the 
 
472 
 
 DESCRIPTIVE ANATOMY. 
 
 second with the suspensory ligament of the spleen ( L . lienis Suspen- 
 sorium), which is situated more to the left, between the upper ex- 
 tremity of the spleen and the posterior edge of the upper wall of the 
 peritoneum. 
 
 C. POSTERIOR WALL. 
 
 § 2539. The posterior wall descends from the upper and posterior 
 edge of the liver, from the cardiac orifice of the stomach, from the 
 left portion of the small curve of this viscus, and from the upper extre- 
 mity of the spleen, above the lumbar portion of the diaphragm, then 
 leaves the posterior wall of the abdominal cavity, and goes on the an- 
 terior face of the pancreas and duodenum, to which organs it adheres 
 very slightly. After leaving the lower edge of the pancreas, the peri- 
 toneum goes downward and forward, and forms the upper layer of the 
 transverse mesocolon, a broad and considerable fold, which receives 
 anteriorly the transverse colon between its two layers, and the inferior 
 layer of which is continuous with the lower part of the posterior layer. 
 
 This lower part descends before the aorta, the vena-cava, and the 
 kidneys, to which organs it slightly adheres, and afterwards goes 
 without forming any fold, on the right or left, or at least without pro- 
 ducing any except those which are very small, on the ascending and 
 descending portions of the colon, goes also to the right side of the kid- 
 ney towards the duodenum, the anterior face of which it covers, inti- 
 mately uniting this whole intestine with the upper extremity of the as- 
 cending colon, and after covering all these parts, is continuous with 
 the anterior wall, on the posterior portion of the transversalis abdomi- 
 nis muscle. 
 
 Only the lower part of the descending colon and the commencement 
 of the rectum, form a considerable fold on the central part of the psoas 
 magnus muscle, and on the upper part of the sacrum. 
 
 Tn the centre of the posterior wall is a fourth fold, directed obliquely 
 from left to right, it descends from the second lumbar vertebra, and is 
 termed the mesentery (mesenterium) . This fold, the root of which is 
 very narrow, enlarges much at its loose edge, which embraces all the 
 small intestine except the duodenum. It is continuous below with the 
 right mesocolon, and gives off a small triangular prolongation, which 
 serves as a mesentery to the vermiform appendage of the cæcum. 
 
 It is continuous above with the centre of the transverse colon. 
 
 In this place the two layers of these folds separate, and receive be- 
 tween them the lower part of the duodenum. 
 
OF THE ABDOMINAL CAVITT. 
 
 473 
 
 D. INFEBIOB WALL. 
 
 § 2540. We may consider as the lower wall of the external fold of 
 the peritoneum, the part of this membrane which corresponds to the 
 pelvic region of the abdominal cavity, and term it the pelvic portion. 
 
 It is attached very loosely to the iliaci muscles, to the lower part of 
 the abdominal muscles, to the levator ani muscle, and the sacral 
 plexus. It is connected forward with the obturator internus muscle 
 and the posterior face of the bladder. It covers posteriorly the upper 
 part of the sacrum, but does not adhere to it strongly, and is reflected 
 inward on the upper part of the rectum. 
 
 It covers below in the two sexes, the inner part of the levator ani 
 muscle, to which it is loosely united. 
 
 The anterior and posterior halves of this lower wall of the perito- 
 neum, are adapted to each other, between the bladder and the rectum, 
 so that in the male the anterior passes from the bladder upon the semi- 
 nal vesicles, but does not touch them, and in the female, from the blad- 
 der upon the upper part of the vagina, and the lower part of the uterus, 
 which it loosely envelops. Having thus arrived backward, it reunites 
 to the posterior, which comes from the rectum, forming a greater or 
 less cul-de-sac between this intestine and the parts we have mentioned. 
 
 This cul-de-sac is limited on the right and left by two longitudinal 
 folds, which extend in the male from the rectum to the lower part of 
 the bladder, in the female from the intestine to the lower part of the 
 uterus, and are termed the semilunar folds ( plieez semilunares). 
 
 These folds are much smaller, and consequently the cul-de-sac is 
 much less distinct from the rest of the peritoneal cavity, the more 
 the rectum and the bladder, or the uterus are distended, because then 
 the peritoneum is enlarged to cover its parts. 
 
 The lateral wall of the pelvic portion of the peritoneum, forms in 
 the small pelvis of the female a considerable fold, termed the broad 
 ligament of the uterus (L. uteri latum). This fold is attached to the 
 upper part of the vagina, to all the lateral wall of the uterus, to the 
 Fallopian tubes, and to the ovaries, closely covers these parts, and 
 lodges between its two folds the vessels and nerves which go to it. 
 
 The most important part of the pelvic portion of the peritoneum, is 
 that included between the inner extremity of the iliac crest and the 
 sy mphy sis pubis . ( 1 ) 
 
 The peritoneum forms in this place two depressions, which are se- 
 parated by the umbilical ligament, and by the prolongation of the 
 
 (1) Hesselbach, Ueber den Ursprung der Leistenbrüche, Wurzburg', 1806. — Id., 
 Ursprung und Fortschritte der Lcisten-und Schekcnlbrüche, Wurzburg, 1816. — Id., 
 Disquisitioncs anatomico-pathologicœ de ortu et progressu herniarum inguinalium 
 et cruralium, Marburg, 1816. — K. Liston, Memoir on the formation and the connec- 
 tions of the crural arch and on the parts contained in inguinal and crural hernia, 
 Edinburgh, 1819. 
 
474 
 
 DESCRIPTIVE ANATOMY. 
 
 peritoneum which surrounds it, and which may he termed the inguinal 
 fossæ ; they are distinguished into external and superior , the large, 
 and internal or inferior , the smaller. At the place where the inguinal 
 canal commences, we usually observe in the peritoneum a small de- 
 pression, which is often connected with a cord formed of cellular tissue, 
 which passes through this canal. This depression frequently forms a 
 greater or less sac. It is always a remnant of the prolongation which 
 formerly extended from the peritoneum into the scrotum. 
 
 The external inguinal fossa represents a pyramid, situated between 
 the peritoneal prolongation and the commencement of the inguinal 
 canal. The internal is adapted on the median line to that of the op- 
 posite side, from which it is always more or less completely separated 
 by the projection of the urachus. It corresponds directly to the ingui- 
 nal ring. 
 
 B. INTERNAL FOLD OF THE PERITONEUM. 
 
 § 2541. The internal fold of the peritoneum which covers the out- 
 side of the parts situated in the cavity of the abdomen, is much thinner 
 than the external. It is not arranged exactly in the same manner in 
 regard to all the parts it covers, for it is attached directly to some, and 
 to others only by more or less considerable prolongations. In several 
 portions it extends on the almost loose part of the surface of the or- 
 gans, and forms prolongations, which are sometimes loose and float- 
 ing, and sometimes contribute also to unite one organ with another, 
 independent of the common envelop. 
 
 All these internal prolongations of the peritoneum, whatever be their 
 relation with the organs, are formed of two layers, all the corrugated 
 faces of which adhere to each other, while the smooth faces are loose 
 and turned outward. We may then term them generally the folds of 
 the peritoneum. 
 
 The folds between the external layer of the peritoneum and the in- 
 testinal canal, are termed the mesenteries (mesenteria).( 1) 
 
 Those which are shorter but broader, and which exist between the 
 external fold of the peritoneum and the other parts, particularly the 
 stomach, liver, spleen, &c., are termed the ligaments of the peritoneum 
 ( L. peritonei). Their names are derived sometimes from their form, 
 and sometimes from the parts which they unite. We have already 
 mentioned most of them, in describing the external layer : and shall 
 return to them when speaking of the epiploon. 
 
 The folds which extend from one viscus to another, are the epiploa 
 (omenta, s. epiploa) .(2) 
 
 (1) J. S. Henninger, De mesenterio, Strasburg, 1714. — J. Fantoni, De mesen- 
 terio, vasis chylifcris et lymphaticis ; in the Diss. anat. renov. V . — Stock, De statu 
 mesenterii naturali et præternaturali, Jena, 1755.— M. Malpighi, De omento, pin- 
 guedine et adiposis ductibus ; in Opp. omn., vol. i. p. 227 
 
 (2) Henrici, Diss. sistens novum descriptionem ct iconem omenti, Copenhagen, 
 1739 —Haller, Omenti nova icon.; in the Icon, anat.fasc. I, and opp. min., vol. i.— 
 
OF THE ABDOMINAL CAVITY. 
 
 475 
 
 Those which only project on the surface of a viscus, are termed the 
 epiploic appendages ( appendices epiploicœ). 
 
 The last two lands of folds differ from all others, as they are ex- 
 tremely thin, so that many anatomists have even considered their reti- 
 culated or perforated structure as a normal arrangement. 
 
 A. MESENTEBIES. 
 
 § 2542. The best mode is to commence the history of the folds of 
 the peritoneum by that of the mesenteries. 
 
 a. Mesentery. 
 
 § 2543. The proper mesentery ( meseiiterium ) is directed obliquely 
 from above downward, and from right to left ; it extends from the left 
 side of the body of the second lumbar vertebra, to the right sacro-iliac 
 symphysis. 
 
 It is composed of two layers, a right and a left, which are separated 
 in the upper two thuds of the mesentery, by the third or the ascending 
 portion of the duodenum, but which unite beyond this portion, and in 
 the lower third of the mesentery. 
 
 The posterior edge, which rests on the vertebral column, is termed 
 the root of the mesentery ( radix mesenterii). It is much shorter than 
 the anterior, by which it is attached to the small intestine, so that its 
 layers separate on arriving at the intestine, which they receive be- 
 tween them, and narrowly embrace them in all their extent. 
 
 The mesentery enlarges imperceptibly from its upper and lower 
 parts, to its centre. Its greatest breadth is about four inches. 
 
 Between the two layers which compose it, and which are easily se- 
 parated, are cellular tissue, fat, lymphatic ganglions, blood-vessels, 
 lymphatic and chyliferous vessels, and nerves. 
 
 It is continuous at its upper extremity with the transverse meso- 
 colon, at the lower, with the triangular mesentery of the vermiform 
 appendix of the cæcum, which is attached to the left side of its circum- 
 ference, and the left side of which is perfectly loose, and continuous 
 with the ascending mesocolon. 
 
 b. Mesocolon. 
 
 § 2544. The colon is not, like the small intestine, attached to the 
 posterior wall of the abdominal cavity by a very long fold, which per- 
 
 Reebmann, De omento sano et morboso, Strasburg-, 1753. — P. Yan Nœmer, De fa 
 hrica et usu omenti, Leyden, 1764. — Chaussier, Essai sur la structure et les usages - 
 des épiploons ; in the Mém. deVac.de Dijon, 1784. — Froriep, Neue Darstellung der 
 Gehroses und der Netze, Weimar, 1812. 
 
476 
 
 DESCRIPTIVE ANATOMY. 
 
 mits it to float freely. On the contrary, it is atttached more firmly and 
 immovably by the mesocolon. 
 
 After covering the centre of the duodenum on the right side, the 
 posterior wall of the peritoneum goes on the ascending portion of the 
 colon, and covers it anteriorly, but not posteriorly, or at least but very 
 rarely, where it is exposed on the anterior face of the kidney. Even 
 when the ascending colon is entirely enveloped by the peritoneum, the 
 fold which attaches it is always very short. 
 
 The cæcum is most generally attached rather more loosely to the 
 upper part of the iliacus muscle. 
 
 There are often detached from its summit two triangular folds, di- 
 rected from right to left, and from above downward, which leave be- 
 tween them a depression, the base of which is formed by the iliacus 
 muscle and the cæcum, and into which, particularly when the cavity 
 is considerable, a greater or less portion of the intestine enters and is 
 strangulated. 
 
 The transverse mesocolon ( mesocolon transverswn ), which is unin- 
 terruptedly continuous with the ascending mesocolon, is an elongated 
 quadrilateral fold, about four inches high, which extends from right to 
 left near the centre of the abdominal cavity, and which is much higher 
 in the centre' than on the sides. 
 
 It arises on the right from the centre of the duodenum, in the centre 
 from the anterior face of the pancreas, often also from the right side of 
 the posterior face of the stomach, farther, and towards the left, from 
 the extremity of the duodenum, and is attached to the transverse colon 
 by its anterior edge. 
 
 At its commencement on the right on the duodenum, it is continu- 
 ous above and below with the portion of the posterior wall of the peri- 
 toneum, which covers the duodenum anteriorly, and intimately unites 
 this intestine to the colon. 
 
 Farther on the right, its upper layer closely unites with a greater or 
 less portion of the great epiploon, so that hence, a quadruple layer 
 from the duodenum to a greater or less portion of the right half of the 
 great curve of the stomach exists, and this union of the right edges of 
 the great epiploon and transverse mesocolon, always closes in this 
 place the sac formed by these two folds. 
 
 It imperfectly divides the internal fold of the peritoneum into two 
 halves, a superior, smaller, and an inferior, which is larger. 
 
 The descending mesocolon, the direct continuation of the preceding, 
 is quadrilateral at its upper part, and does not generally surround the 
 whole circumference of the descending colon. It arises from the upper 
 part of the anterior face of the left kidney, but comes also in its centre, 
 where it is more extensive, from the anterior fold of the posterior tendon 
 of the transversalis abdominis muscle, finally below where it is larger 
 than in any other part, and often also as broad as the transverse me- 
 socolon, from the left psoas muscle and the sacro-iliac symphysis of 
 the same side. 
 
OF THE ABDOMINAL CAVITV. 
 
 477 
 
 A small part of the upper portion of the rectum is attached to the 
 anterior face of the sacrum by a short fold of the peritoneum, termed 
 the mesorectum. 
 
 B. EPIPLOA. 
 
 a. Great epiploon. 
 
 § 2545. The great epiploon, epiploon gastro-colique, descends by 
 its upper edge : 
 
 1 st. From the lower part of the fissure of the spleen, and from its 
 lower extremity, where it is united with the gastro-splenic ligament. 
 
 2d. From all the great curve of the stomach. 
 
 3d. From the commencement of the duodenum. 
 
 It is adapted to the anterior part of the circumference of the trans- 
 verse colon, goes before the small intestine, and generally descends 
 into the pelvis, where it terminates by a loose edge. 
 
 Its straight edge unites with the transverse mesocolon, and is at- 
 tached by the left to the lower extremity of the spleen, and also to the 
 left extremity of the pancreas and the transverse colon, uniting with 
 the posterior wall of the peritoneum. 
 
 • b. Small epiploon. 
 
 § 2546. The small epiploon, epiploon gastro-hepatique ( epiploon he- 
 patico-gastricum), descends from the fissure of the venous canal, from 
 the left portion of the fissure of the vena-portæ, and the capsule of Glis- 
 son, towards the small curve of the stomach, from the cardiac to the 
 pyloric orifice, and floats before the lobe of Spigel. 
 
 The two epiploa communicate by the portion of the peritoneum 
 which covers the anterior and posterior faces of the stomach, and thus 
 forms, with the stomach, the anterior wall of a sac, the lower wall of 
 which is constituted by the transverse colon and the transverse meso- 
 colon, and the posterior by the upper part of the posterior wall of the 
 peritoneum. 
 
 The upper part of this sac, which is placed between the liver and 
 the small curve of the stomach, communicates with the inferior, situa- 
 ted between the small curve and the transverse colon, by a greater or 
 less opening, which is found between the posterior wall of the stomach 
 and that of the peritoneum, in the part where the small curve of the 
 stomach, near its right extremity, is not attached to the posterior wall 
 of the peritoneal sac. 
 
 The whole sac or the cavity of the epiploon communicates with the 
 peritoneal cavity by the foramen of Winslow ( foramen Winslowii), a 
 rounded, oblong opening, situated on the right side of the abdomen, 
 bounded on the right by the fissure of the vena-portæ, forward by the 
 Vol. III. 61 
 
476 
 
 DESCRIPTIVE ANATOMY. 
 
 fasciculus formed by the vena-portæ, the hepatic artery, and the biliary 
 passages, on the left by the first curve of the duodenum, and below by 
 the posterior wall of the peritoneum, which the ascending vena-cava 
 covers in this place. 
 
 When we separate the liver and duodenum, and consequently re- 
 move from this latter organ the portion of peritoneum which extends 
 from its summit to the liver, in forming a sheath around the fasciculus 
 we have mentioned, a more or less broad, semicircular fold is formed, 
 having its loose edge turned downward ; this is termed the hepato- 
 duodenal ligament ( L . hepato-duodenale). 
 
 We may produce also in the same manner an analogous fold be- 
 tween the first curve of the duodenum and the upper extremity of the 
 right kidney. This last fold is the duodcno-renal ligament {L. duo- 
 deno-renale). 
 
 The foramen of Winslow is situated between these two folds. 
 
 c. Epiploic appendages. 
 
 § 2547. The epiploic appendages ( Appendices epiploicœ) are short 
 prolongations of the peritoneal tunic of the large intestine ; they are 
 rounded, oblong, varying in breadth, filled with fat in fleshy people, 
 and with a reddish, gelatinous liquid in lean persons. They arise 
 principally from the anterior side of the edge of thjs tunic. 
 
 They are observed along the whole length of the colon, but they 
 are not arranged exactly in the same manner in all parts of this in- 
 testine. 
 
 They always receive a considerable vascular branch, which comes 
 from the mesocolon. 
 
 They are generally arranged in two rows. 
 
 These rows are situated on the outside and the inside of the intes- 
 tine in the lower portion of the descending colon, on the lower edge in 
 the transverse colon, finally on the internal and anterior edge in the 
 descending colon. 
 
 In this latter point one of the two rows, the longest, is much nearer 
 the intestinal extremity of the mesocolon than in the ascending colon. 
 
 In the ascending colon, the epiploic appendages receive the external 
 and internal branches of the mesenteric vessels. In the rest of the 
 colon their vessels come only from the lower and internal branches of 
 those of the intestine. 
 
 The mesocola form also at intervals near the intestine similar pro- 
 longations, which are directed from above downward. 
 
OP THE ABDOMINAL CAVITY. 
 
 479 
 
 B. PERIODICAL DIFFERENCES. 
 
 I. REGULAR AND GENERAL DIFFERENCES. 
 
 § 2548. 1st. The abdominal cavity is much larger in proportion to 
 the chest, during the early periods of existence, than when the subject 
 is fully grown, but its pelvic portion is infinitely smaller. 
 
 2d. Until the third month of pregnancy it extends by means of a 
 prolongation, the length and the breadth of which are in direct ratio 
 with the youthful age of the new being, and which incloses a portion 
 of the intestinal canal, with the umbilical and omphalo-mesenteric ves- 
 sels, in the umbilical sheath formed by the inner membrane of the ovum, 
 so that this sheath then really makes part of it. The anterior cavity is 
 covered by a prolongation which is also reflected on the viscera which 
 it contains. 
 
 In the fetus of three months, the anterior wall of the peritoneum 
 extends already on the opening of the umbilicus, through which the 
 umbilical vessels enter and depart, but does not give off in this place 
 a prolongation which penetrates into the cord. 
 
 We do not perceive at first any well marked difference between the 
 general ligaments and the umbilical sheath ; but this difference is seen 
 in proportion as the development of the skin progresses. Hence in the 
 full-grown fetus the root of the umbilical cord is surrounded by a cylin- 
 drical fold of skin, which is about four lines long, and is usually more 
 distinct from the umbilical sheath on the right side than the left,(l) 
 the inner face of which is strengthened by some fibres of the linea- 
 alba. 
 
 The umbilical ring is much broader the younger the fetus is. It 
 gradually contracts, and in the full-grown fetus it exactly surrounds 
 the umbilical vessels. Its lower part particularly is intimately united 
 with the umbilical artery by a short and firm cellular tissue ; the cel- 
 lular tissue which unites the upper with the umbilical vein is looser. 
 The umbilical ring is already surrounded in the full-grown fetus with 
 very strong and perfectly developed tendinous fibres, while the linea 
 alba, less advanced in all these respects, is formed only of indistinct 
 and proportionally shorter and narrower tendinous fibres. 
 
 After birth the portion of the cord left on the body of the infant dies 
 in its whole extent where it is covered by the umbilical sheath. In- 
 stead of the cylindrical fold of skin, there forms a depressed cicatrix, 
 the navel or umbilicus , the depression of which depends principally on 
 the disappearance at this period of the prominence previously formed 
 by the umbilical vessels and the gelatine of Wharton. 
 
 (1) Scemmerring, Ucbcr Nabelbrüche, Frankfort, 1811, p. 7. 
 
480 
 
 DESCRIPTIVE ANATOMY. 
 
 It depends also on the general law that the cicatrices of the skin 
 are attended with a greater or less contraction. The collapsing of the 
 umbilical vessels also assists to form it. Afterward the depression 
 increases as much more as there is fat deposited in the surrounding 
 parts, for this fluid never accumulates in the cicatrix. 
 
 The umbilical ring and the peritoneum gradually adhere very inti- 
 mately with the cellular tissue and the skin which covers them. In 
 the book on embryology we shall mention the changes in the umbi- 
 lical vessels. 
 
 3d. In the male and female fetus, the peritoneum forms another cul- 
 de-sac, the diverticulum of JYuck ( diverticulum Nuckii), which extends 
 through the inguinal canal and inguinal ring. This diverticulum is 
 connected with the development of the testicle in the male. It has 
 even the same use in the female, but as it here receives no organ it is 
 much narrower and shorter, and often disappears before the end of the 
 last month of pregnancy. 
 
 The great epiploon appears in the second month of pregnancy. 
 Until the fourth there exists only a simple prolongation of the peri- 
 toneal coat of the stomach, which is not yet connected with the trans- 
 verse colon. 
 
 The epiploic appendages of the large intestine appear at the fifth 
 month of pregnancy. 
 
 II. ACCIDENTAL DIFFERENCES. 
 
 § 2549. The abdominal cavity is considerably distended during 
 pregnancy : but it returns almost entirely to its normal dimensions 
 after parturition. We have not observed any marked difference either 
 in the region of the umbilicus or in other parts, even in those females 
 who have had several children, nor has Sœmmerring.(l) But the 
 skin being much less extensible, wrinkles are formed in the general 
 integuments of the abdomen by pregnancy, which are not seen in fe- 
 males who have had no children. 
 
 C. DIFFERENCES RELATIVE TO SEX. 
 
 § 2550. The abdominal cavity is smaller in proportion to the chest 
 in the male than in the female, in whom it is much longer and nar- 
 rower at its upper part, but much broader in the lower, that is, in its 
 pelvic portion. The hairs of the pubis also differ in their arrangement. 
 In fact in females they suddenly cease, and occupy only the centre of 
 the space between the umbilicus and the symphysis pubis, while in 
 the male they extend in a point to the umbilicus. 
 
 (1) Loc. cit., p. 25. 
 
OF THE ABDOMINAL CAVITY. 
 
 481 
 
 ARTICLE SECOND. 
 
 OF THE ABDOMINAL CAVITY IN THE ABNORMAL STATE. 
 
 A. DEVIATIONS OF FORMATION. 
 
 § 2551. 1st. When the upper half of the body is not perfectly de- 
 veloped, in acephalia vera, the abdominal cavity presents more or less 
 the same deviation of formation at its summit, so that sometimes only 
 the pelvic portion exists, and this also is frequently narrower than in 
 the normal state. 
 
 In other cases, on the contrary, tumors, congestions, liquids, &c., 
 often distend it very much. 
 
 2d. Curvature of the spine, which sometimes, but very rarely, con- 
 stitutes a primitive deviation of formation, naturally causes a greater 
 or less alteration in the form of the abdominal cavity and the situation 
 of the parts within it. 
 
 3d. This cavity not unfrequently presents anomalies depending on 
 the permanence of one of the degrees of formation through which it 
 successively passes, that is, the openings and prolongations first exist- 
 ing at its upper or lower extremity do not disappear in a greater or 
 less portion of their extent. This causes congenital umbilical hernia, 
 and the abnormal communication between the vaginal tunic of the 
 testicle and the cavity of the peritoneum, which give rise to congenital 
 inguinal hernia. 
 
 Frequently also the connections of the abdominal parietes with the 
 parts contained in this cavity, particularly those of the external and 
 internal layers of the peritoneum, are abnormal. 
 
 This abnormal state is sometimes, but rarely, the effect of a primi- 
 tive deviation of formation. It is generally consecutive. 
 
 It is much more common to observe unusual connections, adhesions, 
 which are generally the consequence of an inflammation of the peri- 
 toneum, and which are caused by effusion. Sometimes even in this 
 case all the organs surrounded by the peritoneum are so blended in 
 one mass that they cannot be perfectly separated ; but they generally 
 adhere only in some parts. 
 
 Solutions of continuity are very rare, and generally constitute primi- 
 tive deviations of formation. 
 
 If the adhesions occur so that they produce a kind of bridge between 
 the two parts, this arrangement may induce in the cavity of the abdo- 
 men the same consequences as certain solutions of continuity, as an 
 opening also results from them ; but this is a subject naturally con- 
 nected with that of internal hernias, of which we shall speak here- 
 after. 
 
482 
 
 DESCRIPTIVE ANATOMY. 
 
 4th. The abdominal viscera are not unfrequently displaced. Most 
 of these displacements are termed hernias, ( 1) which term includes 
 every abnormal situation of a viscus which leaves the cavity in 
 which it is normally situated, or which enters into a generally abnor- 
 mal compartment of the cavity in which it is situated. 
 
 The first case constitutes the external , and the second the internal 
 hernias. 
 
 I. EXTERNAL HERNIAS. 
 
 § 2552. The most important points in the history of hernia are, 
 the relations of the displaced parts with the integuments, the na- 
 ture of the herniary parts and the changes in them, finally the place 
 where the hernia occurs, and the peculiar phenomena presented by 
 each species of hernia in the first two respects. 
 
 1st. JYature of the envelops. Beside the integrity of the common 
 integuments, which occurs first in most hernias, the most general con- 
 dition of this anomaly is the existence of a herniary sac, produced by 
 the elongation of the peritoneum. 
 
 The internal hernias differ in this respect from the external : for the 
 parts which have passed through an abnormal opening in the cavity 
 of the abdomen are not surrounded with a herniary sac. Besides 
 sometimes we find no sac in the external hernias, whither it has never 
 existed, as when the peritoneum is torn, or it has been destroyed by 
 compression, suppuration, gangrene. 
 
