A 
 
 SYSTEM OF ANATOMY 
 
 Foil THE USE OF 
 
 '* 
 
 STUDENTS OF MEDIC.- I 
 
 BY CASPAR WISTAR, M. I). 
 
 LATE PROFESSOR OF ANATOMY IN THE IT NITERS ITT -OF i'EJVNSYLTANI.'. 
 
 FOURT H EDITION. 
 
 WITH NOTES AND ADDITIONS- 
 
 BY WILLIAM EDMONDS HORNY ;N M. X). 
 
 AT -JIT^T PROFESSOR OF AWAT03I." IN THE TjSm-AS! ~ ■ 
 
 ^ 7 ^A, MEMBER Ot THE A3lERICA:-r PHi'.':?0 T, ni' . 
 
 Of — 
 
 IN TWO VOLUMES — VOL. II. 
 
 PHILADELPHIA: 
 
 CAREY, LE 4 i- r ' P .THE l ; UT STREE 
 
 1827 
 
M ■ as • 
 
 
 ♦ 
 
 EASTERN DISTRICT OF PENNSYLVANIA, TO WIT; 
 
 BE IT REMEMBERED, that on the twentieth day 
 of August in the forty-ninth year of the Independence of 
 the United States of America, A. D. 1825, H. C. Carey 
 & I. Lea, of the said district, have deposited in this office 
 the title of a book, the right whereof they claim as Pro- 
 prietors, in the words following, to wit: 
 
 cc A System of Aanatomy for the use of Students of Medicine, By 
 “ Caspar Wistar, M. D. Late Professor of Anatomy in the Universi- 
 ty of Pennsylvania. Third edition. With notes and additions. By 
 “ William Edmonds Horner, M. D. Adjunct Professor of Anatomy 
 in the University of Pennsylvania, and member of the American 
 Philosophical Society, &c. In two volumes. Volume II . 55 
 
 In conformity to the act of the Congress of the United States, entitled. 
 An Act for the Encouragement of Learning, by securing the copies of 
 Maps, Charts, and Books, to the authors and proprietors of such copies, 
 'during (lie times therein mentioned.” And also to the act, entitled, 
 
 .' t supplementary to an Act, entitled “ An Act for the Encouraged^^^ 
 of Learning, by securing the copies of Maps, Charts, and Books, 
 
 ••.•‘hors and proprietors of such copies during the times therein mentionM^^ 
 ml extending the benefits thereof to the arts of designing, engraving, and 
 < r 1 ,ing historical and o,her print?.” 
 
 D. CALDWELL, 
 
 Clerk of the Eastern District of Pennsylvania. 
 
CONTENTS OF VOL. II. 
 
 PART VI. 
 
 OP THE NOSE— THE MOUTH— AND THE THROAT. 
 CHAPTER I. 
 