 The herniary sac is principally deficient in phrenic hernia, from a 
 rupture of the peritoneum. 
 
 On the other hand the peritoneum and thè cellular tissue which 
 surrounds it externally gradually thicken and become harder to some 
 extent, particularly at the entrance or neck of the herniary sac, which 
 happens particularly after long compression. 
 
 Not unfrequently also inflammations arise from the prolongations 
 which extend from one point of the circumference of the herniary sac 
 to the others. 
 
 (1) J. G. Gunz, Observationum anatomico-chirurgicarum de herniis libellas , Leip- 
 sic, 1744. — G. Vogel, Abhandlung aller Arten der Brüche, Leipsic, 1756. — P. Pott, 
 'l'reatise on ruptures, London, 1756. — J. T. Klinkosch, Programma quo divisioncm 
 herniarum novamque herniae ventralis speciem proponit , Prague, 1764. — Arnaud, 
 Mémoires de chirurgie, London, 1768, vol. ii. — A. T. Richter, Abhandlung von den 
 Brüchen, Leipsic, 1778. — Monteggia, Qucedam de hernis ; in the Fase. anat. path., 
 1793. — J. and C. Wenzel, Eilf Beobacktungenueber Brüche ; in Loder, Journal für 
 Chirurgie, vol. iii. pt. ii. 1800, p. 217-258. — A. Monro, The morbid anatomy of the 
 human gullet, p. 363-542.— J. F. Meckel, Handbuch der pathologischen Anatomie, 
 vol. ii. pl. i. p. 358-484. — A. Scarpa, Traité pratique des hernies, Paris, 1812-1823. — 
 Lawrence, Traité des hernies, Paris, 1818. J. CÎoquet, Recherches anatomiques sur 
 les hernies de l’abdomen, Paris, 1817-1819. — Breschet, Essai sur la hernie fémorale, 
 Pari3, 1819. 
 
OF THE ABDOMINAL CAVITY, 
 
 483 
 
 2d. Nature of the abdominal organs which form the hernia. We 
 must consider here the quality of the organs, then - state, and their rela- 
 tions with the herniary sac. 
 
 a. Hernia is most generally formed by a portion of the small intes- 
 tine or of the epiploon, more rarely by a portion of the large intestine, 
 still more rarely by the liver or a portion of the urinary or genital 
 organs. We however possess several instances of hernia of the 
 uterus, the ovaries, the Fallopian tubes, and the bladder. An intes- 
 tinal hernia usually includes all the circumference of the intestine. 
 We rarely find in it only a portion of the surface of the organ. 
 
 b. The herniary parts are abnormal, either in respect to their situa- 
 tion only, or also in their functions and texture. This latter case hap- 
 pens particularly when, from a want of proportion between the capa- 
 city of the herniary sac and the volume of the part displaced, this 
 latter is compressed, strangulated, whence it inflames, and even be- 
 comes gangrenous when the disproportion continues. If gangrene 
 occurs, the herniary portion is separated from that which is contained 
 in the abdominal cavity, which causes, when hernia of the intestine 
 exists, the formation of an abnormal opening termed an artificial anus. 
 Some and even large portions of the intestinal canal may be destroyed, 
 although no feces escape into the abdomen, and without the close of 
 the natural opening. This close in fact occurs sometimes from the 
 effusion of fibrin all around the opening produced by the gangrene, 
 which is obliterated at first on the side of the cavity of the intestine, 
 then externally. It occurs even in some cases where there was not 
 the least direct communication between the upper and lower ends of 
 the intestine. 
 
 c. The herniary parts do not generally adhere at first to the herni- 
 ary sac, excepting their envelops, as when, for instance, in the hernias 
 of the ascending or descending colon, the displaced part is primitively 
 united to the sac : but afterward, exsudation which succeeds inflam- 
 mations of the serous membranes so rapidly, causes.the serous mem- 
 brane of the herniary sac to adhere more or less intimately with the 
 displaaed viscus. The hernia is then said to be adherent. 
 
 3d. Certain regions of the abdomen are more subject to hernias than 
 others ; particularly those which have a sloping situation, and which 
 on account of their structure, are but slightly resisting. The most 
 common hernias are bubonocele and merocele, which take place, one 
 through the inguinal ring, the other through the crural arch. The 
 inguinal hernias become scrotal when these viscera descend into the 
 scrotum. The bubonocele is more common in males, and the merocele 
 in females. Next come the umbilical hernias, then the ventral , next 
 those through the foramen ovale , then the phrenic , and lastly the 
 ischiatic and the lumbar. 
 
 a. In inguinal hernia, the viscera always emerge through the in- 
 guinal ring, but do not always come there in the same manner. In 
 the external or oblique inguinal hernia, which is infinitely more com- 
 mon than the other, the viscera emerge through the inguinal anal, so 
 
484 
 
 DESCRIPTIVE ANATOMY. 
 
 that the tumor has at first an oblique direction ; on the contrary, in the 
 internal or right inguinal hernia, it proceeds directly from above down- 
 ward, towards the ring on the inside of the old umbilical artery, and 
 passes through or distends the lower part of the broad internal abdomi- 
 nal muscles which are situated before it. Hence the differences be- 
 tween these two hernias, in respect to their envelops and the relations 
 of the tumor with the adjacent parts. 
 
 The external inguinal hernia is inclosed in all the envelops of the 
 spermatic cord, consequently, in the cremaster muscle and the com- 
 mon vaginal tunic. The spermatic cord is situated behind the tumor, 
 and follows the same direction. The epigastric artery is reflected from 
 without inward, and from below upward, behind this tumor. The form 
 of the hernia is oblong, at least at first. 
 
 The internal inguinal hernia is not generally enveloped by the cre- 
 master muscle and the vaginal tunic, but only by the cellular tissue of 
 the scrotum. It is situated on the inside of the cord, does not pass be- 
 fore it, and sometimes is found behind it. The epigastric artery as- 
 cends at its inner side, and its form is rounder. 
 
 Although these differences occur generally, the rule is however sub- 
 ject to exceptions. Thus in one case, the cremaster muscle evidently 
 passed on the anterior face of an internal inguinal hernia. (1) In ano- 
 ther case, the spermatic cord proceeded transversely on the neck of an 
 internal hernia, towards its inner side, and farther, near its posterior 
 side.(2) Finally, in a third, the epigastric artery ascended to the in- 
 side of the tumor. (3) 
 
 Congenital hernia is a variety of external inguinal hernia, in which 
 the viscera descend in the unobliterated prolongation of the peritoneum, 
 and are consequently situated in the same cavity as the testicle, which 
 even sometimes adheres to them before leaving. We must also com- 
 pare with external inguinal hernia, that recently described as the in- 
 fantile hernia, where the displaced viscera are engaged in the vaginal 
 tube. This hernia may present two forms. Sometimes, in fact, the 
 vaginal tube is open its whole extent, both on the side of the testicle 
 and that of the abdomen, and sometimes only on one side. In the first 
 case the herniary sac does not touch the testicle, as does the organ dis- 
 placed in congenital hernia. In the second, when the vaginal tube is 
 open at its upper part, the hernia is enveloped by a second sac, which 
 forms it, exactly as in any hernia, the part contained in the sac is by 
 this sac. When, on the contrary, the tube is closed above, the sac 
 occupies also the upper part of the vaginal tunic, but in a still more 
 complex, since this tunic sends to it two envelops, an external and an 
 internal. 
 
 The external is arranged as in the second case, and the relations of 
 the vaginal tube are not changed. The internal, on the contrary, is 
 
 (1) Todd, On hernia ; in the Dublin hospital reports. Dublin, 1817, vol. i. p. 231. 
 
 (2) Ibid. 
 
 (3) Hesselbach, Leisten-und Schenkelbruche , Wurzburg, 1815, p. 45. 
 
OF THE ABDOMINAL CAVITY. 
 
 485 
 
 pushed back at its upper part, and reversed by the hernia, whence in 
 this case the sac is smooth externally. We conceive that in ail these 
 cases the number of the envelops of the hernia is augmented, and that 
 it is really provided with a double sac. In the first it may be com- 
 plicated with a common congenital hernia; in the second also, two her- 
 nias may coexist. (1) 
 
 Inguinal hernia is much more common in the male than in the fe- 
 male, because the inguinal ring is broader in the male, and the va- 
 ginal prolongation remains open much longer in him. 
 
 b. Crural hernia takes place below the crural arch. It is rounded, 
 and is generally situated on the inner side of the crural vessels, before 
 the epigastric artery, usually also before the obturator artery, even 
 when the latter comes from the epigastric artery, sometimes, however, 
 behind it. Its neck is situated in the male directly below the upper 
 part of the spermatic cord ; in the female below the lower part of the 
 round ligament of the uterus. It is more common in the female than 
 in the male, on account of the greater distance between the symphysis 
 pubis and the anterior extremity of the iliac crest. 
 
 c. Umbilical hernia occurs either through the umbilical ring, or in 
 its neighbourhood, through a fissure in the linea alba. The first case 
 is the most common when the tumor exists as soon as the child come3 
 into the world, and depends on suspended development. The second 
 is still more so when the hernia is formed there accidentally. It fre- 
 quently has a rounded form, and is rarely oblong. 
 
 d. Ventral hernias are observed principally in the epigastric and the 
 inguinal region, around the ring. 
 
 e. Ovular hernia(2) occurs through the space at the upper and 
 outer part of the foramen ovale. It is then situated very deeply before 
 the obturator vessels and nerves, below and behind the adductor 
 muscles of the thigh. 
 
 f Phrenic hernia(3) supervenes in very different parts of the dia- 
 phragm, and it is destitute of a sac more frequently than any other 
 hernia. It is congenital much more frequently than accidental, which 
 undoubtedly depends on the necessity of extreme violence to produce 
 it, for since when it occurs the viscera are displaced in a direction 
 opposite to their weight. 
 
 g. and h. Hernias through the sciatic notch and the lumbar region, 
 are extremely rare. The second has no peritoneal envelop, and is 
 generally formed by the kidneys. 
 
 (1) We have enlarged a little on this subject, because it does not seem completely 
 exhausted by Todd’s remarks, since the publication of our Handbuch der patholo- 
 gischen Anatomic, vol. i. pt. 2. p. 416. 
 
 (2) Buhle, De hernia obturatoria, Halle, 1819. 
 
 (3) Zwanziger, De herniâ diaphragmaticâ , Halle, 1819. 
 
 Vor,. III. 
 
 G2 
 
486 
 
 DESCRIPTIVE ANATOMY. 
 
 IX. INTERNAL HERNIAS. 
 
 § 2553. The internal hernias( 1) are occasioned by abnormal open- 
 ings, or by culs-de-sac existing in the cavity of the abdomen. 
 
 1st. Abnormal openings exist sometimes in the internal portion of 
 the peritoneum, that which always occurs, and sometimes form after 
 partial adhesions between parts which should be separated. 
 
 The openings of the first kind, which are more rare, occur princi- 
 pally in the mesentery.(2) 
 
 Those of the second class may be developed in all parts. We have 
 observed almost all of them in cadavers. The partial adhesions which 
 give rise to them, may take place, 
 
 a. Between several portions of the intestine. 
 
 b. Between the small intestine and the anterior edge of the liver. 
 
 c. Between the upper face of the liver and the upper wall of the 
 peritoneum. 
 
 d. At the summit of a diverticulum of the ileon, especially by a fila- 
 ment which still exists there, and which is formed by the remnant of 
 the omphalo-mesenteric vessels. (3) 
 
 e. Between the vermiform appendix of the cæcum and a portion of 
 the mesentery, the intestinal canal, and the uterus. (4) 
 
 /. Between the epiploon and the base of the uterus, or any other 
 abdominal organ, or even the parietes of the peritoneum. It is the 
 most common of all the adhesions.(5) 
 
 g. Between the ovary, especially when it is enlarged, and the base 
 of the uterus. 
 
 2d. Abnormal depressions are formed by the mesentery, (6) the blad- 
 der,^) the vagina. (8) In the last case the bladder is situated in the 
 wall of the vagina, particularly the anterior, which is then turned 
 over. (9) 
 
 (1) Meyer, De strangulationibus intestinorum in cavo abdominis , Strasburg - , 
 
 1776. 
 
 (2) Heuermann, Chir. opérât., vol. i. p. 627. — Sauccrottc, in the Mém. de Vac. de 
 ehir., vol. iv. p. 239. — Monro, Anat. of the gullet, p. 537. 
 
 (3) Van Dceveren, Annot. acad. V. — Monro, loc. oit., tab. xx. p. 638. 
 
 (4) Monro, Phys, essays of Edinb., vol. ii. p. 402. — -Otto, Pathol. Anat., p. 280. 
 
 (5) Ruysch, Obs. anat., 65. — Monro, Anat. of the gullet, p. 533. — J. P. Weid- 
 mann, Memoria casus rari in gynœceis prœcipue adnolandi ; cum uteri anticâ facie 
 omenti margo ex aliquâ parte coaluerat ; prœgnans fœtu, medium graviditatis non 
 assecuta, inopinato moritur, Munich, 1818. — Gartshore, in the Med. obs. and inq., 
 vol. iv. p. 223. — Haen, Rat. med., pt. ii. c. iii. § 2. — Knoblauch, Diss. de entero-mcso- 
 eqtocele, Leyden, 1767. 
 
 (6) Neubauer, Descript, anat. rarissimi peritonæi conceptaculi tenuia intestina a 
 reliquis abdom. vise, seclusa tenentis, Jena, 1776. — Van der Kolk, Diss. exhibens 
 observ. varii argumenti, Groningen, 1793. — Lawrence, loc. cit. 
 
 (7) Meckel, Handbuch der pathologischen Anatomie, vol. ii. p. 467. — Cooper, Ueber 
 Brüche, p. 96. 
 
 (8) Meckel, Handbuch der pathologischen Anatomie, vol. ii. p. 450. 
 
 (9) Clarke, Diseases of females, tab. iv. 
 
OF THE ABDOMINAL CAVITY' 
 
 487 
 
 We conceive that these parts, which are then lodged in one of these 
 depressions, can undergo the same changes as in an external hernia. 
 
 B. ALTERATIONS IN TEXTURE. 
 
 2554. We ought to mention particularly the alterations in the tex- 
 ture of the peritoneum,(l) and which are common to it with the other 
 serous membranes. 
 
 This membrane is frequently inflamed in a greater or less extent, 
 and thus more or less broad and firm adhesions are formed. Inflam- 
 mation of it also produces either in its external or internal layer, an in- 
 duration, a thickening which is often very great, several lines in ex- 
 tent. This alteration is caused particularly by a long continued in- 
 flammation. We may also mention another which depends on the 
 same cause, and is almost peculiar to the peritoneum : it is the deve- 
 lopment on its inner face, of numerous small miliary elevations. 
 
 The abdominal cavity is very frequently the seat of dropsy, which is 
 there called ascites. Serum most generally occupies the whole cavity : 
 in some cases only the epiploa are filled. 
 
 Sometimes considerable masses of fat are developed on the inner 
 face of the peritoneum, even in persons not very fleshy. The great 
 epiploon particularly, presents frequent instances of this anomaly, and 
 it has then weighed thirty pounds. (2) 
 
 Ossifications on the external face of the peritoneum are rare : but we 
 frequently see them at intervals on its internal face, particularly on the 
 surface of the spleen. The epiploon sometimes presents a similar for- 
 mation.^) 
 
 Rounded, cartilaginous, and osseous masses, similar to those found 
 loose in the articulations, are rarely developed on the inner face of the 
 peritoneum : they finally become loose, leaving their attachments. 
 
 Hairs occur in the epiploon still more rarely. 
 
 We not unfrequently find on the two faces of the peritoneum, and 
 in the epiploa, serous cysts, and larger or smaller masses of hydatids. 
 The serous cysts also are sometimes detached and become loose. (4) 
 
 The external, and more frequently the internal layer, particularly the 
 epiploa and the mesenteries, also are frequently the seat of accidental 
 
 (1) J. G. Walter, De morbis peritonœi, Berlin, 1787. — Goelicke, De mesentcrii affcc- 
 tibus, Halle, 1742. — Stock, loc. cit. — Rcebmann, loc. cit. — Haider, De morbis omenti, 
 Gottingen, 1786. — A. Portal, Observations sur les tumeurs et engorgemens de V épi- 
 ploon ; in the Mém. sur plus, maladies , vol. i. 1800. p. 67.— Scoutetten, Mémoire 
 sur V anatomie pathologique du péritoine ; in the Archiv, gcn. de méd., vol. iii. p. 
 497; vol. iv. p. 386; vol. v. p. 537. — D. V. Yan Leuwen, De peritonœo ejusque in- 
 fiammatione, Utrecht, 1819. 
 
 (2) Portal, Anat. méd., vol. v. p. 127. 
 
 (3) Mongin, Sur la pétrification de l'épiploon, Paris, 1735. 
 
 (4) Desbas, De hydrope peritonœi saccato, Gottingen, 1761. 
 
48S 
 
 DESCRIPTIVE ANATOMY. 
 
 formations, of more or less solid whitish substances, which are de- 
 scribed as atheromata, steatomata, &e., and which frequently become 
 heavier than the fatty tumors mentioned above. 
 
 Ruptures of the reservoirs in the abdomen, produce effusions into its 
 cavity of bile, blood, or of the contents of the intestines or the uterus. 
 
 The air which sometimes fills the cavity of the peritoneum, or only 
 that of the epiploa, comes from the same source in some cases. But 
 probably this is not always its origin, for sometimes, although very 
 rarely, this fluid is exhaled by the vessels, the action of which is 
 changed. 
 
EMBRYOLOGY. 
 
 489 
 
 BOOK VIL 
 
 EMBRYOLOGY. 
 
 § 2555. When all the parts of the body have acquired their res- 
 pective and normal proportions, and the genital organs also are per- 
 fectly developed, the individual is fit to propagate the species by 
 connection with an individual of the other sex. In describing the 
 perfect state of the genital system, we have already mentioned the 
 conditions on the part of these organs, in order that coition may be 
 productive. The connection of the two sexes causes in the female 
 those changes which result in producing a new organism, and which 
 is termed conception^ 1) 
 
 CHAPTER I. 
 
 CONCEPTION IN THE NORMAL STATE. 
 
 § 2556. Before detailing the phenomena presented by conception 
 we must establish the following corollaries : 
 
 1st. The fetus is produced , and not merely developed, since we per- 
 ceive no trace of it before coition followed by impregnation. 
 
 (1) The works we shall mention treat more or less perfectly of the changes in the 
 organism of the female and of those in the new being: — J. C. Aranzi, De humano 
 fœtu libellus, Venice, 1751. — Fabrice of Aquapendente, De formata fœtu , Padua, 
 1604. — G. Harvey, Exercitationes de generatione animalium, London, 1651. — C. 
 Drelincourt, De conceptû, Leyden, 1685.— M. R. Besler, Admirandæ fabriccc hu- 
 manes muliebris partium generationi inservicntium et fœtus fidelis quinque tabulis, 
 hactenus nunquam visis , delineatio, Nuremberg, 1640. — Haller, Historia nuperœ 
 dissectionis feminœ gravidœ, Gottingen, 1734. — G. Noortwyk, Uteri humani gra- 
 vidi anatome et historia , Leyden, 1743. — D. Monro, The dissection of a woman with 
 child, and remarks on gravid uteri ; in the Ed. phys. and liter, essays, vol. i., art. 
 17. — A. Monro, Additional observations on gravid uterus ; ibid., art. 18. — J. G. 
 Rcederer, leones uteri humani observationibus illustrates, Gottingen, 1759. — C. N. 
 Jenty, Demonstratio uteri prœgnantis mulieris cum fœtu ad partum matur., Nu- 
 remberg, 1761. — Azzoguidi, Observationes ad uteri constructionem pertinentes, Bo- 
 logna, 1773. — G. Hunter, Anatomia uteri gravidi tabulis illustrata, Birmingham, 
 1774.— E. Sandifort, De utero gravido ; in the Obs. anat. pathol., vol. ii., Leyden, 
 1778. — J. Burns, Anatomy of the human gravid uterus, Glasgow, 1797.— Moreschi, 
 De utero gravido, Milan, 1817. — Maygrier, Nouvelles démonstrations d'accouchc- 
 •mens, Paris, 1822. — Mad. Boivin, Mémorial de l’art des accouchemens, Paris, 1824. 
 
490 
 
 DESCRIPTIVE ANATOMY. 
 
 2d. The most general condition necessary to produce it is the action 
 of the normal seminal fluid of the male on the genital organs of the 
 other sex, in a state of maturity, and when their vitality is exalted, 
 
 3d. The most important of the special conditions is the necessity of 
 a certain relation, a certain resemblance, between the male and the 
 female organism.(l) 
 
 The first problem to resolve is the mode in which the semen of the 
 male produces conception. On this subject there are two opinions : 
 
 1st. Some admit that the semen arrives at the ovary through the 
 uterus and the Fallopian tube ; that it causes directly the changes 
 which occur in this organ, and even that its substance unites more or 
 less in the uterus with the product of the ovary, to give rise to the 
 new organism. 
 
 2d. Others think that the semen does not act on the ovary directly, 
 but only secondarily, by a change which it causes in the whole or- 
 ganism or in the genital organs, and does not contribute by its proper 
 substance to form the new organism. 
 
 The principal facts in support of the first hypothesis are : 
 
 1st. The necessity of a channel for the semen, in order that the 
 impregnation may occur, since it does not happen when the cavity of 
 the female genital organs is interrupted. 
 
 2d. The semen found in the uterus and the Fallopian tubes in fe- 
 males who died during or shortly after coition. 
 
 3d. The necessity of copulation even to produce a new organism, 
 for it is difficult to admit that impregnation may occur equally in any 
 part of the body destitute of an epidermis, or at least covered by an epi- 
 dermis as thin as that of the genital organs, as has been asserted. (2) 
 
 4th. The analogy of those animals in which the eggs are impreg- 
 nated on leaving the body of the female by the semen of the male. 
 
 But these facts are not sufficient to demonstrate the exactness of 
 the hypothesis they are adduced to support : 
 
 1st. In regard to the first argument, sterility may possibly depend 
 on other causes, and besides it would follow only that the semen must 
 necessarily act on a certain organ, as the uterus or vagina, in order 
 that impregnation may occur. 
 
 2d. Perhaps the fluid found in the uterus and Fallopian tubes was 
 not semen, but was secreted by the female genital organs, and this is 
 often found in the cavity of these two organs. 
 
 3d. The third argument proves only that the semen must act on a 
 certain organ. 
 
 4th. The fourth proves at most that the condition mentioned is ri- 
 gorous in the animals to which it relates. Still it does not even de- 
 
 (1) Wolstein, Ucber das Paaren und Verpaaren der Menschen und Thiere, Al- 
 tona, 1815. 
 
 (1) Treviranus, Biologie, vol. iii. p. 407. 
 
EMBRYOLOGY. 
 
 491 
 
 monstrate this, as the ova of these animals are surrounded by a thick 
 layer of mucus. 
 
 We may also adduce against this hypothesis and in the support of 
 the second the following arguments : 
 
 1st. The experiments in which yellow bodies at least have been 
 developed, although the Fallopian tubes had been carefully tied.(l 
 
 2d. In careful experiments on generation semen has seldom been 
 found in the uterus, and the consequences of conception are not mani- 
 fested till several days or weeks after coition. 
 
 3d. In most animals the genital organs are so arranged, that on 
 account of their length and tortuousness in the females, the marked 
 prominences on the neck of the uterus, and the shortness of the male 
 organs, it seems almost impossible for the semen to arrive at the 
 ovaries. 
 
 4th. The uniform sensation of pleasure and numerous general signs 
 which attend impregnation. 
 
 Hence it follows that the influence of the male is confined to exalt 
 the formative power in the female to the degree necessary to produce 
 the new being. This increase is manifested, as we shall soon state, 
 by the direct formation in the ovary of a new organ, a temporary 
 testicle , which secretes a fluid possessing the power of spontaneous 
 growth. 
 
 ARTICLE FIRST. 
 
 OF THE CHANGES IN THE GENITAL ORGANS PRODUDED BY 
 COITION AND CONCEPTION.(2) 
 
 I. ORGANS OF COITION. 
 
 § 2557. Coition usually changes the external genital organs very 
 much ; the hymen is generally more or less perfectly destroyed. Its 
 remains give rise to the cancnculoi myrtiformes , which term applies to 
 three or four small eminences, most generally triangular, which are 
 situated on the sides and posterior parts of the vagina. The existence 
 of the hymen is not, however, a certain mark of physical virginity : 
 first, because this membrane has frequently been found, not only in 
 females who had several times had connection, (3) but also in others 
 who had given birth to fetuses more or less advanced, and fetuses even 
 
 (1) J. Haighton, in the Phil. Irans., 1797. 
 
 (2) S. Pineau, Dc virginitatis notis, graviditate el partu, Leyden, 1654. 
 
 (3) Osiander ( loc . cit. . p. 24) mentions several cases of it. 
 
492 
 
 DESCRIPTIVE ANATOMY. 
 
 seven months old ;(1) and second, because it may have been destroyed 
 from other causes, and even may not exist from a primitive deviation 
 of formation. 
 
 The enlargement of the vagina and the disappearance of its corru- 
 gations are still less constant and sensible. 
 
 II. FORMATIVE ORGANS. (2) 
 
 A. OVARIES. 
 
 § 2558. The internal organs of generation are modified not by coi- 
 tion, but only by conception. 
 
 A special body, termed the yelloiv or glandular • body {corpus luteum , 
 s. glandulosum),{3 ) is developed in the ovary. It is a rounded, soft, 
 very vascular tissue, composed of several lobes ; it projects above the 
 surface of the ovary, becomes about as large as a cherry, and incloses 
 a cavity which opens externally. The number of the yellow bodies 
 usually corresponds to that of the new organisms which have been 
 formed. 
 
 From experiments on animals, these bodies arise from the change 
 of one and not probably of several of the vesicles of Graaf, which, from 
 being a simple serous membrane, is changed into a glandular organ, 
 that is, its organism becomes more complex, and it acquires the faculty 
 of producing a liquid different from the serum of the vesicles. As the 
 yellow body differs in its structure from all the other glands, the fluid 
 it secretes has also peculiar characters : it is the generating fluid, the 
 semen of the female. 
 
 The influence of the male semen is the usual and regular cause of 
 this change, which however seems to occur also from the effect of 
 other stimuli, perhaps of the imagination or unnatural indulgences. 
 In fact several rare cases, where yellow bodies have been found in 
 unmarried females and virgins, and always attended with the pheno- 
 mena mentioned above, lead us to think that the formation of these 
 bodies had been preceded by the act of coition, and by impregnation. 
 However as they have been found in animals generally sterile, as 
 mules, our opinion as concerns females is very probable ; but we are 
 not authorized by facts to think that the change of the vesicles of 
 
 (1) Tolberg 1 2 3 , De var. hym ., p. 14. — We have in our cabinet the anatomical speci- 
 men, which is very remarkable. 
 
 (2) M. Malpighi, De cornuum vegetationc, utero , viviparum oris ; in the Opp. 
 omn., Leyden, 1637, vol. i. p. 211.— A. Bertrandi, Observations sur les corps glandu- 
 leux, sur la matrice et sur l'ovaire dans l'état de grossesse; in the Miscell. l'aur., 
 vol. i. 1758. 
 
 (3) Brugnone, De ovariis corum,que corpore luteo cbservationcs anatomicce ; in the 
 Mem. de Darin, 1790.— Itoose, U eher die gelben Körper und Eierstöche , Bruns- 
 wick, 1800. 
 
EMBRYOLOGY. 
 
 49S 
 
 Graaf into yellow bodies can be produced except by an unusual in- 
 crease in the propensity to generational ) 
 
 Some have mentioned yellow bodies found in newly born or very 
 young animals ; but it is easy to reply to this objection that every yel- 
 low substance found in the ovary is not a yellow body. Nor is the 
 argument drawn from the fact that the number of the yellow bodies 
 does not always correspond to that of the offspring, conclusive. If the 
 number of yellow bodies be fewer than that of the offspring produced 
 by the female, this circumstance agrees with their signification, since 
 one yellow body as well as one testicle may produce several new or. 
 ganisms. Farther one or more of these bodies also might disappear 
 or several be blended together. In the case where they were more 
 numerous than that of the offspring : 1st, it is necessary to mention 
 exactly if these which were supernumerary did not arise from anterior 
 conceptions ; 2d, it would be possible, even in admitting that the ani- 
 mal has never conceived previously, that generation has not proceeded 
 beyond the production of a yellow body, or that its production was 
 lost. Besides we are very much disposed to consider as very uncer- 
 tain, observations in the cases where it is pretended that the number of 
 yellow bodies and that of the offspring differed, for the examination of 
 more than two hundred women, and females of different mammalia in 
 the state of pregnancy, has convinced me, that the number of yellow 
 bodies which from the absolute identity of all their characters may be 
 considered as produced by the same generating act , always corresponds 
 to that of the young. Observers known for their correctness have 
 come to the same conclusion, (2) while contrary assertions do not ap- 
 pear to be well supported. 
 
 The cavity of the yellow body is gradually obliterated ; the body 
 itself diminishes, collapses, and hardens. These changes do not 
 happen exactly at the same period, and we have remarked generally 
 in the human species or in animals, at least in respect to the size of 
 the body, they are not very large during pregnancy, while after partu- 
 rition they evidently increase more rapidly. This phenomenon is 
 worthy of notice, as it teaches us that although the function of the 
 yellow body and the ovary generally has passed at this period, vitality 
 however continues to be more active in them on account of the great 
 degree of vitality in the uterus. Farther the yellow body rarely dis- 
 appears entirely, although it diminishes extremely. 
 
 Halier(3) and several others since his time have attributed the dis- 
 covery of the yellow bodies to Yolcher Coiter ;(4) but it really belongs 
 
 (1) Joerg, l’on der Zeugung , p. 151. 
 
 (2) Haller, El phys., vol. viii. pt. ii. p. 29-38. — Hunter, Anatomische Beschreibung 
 des menschlichen schwängern Uterus , Weimar, 1802, p. 20. 
 
 (3) Et phys., vol. viii. p. 33. 
 
 (4) Obs. anat., 1573, p. 124. Vcsiculcc queedam continebant aquam limpidam, 
 queedam luteum humorum. 
 
 VOL. III. 
 
 63 
 
494 
 
 DESCRIPTIVE ANATOMY. 
 
 to Fallopius,(l) who mentioned these bodies twelve years before 
 Coiter, and nearly in the same language. 
 
 Malpighi(2) and Graaf(3) discovered their uses. 
 
 § 2559. According to Osiander(4) the vesicles of Graaf and the 
 yellow bodies have no connection with generation, because the former 
 have no openings. He asserts that after coition the parts which are 
 changed into new organisms are developed on the surface of the ovary 
 in the form of miliary vesicles, one of which is detached and falls into 
 the uterus. He adds that we must consider these corpuscles as ova : 
 1st, because they never appear before impregnation ; 2d, because they 
 are always observed after coition followed by impregnation ; 3d, be- 
 cause many are found in the cadavers of young females dying after a 
 few pregnancies ; 4th, because many are turgescent, others empty, 
 and finally others resemble simple cicatrices ; 5th, because they dis- 
 appear entirely when the female is sterile. 
 
 These reasons do not seem satisfactory to us. The vesicles men- 
 tioned may be developed after copulation and disappear during life, 
 although there were in fact no ova, since coition, when followed by 
 conception, produces as great and to a certain extent even analogous 
 changes in remote parts and in the whole organism. 
 
 Besides we have frequently found the ovaries of females, physically 
 and morally virgins, covered with a very dense miliary eruption, and 
 in them the vesicles were too numerous to admit Osiander’s opinion in 
 respect to them. 
 
 Finally we may alledge against this hypothesis the exact history 
 of the changes in the vesicles of Graaf after impregnation. 
 
 The only argument adduced by Osiander to reject the use attributed 
 to the vesicles of Graaf has no weight except against an unimportant 
 opinion, that the vesicle itself is detached, and that the yellow body 
 grows in its place ; but this has no weight at all when, as seems to us 
 more correct, we consider the yellow body a vesicle’changed, which, 
 according to all observations, is provided on the surface of the ovary 
 with an opening communicating with its cavity, and through which 
 the formative fluid may escape. 
 
 B. FALLOPIAN TUBES. 
 
 § 2560. The only change produced by coition in the Fallopian 
 tubes is this ; soon after this act they are applied to the ovaries, so as 
 to embrace a greater or less portion with their fimbriated extremity, 
 
 (1) Obs. anat., Venice, 1561. Vidi quidem in iisdem ( ovariis ) quasdam veluti 
 vesicas aqua vel humore aqueo, alias lutco, alias vero limpido turgentes ; in the Opp. 
 omn ., Venice, 1606, p. 106. 
 
 (2) Loc. cit , p. 223. 
 
 (3) Lee. cit . , p. 331. 
 
 (4) Handbuch der Entbindungskur, v Hingen, 1802, vol. i p 129-145. 
 
EMBRYOLOGY. 
 
 495 
 
 and to receive the fluid poured out by the yellow body, which they 
 then carry into the uterus. 
 
 Their approximation to the ovaries is favored by the portion of small 
 intestine situated in the lower pelvis ; for this portion tenses the liga- 
 ments of the ovaries and the broad ligaments of the uterus, thus fixes 
 the glands in their position, and applies the tubes to their surface, so that 
 they extend a little on the outside of them.(l) 
 
 c. UTERUS. 
 
 § 2561. The structure of the uterus(2) undergoes remarkable 
 changes in many respects, and the new organism is developed within it. 
 
 Even before we perceive any trace of the new being, we already find 
 the uterus a little enlarged at its upper part, its substance is softer, 
 looser, more lamellar, its component layers are more distinct, its ves- 
 sels are dilated, its inner face is smooth but irregular, extremely vas- 
 cular, and also covered with numerous very minute flocculæ, which 
 cannot be seen except with a microscope, and finally it is covered with 
 a pultaceous matter into which the vessels extend, and which passes on 
 the neck of the organ, so as to close the cavity of the body. This 
 substance resembles coagulated blood. It is thickest at its upper part, 
 where it is connected with the uterus more intimately than in any 
 other place. Below it is very thin and united to the organ more 
 loosely, and even does not adhere to it at all. (3) 
 
 The vaginal orifice and the neck are also filled with a viscous, 
 shining substance, similar to gelatine. 
 
 These changes increase uninterruptedly until the end of pregnancy, 
 which generally continues ten lunar months. 
 
 The fibrous texture becomes more and more distinct : it cannot well 
 be perceived(4) except during pregnancy or in analogous states of the 
 uterus, when this organ also enlarges, as for instance, when abnormal 
 formations are developed within it. It is then certain that if the fibres 
 do not form during pregnancy they are at least developed and very 
 much enlarged at that time. 
 
 (1) Autenrieth, Ueber die eigentliche Lage der innern weiblichen Geschleeht- 
 stheile ; in Reil, Archiv, für die Physiologie, vol. vii. p. 294. 
 
 (2) Beside the works already mentioned in respect to the uterus, consult also : 
 A. Vater, De utero gravido, YVittemberg - , 1725. — Beyer, Utrum in gravidis lotus 
 uterus cequaliter extendatur , Paris, 1729.- — P. A. JBoehmer, Situs uteri gravidi 
 fœtusque , ac sedes in utero, Halle, 1748. — B. S. Albinus, Tabulce uteri gravidi, Ley- 
 den, 1748. — Id., De utero gravido nonnulla ; in the Annot. acad., 1. ii. cap. v. — J. 
 Weitbrecht, De utero muliebri (gravido) observationes anatomicœ ; In N. C. Petrov., 
 vol. i. p. 337. 
 
 (3) Pke case of a young woman who poisoned herself in the first month of her 
 pregnancy, by 'Ph. Ogle ; to which is added an account of the appearances after 
 death, by J. Hunter ; in the London med. trans. for the improvement of med. and 
 chir. knowledge, vol. ii. p. 63. 
 
 (4) This remark had been made already by Vesalius (De corp. hum. fab., book v. 
 c. xv.), and by Santorini after him ( Observ . anat., c. x-i, § 13). 
 
496 
 
 DESCRIPTIVE ANAT0MT. 
 
 Hence why the uterus, although it enlarges and becomes much 
 softer, is not only distended but enlarges considerably. 
 
 Some days after parturition occurs, when the term of pregnancy 
 has been normal, the uterus weighs at least twenty-four ounces, as we 
 have proved by examining twelve cadavers of females dying at this 
 period ; so that even then, although the organ had already collapsed, 
 its weight was to that of the uterus in a virgin as 24 : 1. 
 
 Another question now presents itself, viz. do the parietes of the 
 uterus, which, from the preceding remarks, are not only distended, but 
 also become thicker, remain the same, or do they grow thinner ? The 
 latter perhaps is true, notwithstanding the increase in mass and 
 weight, on account of the considerable extension of the uterus during 
 pregnane}^. 
 
 This problem has been resolved several different ways.(l) 
 
 Those who admit that the parietes of the uterus preserve the same 
 thickness, or even become thicker, explain the contrary assertion by 
 saying that the thickness of the uterus, considered generally, varies in 
 the state of pregnancy, (2) and that an uterus, when filled with the 
 product of conception, has not the same thickness in every part. (3) 
 We may also say that sometimes the uterus, from a pathological state, 
 is not properly developed, and is only distended, which perhaps is one 
 of the causes which contribute to render parturition painful. 
 
 Our observations made upon sixteen uteri at all periods of gestation, 
 lead us to think that very probably the parietes become a little but not 
 much thicker at first, and that towards the end of pregnancy they 
 gradually become much thinner. 
 
 In fact we have found the parietes of the uterus six lines thick, three 
 weeks after conception ; five, at the beginning of the third month ; four, 
 at the commencement of the fourth ; at the end of this month, four in 
 two cases: three at the upper part, and four at the lower in a third, 
 and five in a fourth case ; at five months, three lines thick in one case, 
 two at the upper part, and four in the lower in another ; at six and seven 
 months, a little less than three ; at eight months, from two to two and 
 a half lines in one case, and in another, three lines at the upper part, 
 and more than four at the lower : they have appeared to us a little 
 thinner at nine months. 
 
 On the contrary the uterus when collapsed after parturition is gene- 
 rally an inch thick at the end of seven, eight, and nine months. 
 
 The veins and the arteries of this organ are extremely dilated, so 
 that the venous trunks are as large as the axillary veins. These two 
 orders of vessels become less tortuous as the uterus enlarges. 
 
 (1) Hallor has collected most of the opinions on this subject (El phys., vol. viii. p. 
 2. p. 58). 
 
 (2) For instance, F. A. Walter, De pohjpis ; in the Anno/. Ac. Ecrol., 1786, p. 3. 
 
 (3) Hunter, loc. cit., p. 21. 
 
EMBRYOLOGY. 
 
 497 
 
 The dilated veins of the uterus have very improperly been termed 
 sinuses. 
 
 The place where the blood-vessels are most developed is where the 
 new organism unites directly with that of the mother, that is, at the 
 insertion of the placenta. 
 
 § 2562. The form of the uterus is also considerably changed. As 
 the body only of the organ is developed during most of pregnancy, the 
 disproportion between it and the neck always becomes greater, and 
 even, as when the neck is finally distended, in the latter periods of 
 pregnancy it shortens in proportion as it enlarges, the disproportion 
 only becomes still more perceptible, so that the uterus is rather oval 
 than pyriform, especially near parturition. 
 
 This organ also becomes considerably thicker from before backward 
 in proportion to its breadth than it was before, although it still conti- 
 nues to be a little more broad than thick. 
 
 The orifice of the vagina begins to become round at the first month. 
 
 § 2563. Great changes supervene also in the situation of the 
 uterus. 
 
 During the first two months of pregnancy the uterus gradually de- 
 scends a little in the pelvis, so that its orifice is more easily perceived 
 with the finger introduced into the vagina ; but at three months it 
 begins to reascend, and also changes its direction, its base goes farther 
 forward, and its orifice backward. These changes increase so much, 
 as pregnancy advances, that it becomes more and more difficult to 
 reach the os tincæ, and more so as the lower part of the anterior wall 
 of the uterus is crowded from above downward, before it, by the lower 
 part, the head of the child. In most cases, in proportion as the uterus 
 is developed, its base rises, and becomes evident through the distended 
 integuments of the abdomen. 
 
 The anterior face of the organ, especially in the latter months of 
 pregnancy, is situated directly behind the anterior wall of the abdo- 
 minal cavity. It pushes the small intestine upward, backward, and 
 on the sides ; at least this intestine very rarely descends between the 
 uterus and the anterior wall of the abdomen,(l) and this case probably 
 never happens at the end of gestation. 
 
 § 2564. After parturition the uterus contracts, and in a few days its 
 parietes are more than an inch thick. (2) 
 
 Its volume returns gradually, and even during the first few weeks, 
 to the size it had before pregnancy ; its vessels contract, and at the 
 same time its loose and lamellar structure disappears. It however 
 always remains larger and softer than in a female who has never 
 borne children. It begins to diminish much and to become harder 
 only at an advanced age. 
 
 (1) 1). Monzo, in the Edinb. Essays, an. ob., vol, i. p. 456. At the sixth month of 
 pregnancy. 
 
 (2) Hunter, loc. cit. 
 
498 
 
 DESCRIPTIVE ANATOMY. 
 
 The orifice of the vagina, which in the latter period of pregnancy 
 had become a rounded opening, resumes its ancient form : but it is 
 generally torn more or less deeply, whence it is uneven and corru- 
 gated. The lips, particularly the posterior, are thicker and longer. 
 They are adapted to each other less exactly. 
 
 ARTICLE SECOND. 
 
 DEVELOPMENT OF THE NEW ORGANISM.(l) 
 
 § 2565. The first origin of the new organism is very obscure. We 
 do not know whether the fluid secreted in the yellow body directly 
 assumes any form, so that the ovary furnishes a vesicle filled with 
 liquid, which is the first trace of the ovum or of the envelops ( involucra , 
 s. membranoe) of the fetus : or if this change takes place only in the 
 tube, perhaps even in the uterus. 
 
 The possibility of the development of the new organism in the ovary 
 does not prove that the fluid of the vesicles is changed there in the 
 normal state; we ought only to conclude that when this fluid does 
 not arrive in the uterus it may assume in every other part the form of 
 an ovum. 
 
 It is very doubtful(2) whether the ova, discovered in the Fallopian 
 tubes, (3) of animals, were really %hat they were supposed to be, and 
 more so because other observations render another mode of develop- 
 ment probable, and particularly that the ovum takes its form in the 
 uterus. (4) 
 
 But there is a rounded vesicle, composed of several membranes 
 adapted to one another, and containing different fluids, constantly 
 formed before the fetus. The fetus is developed within the ovum, 
 which connects it wfith the organism of the mother. As the human 
 ovum is generally ruptured at its lower part at the period of parturi- 
 tion, and the infant is delivered before it, it is termed the secundines 
 ( secundo: , s. secundinu). 
 
 (1) Beside the works cited above, which treat also of the changes in the genital 
 organs, consult : T. Kerkring, Anthropogenia, Amsterdam, 1670. — M. Schurig, 
 Embryologia, Dresden, 1732. — F. G. Danz Grundriss der Zergliederungskunde des 
 ungebornen Kindes , Frankfurt, 1792-1793. — C. F. Burdach, De primis momentis 
 formationis fœtus, Königsberg, 1814. — O. C. Lucæ, Grundriss der Entwieklungs- 
 geschichtc des menschlichen Körpers, Marburg, 1819. — Beclard, Embryologie, ou 
 Essai anatomique sur le fœtus humain, Paris, 1820. 
 
 (2) Hartmann, Dubia de generatione viviparorum ex ovo, Koningsberg, 1699, 
 
 9 14. 
 
 (3) De Graaf, De mulierum organis, cap. xvi. — G. Cruikshank, in the Phil, 
 frans., 1797. 
 
 (4) J. C. Kuhlemann, Observations circa generationis negotium in ovibusfactœ, 
 Gottingen, 1753.— Haller, De quadrupedum utero, conceptu et fœtu ; in the Opp. 
 min., vol. ii. p. 32. 
 
OF THE GENITAL SYSTEM, 
 
 -499 
 
 I. ENVELOPS OF THE FETUS. 
 
 § 2566. The membranes of the ovum(l) are much larger and hea- 
 vier the farther the fetus is from the period of its formation. Taken 
 with the fluid they contain, they are at first much heavier than the 
 fetus, and they even weigh more than it at the end of the third month, 
 after being emptied, although the disproportion is then less, as may 
 easily be conceived. At the end of the third month, that is, after about 
 the first third of fetal existence, their weight is nearly equal. After 
 this period an inverse relation exists, so that the mean weight of the 
 membranes of the ovum is to that of the fetus as 1 : 8, since a well 
 grown fetus weighs about eight pounds, and the weight of the se- 
 cundines, including that of the cord, weighs rather more than one 
 pound. 
 
 The first trace of the fetus is the substance which fills the uterus 
 soon after coition, and which seems to be only coagulated blood. 
 
 This substance forms the most external membrane of the ovum, the 
 deciduous membrane. 
 
 A. DECIDUOUS MEMBRANE. 
 
 § 2567. The deciduous membrane, épichorion, Ch. (JVf. decidua, s. 
 caduca, tunica ovi exterior , membrana Hunteri),{2 ) which surrounds 
 
 (If Beaide the works already mentioned, particularly those of Nortwyck, Sandi- 
 fort, and Hunter, consult : A. Vater, Mus. anat. propr., tab. viii. Wittemberg, 1701. 
 — Ruyscb, Thés, anat., VI. tab. i. and ii.— G. Vater, Mola prœgnans, with a plate. 
 — O. Borrich, Abortus humanus examinatus ; in the Act. Hafn., vol. ii. p. 49. — B. S. 
 Albinus, De vasis placentae parvulorum embryonum et de involucro, quo édita eorum 
 ova continentur ; in the Annot. acad., lib. i-xvii. — Id., Nonnulla de embryonibus 
 humanis ovisque, quibus continentur, ibid., xix. — P. A. Boehmer, Instil, osteol., Halle, 
 1751, tab. i. f. 7, 8.— D. C. Burdach, De lœsione partium fœtus nutritioni insertion- 
 tium abortus causa, Leipsic, 1768. — E. Sandifort, De ovo humano, absque ullo fœtus 
 indicio, et placentœ in hydatides degeneratione ; in the Obs. anat. path., book ii-iii. 
 p. 76. — Id., De ovo humano , ibid., book iii-vi. p. 91. — Blumenbach, Institutiones 
 phys., 1787, tab. iv. — S. T. Sœmmerring, Icônes embryonum humanorum, Frankfort, 
 1799. — Denman, Practice of midwifery, London, 1801, tab. vi-viii. — Wrisberg, Obs. 
 anat. obst. de structura ovi et secundinarum humanarum in partu naturali et per - 
 fecto collectas, Gottingen, 1782. — C. G. Krummacher, Diss. sistens observationes 
 quasd. anat. circa velamenta ovihumani, Duisburg, 1790. — J. F. Lobstein, Essai sur 
 la nutrition du fœtus, Strasburg, 1802. — Samuel, De ovorum mammalium vêla- 
 mentis, Wurzburg, 1816. — Dutrochet, Recherches sur les enveloppes du fœtus ; in 
 the Mém. de la soc. méd. d’émul., vol. viii., 1817, p. 1-60. — G. Cuvier, in the Mém. 
 du Museum , vol. iii. — Dutrochet, Observ. sur la structure de l’œuf des mammifères 
 et examen de la doctrine de Cuvier sur cette matière ; ibid., p. 760-767. — Dutrochet, 
 Mém. sur les enveloppes du fœtus ; in the Journ. compl. du Diet, des sc. méd., vol. 
 v. p. 241. — Velpeau, Sur les membranes du fœtus ; in the Archiv, gén. de méd., No- 
 vember and December, 1824. 
 
 (2) Haller, Elem. phys., vol. viii. p. 183. — Osiander, Handbuch der Entbindung- 
 skunde, pt. i. p. 191. — F. J. Moreau, Essai sur la disposition de la membrane ca- 
 duque, sa structure et ses usages , Paris, 1814. 
 
500 
 
 DESCRIPTIVE ANATOMY. 
 
 the envelops of the ovum belonging to the fetus, is attached by its 
 inner face to the chorion, and by its external face to the inner face of 
 the uterus. 
 
 It is entirely different from the other membranes, is thicker, more 
 opaque, but infinitely less solid. It has about the consistence of coa- 
 gulated fibrine, which it also resembles in its yellowish color. 
 
 Its thickness is not the same in all parts of its extent. It is gene- 
 rally thicker in the region of the placenta, and smaller at the lower 
 part, opposite the internal orifice of the uterus, than in any other 
 point. 
 
 It always diminishes from the moment of its origin, so that finally 
 it is scarcely half a line thick. Its external face is at first uneven and 
 corrugated ; but in time it becomes smoother, as is- already its in- 
 ternal face. The connections which unite it to the uterus are much 
 looser in the early periods than at the end of pregnancy. 
 
 It presents in a greater or less portion of its extent more or less evi- 
 dent perforations, which give it a reticulated or cribriform appearance. 
 
 It receives a great number of vessels, which are prolongations of 
 those of the uterus, and which descend obliquely into it. 
 
 § 2568. The deciduous membrane not only surrounds the ovum : it 
 forms a double layer around it, and it is consequently arranged like 
 the serous membranes. 
 
 In fact, beside the portion of this membrane which unites it by its 
 external face to the internal face of the uterus, there is a second which 
 is reflected on the preceding, and is contained within it. 
 
 This second layer is attached by its inner face to the chorion, and is 
 loose on its external face, while the other fold is loose on its internal 
 face, and adheres to the uterus by the external. 
 
 The first fold of the membrane is called the external or true deci- 
 duous membrane (AI. decidua externa, s. vera) : the other is termed 
 the internal or reflected deciduous membrane (AI. decidua interna , s. 
 reflexa ) ; it has also very improperly been termed the fungous deci- 
 duous membrane (chorium fungosum). 
 
 The arrangement of the deciduous membrane however differs from 
 that of the serous membranes, because the external fold is not only 
 reflected upon the chorion, but also on leaving this point, where it is 
 inflected, it is extended on the latter, which it consequently envelops 
 in every part.(l ) 
 
 (1) Moreau (he. cit., p. 16) rloes not assent to this opinion. When the ovum is sepa- 
 rated from the uterus it seems in fact enveloped in every part by the deciduous 
 membrane : but according- to him, as the flocculent tissue which covers the placenta 
 at the third or fourth month of pregnancy does not exist in the first, and as from 
 the fifth to the seventh month it is changed into a real cellular tissue, to form the 
 uterine portion of the placenta, into which the vessels of the fetus open with the 
 uterine veins, we must consider it a tissue of secondary formation, similar to the 
 deciduous membrane, with which it i* continuous, and not as a part or appendage 
 of this membrane. F. T. 
 
EMBRYOLOGY. 
 
 501 
 
 The reflected deciduous membrane particularly is thin and reticu- 
 lated, and it is much thinner than the chorion. It likewise becomes 
 much thinner ns the ovum enlarges. It also approaches the external 
 deciduous membrane, to which it is finally more or less adherent. 
 
 § 2569. The external deciduous membrane never extends beyond 
 the internal orifice of the uterus. On leaving this point the uterus or 
 the neck is filled only with a gelatinous fluid. 
 
 According to some observers the external deciduous membrane ex- 
 tends to a certain extent in the tubes, especially on the side where the 
 yellow body is formed, (1) and it isopen at the place of the uterine 
 orifices of the tubes, as also at its lower part, that which passes on 
 the inner orifice of the uterus. (2) Perhaps these openings exist at 
 first, but the membrane seems to change very soon into a perfectly 
 closed sac, since the lower opening does not exist during the first 
 month, (3) and the upper'two are also effaced at the second. (4) 
 
 § 2570. It is not very easy to explain how the reflected deciduous 
 membrane is formed. Most probably the ovum, or the fluid from 
 which it is produced, penetrates into the substance of the deciduous 
 membrane, which is always very soft and very loose, but which pre- 
 sents these characters primitively, the spaces resulting from them 
 afterwards close, and the ovum is then developed in the cavity of 
 the membrane. (5) 
 
 This theory agrees with the observations from which it has been 
 concluded that the external and internal deciduous membranes are pri- 
 mitively distinct, that the external appears first, on leaving the base of 
 the uterus, as a membrane possessing longitudinal blood-vessels, and 
 consequently composed apparently of bands which have the same di- 
 rection, and that the internal is developed afterward, on leaving the 
 inner face of the preceding, and possesses horizontal vessels : so that 
 the ovum on arriving at the uterus falls into a cavity, the roof and 
 parietes of which are formed by the external deciduous membrane, 
 while the floor is constituted by the reflected deciduous membrane. (6) 
 
 (1) J. Hunter, in the Trans, for the improv., vol. ii. p. 67. 
 
 (2) G. Hunter, Loc. cit., p. 77. 
 
 (3) J. Hunter, loc. cit., p. 67. 
 
 (4) Lobstein, Sur la nutrition du fœtus, p. 4. 
 
 (5) Moreau asserts that when the ovule enters the uterus through the Fallopian 
 tube, it only pushes before it the deciduous membrane, which is already a little or- 
 ganized before its arrival ; that it is covered, as is every internal viscus, by the 
 serous membrane of the sphlancnic cavity in which it is situated; that this keeps it 
 in contact with that portion of the uterus to which it is attached ; that it is reflected 
 on it on leaving the place where the placenta is formed, and which is the only part 
 not covered by it ; that the three openings admitted by Hunter do not exist : in a 
 word, that the deciduous membrane is arranged exactly like the serous membranes. 
 This theory is more probable than the ancient, and has been developed by Velpeau, 
 who supports it by the observation and dissection of a dozen human ova. F. T. 
 
 (6) Burns, Observations on the formation and structure of the human ovum ; in 
 the Edinb. med. and surg. Journal, voL ii. p. 1-4. 
 
 VOL. III. 
 
 64 
 
502 
 
 DESCRIPTIVE ANATOMY. 
 
 At least it follows from these same observations that the ovum is 
 not introduced into the substance of the deciduous membrane at the 
 same period as when this membrane is developed on the inner face of 
 the utevus,(l) since the phenomena mentioned by us have been ob- 
 served in the cases where the ova are still contained in the tubes. (2) 
 
 § 2571. Notwithstanding its early appearance, the deciduous mem- 
 brane does not belong to the fetus, and is not indispensable for its 
 development, since it also forms equally in the uterus in cases of extra- 
 uterine fetation, and the fetus then is not the less developed, although 
 destitute of it. (3) 
 
 B. MEMBRANES OF THE FETUS. 
 
 § 2572. The ovum, on the contrary, includes other parts which are 
 essentially connected with the formation of the fetus. These parts are 
 the chorion, the amnios, the umbilical vesicle, and the allantoid mem- 
 brane, which we proceed to describe, without regard to the order in 
 which they form, nor the part they take in the special vitality of the 
 fetus. 
 
 I. CHORION. 
 
 § 2573. The chorion ( chorion , s. chorion pellucidum, s. JYI. vascu- 
 losa, s. extima ), the most external of the special membranes of the 
 ovum, is thin, transparent, and villous on its two faces, particularly 
 the external. The villosities of this latter are much longer than those 
 of the internal and ramify. 
 
 The external villosities are masses of vessels, the trunks of which 
 unite to form the umbilical vessels. 
 
 These vessels are at first single, but more or less prominent at in- 
 tervals like varices, and are composed only of veins. (4) 
 
 Notwithstanding its thinness and transparency, the chorion is formed 
 of two layers, an internal and an external, between which wind small 
 vascular trunks communicating with the villosities, and which arise 
 from them. (5) 
 
 (1) Hunter, loc. cit., p. 81. 
 
 (2) Burns, loc. cit., p. 3. 
 
 (3) Chaussier, in the Bull, de la fac. de Paris, 1814, no. 6, vol. iv., p. 137. 
 
 (4) Lobstein, loc. cit., p. 65. 
 
 (5) This opinion, admitted by Hewson, Bojanus, and Dutrochet, is rejected by 
 
 Velpeau. He thinks that the chorion is always formed by a single layer, and if it 
 is cccisidered to be formed by two, it is only because rather a thick membranous con- 
 cretion forms between it and the placenta when this latter is developed, which may 
 be separated into several layers. As the placenta is developed on the outside of the 
 chorion, the same anatomist also states that it covers the fetal face of this organ, and 
 is even reflected on the cord, with which it arrives at the umbilicus, where it blends/ 
 with the skin of the fetus. F. T. 
 
EMBRYOLOGY. 
 
 503 
 
 Its external face is united with the internal face of the deciduous 
 membrane, and by the internal with the amnios. 
 
 Although there may be on its external face only a great develop- 
 ment of vessels, we cannot, however, demonstrate the existence of 
 these latter in its substance. In fact many observers have admitted 
 them, and even very recently it has been adduced in favor of their 
 existence that the deciduous membrane contains so many of them, 
 because, they say, these last must penetrate into the chorion ; and 
 the vessels of the deciduous membrane seem to us to have with those 
 of the chorion a relation similar to that between the vessels of the 
 uterine portion and those of the fetal portion of the placenta, and in 
 this hypothesis we can easily conceive of the great vascularity of the 
 deciduous membrane. 
 
 The chorion has no lymphatic vessels or nerves. 
 
 § 2574. Its form and connections vary much at different periods of 
 the life of the fetus. It is proportionally much thicker at first than it 
 is subsequently: it is thicker than even the anmios, but gradually 
 becomes thinner. 
 
 At this period also its structure and thickness are uniform in every 
 part. 
 
 Its external face is villous in every part, and these villosities are 
 at first longer than they are afterward and in the second month are 
 tortuous and proportionally longer than before.. But after the third 
 month these villosities gradually disappear in most of its extent, usually 
 from below upward, so that the outer face of the membrane is finally 
 almost smooth, and the portion which surrounds the insertion of the 
 umbilical cord is the only one where we still observe the villosities 
 compactly arranged, and uniting to form the cord. 
 
 This place forms with the deciduous membrane a rounded mass, 
 which in the full-grown fetus occupies about the third of the circum- 
 ference of the ovum, and is termed the placenta. 
 
 The chorion, which forms its inner face, is much thicker there than 
 in other parts. 
 
 At first this membrane is united to the deciduous membrane more 
 loosely than it is subsequently ; but it is gradually attached to it so 
 intimately that they are separated with difficulty, particularly on the 
 circumference of the placenta, where the union occurs by numerous 
 filaments, remnants of vascular villosities, with which its whole sur- 
 face is at first covered. 
 
 II. AMNIOS. 
 
 § 2575. The amnios ( amnion , s. tunica ovi intima ) is a very thin 
 and transparent membrane, which directly envelops the fetus. Its ex- 
 ternal face adheres but feebly to the chorion, except where it covers 
 
504 
 
 DESCRIPTIVE ANATOMY, 
 
 the inner face of the placenta : the internal, on the contrary, is loose. 
 These two faces are perfectly smooth, excepting always some very 
 loose cellular tissue which covers the external. 
 
 Often and perhaps even always during the early periods of preg- 
 nancy, this membrane is more or less separated from the chorion, which 
 is much more extensive, and between them is a fluid termed the false 
 waters of the amnios ( liquor amnii spurius ). But this liquid disap- 
 pears early, at the second montb,(l) when the two membranes touch, 
 although they are sometimes separated at the fourth and fifth 
 months. (2) 
 
 The amnios is reflected on itself at the origin of the umbilical cord, 
 covers the umbilical vessels, of which it forms the external envelope 
 on the sheath, and extends to the anterior face of the abdomen, where 
 it is continuous with the projecting portion of the skin of this region 
 which forms the umbilicus. 
 
 As yet neither blood vessels nor nerves have been found in the am- 
 nion, although very probably the substance which serves to unite it 
 with the chorion contains the passages through which the nutritious 
 and secretory fluid penetrates to it. 
 
 § 2576. This membrane contains a liquid termed the waters of the 
 amnios ( liquor amnii), (3) which varies in several respects at different 
 periods of the life of the fetus. 
 
 In regard to its physical qualities it is limpid and more or less trans- 
 parent in the early periods of pregnancy ; but at the end it becomes 
 turbid and more or less flocculent. It is also at first thinner and less 
 viscous. 
 
 It has a strong odor, analogous to semen. Its taste is slightly 
 saltish. 
 
 It contains a considerable number of globules. 
 
 Its specific gravity is a little less than that of water. 
 
 Its absolute and relative quantities vary at different periods of preg- 
 nancy. The nearer the fetus is to its period of formation, the more 
 abundant proportionally the waters of the amnios. 
 
 (1) Hunter, p. 67. 
 
 (2) Lobstein, p. 23-24. 
 
 (3) Franck, De liquore amnii, Gottingen, 1764. — F. A. Koenig, De aquis ex utero 
 gravidarum et parturientium profluentibus, Halle, 1769. — J. P. Hettler, De liquoris 
 amnii natura ac indole, Giessen, 1776. — H. Van den Bosch, De nalurâ ét utilitale 
 liquoris amnii, Utrecht, 1792. — P. Scheel, Diss. de liquoris amnii arteriæ aspcrœ 
 fœtuum humanorum naturâ et usu, cui adjeclus est appendix sistens gencraliora 
 qucedam de liquore amnii, Copenhagen, 1799. — Bunivaand Vauquelin, Expériences 
 sur les eaux de V amnios ; in the Ann. de chimie, vol. xxxiii., and Mém. de la soc. 
 méd. d’ém., vol. iii. p. 229. — F. F. Reuss and F. A. F.mmert, Chemische Untersu- 
 chung des Fruchtwassers aus dem zeitigen Ei und der käsigen Materie auf der 
 Haut der neugebornen Kinder: in Osiander, Annalen , Gottingen, 1801, vo). ii. p. 
 107. — G. Egeling, De liquore amnii, nee non positiones mcdici argumerti, Leyden, 
 1813. — G. F. Fuckel, De liquoris amnii in fœtus corporis superficial! pressions , Mar- 
 burg, 1819. 
 
EMBRYOLOGY. 
 
 505 
 
 About the middle of gestation their weight nearly equals that of the 
 fetus. 
 
 From this period they gradually diminish, so that even when the 
 fetus is delivered without breaking the membranes, they do not weigh 
 more than a pound, and in common parturition not more than eight 
 ounces. 
 
 Their absolute like their relative quantity increases at first, but after- 
 wards diminishes. Thus, for instance, we find only thirty-six ounces 
 from the third to the fourth month. 
 
 In regard to chemical composition it is to be regretted that the 
 waters of the amnios in the female have not yet been analyzed, nor 
 comparative experiments made, which however are not difficult, in 
 animals at different periods of gestation. All those we possess were 
 made on the waters received at the moment of parturition, that is, in 
 the latter periods of pregnancy. 
 
 According to Scheel the waters of the amnios contain free oxygen ; 
 but the analyses of it made since(l) have not confirmed this asser- 
 tion.^) We find in it no traces of loose alkali. 
 
 The fluid portion is composed of a considerable quantity of water, a 
 little albumen, a still smaller proportion of gelatine, of the hydrochlo- 
 rates of ammonia and soda, and of phosphate of lime. Heat, alcohol, 
 and acids do not change. it, or but very slightly. 
 
 The fîocculæ are very similar to the mucus of the mucous mem- 
 branes. (3) 
 
 Some think that the waters of the amnios are formed by the fetus 
 and others by the mother. The first represent it as an excretion, 
 and the second as a nutritious substance. 
 
 Among the first some think it comes from the urine of the fetus, and 
 others that it is exhaled by the skin. 
 
 Many(4) suppose that its composition is mixed, especially in the 
 latter periods of pregnancy, that it is formed partly of the excretion of 
 the fetus, partly also by a nutritious substance. 
 
 The most probable opinion is, that the waters of the amnios are 
 secreted at least in great part by the vessels of the mother, although 
 at the end of pregnancy they are furnished partly by the fetus. We 
 have been led to this opinion because it seems infinitely probable that 
 this liquid serves for the nutrition of the fetus. In fact : 
 
 1st. As it seems to contain more nutritious substance than during 
 the first periods, because more coagulum is produced by heat and al- 
 
 (1) Lassaigne (Sur V existence d’un gaz respirable dans les eaux de l’ amnios ; in 
 
 (he Archiv, gên. de Méd., vol. ii. p. 308) has found in the amniotic fluid of the sow 
 4.130ths. of a gas similar to the atmospheric air, as it was composed of azote 98.3, 
 and of oxygen 21.7. F. T. 
 
 (2) Van Doeveren, Obs. acad., c. vii. p. 103. 
 
 (3) Emnaert, loc. cit., p. 116. 
 
 (4) Emmert, p. 121. 
 
506 
 
 DESCRIPTIVE ANATOMY. 
 
 cohol,(l) we can explain this difference by admitting that the nutri- 
 tious substance has been absorbed at first, and that when it is less 
 abundant it has been replaced by another mode of nutrition. 
 
 2d. The waters of the amnios are probably absorbed by the skin ; 
 for after tying a ligature around the limbs of a fetus plunged into this 
 liquid, the sub-cutaneous lymphatics soon swelled, while those of the 
 limbs which were not tied were empty. (2) Secondly, fetuses have 
 been born with the mouth closed, and with an umbilical cord entirely 
 separated from the placenta, closed and rounded at its loose extre- 
 mity.^) 
 
 3d. The amniotic fluid also penetrates through the mouth, since it 
 has been found in the stomach, esophagus, cavity of the tympanum, 
 and trachea, where it has been easily recognized both by its physical 
 properties, (4) as by the silky «hairs of the child, and also the meco- 
 nium. (5) 
 
 4th. Correct observations teach us that the fetus inspires and swal- 
 lows, by which the waters of the amnios penetrate into the digestive 
 and air passages.(6) 
 
 5th. Animals newly born have been nourished for several weeks by 
 keeping them in the waters of the amnios. (7) 
 
 But besides these uses relative to nutrition, the waters of the amnios 
 fulfill other functions which contribute directly or indirectly to preserve 
 the fetus : 
 
 1st. They preserve it from all commotion and compression. 
 
 2d. They keep up the normal distention of the womb. 
 
 3d. They connect the ovum and the uterus most intimately. 
 
 4th. They moderate the pressure of the fetus on the uterus. 
 
 But they do not serve, as has been said, to prevent the obliteration 
 of the openings and the cavities of the body :(8) first, because we not 
 unfrequently find such anomalies ; second, because the mucous mem- 
 branes have no tendency to adhere, at least unless alterations in tex- 
 ture supervene in them. The observations of abnormal anuses, which 
 continued open for many years, proves also that these secrete fluids 
 enough to prevent the union of their surfaces. 
 
 The waters of the amnios are useful also in parturition, because 
 they dilate the orifice of the uterus, and lubricate the external organs 
 of generation. 
 
 (1) Osiander, Annalen , vol. i. pt. i. p. 190-200.— Lobstein, loc. cit., p. 103. We have 
 always observed this in the fetuses of the ewe. 
 
 (2) Brug-mans, in Van den Bosch, loc. cit., p. 466, 467. 
 
 (3) Ibid. 
 
 (4) Winslow, Herlioldt, Rafn, Abildgaard, Scheel; in Scheel, loc. cit., p. 12. 
 
 (5) Osiander, Handbuck der Entbindungskunde, vol. i. p. 237. 
 
 (6) Winslow, in Scheel, loc. cit., p. 12. — Bedard, in the Bull. <le la fac. de Paris, 
 1813, no. 6-8. 
 
 (7) Weydlich, in Pohl, Embryochemia, Erlangen, 1806, 5 12. 
 
 (8) Lucæ, in Fuckel, p. 10. 
 
EMBRYOLOGY, 
 
 507 
 
 III. PLACENTA AND UMBILICAL CORD, 
 
 A. PLACENTA. 
 
 § 2577. The placenta(l) is generally a rounded, oblong, soft, but 
 solid mass, particularly at its circumference, and is composed of the cho- 
 rion and the deciduous membrane. It is the most vascular part of the 
 ovum, that by which it is attached most intimately to the uterus. 
 
 This body is generally eight inches long in its greatest diameter, six 
 in the smallest, and one thick ; but it gradually becomes thinner to- 
 wards the circumference. Its thickest portion is where the umbilical 
 cord is detached from it. It is generally inserted, especially in the first 
 pregnancy, at the upper and posterior part of the uterus, a little to the 
 right. None of the mechanical explanations of this phenomenon are 
 satisfactory.(2) 
 
 The placenta is composed of a considerable number of lobes ( colyle - 
 dones ), which vary in size, and are rounded and irregular in form ; 
 they are particularly apparent on its outer or uterine face, and render 
 it very uneven. 
 
 About the period when the fetus is full-grown, it is covered at its 
 outer face by a layer very similar to the deciduous membrane, which 
 extends not merely from one lobe to another, but penetrates between 
 them and unites very intimately with the vessels of the placenta. 
 These last communicate with those of the uterus. Between them and 
 the placenta are very large veins. We remark particularly on the 
 circumference of the placenta a circular vein, into which several veins 
 of the deciduous membrane open. 
 
 Although this layer is similar in structure to the deciduous mem- 
 brane, it seems however to form afterward, since the portion of this 
 latter which corresponds to the placenta disappears soon after its union 
 with the uterus, and the layer in question exists only during the latter 
 half of pregnancy. (3) 
 
 The inner face of the placenta is smooth and formed by the chorion, 
 which is thicker there than in any other part, and the amnios covers 
 also its inner face. 
 
 We remark in it the largest of the branches and trunks of the three 
 umbilical vessels which unite the body of the fetus with the mem- 
 branes of the ovum. 
 
 The placenta grows constantly and absolutely after it is first 
 formed ; but it diminishes in proportion to the fetus and the other parts 
 
 (1) G. Munnibs van Cleef, De usu placentae humanae comparatione ejusdem cum 
 animalium placentis illustrait), Utrecht, 1819. 
 
 (2) B. F. Osiander, De causa insertionis placentae in uteri oriflcium ex novis 
 circa generationem humanam observationibus et hypothesibus declaratâ, Gottingen, 
 
 (3) Wrisberg, Descript, ovi et secund., § 183. Lobstein, loc. cit., p. 58. 
 
50S 
 
 rr.scuiPTivE anatomy. 
 
 of the ovum, since the vessels of the chorion are mostly’and gradually 
 obliterated. Even a part of those of the placenta gradually close, and 
 then appear so many cords filled here and there with phosphate of 
 lime, particularly towards the upper face of the organ. This deposit 
 occurs also out of the vessels. It is a sign of maturity, of old age, of 
 the mortification of placenta, and it is therefore observed only when 
 the latter is about to be detached. 
 
 The maturity of the placenta is indicated by its receiving fewer 
 vessels ; it becomes dryer, and even diminishes in its mass and 
 size,(l) although these changes are much less evident in the female 
 than in the females of animals. (2) We must then consider them as a 
 commencement of separation between the organism of the child and 
 that of the mother, as a prelude to parturition. 
 
 E. UMBILICAL CORD. 
 
 § 2578. The umbilical cord (funiculus umbilicalis ) is composed at 
 least of the following parts during all of fetal existence. 
 
 1st. The umbilical vein and two arteries. 
 
 2d. A soft, semi-fluid, and gelatinous substance, which surrounds 
 these vessels, and is termed the gelatine of Wharton ( gelatina Whar- 
 toniana) . 
 
 3d. The urachus. 
 
 4th. The umbilical sheath ( vagina umbilicalis), which surrounds all 
 these parts, and which proceeds from the amnios. 
 
 It also contains during the early periods, and particularly until the 
 third month : 
 
 5th. A portion of the intestinal canal, which is much larger the 
 younger the fetus is. 
 
 6th. The whole or a part of the umbilical vesicle. 
 
 7th. The omphalo-mesenteric vessels. 
 
 Hence why it is then much larger than it is subsequently. 
 
 At first until the second month, sometimes even later than this, but 
 then an anomaly exists, the umbilical vesicles are straight. They 
 gradually become more or less tortuous, and the cord also assumes 
 this appearance, the more so as its caliber also diminishes. It is cu- 
 rious that these inflexions generally take place in the same direction, 
 from left to right, which occurs nine times to one, judging from our 
 observations. 
 
 The gelatine of Wharton varies in quantity. Hence the difference 
 between fat and lean cords. 
 
 (1) Lobstcin, loc.cit.,y>. 141, 142. 
 
 (2) Joerg, Leber die Zeugung, p. 220. 
 
EMBRYOLOGY. 
 
 50D 
 
 We may inject this gelatinous substance(l) with mercury by com- 
 pressing it a long time ; but we cannot conclude certainly from this 
 that it receives special vessels for transmitting a fluid from the placenta 
 into the body of the fetus. We can at most conclude from this expe- 
 riment that the gelatine of Wharton is composed of tunnels adapted 
 one to another, formed by cellular tissue, and containing a substance 
 in motion which probably serves to nourish the fetus. (2) Although 
 different ancient and modern anatomists assert they have discovered 
 some lymphatic vessels in the umbilical cord, (3) neither Lobstein nor 
 myself(4) have perceived them, notwithstanding all our researches on 
 this subject. 
 
 The umbilical sheath envelops the parts which form the cord, but 
 not tightly. It differs more from the skin of the fetus the older the 
 fetus is. 
 
 We have not been able to satisfy ourselves of the existence of nerves 
 in the umbilical cord, (5) and we therefore do not admit them. (6) 
 
 § 2579. The umbilical cord does not generally arise from the centre 
 of the placenta, but is inserted a greater or less distance from its edge. 
 It is attached to the anterior face of the abdomen, as much lower, the 
 younger the fetus is, and on leaving this part its constituent portions 
 separate. 
 
 It varies in size and length at different periods of fetal existence. 
 
 At first and until the end of the first month it does not exist, and the 
 fetus rests directly on the amnios. 
 
 When it once begins to appear, it extends continually until the fetus 
 is matured, so that it is generally about two feet in length at this time, 
 and hence nearly as long as the full-grown fetus. 
 
 We must however remark that these two periods are generally se- 
 parated by a third, during which the umbilical cord is proportionally 
 longer, and exceeds more or less that of the fetus ; this occurs at least 
 from the end of the second to the end of the sixth month. 
 
 At the end of pregnancy, however, the cord is from one to two feet 
 long. 
 
 § 2580. The placenta and the umbilical cord establish the commu- 
 nication between the child and the mother. The first is essentially 
 composed of two different parts, the fetal and the uterine portion. 
 
 (1) Uttini, Sur les vaisseaux absorbans du placenta; in the Mem. dell' inst. naz • 
 ital., vol. i. 
 
 (2) Lobstein, loc. cit., p. 38. 
 
 (3) Michaelis, Observationes circa placentce ac funiculi umbilicalis vasa absorben- 
 tia, Gottingen, 1790. 
 
 (4) Loc. cit , p. 84. 
 
 (5) Chaussier and Ribes assert that they have followed the filaments of the gan- 
 
 glionnary nerves of the fetus along the umbilical vessels into the placenta. (Chaus- 
 sier, Expériences nouvelles sur le digestion , et’remarques ace sujet; in the Journ. 
 univ. des sc. méd., vol. i. p. 233.) F- T. 
 
 (6) E. F. Durr, Diss. sistens funiculum umbilicalem nervis carere, Tubingen, 
 1815. — L. S. Rieck, Utrum funiculus umbilicalis nervis polleat, aut careat, Tubin- 
 gen, 1816. 
 
 Vol. III. 
 
 65 
 
510 
 
 DESCRIPTIVE ANATOMY. 
 
 The fetal portion is formed by ramifications of the umbilical vessels 
 and by the chorion ; the uterine by the prolongations of the uterine 
 vessels and by the deciduous membrane. These two portions are 
 united much more intimately the older the fetus is ; but their respective 
 vessels always remain separate, so that the arteries and veins of the 
 uterine portion communicate directly, as do those of the fetal placenta. 
 Hence why injections of the uterine vessels, even when most success- 
 ful, fill only the uterine placenta, while those through the umbilical 
 vessels fill only the fetal portion. Hence also when we inject the 
 placenta detached from the body, or when it is not separated from the 
 body of the living infant, so that the blood circulates uninterruptedly 
 within it, there is no dribbling of blood from its loose surface. Hence 
 the pulses of the mother and the umbilical cord are not isochronous. 
 
 This explains why children born without the rupture of their en- 
 velops can live a greater or less length of time, the circulation conti- 
 nuing perfectly/ 1 ) and probably only the change of temperature 
 obliges us to open all the envelops, although Wrisberg has prolonged 
 the experiment for nine minutes, and Osiander for a quarter of an hour 
 
 The same fact explains why the cord, which remains for a long 
 time in communication with the mother, after being separated from the 
 body of the fetus, presents only a slight running, produced by the small 
 quantity of blood contained in the fetal placenta. 
 
 Finally why fetuses can survive not only several hours when their 
 mother perishes from hemorrhage, but can also preserve more or less 
 the quantity of blood they generally possess. 
 
 § 2581. The internal or fetal placenta is composed only of number- 
 less ramifications of the umbilical arteries and vein, surrounded by a 
 vaginal prolongation of the chorion. 
 
 The arteries and the veins always proceed together and are very 
 much curved, like the trunks ; their final ramifications even accom- 
 pany each other constantly, so that we find a small artery and vein 
 inclosed in the same vaginal prolongaion of the chorion. 
 
 This arrangement however occurs only in the latter periods of preg- 
 nancy ; for during the early stages, the vessels of the fetal placenta 
 are single and only venous, like those of the chorion in general. 
 
 Besides these vessels, we find in the placenta white tendinous fila- 
 ments which arise from the chorion, enter with it between the vascular 
 trunks, and seem to be only obliterated vessels, which are often half 
 open and receive injections. 
 
 If we except a considerable and oblique anastomosis between the 
 two umbilical arteries at the base of the placenta, their subordinate 
 branches do not communicate from one lobe to another within this 
 body. There is no other anastomosis between the branches of the 
 
 (1) In the experiments of Rœderer, Wrisberg-, and Osiander (Rœderer, De vi 
 imaginationisinfœtumnegandâ, Gottingen, 1756. — Wrisberg, Obs. de struct, ovi ; 
 in the Comment., vol. i. p. 618. — Osiander, Annalen, vol. i. pt. i. p. 27-28), which we 
 have repeated with the same results on dogs, cats, and rabbits. 
 
EMBRYOLOGY 
 
 511 
 
 umbilical vein. On the contrary the arteries and veins are continuous 
 by proportionally very large anastomoses. 
 
 This portion of the placenta is proportionally of a very loose tissue ; 
 the solidity of the whole mass depends on that of the next portion. 
 
 The placenta has no lymphatic vessels ; and we cannot strictly de- 
 monstrate in it the existence of nervous filaments. 
 
 § 2582. The uterine or external portion of the placenta is much 
 firmer than the internal, and formed by the membrane similar to the 
 deciduous membrane mentioned by us above. 
 
 This membrane covers its outer face, and gives it a warty appear- 
 ance ; but at the same time it sends internally numerous irregular 
 prolongations, which penetrate between the most minute ramifications 
 of the umbilical vessels, with which they form alternate elevations and 
 depressions. 
 
 The uterine placenta, like the whole deciduous membrane which cor- 
 responds to it, is formed by the uterus, and its vessels are prolongations 
 of the uterine vessels. 
 
 The arteries are very tortuous, and the diameter of the largest is 
 nearly a line. The veins, which are less tortuous, but which go ob- 
 liquely to the placenta, are infinitely broader. Numerous ramifica- 
 tions of veins arise from the deciduous membrane, which, after uniting 
 in trunks, are distributed principally on the edge of the placenta. 
 
 The arteries and veins communicate in the uterine placenta, not by 
 anastomoses, but by large cellules which may be completely filled, 
 either through the venous or arterial trunks, and in which the injection 
 is always effused before passing from the arteries into the veins. 
 
 These cellules should be considered as the larger openings of the 
 vessels, since they have no special membranes, and form also large 
 islands. 
 
 § 2583. Notwithstanding the separation of the two circulations in 
 the placenta, there is, however, between its two constituent portions 
 and their vessels a relation of mutual action, which may be compared 
 to that existing between the air and the blood in the lungs, or between 
 the food and the chyliferous vessels in the intestinal canal. 
 
 § 2584. The uterine placenta is only a transient production, of 
 which the uterus is in great part disencumbered when the fetal pla- 
 centa is expelled, although a portion of the deciduous membrane is 
 not perfectly detached from the inner face of the organ until several 
 days after delivery. 
 
 From this intimate connection between the uterine placenta and the 
 uterus, although the section of the cord occasions only a slight and mo- 
 mentary flow of blood, as we have said above, there is, on the con- 
 trary, a greater or less hemorrhage from the rupture of its vessels 
 when this portion is detached, which is soon stopped by the contrac- 
 tion of the uterus. 
 
512 
 
 DESCRIPTIVE ANATOMY. 
 
 IV. UMBILICAL VESICLE AND ALLANTOID MEMBRANE. 
 
 § 2585. Beside the membranes hitherto mentioned, the existence of 
 which is certain, there are two not so generally admitted, but which 
 are similar in form and situation, but differ from the two preceding in 
 these two respects. They are the umbilical vesicle and the allantoid 
 membrane. These two membranes do not form superimposed sacs 
 and envelops of the fetus, but are situated between the chorion and 
 the amnios. They do not continue as long as the other two mem- 
 branes, since they disappear, or at least become inactive, at the third 
 month of pregnancy. They however cannot be confounded with each 
 other, nor can we suppose, with Lobstein, for instance, (1) that the 
 umbilical vesicle of man is the allantoid membrane of animals. They 
 are two entirely different organs, which coexist in most vertebrated 
 animals, and apparently in man also. 
 
 A. UMBILICAL VESICLE. 
 
 § 2586. The umbilical vesicle ( V. umbilicalis , s. saccus vitellarius, s. 
 vesica vitellaria, s. intestinalis , s. processus infundibuliformis , s. hydatis 
 funiculi) is constant. Although Osiander has asserted that it should 
 be considered as a pathological phenomenon, occurring only in mon- 
 strosities, (2) it really exists in every ovum during the early months of 
 pregnancy. 
 
 The umbilical vesicle of man corresponds neither to the allantoid mem- 
 brane of the mammalia(3) nor of birds : for the arguments drawn from 
 its constancy, transparency, the clear and limpid fluid which fills it, 
 its situation between the other membranes of the ovum, and the exist- 
 ence of vessels on its surface, adduced in favor of this comparison, are 
 so many circumstances which demonstrate still better its analogy 
 with the umbilical vesicle of the mammalia, and the vitelline sac of 
 birds. 
 
 The nature of its vessels and its connections with the intestinal 
 canal also support this analogy. Besides as the allantoid membrane 
 is independent of it in the mammalia and in birds, and probably also in 
 man, Lobstein’s opinion cannot be admitted. 
 
 § 2587. This vesicle is as much larger proportionally as the fetus is 
 younger, and it at first probably exceeds it in size ; at least Lobstein has 
 figured a case of this kind, (4) and we have one almost similar before 
 
 U3. 
 
 (1) Loc. cit., p. 44. 
 
 (2) Salzburg med. chir. Zeitung , 1814. 
 
 (3) Lobstein, loc. cit., § 41-45. 
 
 (4) Loc. cit., tab. i. 
 
EMBRYOLOGY. 
 
 513 
 
 The umbilical vesicle figured by Lobstein is the largest known. 
 We may judge from it that the organ is at first about six lines in dia- 
 meter. 
 
 The largest umbilical vesicles before us are one half or more smaller ; 
 this agrees with the dimensions given by most authors, 
 
 § 2588. This organ is at first situated directly against the anterior 
 face of the fetus ;(1) but it removes from it after the end of the first 
 month, and is then situated on the outside of the umbilical sheath. 
 
 § 2589. We know nothing certain in regard to the period when the 
 umbilical vesicle appears. Judging from analogy with birds, as it 
 corresponds to the vitelline sac, we might conclude that it arises be- 
 fore all other parts of the ovum, and on this account it has even 
 been asserted that the false germs are umbilical vesicles, and not sacs 
 formed by the chorion and amnios, as is generally supposed.(2) Al- 
 though the received opinion be not perhaps applicable to all cases, 
 we however shall continue to follow it until the contrary is proved by 
 positive facts. 
 
 According to Hunter, (3) the umbilical vesicle sometimes continues 
 to the end of pregnancy ; but it is not larger at this period than in an 
 ovum of two or three months, and is from half an inch to an inch and 
 a half distant from the insertion of the umbilical cord in the placenta. 
 We regard this fact as very rare, having found it only twice in a great 
 number of deliveries. 
 
 § 2590. The umbilical vesicle is formed by rather a thick granular 
 membrane, which does not tear when forcibly distended with water. (4) 
 It gradually collapses, is covered with wrinkles, and becomes opaque. 
 The omphalo-mesenteric vessels are distributed in it. 
 
 It contains a whitish fluid, which gradually diminishes, becomes 
 thick, and finally hardens. 
 
 § 2591. We have treated of its connections with the fetus at some 
 length in the histoty of the development of the intestinal canal, and we 
 have attempted to demonstrate that very probably it communicates 
 with the ileon by the omphalo-mesenteric vessels and by a canal. 
 
 § 2592. Its constancy, its great size in the commencement, and its 
 probable existence before other parts, prove that it takes a very im- 
 portant part in the development of the fetus. 
 
 Judging from what occurs in birds, its contents pass into the body 
 of the fetus, and serve for nourishment, like yolk to the chicken. It 
 however disappears sooner than the vitelline sac. 
 
 § 2593. Opinions are still divided on the question whether there is, 
 as in all the other mammalia, an allantoid membrane ( allantois , s, 
 
 (1) Lobstein, loc. cit., p. 46. 
 
 (2) Oken, Beyträge, pt. ii. p. 83. 
 
 (3) Anatomie des schwängern Uterus, p. 68, 
 
 (4) Lobstein, toc. cit., p. 43. 
 
su 
 
 DESCRIPTIVE ANATOMY. 
 
 membrann media, )(\) which communicates with the bladder through 
 the urachus. 
 
 Needham, (2) Hale, (3) Bidloo,(4) Hoboken, (5) de Graaf,(6) 
 Littré, (7) Rouhault,(8) Neufville,(9) Haller, (10) Emmert,(ll) 
 Joerg,(12) Dutrochet.,(13) and Cuvier, (14) admit it. Paré, (15) Har- 
 vey, (16) Ruysch.(17) Heister, (18) Troortwyk,(19) Neu, (20) Albi- 
 nus,(21) A. Monro, (22) Danz,(23) and Hunter, (24) deny it. Al- 
 though some of the numerous facts adduced to support it are false, 
 and others but slightly conclusive, we however agree with the first of 
 these two opinions, because we have found in a human fetus about 
 four weeks old, between the chorion and the amnios, and independent 
 of the umbilical vesicle, a larger pouch, with thin parietes, collapsed, 
 and containing a limpid fluid. (25) We have seen this since. 
 
 Its existence may be supported : 
 
 1st. By the cases where we have found in the other membranes a 
 pouch different from the umbilical vesicle. In fact some observations 
 of this kind are very suspicious ; but we have several times been sa- 
 tisfied of the existence of a delicate layer, differing from the rest of the 
 ovum, which first forms a close vesicle until about the end of the se- 
 cond month of pregnancy, and which afterward appears as a thin 
 lamina. 
 
 2d. By the space between the amnios and the chorion. This space 
 is greater in the early periods than afterward, and is filled by a fluid 
 
 (1) R. Hale, The human allantoid discovered ; in the Phil, trans., p. 270, — Sel- 
 lius, De allantoide , Kiel, 1729. — C. de Neufville, De allantoide humanâ, Leyden, 
 1736. — Haller, De allantoide, 1739. — J. G. Betschler, Diss. num a fœtu urina secer » 
 natur et sécréta excernalur, Berlin, 1820. 
 
 (2) De formato fœtu , c. iii. 
 
 (3) Doc. cit. 
 
 (4) Tab. anat., 58, lit. E. 
 
 (5) Anat. secund. hum. rep., p. 428. 
 
 (6) De mulier. org., cap. xv. ; Opp. omn., p. 283. 
 
 (71 Mêm. de Paris, 1701, p. 115. 
 
 (9) Osservaz. anat. fis., Turin, 1724, p, 21. 
 
 (9) Doc. cit. 
 
 (10) Doc. cit. 
 
 (11) Nachtrag zu den beiden Abhandlungen über das Nabelblaschen ; in tha 
 Archiv, für die Physiologie, vol. x. p. 373. 
 
 (12) Die Zeugung, p. 288. Joerg however draws hie conclusions solely from the 
 space often existing between the chorion and the amnios. 
 
 (13) Doc. cit. 
 
 (14) M.ém. de Mus., vol. iii. 
 
 (15) Anat. chir., 1. ii. c. xxxv. 
 
 (16) Exerc. de gener. c. de memb. et humor. 
 
 (17) Thesaur. 3, no. 57 ; th. 9, no. 21. 
 
 (18) Eph. nat. curios, cent. II., obs. 190. 
 
 S De utero gravido ; p. iii., De allantoide. 
 
 De diff. fœt. et adulti, p. 105. 
 
 (21) Annot. acad., 1. i. c. xix. p. 75. 
 
 (22) Essays of a soc. of Edinb., vol. ii. 
 
 (231 Doc. cit., p. i. § 12. 
 
 (24) Anatomie des menschlichen schwängern Uterus, p. 84. 
 
 (25) Deutsches Archiv, für die Physiologie , vol. iii. tab. i. fig. 2. 
 
EMBRYOLOGY. 
 
 515 
 
 which is sometimes very abundant at parturition, and which forms 
 what is termed the false ivaters. 
 
 3d. By the analogy with other animals. 
 
 This vesicle has always very thin parietes, which are more delicate 
 than those of the other membranes. 
 
 Tt is not certain that it communicates at any period with the ura- 
 chus. Dutrochet admits this communication, but has never observed 
 it. It however probably exists, at least in the early periods of gesta- 
 tion, either from analogy, or because the urachus makes part of the 
 umbilical cord, or finally from the possibility of following it there more 
 or less to the placenta, (1) of introducing into it a liquid, (2) and even 
 of demonstrating within it an immediate connection between this body 
 and the allantoid membrane. (3) We have been able more or less 
 easily to follow the urachus in almost its whole length at every period 
 of pregnancy, and even to fill it partially wdth mercury : but we have 
 never been able to prove that it communicated either with the space 
 between the two proper membranes, or with the allantoid membrane. 
 
 We do not know certainly how long the allantoid membrane exists. 
 
 We have seldom been able to trace it evidently in the latter months 
 of pregnancy. 
 
 § 2594. The allantoid membrane is generally considered as the re- 
 servoir of the urine, which is carried to it by the urachus from the 
 bladder. 
 
 This is the opinion of most physiologists and physicians. 
 
 Joerg thinks even that the allantoid membrane itself secretes 
 urine, (4) which is not very probable, since the kidneys exist, and are 
 more developed than at subsequent periods of life. 
 
 Harvey, (5) Lobstein,(6) and Oken,(7) have advanced another opi- 
 nion. 
 
 Harvey maintains that the liquid of the allantoid membrane is not 
 urine, but a nutritious fluid : 
 
 1st. Because it exists in the ova where there is no fetus.(8) 
 
 2d. Because it is abundant when the organ is formed. (9) 
 
 3d. Because the allantoid membrane is at first proportionally and 
 even absolutely much larger than subsequently, (10) while it is ad- 
 mitted that the secretion of the urine is in a direct ratio with the ad- 
 vanced age of the fetus. 
 
 (1) Albinus, in Neufville, p. 42, 43. — Hunter, loc. cit., p. 45. — Cruikshank, ibid. 
 
 (2) Noreen and Rœderer. — A. Monro, in the Edinb. phys. essays and obs., vol. i. 
 p. 485. — Ridley, Obs. med. pr., London, 1703. 
 
 (3) Albinus, in Neufville, p. 43. But this undoubtedly refers to the umbilical 
 vesicle. 
 
 (4) Zeugung , p. 298. 
 
 (5) De gener. anim., Amst., 1662, p. 364. 
 
 (6) Loc. cit., p. 53. 
 
 (7) Bey träge, pt. i. p. 29. 
 
 (8) Harvey. 
 
 (9) Id. 
 
 (10) Lobstein, p. 54. 
 
516 
 
 DESCRIPTIVE ANATOMY. 
 
 4th. Because we cannot conceive why the urinary secretion should 
 be the most important function in the fetus.(l) 
 
 5th. Because the allantoid membrane is deficient in some mamma- 
 lia, and it is very improbable that the fetuses of some animals should 
 secrete urine and others not. (2) 
 
 6th. Because it is very difficult in the nearly perfect fetus of the 
 adult to pass air from the bladder into the allantoid membrane. (3) 
 
 7th. Because the fluid would not be excretory, since a considerable 
 number of umbilical veins (absorbents) are distributed in the enveloping 
 membrane. (4) 
 
 8th. Because the fluid differs from the urine. (5) 
 
 But all these arguments prove nothing against the old opinion, or in 
 favor of that of the writers who adduce them. 
 
 1st. The existence of the allantoid membrane and its fluid without 
 a fetus proves nothing, and that considered as such may be something 
 else, or the fetus may not be deficient. 
 
 2d and 3d. The size of the allantoid membrane and the quantity of 
 its fluid during the early period of gestation, are explained very well 
 by the more rapid progress of all the formations at this period, and 
 because very probably the other excretions do not take place then, or 
 at least but slightly. 
 
 4th. The size of the allantoid membrane does not prove that the 
 urinary secretion is the most essential of all the functions, but only 
 that it replaces in great part all the other excretory systems, from the 
 simple reason that the products of the action of these latter had been 
 in contact with the fetus during the whole of pregnancy. 
 
 5th. This fact is entirely incorrect, for the allantoid membrane is 
 very constant. Farther its absence might possibly be compensated 
 for in some way. 
 
 6th. In this case the same difficulty exists in passing air from the 
 allantoid membrane into the bladder, (6) while it is very easy during 
 the early periods of gestation, as we have more than once proved. It 
 follows then at most from this fact, that the quantity of urine secreted 
 gradually diminishes, and collects in the bladder. 
 
 7th. This objection rests upon confounding the allantoid membrane 
 with the chorion. The vessels do not belong to it, but to this latter ; 
 at least they do not absorb within it, but in the cavity of the uterus. 
 
 8th. It does not follow, for several reasons, from the fact reported, 
 that the liquid was not urine. 
 
 We cannot consider the allantoid membrane as the formative mem- 
 brane of the urinary and genital apparatus, or of the bladder, (7) for it 
 
 (1) Id., ibid. 
 
 (2) Id., ibid. 
 
 (3) Oken, p. 58. 
 
 (4) Harvey. 
 
 (5) Oken, p. 39 
 
EMBRYOLOGY. 
 
 517 
 
 birds it arises very evidently from the urinary system, and does no; 
 exist in the ova of the batracia. 
 
 The bladder is not formed by the urachus ;(1) but the canal corre- 
 sponding to the bladder and urachus, which was at first uniformly 
 narrow, enlarges at its lower part, is completely developed and be- 
 comes the bladder, while the upper part, which is not developed in the 
 same manner, remains the urachus. 
 
 II. ORIGIN OF THE OVUM, AND THE ORDER IN WHICH ITS PARTS FORM. 
 
 § 2595 . It is extremely difficult to determine the period at which 
 the ovum first appears. Although the duration of pregnancy is ascer- 
 tained with certainty, it does not necessarily follow that the new or- 
 ganism always begins to form at the same period, for the development 
 of the embryos of birds proves that although the ova are all matured 
 at the same period, there is, however, a great difference between em- 
 bryos of the same brood in the development of different organs, or of 
 the whole body. 
 
 From the eighth day after coition a tendency to form the deciduous 
 membrane, and also the fetal portion of the ovum, (2) has been ob- 
 served. 
 
 From the rapidity with which the transitory or permanent parts of 
 the body form successively in the superior animals, and from the pro- 
 portionally very small number of perfect observations on the develop- 
 ment of the ovum in particular, it is extremely difficult to determine if 
 the different parts of this latter, described in the preceding article, form 
 at the same time or at different periods, and also the order of their 
 appearance, and their part in the formation and development of the 
 fetus. 
 
 Very probably, however, the deciduous membrane begins to form at 
 the same time as the ovum, or the fetal portion of it, since we observe 
 the changes in the uterus, connected with its appearance, very early, 
 even before the latter is seen there. 
 
 Hitherto physiologists have generally considered the chorion and 
 the amnios as the most essential parts of the ovum, those which arise 
 first ; and even now the external of the two membranes to which the 
 least advanced ova can be reduced is considered the chorion, and the 
 internal as the amnios. 
 
 Analogy with the development of animals inferior to the mammalia, 
 however, renders it very probable that the umbilical vesicle is deve- 
 loped the first, and that the other membranes form after it, since in the 
 animals mentioned,' the vitelline sac, which corresponds to the umbili- 
 cal vesicle, appears long before all other parts of the ovum, which 
 precede only the body of the fetus. 
 
 (1) Ibid., p. 290. 
 
 (2) Home, Phil. Irans., 1817, pt. ii. p. 256-261. 
 
 66 
 
 VOL. III. 
 
518 
 
 DESCRIPTIVE ANATOMY. 
 
 III. FETUS. 
 
 § 2596. It is very difficult to determine precisely the period when 
 the human fetus(l) forms. This ought not to surprise, for this is still 
 more uncertain in the history of the oviparous animals even, notwith- 
 standing the greater facilities they present to the observer, and the 
 numberless observations upon them. It however is certain that a 
 greater or less length of time elapses after coition, followed by impreg- 
 nation, before the ovum becomes visible. 
 
 We may admit generally that it appears in the second week after 
 coition, and there are very probably greater or less differences in this 
 respect. Haller’s(2) opinion, however, that the fetus does not become 
 visible till the end of the third week does not seem to be entirely cor- 
 rect, since it does not agree, among others, with Home’s observation 
 mentioned in the preceding article. 
 
 I. MODE OF ORIGIN» 
 
 § 2597. The problem of the mode of origin of the fetus is still more 
 difficult, and all that has been said on this subject is reduced almost to 
 hypothesis, instead of observations and facts. 
 
 It is certain, however, that the fetus is united to its membranes from 
 the first. 
 
 The contrary opinion that it arises in the waters of the amnios, 
 without any adhesion, cannot be sustained. It is supported by the 
 following arguments :(3) 
 
 (1) Beside the works already cited in the course of this book, consult also: 1st. 
 On the form and structure of the fetus: — Cas3ebohm, Dc differentia, fœtus et adulti 
 anatomiccï, Halle, 1730. — C. J. Treu, De jlifferentiis quibusdam inter hominem. 
 nalumet nascendum intercedenlibus, Nuremberg, 1736. — Hebenstreit, Programma 
 de anatomc hominis reccns noli, Leipsic, 1739. — Treu, Descriptio et delineatio em- 
 bryonum humanorum ; in the Comm. Nor., 1739. — J. G. Rœderer, De fœtuperfecio, 
 Gottingen, 1750. — J. A. Langguth, De anatomice embryonis trium cum dvmidio 
 mensium, Wittembcrg, 1751. — J. G. Rœderer, De fœtu observationes, Gottingen, 
 1758. — H. A. Wrisberg, Descriptio anatomice embryonis observationibus illustrata, 
 Gottingen, 1764. — A. È. Koelpin, De fœtus et adulti différentiis, Gripswald, 1764. — 
 J. F. Dietz, Differentia fœtus ab adulto, Giessen, 1770. — A. and F. Rosslein, Dediffe- 
 rentiis inter fœtum et adultum , Strasburg, 1783. — Autenrieth, Supplémenta ad his- 
 toriam embryonis humani, Tubingen, 1797. — S. T. Sœmmerring, Icônes embryonum, 
 Frankfort, 1799. — 2d. On its mode of existence: — Rose, De natv.râ embryonis hu- 
 mani, Leipsic, 1774. — J. Van Solingen, De vitâfœtàs propriâ , Utrecht, 1782. — A. 
 Brendel, De nutritione fœtîis in utero materno, Wittcmberg, 1704. — Treu, De chylosi 
 fœtûs, Altdorf, 1715. — Bernhardi, De nutritione fœtus in utero, Halle, 1732. — J. de 
 Diest, An sui sanguinis solus opif ex fœtus, Paris, 1725. — A. Nann, Eversa vasorum 
 rubrorum uteri anastomosis et communicatio cum placenta, Erford, 1751.— R. 
 Forsten, Q uœsliones medicœ, Leyden, 1774. — Scha ffer, De commercio fœtûs cum 
 ■maire per nervös, Erlangen, 1775. — Richard, De modo nutritionis fœtûs, Erford, 
 1783. — Stoy, De nexu inter matrem et fœtum, Halle, 1786. 
 
 (2) El. phys., vol. viii. p. 61. 
 
 (3) C. F. Burdach, De priinis momcnlisformationis fœtûs, Königsberg, 1814. 
 
EMBRYOLOGY. 
 
 519 
 
 1st. The nervous system, which forms before all the other parts, is 
 never united with the ovum. 
 
 2d. A film is gradually developed in the midst of the fluid of the 
 amnios, which is the fetus. 
 
 3d. The fetus is straight originally, although it is the general opi- 
 nion that it curves from the moment of its origin. 
 
 All these arguments are easily refuted. 
 
 In fact the part first formed has not been strictly determined. It 
 seems probable to us that the rudiment first seen is the common base 
 of several parts, and even in the inferior animals one organ, and in the 
 most inferior the apparently homogeneous substance of their .body re- 
 presents several organs at the same time. Secondly, we can well 
 conceive that the nervous sy r stem appearing first, it is primarily con- 
 nected with the envelops of the ovum. 
 
 The second argument does not rest upon facts ; and we do not see 
 why the fetus could not be formed straight as well as curved from 
 some portion of the ovum. 
 
 Finally, another circumstance also exists against this opinion, viz. 
 the membrane of the amnios and the liquid it contains certainly'' appear 
 after the fetus in birds, and the fetus of these animals is connected with 
 the ovum at its first appearance. 
 
 The same is true doubtless of the human fetus. It is developed 
 “then on the ovum, and at the expense of one of its parts. 
 
 Another question now presents itself : At the expense of what part 
 of the ovum is it developed, and how does this development occur? 
 
 Judging from analogy with the other vertebrated animals, the hu- 
 man fetus is very probably developed upon the umbilical vesicle, and 
 at its expense. But analogy alone does not merely favor this hypo- 
 thesis, in support of which we may r also alledge the greater considera- 
 ble size of the umbilical vesicle at first, and the position of the lower 
 part of the fetus directly upon this pouch. 
 
 II. FORM. 
 
 § 2598. After its origin the fetus presents an almost infinite number 
 of degrees in its form and structure, the most general of which have 
 already been mentioned in the introduction, while-freating of the eight 
 laws of the organic formation, or in descriptive anatomy, in stating in- 
 regard to each system and each organ the peculiarities which charac- 
 terize it at different periods of its development. 
 
 The body of the fetus is longer at its first appearance than it is sub- 
 sequently. 
 
 The portion of its body which appears first, corresponds almost ex- 
 clusively to the trunk ; we only'- remark at its upper part a small pro- 
 minence separated from the rest .by a fissure, which is by no means 
 equal in -thickness to the central part of the body. This prominence 
 is the rudiment of the head. 
 
520 
 
 DESCRIPTIVE ANATOMY. 
 
 As yet there is no trace of extremities, nor of the other prominences, 
 particularly of the nose, the ears, and the genital parts. 
 
 The fetus has then the form of a worm. 
 
 It is entirely or almost entirely straight ; \ve only remark that the 
 dorsal face is slightly convex, and the abdominal slightly concave. 
 
 It is attached to the inner membrane of the ovum directly, or by a 
 very short umbilical cord at its lower extremity, or by the part of its 
 body directly above this extremity. 
 
 When the umbilical cord is inserted above the lower extremity of 
 the body, this extremity slightly curves from behihd forward, in the 
 form of a tail. 
 
 All the openings which afterward exist are now completely closed. 
 
 The head gradually becomes proportionally large, so that towards 
 the commencement of the second month it forms nearly half of the 
 whole body. It is generally smaller before and after this period. 
 
 The body of the fetus curves much at its upper and lower- extremi- 
 ties : the head is continuous with the* trunk at a right angle, and its 
 lower portion, which corresponds with the chin, is attached only to the 
 top of the chest ; the trunk is perfectly straight ; there is no trace of 
 the neck externally until the end of the second month. 
 
 Until the middle of the third month the lower extremity of the ver- 
 tebral column is curved from behind forward and from below upward, 
 projects below the anus, and represents the rudiment of a tail, which 
 is at first very long ; this gradually shortens and finally disappears 
 entirety, but it is always attached by its inner face. 
 
 The limbs appear in the fifth week of pregnancy : the superior ge- 
 nerally a little sooner than the inferior. They then have the form of 
 small tubercles terminated by a blunt summit. The superior are si- 
 tuated directly below the head, and the inferior directly before the 
 caudal extremity. Both proceed from behind forward, but a little also 
 from within outward, on account of the greater development of the 
 abdominal cavity. Sometimes also the superior go a little from above 
 downward, and the inferior slightly from below upward, but this ar- 
 rangement is by no means constant ; they often also, particularly the 
 inferior, assume an entirety opposite arrangement. 
 
 During the sixth week, and until the seventh, the stump which first 
 appeared and which gradually lengthened, is divided into a peripheri- 
 cal and a central segment : these segments correspond to the hand 
 and fore arm, to the foot and leg. 
 
 One or two weeks afterward a third appears, which represents the 
 arm and the thigh. 
 
 The segments formed last are much shorter than those which ex- 
 isted previousty, although the contrary is true when the fetus is per- 
 fectly developed. 
 
 About the period when the stump of the limb begins to divide into 
 an internal and an external part the latter becomes round, and enlarges 
 at its loose extremity, and a single band-like eminence is frequently 
 developed at its summit, from which it is separated by a depression. 
 
EMBRYOLOGY. 
 
 521 
 
 Thi3 eminence soon gradually divides to form the fingers, which are 
 at first proportionally short and thick, and which until the third month 
 are still united by a thin substance similar to the membrane between 
 the toes of web-footed animals, or the bones of the fins in fishes. 
 
 This uniting substance, this thin membrane, gradually disappears 
 from the summit to the base of the fingers and toes. 
 
 The upper limbs appear before the lower ; they also pass through 
 all their successive degrees of formation more rapidly than the latter. 
 They are for a long time absolutely larger, so that at five years of age 
 the four limbs have nearly the same length. 
 
 When the limbs appear we begin to see also the external genital 
 organs, the nose, the eyes, the ears, and the mouth, the successive de- 
 velopment of which follows the course mentioned when treating of 
 each of these organs. 
 
 The insertion of the umbilical cord gradually ascends. The umbi- 
 licus, however, is still proportionally much nearer the symphysis pubis 
 in the full-grown fetus than in the adult, which difference is directly 
 connected with the gradual diminution of the liver. 
 
 III. GROWTH. 
 
 § 2599. The fetus, which is at first only some lines long, gradually 
 becomes in ten lunar months about a foot and a half in length, and 
 about six pounds in weight. 
 
 The increase is very rapid at first, and afterwards is gradually 
 slower. It is asserted that it diminishes at the second month, that it 
 becomes more active in the third month, but especially during the se- 
 cond half of the fourth, that it is evidently most rapid in the centre 
 of pregnancy, and that it consequently becomes slower until the end 
 of pregnancy.(l) This proposition is proved with difficulty, for indi- 
 vidual differences may easily lead into error. We may however con- 
 ceive it to a certain extent, by attributing this slowness to the disap- 
 pearance of the umbilical vesicle about this period, and that it is not 
 completely replaced by another mode of nutrition. 
 
 IV. VITAL PHENOMENA. 
 
 § 2600. At the period of its appearance the fetus never makes part 
 of the organism of the mother. Its relations with the mother are the 
 same as those between the child and the external world. It lives a 
 peculiar life, as is demonstrated by the mode of connection between 
 the two organisms mentioned above. 
 
 (1) Autcnrieth, Suppl, ad. hist, embryon., p. 415. — Scemmcrring, leones embryo- 
 nutti, p. Ü. 
 
523 
 
 DESCRIPTIVE ANATOMY. 
 
 Among the vital phenomena those connected with the formation are 
 developed in the greatest degree, and at the expense of the rest. This 
 is proved by the rapidity with which the fetus increases in weight and 
 volume. 
 
 But the different functions of nutrition take place precisely in the 
 same manner in all essential respects before and after birth. We have 
 already mentioned the activity of the urinary secretion. The intestinal 
 canal and the skin are also active. 
 
 § 2601. We find very early in the intestinal canal of the fetus a 
 fluid which has not the same qualities at all periods. Until about the 
 centre of fetal existence this liquid is whitish and mucous : but it after- 
 wards changes to a yellowish green, which is thicker and more vis- 
 cid. It gradually becomes of a darker color in the large intestine, 
 until finally in the latter periods of pregnancy it has the same qualities 
 in the whole intestinal canal, so as to distend it. It is termed the 
 meconium. It is formed of about two thirds of water, about one third 
 of a peculiar substance, similar to vegetable matter, and of some hun- 
 dredths of mucus.(l) 
 
 Opinions vary in regard to the origin of the mec'onium. Some con- 
 sider it a residuum of the fluid of the amnios swallowed by the fetus ; 
 others think it formed from the secretion of the intestines. 
 
 Although the fetus very probably swallows and digests the fluid of 
 the amnios, yet as meconium has been found also in the intestines of 
 fetuses destitute of a head and mouth, (2) in a portion of the canal 
 situated below a septum which interrupted the continuity of the 
 tube, (3) in a separate end of the intestine which was closed in every 
 part, in the rudiment of a fetus adhering to another regularly formed 
 fetus, (4) and finally in the intestines of another perfect body, (5) it is 
 clear that the deglutition of the waters of the amnios are not necessary 
 to produce it. If consequently we sometimes find it only above the 
 obstacle, when the intestinal canal is obliterated in any part, (6) we 
 must not conclude from this that the fluid of the amnios has been 
 swallowed, and that the meconium is formed from it, (7) but it follows 
 at most that the secretion takes place principally at the upper part of 
 the alimentary canal. We thus explain the peculiar color of the me- 
 conium, which might be attributed to the bile, since the tint of this 
 fluid changes at the same time with it, (8) as we have ascertained, and 
 
 (1) Bouillon-Lagrange, in the Annales de chimie , vol. lxxxvi. and Ixxxvii. 
 
 (2) R. de Graaf, De mulier. org. ; in the Opp. omn., p. 292.— Odhelius, in the 
 fSchwcd. Abhandlungen , 1785, p. 176. — Gilibert, Advers. med. pract., p. 132. 
 
 (3) Pied, in the Journ. de med., an. x., frimaire. 
 
 (4) Simmons, Aledical facts , vol. viii., London, 1800, p. 7. 
 
 (5) Brugmans, in Bernard, Q uœst. var.med. argum., Leyden, 1796. De meconi. 
 origine, p. 31. 
 
 (6) Horch, Eph. nat. cur., dec. iii. a iii. p. 188.— Uesgranges, in the Journ. de 
 méd., an. x., thermidor. — Osiander, Neue Denkwürdigkeiten, vol. i. p. 179. 
 
 (7) Osiander, Handbuch der Entbindungskunde, vol. i, p. 237. 
 
 (8) Lobstein, p. 132. , 
 
EMBRYOLOGY, 
 
 523 
 
 as in an acephalous full-grown fetus the intestine contained a viscous, 
 semitransparent mucus, not colored black. (1) 
 
 It, however, remains to be ascertained whether this hypothesis has 
 any foundation, since the authors who describe the cases mentioned by 
 us formally indicate the existence of a yellow matter having the qua- 
 lities of meconium, and chemical analysis has not proved in it the 
 existence of bile. (2) 
 
 However this may be, the bile seems to have some part in pro- 
 ducing the meconium. In fact in some cases, particularly in that 
 mentioned by Sims, and the subject of which was a child two years 
 old, obliteration might be caused consecutively ; in others, as in that 
 described by Brugmans, some difference is stated between the meco- 
 nium in that portion of the intestine which communicated with the 
 biliary system and that inclosed in the lower intestine. Thus although 
 the bile is not found in this fluid, it may perhaps contribute to produce 
 it. Possibly also when the liver is deficient the intestinal canal sup- 
 plies the action of this gland. 
 
 § 2602. The surface of the body of the fetus is covered with a sub- 
 stance of a peculiar character, termed the vernix caseosa. (3) 
 
 This substance is yellowish white, viscous, and fatty. 
 
 From its chemical composition it is between the fibrin and the fat, 
 and very much resembles adipocere.(4) 
 
 It does not exist during the whole of gestation, but begins to appear 
 about the sixth month. 
 
 Opinions are divided in respect to its origin. Some consider it as a 
 precipitate from the waters of the amnios deposited on the surface of 
 the body of the fetus :(5) others think it is secreted by this latter.(6) 
 
 This last opinion is very probably more correct than the other. In 
 fact : 
 
 1st. The glandular system, particularly that of the sebaceous 
 glands of the skin, is much more developed in the fetus than subse- 
 quently. 
 
 2d. The vernix caseosa is very abundant in the parts where these 
 glands are very numerous, in the head, the axillae, and the inguinal 
 regions. 
 
 (1) Monro, Trans, of a soc. of Edinburgh , vol. i. p. 216. 
 
 (2) Simmons, loc. cit., p. 7. 
 
 (3) J. J. G. Schulz, De ortu et usu caseosæ vernicis, 'Helmstadt, 1788. 
 
 (4) Buniva and Vauquelin, Annales de chimie , vol. xxxiii. — Emmert and Reusa 
 Chemischi Untersuchung des Fruchtwassers aus dem zeitigen Ei und der käsigen 
 Materie auf der Haut des neugebornen Kindes ; in Osiander, Annalen vol ii 
 
 p. 122. 
 
 (5) Boehmer, De aquis ex utero gravid, et partur. prof., Halle, 1769, § ii. 
 
 Schulz, loc. cit. 
 
 (6) Levret, Art des accouchemens , 1766, p. 75. — Schulze, Anweisung zur Hebam- 
 menkunt , Hildburgshausen, 1770, p. 49.— Wrisberg, in Rcederer, Eiern, artis obstet., 
 note 37.— Bmmert, loc. cit., p. 134.— Lobstein, loc. cit., p. 99.— Hunter, Anat. des 
 swang. Uterus, p. 96. 
 
524 
 
 DESCRIPTIVE ANATOMY. 
 
 3d. It is found only in the fetus : the membranes of the ovum and 
 the umbilical cord present no trace of it. 
 
 4th. It is very similar to the substance furnished by the sebaceous 
 glands of the glans penis, and its qualities do not allow it to be re- 
 garded as a precipitate from the waters of the amnios. 
 
 § 2603. We shall demonstrate hereafter that the fetus respires by 
 means of the placenta. 
 
 We shall also mention the differences presented in it by the fetal 
 circulation. 
 
 § 2604- The motions of the voluntary muscles are but slight. They 
 generally begin to be felt about the middle of pregnancy, although we 
 cannot conclude from this that they do not occur before, since they 
 may be unperceived on account of the smallness of the fetus, and the 
 abundance of the waters of the amnios. 
 
 § 2605. The fetus necessarily derives in the body of the mother 
 the materials for its growth, preservation, and its secretions. But 
 here a question presents itself: Are there or not several modes of nu- 
 trition ? 
 
 Different authors, particularly Hippocrates, Aristotle, Galen, Mon- 
 ro, (1) and Danz,(2) admit only one mode of nutrition, and consider the 
 umbilical vein as the only channel through which nutrition comes to 
 the fetus. 
 
 Others believe in the existence of several other channels, as the skin 
 and the system of the mucous membranes, in a greater or less extent. 
 According to this last hypothesis, the waters of the amnios are the 
 source of nutrition for the fetus. 
 
 Several ancient writers, cited by Haller, (3) and among the moderns, 
 Vas, (4) Brugmans,(5) Van der Bosch, (6) and Osiander,(7) admit that 
 the skin absorbs. 
 
 Opinions vary much in regard to the extent of the poition of the 
 system of the skin which contributes to nutrition. 
 
 According to Harvey, (8) Lacourvee,(9) Haller, (10) Treu, (11) and 
 Darwin, (12) absorption takes place only by the intestinal canal. 
 
 Scheel(13) asserts that it occurs also by the lungs, into which the 
 waters of the amnios come through the mouth and nose. 
 
 (1) Monro, Essay on the nutrition of the fetus ; in the Ed. mcd. essays, vol. ii. 
 p. 102. 
 
 (2) Zerglicderungskundc des neugebornen Kindes. 
 
 (31 El. phys ., vol. viii. p. 205. 
 
 (4) C. J. Vos, IJe nutritione imprimis nervosa, Utrecht, 17S9. 
 
 (5) In Van den Bosch, De natura el ulilitate liquoris amnii, Utrecht, 1792. 
 
 (6) Ibid. 
 
 (7) Handbuch der Entbindungskunde, vol. i. p. 237. 
 
 (8) De gcneralione , Amsterdam, 1662, p. 253, 368. 
 
 (9) De nutritione, fœtus in utero paradoxa, Dantzic, 1655. 
 
 (10) El. phys., vol. viii. pt. i. p. 201. 
 
 (11) De chylosi fœtus, Altdorf, 1715. 
 
 (12) Zoonomic, vol. i. 
 
 (13) De liquoris amnii ulilitalc, Copenhagen, 1795. 
 
EMBRYOLOGY. 
 
 525 
 
 To these parts Lobstein(l) adds the genital organs also. 
 
 Finally, Oken(2) thinks that the mammae also absorb ; but instead 
 of admitting, as had already been done, (3) that the fetus absorbs the 
 milk secreted by its proper mammae, he asserts that these latter organs 
 absorb only the waters of the amnios, and that the fluid introduced by 
 them is carried by their lymphatic glands into the thymus gland, 
 whence it enters the thoracic canal. 
 
 The following have been considered also as sources of the nutrition 
 of the fetus : 
 
 1st. The fluid of the umbilical vesicle. (4) 
 
 2d. That of the allantoid membrane. (5) 
 
 . 3d. The gelatine of Wharton.(6) 
 
 Those who maintain several modes of nutrition think that they are 
 brought into use simultaneously or successively. The first opinion 
 has more supporters than the second. 
 
 We can hardly arrive at positive results until we have mentioned 
 and discussed the arguments of each party. 
 
 § 2606. Those physiologists who think that the materials of nutri- 
 tion are brought to the fetus through the umbilical vein, rest their opi- 
 nion upon the following facts : 
 
 1st. The constant and general existence of the umbilical cord, the 
 chorion, and the placenta. 
 
 2d. The ' peculiar structure of these organs, and their connections 
 with the fetus. 
 
 3d. Their early appearance. 
 
 4th. The villosities of the chorion are at first only venous, so that 
 they have no function but that of absorption. (7) 
 
 5th. The fatal consequences which the interuption in the circula- 
 tion of the blood causes in the nutrition and vitality of the fetus. 
 
 The arguments cited by the partisans of nutrition by the waters of 
 the amnios generally, are : 
 
 1st. The existence of nutritious materials in this fluid. 
 
 2d. The gradual disappearance of these materials, and the diminu- 
 tion of the liquid near the end of pregnancy. 
 
 3d. The fetus continues to live and be nourished, although the cord 
 is altered in texture, obliterated, and even entirely separated from the 
 body, the umbilicus being perfectly closed at birth. 
 
 (1) Essai sur Innutrition du fœtus, p. 102. 
 
 (2) Zeugung , Hamburg’, 1805, p. 162. 
 
 (3) Danz, toc. cit., vol. ii. p. 71. 
 
 (4) Needham, De formato fœtu, Loudon, 1C67, p. 79. — Blumenbaeh, Specim., 
 physiolog. comp, inter animalia cal. sang. ovip. et vivip., Gottingen, 1786.— Id., 
 Instit. physiol., p. 449. — Soemmerring, in Haller, Grundriss der Physiologic , 1796, 
 vol. ii. p. 800. — Lobstein, loc. cit . — Emmert, Vcbcr das Nabclblaschen ; in Riel, _4r- 
 chiv. für die Physiologic, vol. x. p. 77.— Jocrg, Zeugung, p. 286. 
 
 (5) Harvey, Lobstein, Oken. 
 
 (6) Lobstein. 
 
 (7) Lobstein, loc. cit., p. 117. 
 
 VOL. III. 
 
 67 
 
526 
 
 DESCRIPTIVE ANATOMY. 
 
 4th. It is a fact that no substance can be placed next to the body, 
 but a mutual action and reaction is established. 
 
 5th. The parts with which the fluid of the amnios is in relation 
 possess the power of absorption. 
 
 We consider the following as facts which demonstrate absorption 
 particularly by the skin : 
 
 1st. The experiments where the lymphatics of the skin are filled 
 with the fluid of the amnios. 
 
 2d. The known instances of fetuses without a mouth and an umbi- 
 lical cord. 
 
 Those who think that the mucous surfaces absorb, rest their opinion 
 on the following arguments : 
 
 1st. The necessity that the waters of the amnios should penetrate 
 internally in cases of fissure of the mouth and palate, although the 
 fetus does not become thinner. 
 
 2d. The existence of this liquid in the upper part of the intestinal 
 canal, the lungs, and even the vagina. 
 
 3d. The products of digestion found in the intestinal canal. 
 
 4th. The downy hairs of the fetus found in the meconium. 
 
 5th. The motions of deglutition observed in fetuses immersed in the 
 fluid of the amnios. Their attempts at biting and sucking before and 
 after birth. 
 
 6th. The existence of the meconium at the upper part of the intes- 
 tine, when the canal is interrupted in any portion of its extent. 
 
 Those physiologists who think that the liquid in the umbilical vesi- 
 cle contributes to nutrition, cite : 
 
 1st. The analogy of this organ with the vitelline sac of the other 
 vertebrated animals, and the evident passage of the liquid into the 
 intestinal canal. 
 
 2d. The great size of the umbilical vesicle, then its wasting, at- 
 tended with a change in the nature of the fluid within it. 
 
 We have already mentioned the arguments for thinking that the 
 liquid of the allantoid membrane contributes to nutrition. 
 
 Those who think that the gelatine of Wharton also assists in this 
 function, adduce : 
 
 1st. Its nutritious properties. 
 
 2d. Its abundance in the early periods of fetal existence, which is 
 connected with the shortness and size of the umbilical cord, since the 
 size of this cord does not depend solely on the presence of a greater 
 number of parts within it. 
 
 3d. The observations of Noortwyk, Rcederer, and Uttini, which 
 have shown that fluids can be made to pass into the gelatine of 
 Wharton. 
 
 4th. The greater proportional development of the vessels and glands 
 of the lymphatic system in the upper half of the anterior face of the 
 
F.MERYOLOG Y. 
 
 527 
 
 bodj r on leaving the umbilicus, but principally in the anterior medias- 
 tinum,^) which fact we have always proved. 
 
 § 2607. Those who admit but one mode of nutrition, particularly 
 that by the umbilical vein, adduce, first the fact that other channels, 
 particularly the absorption of the waters of the amnios by the skin and 
 the mucous membranes, are insufficient ; and secondly that it is 
 indispensably necessary to the life of the fetus for this passage should 
 be open. 
 
 1st. The following reasons are alledged as leading one to think that 
 nutrition by the waters of the amnios is not probable. (2) 
 
 a. The liquid is formed from the blood of the fetus. 
 
 b. It contains but little nutritious substance.(3) 
 
 c. A very marked alteration in its composition has no effect on the 
 life or health of the fetus. 
 
 d. The fetus continues to live a greater or less length of time after 
 the dribbling of the waters. (4) 
 
 e. The instances of the fetus having lived, although the umbilical 
 cord was interrupted, obliterated, or separated from the body, are not 
 authentic. 
 
 f. There is a considerable quantity of the amniotic fluid at the end 
 of gestation. (5) 
 
 2d. Nutrition by the skin particularly has been opposed by the fol- 
 lowing arguments :(6), 
 
 a. The caseous envelop which covers it. 
 
 b. The necessary stagnation of the liquid in the cellular tissue after 
 penetrating it. 
 
 c. The viscidity of the waters of the amnios, which render them 
 unfit to enter through the skin. 
 
 3d. The arguments against the entrance of this liquid through the 
 mouth are : 
 
 a. The want of similitude between the waters of the amnios and 
 the fluid in the stomach. (7) The dissimilarity even between these 
 waters and the meconium. (S) 
 
 b. The impossibility of swallowing unless respiration occurs.(9) 
 
 c. The frequent closing of the mouth. (10) 
 
 d. The fact that milk injected into the amnios does not enter the 
 oral passages.(ll) 
 
 (1) Lobstein, p. 139. — Monro, loc. cit., p. 143. — Van den Bosch, loc. cit. 
 
 (2) Danz, p. 59. 
 
 (3) Van den Bosch, in Schlegel, p. 458. 
 
 (4) Van den Bosch, p. 458. 
 
 (5) Monro, p. 166. 
 
 (6) Haller, El. phys., viii. p. 205. 
 
 (7) Monro, p. 163. — Van den Bosch, p. 460. 
 
 (8) Danz, p. 60. 
 
 (9) Danz, p. 59. 
 
 (10) Monro, p. 173. — Van den Bosch, p. 458 459. 
 
 (11) Monro, p. 175. 
 
528 
 
 DESCRIPTIVE ANATOMY. 
 
 c. If the amniotic fluids penetrate into the oral cavity by any pres- 
 sure, they would be introduced into the trachea as well as into the 
 esophagus.(l) 
 
 /. Iustances of acephalous and astomatous fetuses, which however 
 were fleshy.(2) 
 
 g. The products of digestion found in the intestinal canal prove no- 
 thing, since they may arise solely from the action of this organ, (3) and 
 tho more as meconium also has been found above the point where ob- 
 literation had occurred. (4) 
 
 h. The existence of the meconium and the hairs in the stomach 
 prove nothing, for hairs might be developed in the alimentary canal, 
 and the meconium pass up through the intestines into the stomach. (5) 
 
 i. We may also consider deglutition and the sucking of the newly 
 born child as valueless, since numerous other phenomena supervene at 
 the period of birth, although the system has made no previous at- 
 tempts, and the latter had already commenced before parturition by 
 swallowing the waters of the amnios. 
 
 j. The existence of the amniotic fluid in the stomach is abnormal, 
 and results from powerful compression. (6) 
 
 4th. We have already refuted previously the arguments which go 
 to prove that the fluid of the allantoid membrane contributes to nu- 
 trition. 
 
 § 2608. We have now to examine whether all the arguments 
 alledged against the hypothesis that the fetus is. nourished by the fluid 
 of the amnios are sufficient to refute it. 
 
 Strict inquiry determines that they are not. 
 
 1st. It is not proved, and it is not even probable, that the waters of 
 the amnios are formed from the blood of the fetus, since the vessels of 
 the chorion may not necessarily be other than the organs of nutrition, 
 and the fluid of the amnios may be secreted by the uterus. 
 
 2d. The slight proportion of nutritious materials proves nothing, 
 because nutrition may be well performed with substances which con- 
 tain less of it, and also because the fluid of the amnios at first contains 
 more of it ; finally because the greater energy of the formative power 
 in the fetus is a sufficient compensation. 
 
 3d. The third and fourth arguments prove at most only that the 
 liquid of the amnios is not the only source of nutrition in the fetus, or 
 that the fetus might exist for some time without it : even this latter 
 circumstance does not follow, for it is not probable that the fluid of the 
 amnios is ever reproduced after it has escaped. 
 
 (1) Danz, p. 59. — G. J. C. Themelius, Comment, qui nulritionem fœtus in utero 
 per vasa umbilicalia solum fieri, occasione monstri ovilli sine ore et faucibus nati 
 ostenditur, Leipsic, 1751. — Van den Bosch, p. 459. 
 
 (2) Danz, p. 60. 
 
 (3) Van den Boscli, p. 461. 
 
 (4) Brugmans, in Van den Bosch, p. 461. 
 
 (5) Monro, p. 177, 178. 
 
 (6) Danz, p. 59, 60. 
 
EMBRYOLOGY. 
 
 529 
 
 4th. We cannot apply to several well attested cases of infants being 
 bom with the umbilical cord really obliterated, the too general objection 
 that all those of this kind are not authentic ; the only conclusion how- 
 ever to be drawn from this is, that the fetus can support for some time 
 the interruption of its communications with the uterus through the 
 medium of the cord. 
 
 5th. The existence of a great quantity of the liquid of the amnios 
 at the end of pregnancy, is without value, since the absolute quantity 
 of the liquid is generally very much diminished at this period. If it 
 is less in quantity in the latter periods of gestation, the only conclusion 
 to be drawn from this is, that it is then less necessary, which coincides 
 with the hypothesis that it serves for nutrition, as the formative acts 
 have then more power, and also possibly another more efficacious 
 mode of nutrition is then developed. 
 
 The arguments adduced against nutrition through the skin are 
 easily refuted. 
 
 1st. The vernix caseosa does not exist in the early periods of gesta- 
 tion, that is, v/hen the fluid of the amnios contains most nutrition, and 
 when the formative acts are most rapid. Even when it is seen, it does 
 not form on the skin a uniform layer which covers it so as to prevent 
 absorption. 
 
 2d and 3d. There is no proof that the stagnation of the amniotic 
 fluid under the skin is necessary, and of the impossibility of its pene- 
 trating farther. This stagnation, on the contrary, is very improbable. 
 
 The arguments adduced against nutrition by the mouth are not con- 
 clusive : for, 
 
 1st. The dissimilarity between the fluid in the stomach and the fluid 
 of the amnios is easily explained by a change in these latter ; farther, 
 we have often remarked a perfect identity between the two fluids. 
 
 2d. The impossibility of swallowing without breathing is not de- 
 monstrated, and certainly is not a fact. Farther, the fluid of the 
 amnios might enter into all the cavities, without being swallowed. 
 
 3d. The closing of the mouth is a useless argument, since this 
 does not always occur, and the mouth has been observed to be open 
 in the fluid of the amnios. 
 
 4th. The same is true in regard to the non-entrance of the milk, -for 
 in these experiments the animal was dead. 
 
 5th. The penetration of the fluid of the amnios with the trachea is 
 unattended with inconvenience ; . perhaps even it is useful. Farther 
 observation seems to demonstrate that it really occurs. 
 
 6th. The acephalous fetuses only prove that this passage is not the 
 only channel through which nutrition takes place, 
 
 7th. The development of the hairs is so rare a phenomenon that the 
 constant existence of these hairs in the meconium should be considered 
 as a very peremptory argument in favor of the introduction of the fluid 
 of the amnios into the alimentary passages, although the presence of 
 the meconium proves nothing. Besides these hairs resemble the silky 
 down of the fejus. 
 
530 
 
 DESCRIPTIVE ANATOMY. 
 
 8th. Although we reject, and with reason, the opinion that swal- 
 lowing of the waters of the amnios would be a kind of prelude to 
 sucking and deglutition, it does not follow that when this liquid is 
 found in the stomach its presence should be regarded as unusual. 
 
 § 2609. Thus the nutrition of the fetus .by the fluid of the amnios 
 still continues at least very probable. 
 
 It is no less difficult to doubt the nutrition by the fluid of the umbi- 
 lical vesicle and the gelatine of Wharton. We have reason to think 
 that the whitish fluid contained in the placenta constantly passes into 
 the body of the fetus through the umbilical cord. 
 
 But it is very improbable that the fluid of the allantoid membrane 
 contributes to its nutritional ) 
 
 § 2610. We have now to examine if nutrition by the umbilical vein 
 rests on as firm a base as those assert who think it the only -source of 
 nutrition. 
 
 We cannot at least deny that the contrary opinion can be main- 
 tained, since the facts alledged prove only the necessity of the circula- 
 tion of the blood in the chorion and placenta, but establish nothing 
 in regard to the function of these parts. 
 
 Farther, as the fetus is nourished in three other modes, and as it 
 cannot be proved that these three modes are insufficient, we have a 
 right to admit that the circulation of the blood in the placenta by the 
 vessels of tire fetus has not the uses commonly assigned to it, provided 
 always that we mention others which are probable. 
 
 But this is possible. In fact this function corresponds to respiration ; 
 several physiologists, both ancient and modern, have compared the 
 placenta to the lungs.(2) 
 
 The arguments in favor of this opinion are : 
 
 1st. The general necessity of respiration, which cannot be performed 
 in any other manner. 
 
 2d. The analogy between the pulmonary and placental circulations, 
 the placenta and lungs both receiving the blood, from which the se- 
 tt) G. F. St. Hilaire (Monstruosités humaines , p. 279) having’ found in the intes- 
 tinal canal an anomocephalus of real fecal matters, moulded even into lumps in the 
 post-ccecal intestine, was led by this phenomenon to examine the proper nutrition of 
 the fetus. He thinks that the mucus secreted in the alimentary passages, and which 
 is in too great a quantity to be used simply as a lubricating fluid, is the aliment first 
 digested; that it is taken up at first by the digestive organs, then by thechyliferous pas- 
 sages, it is the source of the nutritious fluid, which thus flows constantly into the 
 circulatory system, and which at each passage is gradually animalized. Considered 
 in this manner, the nutrition of the fetus would resemble that of the adult. This 
 hypothesis, in accordance with which the discharge of mucus would be caused by 
 the irritation of the mucous membranes by the bile, is very ingenious, but is impro- 
 bable. In fact we should be obliged to admit that the alimentary tube acts in two 
 totally different ways in regard to the mucus, one action forming the mucus, the 
 other converting it, changing it into chyle. F. T. 
 
 (2) Mayow, Duverney, Vallisneri, Cheselden, Hérissant, Bœerhaave, and Jampert, 
 in Haller, Elem. physiol., vol. viii. p. 254. — Eckardt, Q uestio an duæ arteriœumbili- 
 cales feetui pulmonum loco inserviunt, Jena, 1761. — E. Darwin, Zoonomie, vol. i. — 
 B. N. G. Sclireger, Defunctione placentae uterinæ, Erlangen, 1795. — Lobstein, loc. 
 cit. — Oken, Der Atmungsprocess des Fötus ; in Lucina , vol. iii. p. 294. 
 
EMBRYOLOGY. 
 
 531 
 
 cretion and nutrition of the body are derived, and which must conse- 
 quently be renewed. 
 
 3d. The analogy between the animals which breathe by bronchiæ, 
 and the fetus of the animals which have lungs. 
 
 4th. The rapidity with which death ensues, when the circulation' 
 through the placenta is interrupted. 
 
 5th. The analogy with birds and reptiles, in which the blood of the 
 umbilical vessels really undergoes through the egg-shell the changes 
 produced by respiration. 
 
 Very probably then the blood of the fetus is really changed in the 
 placenta, similarly to what it is in the lungs, and the arterial blood of 
 the mother replaces the circulating medium, which is acted upon by 
 the oxygen. 
 
 We cannot adduce against this hypothesis that there is no differ- 
 ence in the color of the blood in the umbilical vein and arteries, as se- 
 veral observers worthy of confidence have proved, and as we have 
 satisfied ourselves on several occasions ; for possibly the fetus having 
 but little need of oxygen its blood absorbs but a small quantity, and 
 consequently its color is but slightly changed. 
 
 Schweighæuser has advanced an opinion directly the opposite of 
 this.(l) He thinks that the function of the placenta is to change that 
 which the umbilical veins bring to it into venous blood, and which 
 does not suffer this change in the body of the fetus, in order to render 
 it proper to secrete the bile and to form the solid parts, particularly the 
 nervous system. But this hypothesis is supported by no fact, but it is 
 opposed by several. Thus nutrition in general, and that of the 
 nervous system particularly, is performed by the arterial blood ; the 
 bile may be formed from this blood. Besides the respiratory function 
 of the placenta is imperfect, and consequently the difference between 
 the blood in the umbilical vein and arteries is almost nothing. We 
 cannot consider that of the vein as pure arterial blood, since it has 
 already circulated very extensively in the upper half of the body. 
 Finally, in the ovum of birds the blood of the umbilical artery is black, 
 and that of the vein is red. 
 
 The placenta then is principally a respiratory organ, by means of 
 the circulation in the umbilical vessels. (2) 
 
 (1) &ur quelques points de physiologie relatifs à la conception et à l'économie or- 
 ganique du fœtus, Strasburg-, 1812, p. 19. 
 
 (2) G. F. St. Hilaire (Philosophie anatomique, p. 538) thinks that the fetus respires 
 
 through allits pores like the aquatic insects, that it separates the air from thcsurround- 
 ing liquids, and that the uterus performs the part of the right ventricle by sending 
 the amniotic fluid into all the integuments of the body. This opinion has been con- 
 firmed by Lassaigne’s discovery of a gas very analogous to the atmospheric air in 
 the amniotic fluid. Muller has enlarged upon this (De respirations fœtus commen- 
 tatio physiologica, Leipsic, 1823). This author thinks that the necessity of respira- 
 tion of the fetus is to that of the child as 10 : 15, or as 2 : 3. But the placenta also 
 concurs in it as well as the amniotic fluids. The fine experiments of Edwards on 
 the asphyxia of the batracia are naturally connected with this great question, and 
 may contribute to resolve it. F - T. 
 
532 
 
 DE8CRIPT1VE ANATOMY. 
 
 The liver probably assists in this function, since the umbilical vein 
 ramifies very extensively before carrying the blood into the ascending 
 vena-eava. 
 
 The more gross nutritious substance is introduced through the 
 channels mentioned above. 
 
 But all these channels do not exist during the whole of fetal exist- 
 ence. 
 
 The umbilical vesicle first becomes inactive in the second month of 
 pregnancy. After the first half of gestation, nutrition by the waters of 
 the amnios diminishes much, because the fluid lessens in quantity and 
 nutritious qualities, and the vernix caseosa diminishes absorption by 
 the skin. It would seem then that latterly no other channel exists 
 but the gelatine of Wharton. 
 
 V. duration of the fetal state, and birth. 
 
 §2611. The fetal state usually continues ten lunar months. After 
 this period the fetus is born , that is, it is detached from the body of the 
 mother, and enters into a direct relation with the general organism, 
 being now capable of an independent existence. 
 
 It however is frequently separated before the normal end of gesta- 
 tion ; this is termed abortion (abortus). The union between the two 
 organisms rarely continues too long ; this is termed a late birth (partus 
 tardivus , s. serotinus). ( 1) 
 
 The fetus cannot survive independent of the mother until the sixth 
 month of gestation : even then it generally dies. (2) It has long been 
 disputed to what extent beyond the common period the birth may be 
 protracted ; and the discussion is not terminated. The possibility of 
 the fact cannot be doubted, and is attested by several authentic in- 
 stances. We cannot, however, deny that a great many of them re- 
 lated depend on the necessity in order to render them legitimate, of 
 a conception supervening in the mother, after the death of the hus- 
 band. 
 
 § 2612. Parturition is accomplished by the contraction of the uterus, 
 aided by that of the abdominal muscles. These contractions com- 
 mence at the base of the organ, while the slighter fibres of the neck 
 gradually cease to act. Hence the cavity of the uterus shortens and 
 contracts, and consequently all parts of the organ, except the lower, 
 greatly compress the fetus, which escapes through the part which 
 presents the least resistance,, that is, through the dilated orifice of the 
 uterus, whence it passes into the vagina, and then through the ex- 
 ternal orifice of the genital organs. 
 
 (1) Ucbcrfriili-und spätreife Geburlcn, Mannheim, 1807. 
 
 (2) The case of a fetus, said to be only five months old, which lived nine months, 
 has recently been reported. (V. Kodman, iu the Kd. mod. and sui t?. Journal , vul. xi, 
 |\ 455 ; vol. xii. p. 251.) 
 
EMBRYOLOGY. 
 
 533 
 
 Usually, about as one thousand times to one, the membranes of the 
 ovum, which enter the first, break before the fetus has left the cavity 
 of the uterus, and most of the fluid of the amnios escapes. After the 
 fetus is expelled the uterus is freed from the ovum, by the contraction 
 of the organ following parturition, which very much diminishes the 
 extent of the surface by which it adheres, and ruptures the vessels 
 which unite the placenta. When the posterior fold is once detached 
 the final contractions of the uterus cause its expulsion. 
 
 The connections between the ovum and the ftterus are rarely de- 
 stroyed by the first contractions of the latter, and the child is bom 
 enveloped in its membranes, like the young of the mammalia. This 
 case probably happens only in continued pregnancies. It is normal, 
 on the contrary, in abortion. 
 
 § 2613. After parturition, lactation also establishes, for a greater or 
 less length of time, a material connection between the mother and the 
 child. 
 
 The mammae during pregnancy are changed like the uterus. They 
 enlarge, become more vascular, softer, and looser. Their granulations 
 are more distinct. In a word, they resemble the other glands, the 
 secretory activity of which continues uninterruptedly, while preg- 
 nancy assimilates the uterus to the muscles which are constantly in 
 action. 
 
 The secretion of the milk begins in the last weeks of pregnancy, but 
 it is very imperfect. 
 
 The human milk, like that of the other females of the mam- 
 malia, is decomposed by rest into two parts, one fat and yellowish, the 
 other serous ; the former, or the cream, divides into butter and butter- 
 milk. The cream and the creamy milk both contain a substance ana- 
 logous to albumen, the caseous substance, of which there is but little 
 in the milk of the female, and it is there softer and less coagulable than 
 in that of other animals. It is coagulated by heat and acids, and thus 
 it may be obtained separately. The serous portion of the milk, when 
 entirely freed from caseous substance, has a sweetish taste, which is 
 owing to the sugar of milk, which abounds in the milk of the female. 
 Many calcareous salts exist in the caseous matter. The slight quan- 
 tity of this latter and its softness prevents the milk of the female from 
 coagulating, or at least but slightly. It is asserted that its cream 
 does not give butter, which is not true. 
 
 Vol. 111. 
 
 6S 
 
534 
 
 DESCRITTIVE ANATOMV. 
 
 CHAPTER II. 
 
 OF CONCEPTION IN THE ABNORMAL STATE. (1) 
 
 § 2614. The anomalies in the genital organs connected with coition, 
 pregnancy, and parturition, are less numerous and less worthy of no- 
 tice than those presented by the new organism. 
 
 I. GENITAL ORGANS. 
 
 § 2615. An anomaly sometimes occurring in the organs of coition 
 is the continuance of the hymen after copulation, and sometimes after 
 parturition. It deserves attention, as it indicates that the presence of 
 this fold is not a certain sign of virginity, and as it renders parturition 
 difficult, particularly when the hymen is solid. 
 
 Among the anomalies of the genital organs of the female, of which 
 we have already spoken above, the adhesion of the abdominal extre- 
 mities of the Fallopian tubes with the adjacent organs, particularly 
 with the anterior and posterior face of the broad ligaments, the uterus, 
 the bladder, the rectum, and the ovaries, and the obliteration of their 
 abdominal orifices, are principally results of coition. These two states 
 are observed particularly in prostitutes, (2) where they are probably 
 produced by the frequent and excessive stimulation of the genital 
 parts. They are also common in sterile females, and should be re- 
 garded as the most usual cause of sterility, since they prevent the 
 motion of the tubes, and the entrance of the fluid from the ovaries into 
 the uterus. 
 
 II. NEW ORGANISM. 
 
 § 2616. We shall examine here, among the anomalies which may 
 supervene on conception and in the formation of a new organism, only 
 those which affect the whole new being and the ovum particularly, 
 since we have already mentioned the deviations in the formation of 
 the fetus, either generally or particularly, in the several parts of this 
 work. 
 
 1st. The first anomaly of the ovum is the place where it is formed. 
 The anomaly is greatest in this case when the ovum is situated out of 
 
 (1) Wrisberg, De secundinarum humanarum varietate, Gottingen, 1773. — Schæfer, 
 De placentœ uterinœ morbis, Leipsic, 1799. — Michaelis, De placenta humana, ana- 
 tomice, physiologice et palhologice considerata, Erford, 1782. — Hebenstreit, De funi- 
 culi umbilicalis pathologia, Leipsic, 1747. 
 
 (2) Walter, Ueber die Krankheiten des Bauchfelles , p. 13. — Langstaff, in the Med. 
 chir. trans., vol. viii. p. 505. 
 
EMBRYOLOGY. 
 
 535 
 
 the uterus. This is termed extra-uterine conception or gestation (con- 
 ceptions. graviditas extra-uterina) .(1) The ovum is then developed 
 ia the ovary, in the abdominal cavity, or in the Fallopian tube. (2) 
 The uterus generally changes as it does in pregnancy ; this organ is 
 enlarged, softens, and a deciduous membrane forms in it. In the 
 cases where it is asserted that the latter did not exist, it had probably 
 already disappeared, or it was developed imperfectly.(3) The ovum 
 is destitute of it. 
 
 As to the fetus : 
 
 a. It is regularly formed, a very rare phenomenon, observed princi- 
 pally in abdominal pregnancy. 
 
 b. It is dead ; this is more frequent, and causes in the adjacent parts, 
 principally the rectum, the integuments, or the vagina, rarely in the 
 bladder, the formation of an abscess, and is usually discharged through 
 the opening in pieces, more rarely entire. 
 
 c. Long before the first months of pregnancy have elapsed, and even 
 during its first fifth, the too slightly extensible part in which the fetus 
 is developed is ruptured, and the mother dies from an internal hemorr- 
 hage, which termination is observed particularly in pregnancy of the 
 Fallopian tubes. 
 
 d. The fetus and its envelops less rarely adhere, and ossify more or 
 less perfectly. The mass often continues so for years, and the female 
 lives. 
 
 More commonly the situation of the placenta in the uterus varies, 
 being developed, particularly in twin pregnancies, at the lower part of 
 the ovum, on the edge of the orifice of the uterus (placentas prcevia, s. 
 oblata). 
 
 Finally, a more common anomaly is the twisting of the umbilical 
 cord. 
 
 2d. The simultaneous formation of several ova and fetuses. The 
 following are the most general remarks on this subject : 
 
 a. There is generally a predisposition to this anomaly, since the 
 same parents and the same mothers produce several twins. 
 
 b. The number of coexisting fetuses is never more than five. We 
 may generally admit that twin pregnancies are to common preg- 
 nancies as 1 . 100, triplets as 1 : 1000, and quadruplets as 1 : 50,000- 
 60,000. 
 
 (1) See our Handbuch der pathologischen Anatomic, vol ii. p. 160-180. — J. H. 
 Giessmann, Diss. dc conceptione duplici uterina vimirum ct ovaria uno eodemque 
 temporis momento facta, Marburg’, 1820. — F. F, Susewind, De graviditate ovaria, 
 Berlin, 1820. 
 
 (2) It may also be developed in the proper substance of the uterus, although not 
 
 separated from the tissue of this vise ns by a cyst. This has been observed by 
 Schmitt, Hedrich, Carus, and Breschet. Carus (Zur Lehre von Schwangerschaft 
 und Gebert, Leipsic, 1822) thinks, but wrongly, that in these cases the ovule glides 
 and lodges between the peritoneum and the uterus. F. T. 
 
 (3) This occurred in a case reported by' Langstaff. (Med. c hir. trans., vol. vij. p. 
 441.) 
 
53G 
 
 DESCRIPTIVE ANATOMY. 
 
 c. Generally in a case of twins or triplets the placentas are united 
 in one, but there are two or three choria, two or three amnia, and two 
 or three umbilical cords, so that the two or three fetuses are entirely 
 separate. When two are situated in the same cavity the intermediate 
 septum has evidently been destroyed. 
 
 The umbilical vessels usually communicate on the inner face of the 
 placenta by a large transverse anastomosis, which arises at the root of 
 the cord. This anastomosis is rarely deficient. This has been wrongly 
 termed a third placenta.(l) 
 
 We do not as yet know how the umbilical vesicle is arranged where 
 there are numerous fetuses. 
 
 d. In regard to the fetuses, even when there are but two, one and 
 sometimes both are small and imperfect, often to a great degree, for 
 most monsters which are very abnormal are generally twins. (2) This 
 phenomenon is still more evident when there are more than two fe- 
 tuses, for then all are generally smaller, and are not nourished as well 
 as usual. Sometimes also the existence of two fetuses causes the 
 death of one of them at a more or less advanced period. 
 
 e. In a twin pregnancy, and still more in triplets, parturition usually 
 occurs before the regular period of gestation. Generally all the fe- 
 tuses, and even those which are dead, leave the uterus at the same 
 period. Sometimes, however, one of the two is expelled prematurely, 
 while the second remains until the regular period, and is then born. (3) 
 In some cases, but this is less remarkable, the dead infant is not bom 
 till some days after the other, which is perfectly full grown. (4) 
 
 The fetuses which coexist in the uterus have generally been pro- 
 duced by the same generative act. They are formed much less com- 
 monly by several successive actions ; this constitutes superfeiation 
 ( superfelatio).(5 ) The possibility of this fact is proved, first, by cases 
 where the woman has borne two children of different color, and as- 
 serted that she had cohabited with men of different races ; secondly, 
 by those, although they are less authentic in fact, which mention full 
 grown children born at an interval of several weeks, and even several 
 months. 
 
 § 2617. Superfetation is explained: 
 
 1st. By the existence of a more or less divided uterus. (6) 
 
 2d. By a productive coition, followed by another also productive, 
 before the ovum produced by the first had arrived into the uterus. (7) 
 
 (It Stalpart van der Wiel, cent. i. p. 75.— Otto, Path. Anal., p. 38. 
 
 (2) Meckel, Handbuch der pathologischen Anatomie, vol. i. p. 55. 
 
 (3) J. Chapman, Singular case of expulsion of a blighted fetus and placenta at 
 seren months, a living child still remaining the full period of utero-gestalion ; in 
 the Med. chir. trans., vol. ix. p. 194. 
 
 (4) Clarke, in the Med. and phys. Journ., vol. xvi. p. 53. 
 
 (5) J. P. Gravel, Re svpcrfetatioue conjectures, Strasburg 1 , 1738. — M. Tydeman, 
 l)e superfetatione, Utrecht, 1 783. — T. Roose, De super fetatione nonnulla , Bremen, 
 1801. — .1. C. Varrentrapp, C'omm. in T. Roose dc superfetatione, Frankfort, 1803. 
 
 (6) Gravel, Roose. 
 
 (7) Varrentrapp. 
 
EMBRYOLOGY. 
 
 537 
 
 3d. By the laceration of a portion of the deciduous membrane, 
 which forms a passage for the semen to the Fallopian tube.(l) 
 
 Thus all the theories given are purely mechanical. These expla- 
 nations are by no means worthless ; superfetation, however, more pro- 
 bably, depends principally on the fact that one coition calls into action 
 several vesicles, which do not arrive at the same degree of vital ac- 
 tivity simultaneously, even as in birds a single copulation is sufficient to 
 impregnate a considerable number of yolks, which differ much in res- 
 pect to their development. 
 
 Superfetation may also depend, in certain rare cases, on no 
 mechanical cause, but on the fact that the capacity of the genital 
 organs and the whole organism of the female is not unfitted by the 
 first conception for a second during the course of the other ; even as 
 the disposition for contagious diseases, to which generation is so ana- 
 logous, is commonly lost by the first infection, although a second su- 
 pervenes in rare cases ; or as one exanthematous affection is gene- 
 rally, but not always, arrested by another. 
 
 § 2618. The new organism is sometimes destitute of certain parts. 
 The most common anomaly in this case is the absence of the fetus, 
 which undoubtedly depends generally on the fact that this latter has 
 perished sooner or later, since the ovum is commonly formed of all the 
 parts which normally compose it, and we there perceive even more or 
 less evident proofs of the previous existence of a fetus. 
 
 The placenta is deficient more rarely. In one case of the kind re- 
 cently described(2) it was asserted that the umbilical cord was at- 
 tached to the inner face of the ovum in the form of a button. 
 
 The defect of an umbilical vessel, particularly of an artery, is more 
 common. 
 
 We more rarely find the umbilical vein double, which establishes an 
 analogy with most mammalia. 
 
 § 2619. The deviations in the formation of the ovum relate princi- 
 pally to the placenta and the umbilical cord. 
 
 The placenta is sometimes but proportionally very rarely divided 
 into several lobes (; ■placenta succenturiata ), only two of which generally 
 appear, although there are sometimes seven. One of these lobes is 
 generally larger than the others. This anomaly consists in a suspen- 
 sion of development. We have observed it principally in pregnancy 
 with twins, and we have always been satisfied that authors were 
 mistaken in saying that the umbilical vessels then divided unusually 
 soon. 
 
 This premature division of the umbilical vessels, even within the 
 membranes of the ovum, is rare : but it is still more so for the vessels 
 to separate on the outside of the body of the child. 
 
 (1) Tydeman. 
 
 (2) Conby, in the Salz. med. chir. Zeitung, 1819, no. 43. 
 
53S 
 
 DESCRIPTIVE ANATOMY. 
 
 We must arrange here the knots of the umbilical cords termed true, 
 when they are real,(l) and false , when they consist only in more or 
 less compact circumvolutions of the umbilical vessels. 
 
 § 2620. The umbilical cord presents anomalies in its extent. Some- 
 times it is too short, being only four inches in length. Less frequently 
 it is unusually long, being fifty inches in length. Sometimes also it is 
 very thin or lean , which depends on the small quantity of the gelatine 
 of Wharton. In other cases it is unusually fat. 
 
 The placenta is commonly much larger and much thinner than 
 usual in abdominal pregnancy. 
 
 Here are referred the change of the vessels of the placenta into 
 larger and smaller vesicles, entirely closed and united by contracted 
 portions, which seem to depend on the permanence and the ultimate 
 development of a state primitively normal. 
 
 § 2621. Anomalies in the connections relate to those of the ovum 
 with the uterus or fetus. Sometimes, but rarely, the first are firm. 
 
 Sometimes the fetus is not connected with the ovum. This pheno- 
 menon is not rare in the early periods of gestation, and we may also 
 consider it as the result as well as the cause of the death of the fetus. 
 But authors relate also cases in which this insulation was observed at 
 an advanced age of pregnancy. Here we refer to the observations of 
 Chatton,(3) Stalpart van der Wiel, (4) Rommel, (5) Mason Good, (6) 
 and Osiander.(7) 
 
 All these facts are not equally authentic. Thus Stalpart van der 
 Wiel did not observe the case mentioned by him until several months 
 after birth ; there was at the time an inversion of the bladder ; the 
 umbilicus was situated too low, and blended with the upper part of the 
 bladder, and seemed to be deficient. 
 
 On the other hand the fetus is sometimes connected with the mem- 
 branes of the ovum too intimately. 
 
 Here are referred the cases where the umbilical cord is inserted in 
 an unusual part of the body, and is there attached in a greater or less 
 extent before arriving at the abdominal cavity. (8) 
 
 Such are also those(9) in which, besides the umbilical cord, a liga- 
 ment arose from the membranes of the ovum, and was attached to the 
 body of the fetus. (10) 
 
 (1) Delius, De noclis veris in f uniculo umbilicali, Gottingen, 1605. 
 
 (2) Gregurini, De hydrope uteri , Halle, 1795. 
 
 (3) Ephem. Gallic, ann ., 673, fol. 69, cited by Stalpart van der Wiel, Obs. rar. 
 cent. ii. pt. ii. p. 329. 
 
 (4) Observât, rar. med. chir., cent. ii. pt. i. obs. 32. 
 
 (5) Eph. nat. cur., dec. ii. ann. vii. obs. 209. 
 
 (6) Stark, Neues Archiv., vol. i. p. 357. 
 
 (7) Annalen, vol. i. pt. i. p. 199. 
 
 (8) Meckel, Handbuch der pathologischen Anatomie, vol. ii. pt. i. p. 56. 
 
 (9) lbid. 
 
 (10) G. F. St. Hilaire attributes the frequent monstrosities of the fetus which so 
 
 frequently deform it, to these folds. F. T. 
 
EMBRYOLOGY. 
 
 539 
 
 § 2622. The principal alterations of texture are, the too great hairi- 
 ness of the membranes of the ovum, generally attended with their 
 thickening : the development of the new formations in the placenta,(l) 
 or of serous cysts in the cord ; finally, the changes of the whole ovum, 
 termed moles, and which are divided into several classes, according to 
 the different substances which form them. 
 
 § 2623. Parturition presents numerous anomalies, the causes of 
 which exist in the body of the mother, or in that of the child, or in 
 both. These anomalies become also the source of several of those 
 mentioned when speaking of the genital organs, particularly of dif- 
 ferent deviations of formations, as lacerations of the uterus, the vagina, 
 adhesion and obliteration of the orifice of the uterus, the vagina, and 
 the vulva, after an injury. 
 
 (I) Clarke, in the Phil, trans., 1798, p. 11. 
 
, 
 
 . 
 
INDEX TO VOLUME III 
 
 PAGE 
 
 Sect. II. Periphery of the nervous system, . . . „ 4 
 
 Chap. I. Nerves of the spinal marrow, ..... 5 
 
 Art. i. Dorsal nerves, ....... 8 
 
 Art. 11 . Lumbar and sacral nerves, . . . . .11 
 
 A. Anterior branches, . . . . . . .13 
 
 B. Nerves of the lower extremities, ... . . 15 
 
 I. Obturator nerve, . . . . . . . 15 
 
 II. Crural nerve, ....... 16 
 
 III. Sciatic nerve, . . . . . . .17 
 
 а. Peroneal nerve, ..... . . 18 
 
 б . Tibial nerve, ....... 19 
 
 Art. iii. Cervical nerves, ....... 21 
 
 A. Nerves of the upper extremities, ..... 22 
 
 I. Thoracic nerves, ....... 24 
 
 II. Scapular nerve, ....... 24 
 
 III. Axillary nerve, ....... 24 
 
 IV. Radial nerve, ....... 25 
 
 V. External cutaneous nerve, ...... 26 
 
 VI. Median nerve, ....... 26 
 
 VII. Ulnar nerve, ....... 27 
 
 VIII. Internal cutaneous nerve, . . . . . 29 
 
 B. Superior cervical nerves, ...... 29 
 
 I. Diaphragmatic nerve, ...... 30 
 
 II. Fourth cervical nerve, ...... 31 
 
 III. Third cervical nerve, ...... 32 
 
 IV. Second cervical nerve, ....... 33 
 
 V. First cervical nerve, . . . . . . 34 
 
 Chap. II. Encephalic nerves, ...... 36 
 
 I. Hypoglossal nerve, ....... 39 
 
 II. Accessory nerve, ....;.. 42 
 
 III. Pneumogastric nerve, . . . . . .44 
 
 IV. Glosso-pnaryngeal nerve, . . ■ . . . .60 
 
 V. Auditory nerve, ....... 52 
 
 VI. Facial nerve, ........ 53 
 
 i. Ascending branches, . . ... . . .55 
 
 a. Temporal nerves, ....... 55 
 
 b. Malar nerves, ....... 56 
 
 11 . Anterior branches or buccal nerves, . • . 66 
 
 in. Descending branches, . . . • • . 56 
 
 VII. External motor nerve, ...... 67 
 
 VIII. Trifacial nerve, ....... 59 
 
 A. First branch, ........ 62 
 
 B. Second branch, ....... 65 
 
 C. Third branch, ........ 71 
 
 IX. Internal motor nerve, ....... 75 
 
 X. Common motor nerve, ....... 76 
 
 XI. Optic nerve, ........ 77 
 
 Chap. III. Ganglionnary nerve, ...... 83 
 
 I. Central portion, ........ 85 
 
 II. Limiting cord and its branches, ..... 08 
 
 A. Superior cervical ganglion, ..... gg 
 
 I. Upper branches, • - • • • 80 
 
 V Oh. Ill 
 
 69 
 
542 
 
 INDEX. 
 
 PAGE 
 
 II. External branches, 92 
 
 III. Internal branches, . . _ _ ! 92 
 
 IV. Anterior branches, - . . . * . 92 
 
 V. Inferior branches, ...... 93 
 
 B. Middle cervical ganglion, . . . . 94 
 
 C. Inferior cervical ganglion, ...... 95 
 
 I. Cardiac plexus, 96 
 
 D. Thoracic ganglions, 96 
 
 i. Splanchnic nerve, ....... 97 
 
 11. Small sphlanchnic nerve, . . . j 97 
 
 E. Abdominal ganglions, • 97 
 
 Chap. IV. Differences in the nerves during development, ... 99 
 
 Chap. V. Parallel between different nerves, . . . ’ 101 
 
 BOOK III. Splanchnology, . . . . . . .109 
 
 Sect. I. Organs of sense, . . . . . . .110 
 
 Chap. I. Organ of hearing, . . . - . . . .Ill 
 
 Art. i. External ear, ....... 112 
 
 A. Cartilage of the ear, . . . . . . 442 
 
 B. Muscles of the external qar, ...... 114 
 
 I. Muscles moving the external ear, . . . . .114 
 
 A. Attollens auricula, . . ... . 115 
 
 B. Retrahentes auricula:, . . . . . .115 
 
 C. Attrahens auriculae, ...... 115 
 
 II. Muscles moving certain parts, . . . . .115 
 
 a. Tragicus, . . . . . . .116 
 
 b. Antitragicus, . . . . . . .116 
 
 c. Hclicis major, . . . . . . . 116 
 
 d. Helicis minor, 1 ....... 116 
 
 e. Transversus auriculæ, . . . . . .116 
 
 Art. ii. Internal ear, ....... 117 
 
 A. Externalportion, ....... 117 
 
 I. Osseous portion, ....... 117 
 
 II. Membrane of the tympanum, . . . . .118 
 
 B. Middle part, ... ..... 119 
 
 I. Tympanum, . . . . . . .119 
 
 II. Eustachian tube, ....... 121 
 
 III. Bones of the ear, 121 
 
 a. Malleus, ........ 122 
 
 b. Incus, ......... 122 
 
 c. Lenticular bone, ....... 123 
 
 d. Stapes, ........ 123 
 
 IV. Muscles of the bones of the ear, ..... 123 
 
 a. Muscles of the malleus, ...... 124 
 
 1. Tensor tympani muscle, ..... 124 
 
 2. Laxator tympani major muscle, .... 124 
 
 3. Laxator tympani mirtor muscle, .... 124 
 
 b. Stapedius muscle, ...... 125 
 
 C. Labyrinth, ........ 125 
 
 I. Osseous labyrinth, ....... 125 
 
 a. Vestibule, ....... 126 
 
 b. Semicircular canals, . . . . . .126 
 
 c. Cochlea, ........ 127 
 
 d. Aqueducts, ....... 129 
 
 II. Membranous labyrinth, ...... 131 
 
 III. Auditory nerve, ....... 132 
 
 Art. hi. Differences dependent on development, .... 134 
 
 Art. iv. Abnormal state of the organ of hearing, . . . 140 
 
 Chap. II. Organ of sight, ....... 143 
 
 Art. i. Parts which protect the eye, ..... 143 
 
 I. Eyelids, ......... 144 
 
 A. Eyelashes, ........ 144 
 
 B. Meibomian glands, ....... 144 
 
 C. Palpebral cartilages, . . . . . . . 144 
 
 D. Muscles of the eyelids, ...... 146 
 
INDEX. 
 
 543 
 
 P 
 
 A. Orbicularis palpebrarum, . . . ... 
 
 B. Levator palpebræ superioris, . . . - . 
 
 E. Caruncula lachrymalis, ...... 
 
 II. Eyebrows, . .•> .... 
 
 ill. Lachrymal passages, ...... 
 
 A. Lachrymal gland, . ...... 
 
 K. Lachrymal puncta and lachrymal passages, 
 
 C. Lachrymal sac, ....... 
 
 Art. ii. Globe of the eye, ....... 
 
 I. Membranes of the eye, ...... 
 
 A. External membranes, ...... 
 
 A. Sclerotica, ....... 
 
 B. Transparent cornea, ...... 
 
 B. Choroid membrane and iris, ..... 
 
 A. Choroid membrane, ...... 
 
 B. Ciliary body, . . . . 
 
 C. Iris, 
 
 D. Pigment, ....... 
 
 C. Retina, ........ 
 
 II. Humors of the eye, ....... 
 
 A. Vitreous humor, ....... 
 
 i. Crystaline lens, ....... 
 
 B. Aqueous humor, ...... * 
 
 Art. hi. Muscles of the eye, ...... 
 
 I. Straight muscles, ....... 
 
 i. Rectus superior, ....... 
 
 ii. Common tendon of the other three, .... 
 
 nr. Rectus externus, ....... 
 
 iv. Rectus inferior, ....... 
 
 v. Rectus internus, ....... 
 
 II. Oblique muscles, ....... 
 
 i. Obhquus superior, ....... 
 
 ii. Obliquus inferior, . . . . . 
 
 Art. iv. Functions of the eye, ...... 
 
 Art. v. Differences in the eye dependent on development, 
 
 Art. vi. Abnormal state, ....... 
 
 Chap. III. Organ of smell, ....... 
 
 Art. i. Perfect state, •-..... 
 
 I. Cartilaginous nose, ._ ... 
 
 • II. Muscles of the nose, ....... 
 
 A. Levator alæ nasi labiique superioris, .... 
 
 B. Compressor narium, ...... 
 
 C. Depressor alæ nasi, ...... 
 
 D. Depressor narium, ....... 
 
 III. Mucous membrane, ....... 
 
 IV. Nerves, ........ 
 
 AnT. ii. Differences in the nose depending on development, 
 
 Art. hi. Abnormal state, ....... 
 
 Sect. II. Of the viscera, ....... 
 
 Chap. I. Digestive organs, ....... 
 
 Art. i. Upper portion of the alimentary canal, .... 
 
 I. Cephalic portion, ....... 
 
 A. Oral cavity generally, ...... 
 
 i. Perfect state, . . . . . • . 
 
 ii. Differences depending on development, 
 
 in.- Abnormal state, ...... 
 
 B. Parts which compose the oral cavity, .... 
 
 i. Lips and cheeks, ....... 
 
 A. Form, ........ 
 
 B. Muscles of the lips, ...... 
 
 a. Orbicularis oris, . . 
 
 b. Buccinator, ....... 
 
 c. d. Zygomatici, . . . . . . * 
 
 e. Levator anguli oris, ... ... 
 
 'AGE 
 
 146 
 
 147 
 
 147 
 
 148 
 
 148 
 
 143 
 
 149 
 
 150 
 
 151 
 
 152 
 
 152 
 
 152 
 
 153 
 
 154 
 
 155 
 
 155 
 
 158 
 
 162 
 
 163 
 
 165 
 
 165 
 
 166 
 
 169 
 
 169 
 
 170 
 
 170 
 
 170 
 
 170 
 
 171 
 
 171 
 
 171 
 
 171 
 
 172 
 
 172 
 
 174 
 
 177 
 
 187 
 
 187 
 
 188 
 
 189 
 
 189 
 
 189 
 
 189 
 
 190 
 
 190 
 
 190 
 
 192 
 
 193 
 
 194 
 
 196 
 
 199 
 
 199 
 
 199 
 
 199 
 
 200 
 
 201 
 
 202 
 
 202 
 
 202 
 
 203 
 
 203 
 
 203 
 
 204 
 
 204 
 
544 index-.-. 
 
 PAGE 
 
 f. Levator labii superiors, ..... 204 
 
 g. Anomalus faciei, ...... 205 
 
 h. Levator alæ nasi labiique superioris, . . . 205 
 
 i. Depressor anguli oris, ...... 205 
 
 j. Depressor labii inferioris, ..... 206 
 
 k. Levator menti, ...... 206 
 
 n. Palate, ........ 206 
 
 A. Form, ........ 206 
 
 B. Muscles of the soft palate, ., . ... 207 
 
 a. Constrictors of the isthmus of the fauces, . . 207 
 
 a. Palato-pharyngeus, . . . ' . . 207 
 
 b. Glosso-pharyngeus, ..... 207 
 
 b. Muscles which dilate the isthmus, .... 208 
 
 a. Levator palati mollis, ..... 208 
 
 b. Tensor palati mollis, ..... 208 
 
 C. Palato-staphylinus, ........ 208 
 
 Hi. Tongue, ........ 209 
 
 A. Normal state, ....... 209 
 
 a. Muscles of the tongue, ..... 209 
 
 a. Muscles of the hyoid bone, .... 210 
 
 1. Mylo-hyoideus, . . . . . 210 
 
 2. Genio-hyoideus, . . . . . . 210 
 
 3. Stylo-hyoideus, . . . . . . 211 
 
 4. Sterno-hyoideus, ..... 211 
 
 5. Omo-hyoideus, . . . . . .211 
 
 b. Special muscles of the tongue, .... 212 
 
 1. Genio-glossus, ...... 212 
 
 2. Hyo-glossus, ...... 212 
 
 3. Stylo-glossus, ...... 213 
 
 4. Lingualis, ...... 213 
 
 b. Envelops of the tongue, ..... 214 
 
 B. Abnormal state, ...... 217 
 
 iv. Oral glands, ....... 217 
 
 A. Normal state, ....... 217 
 
 a. Muciparous glands, ...... 217 
 
 b. Salivary glands, ...... 218 
 
 a. Parotid gland, . . . . . .219 
 
 b. Submaxillary gland, ..... 220 
 
 c. Sublingual gland, . . . . . . 221 
 
 B. Abnormal state, ...... 222 
 
 v. Teeth, . . . . . . . 223 
 
 A. Normal state, ....... 223 
 
 a. Perfect state, ....... 223 
 
 b. Differences depending on development, . . . 230 
 
 a. General remarks, ...... 230 
 
 b. Special remarks, . . . . . . 235 
 
 1. Deciduous teeth, ...... 235 
 
 2. Permanent teeth, ..... 237 
 
 B. Abnormal state, . . . . . . 242 
 
 а. Deviations of formation, ..... 242 
 
 б. Alterations in texture, ..... 246 
 
 H. Cervical and thoracic portions, ..... 247 
 
 A. Perfect state, ........ 247 
 
 i. Pharynx, . . . . . . . . 247 
 
 A. Constrictor pharyngis inferior, .... 248 , 
 
 B. Constrictor pharyngis médius, .... 249 
 
 C. Constrictor pharyngis superior, .... 249 
 
 D. Stylo-pharyngeus, ...... 249 
 
 ii. Esophagus, ....... 250 
 
 B. Abnormal state, ....... 252 
 
 i. Deviations of formation, ...... 252 
 
 ii. Alterations of text ure, : 254 
 
 Art. ii Middle and lower portions, ..... 255 
 
 A. Perfect state, . . ... . . . . 255 
 
INDEX. 
 
 545 
 
 PAGE 
 
 I. Stomach, ........ 256 
 
 A. Situation, ........ 256 
 
 B. Form, ........ 256 
 
 C. Dimensions, ....... 257 
 
 D. Attachments, ....... 257 
 
 E. Membranes, . . . . . . . 258 
 
 F. Pyloric valve, ....... 260 
 
 G. Transient modifications in form and situation of the stomach, 261 
 
 H. Function of the stomach, ..... 261 
 
 I. Sexual differences, ...... 262 
 
 II. Small intestine, . . . . . . ■ . 262 
 
 A. Duodenum, ....... 263 
 
 B. Membranes of the small intestine, . . . . 264 
 
 C. Valves, . . . . . . . 265 
 
 D. Villosities, ....... 266 
 
 E. Glands, . . . . . . . 267 
 
 F. Functions of the small intestine, .... 268 
 
 III. Large intestine, ....... 269 
 
 A. Situation and attachments, ..... 269 
 
 B. Division of the large intestine, ..... 269 
 
 A. Ileo-colic valve, ...... 269 
 
 B. Cæcum and vermiform appendix, .... 270 
 
 C. Ascending colon, ...... 271 
 
 D. Transverse colon, ...... 271 
 
 E. Descending colon, ...... 272 
 
 F. Rectum, ....... 272 
 
 C. Form, . . . . . . . . 274 
 
 D. Length and breadth, ...... 274 
 
 E. Arrangement of the tunics. ...... 274 
 
 A. Peritoneal coat, . . . . . . • 274 
 
 B. Muscular membrane, ...... 274 
 
 C. Mucous membrane, ...... 275 
 
 F. Muscles of the anus, ...... 276 
 
 A . Sphincter ani externus, ..... 276 
 
 B. Sphincter ani internus, . . . . 276 
 
 G. Functions of the large intestine, .... 277 
 
 B. Differences depending on development, .... 277 
 
 A. Mode of development, ...... 277 
 
 B. Situation, ........ 283 
 
 C. Dimensions, ....... 284 
 
 D. Form, ........ 285 
 
 Art. hi. Intestinal canal in the abnormal state, .... 286 
 
 Art. iv. Glandular organs, ...... 286 
 
 I. ' Liver, ......... 298 
 
 II. Pancreas, ........ 316 
 
 III. Spleen, ........ 317 
 
 Art. v. Vessels and nerves of the intestinal canal, . . . 322 
 
 Chap. II. Organs of voice and respiration, . . . . . 323 
 
 Art. i. Organs of voice, ....... 323 
 
 I. Larynx, ......... 323 
 
 A. Cartilages of the larynx, ...... 324 
 
 I. Thyroid cartilage, ...... 324 
 
 II. Cricoid cartilage, ...... 325 
 
 III. Arytenoid cartilages, ...... 325 
 
 IV. Round cartilages, ...... 325 
 
 V. Cuneiform cartilages, . , . . . 325 
 
 VI. Epiglottis, ....... 325 
 
 B. Ligaments of the larynx, ...... 327 
 
 I. Special ligaments, ....... 327 
 
 A. Between the thyroid and cricoid ligaments, . . 327 
 
 a. Middle thyro-cricoid ligament, .... 327 
 
 b. Lateral thyro-cricoid ligament, .... 327 
 
 B. Ligaments between the thyroid cartilage and hyoid bone, . 327 
 
 a. Middle thyro-hyoid ligament, .... 327 
 
546 
 
 INDEX. 
 
 PAGE 
 
 b. Lateral thyro-hyoid ligament, \ 327 
 
 C. Ligaments between the cricoid and arytenoid cartilages, . 328 
 
 D. Ligament between the arytenoid and round cartilages, . 328 
 
 E. Ligaments of tbe epiglottis, . . . . . 328 
 
 a. Epiglotti-hyoid ligament, ..... 328 
 
 b. Thyro-epiglottid ligament, ..... 328 
 
 F. Ligaments between the thyroid and arytenoid cartilages, . 328 
 
 c. Inferior thyro-arytenoid ligament, .... 328 
 
 6. Superior thyro arytenoid ligament, .... 329 
 
 C. Mucous membrane and glands of the larynx, . . . 329 
 
 D. Musclps of the laryDx, ...... 329 
 
 I. General muscles of the larynx, ..... 330 
 
 a. Sterno-thyroideus, ...... 330 
 
 b. Hyo-thyroideus, ...... 330 
 
 II. Special muscles of the larynx, ..... 330 
 
 a. Crico-thyroideus, ...... 330 
 
 b. Crico-arytenoideus, ...... 331 
 
 a. Crico-arytenoideus lateralis, .... 331 
 
 b. Arytenoides obliquus et transvcreus, . . . 331 
 
 c. Thyro-arytenoideus, ..... 332 
 
 d. Thyfo-epiglotticus, . . . . 332 
 
 E. Nerves of the larynx, ...... 332 
 
 F. Functions, ........ 333 
 
 II. Sexual differences, ....... 337 
 
 III. Differences dependent on age, ..... 338 
 
 IV. Abnormal state, ....... 33S 
 
 A rt. ii. Organs of respiration, ...... 340 
 
 I. Normal state, ........ 340 
 
 A. Lungs, . . . . . . . 340 
 
 I. Perfect state, . ... . . . . 340 
 
 A. Form, ......... 341 
 
 B. Situation, . . . . . '. .341 
 
 C. Color 342 
 
 D. Texture, .... ... 342 
 
 a. Trachea, ....... 342 
 
 a. Fibrous tissue, ...... 342 
 
 b. Cartilage, ....... 343 
 
 c. Muscular fibres, . . . . ... 344 
 
 d. Mucous membrane, ..... 344 
 
 b. Blood-vessels of the lungs, ..... 345 
 
 c. Lymphatic glands and vessels, .... 340 
 
 d. Nerves, . . . • • • • 340 
 
 e. Pleura, ....... 340 
 
 J. Weight of the lung, ...... 348 
 
 s\ Capacity, ....... 348 
 
 A. Force,. 351 
 
 i. Function, . . . . ■ • . 352 
 
 II. Sexual differences, ...... 352 
 
 III. Differences from development, . ... . . 352 
 
 n. Abnormal state, ....... 355 
 
 Art. in. Cavity of the thorax, ...... 358 
 
 I. Motions of the chest, ....... 359 
 
 II. Sexual differences, . ..... 359 
 
 III. Differences from development, ..... 359 
 
 IV. Abnormal state, ....... 300 
 
 Art. iv. Glands near the organs of voice and respiration, . . 300 
 
 I. Thyroid gland, . . . . . • • • ’ 361 
 
 II. Thymus gland, ....... 364 
 
 Chap. III. Urinary system and renal capsules, .... 366 
 
 Art. i. Urinary system, ....... 366 
 
 A. Perfect state, ........ 366 
 
 I. Kidneys, ........ 367 
 
 A. Number and situation, ...... 367 
 
 B Form, ........ 367 
 
INDEX. 
 
 547 
 
 C. Volume and weight, 
 
 D. Consistence and color, 
 
 E. Structure, 
 
 P. Texture, . . . .? 
 
 G. Vessels, .... 
 
 0. Nerves, .... 
 
 If. Ureters, .... 
 
 III. Bladder, .... 
 
 jV. Urachus, .... 
 
 V. Urethra, .... 
 
 13. Functions of the urinary organs, 
 
 C. Sexual differences, 
 
 D. Differences from development, 
 
 Aut. ii. Abnormal state, 
 
 I. Deviations of formation, 
 
 II. Alterations of texture, 
 
 III. Foreign bodies, 
 
 A. Entozoaires, 
 
 B. Calculi, .... 
 
 Abt. hi. Renal capsules, 
 
 I. Normal state, .... 
 
 A. Situation, .... 
 
 B. Form and volume, 
 
 C. Weight, .... 
 
 D. Consistence and color, 
 
 E. Texture, .... 
 
 II. Differences of races, v 
 
 III. Differences from development, 
 
 IV. Function, .... 
 
 V. Abnormal state, 
 
 Chap. IV. Organs of generation, 
 
 Aht. i. Normal state, 
 
 I. Proper genital organs, 
 
 A. Female organs, 
 
 1. Formative organs, 
 
 A. Ovaries, . . 
 
 B. Fallopian tubes, 
 
 C. Uterus, .... 
 
 II. Organs of copulation, 
 
 A. Vagina, .... 
 
 B. Hymen, .... 
 
 C. Clitoris, .... 
 
 D. Nymphae, 
 
 E. External labia, 
 
 F. Mucous crypts, 
 
 G. Constrictor vaginae muscle, 
 
 IR. Vessels and nerves, 
 
 IV. Properties and functions, 
 
 B. Male organs, 
 
 I. Formative organs, 
 
 A. Testicles, 
 
 B. Epidydimis, 
 
 C. Ductus deferens, 
 
 D. Seminal vesicles, 
 
 E. Prostate gland, 
 
 II. Organs of copulation— penis, 
 
 A. Form and situation, 
 
 B. Size, .... 
 
 C. Composition, 
 
 D. Muscles of the perineum, 
 
 a. Ischio-cavernosus, 
 
 b. Bulbo-cavernosus, 
 
 e. Constrictor urethrae, 
 a. Trans versus perinei, 
 
 PAGE 
 
 368 
 
 368 
 
 368 
 
 368 
 
 371 
 
 372 
 
 372 
 
 373 
 
 376 
 
 377 
 377 
 382 
 382 
 384 
 384 
 
 387 
 
 388 
 388 
 388 
 392 
 392 
 3Ô2 
 392 
 392 
 
 392 
 
 393 
 
 393 
 
 394 
 494 
 
 395 
 
 396 
 
 397 
 
 397 
 
 398 
 398 
 
 398 
 
 399 
 
 400 
 408 
 
 408 
 
 409 
 
 409 
 
 410 
 
 411 
 411 
 
 411 
 
 412 
 
 412 
 
 413 
 413 
 413 
 
 418 
 
 419 
 
 419 
 
 420 
 
 421 
 
 421 
 
 422 
 422 
 425 
 
 425 
 
 426 
 
 426 
 
 427 
 
548 
 
 INDEX. 
 
 b. Levator ani, .... 
 
 III. Vital properties and functions of the male genital orga 
 II. Mammæ, 
 
 Art. n. Periodical differences, 
 
 I. Female organs, 
 
 II. Male organs, 
 
 Art. iii. Differences dependent on races, 
 
 Art. iv. Comparison of the male and female genital 
 Art. v. Genital organs in the abnormal state, 
 
 Chap. V. Abdominal cavity, 
 
 Art. i. Normal state, 
 
 A. Perfect state, 
 
 I. Cavity in general, 
 
 A. Composition, 
 
 II. Form, 
 
 C. Dimensions, 
 
 D. Changes in form and 
 
 II. Peritoneum, 
 
 A. External fold, 
 
 A. Anterior wall, 
 
 B. Superior wall, 
 
 C. Posterior wall, 
 
 D. Inferior wall, 
 
 B. Internal fold, 
 
 A. Mesenteries, 
 
 B. Epiploa, 
 
 B. Periodical differences, 
 
 Art. ii. Abnormal state, 
 
 BOOK VII. Embryology, 
 
 Chap. I. Conception in the normal state, 
 
 Art. i. Changes in the genital organs produced by coition and conception, 
 
 I. Organs of coition, 
 
 II. Formative organs, 
 
 A. Ovaries, 
 
 B. Fallopian tubes, 
 
 C. Uterus, 
 
 Art. ii. Development of the fetus, 
 
 I. Envelops, 
 
 A. Deciduous membrane, 
 
 B. Membranes of the fetus, 
 
 I. Chorion, 
 
 II. Amnios, 
 
 III. Placenta and umbilical cord, 
 
 II. Origin of the ovum, and order in which its parts form 
 
 III. Fetus, 
 
 I. Mode of origin, 
 
 II. Form, 
 
 III. Growth, 
 
 IV. Vital phenomena, 
 
 V. Duration of the fetal state and birth, 
 
 Chap. II. Conception in the abnormal state, 
 
 PAGE 
 
 427 
 
 428 
 432 
 436 
 438 
 '45 
 452 
 452 
 4p4 
 «7 
 467 
 467 
 
 467 
 
 468 
 468 
 •io8 
 
 468 
 
 469 
 
 470 
 
 470 
 
 471 
 
 472 
 
 473 
 
 474 
 
 475 
 477 
 479 
 481 
 489 
 489 
 491 
 
 491 
 
 492 
 492 
 
 494 
 
 495 
 
 498 
 
 499 
 499 
 502 
 
 502 
 
 503 
 507 
 
 517 
 
 518 
 
 518 
 
 519 
 521 
 521 
 532 
 534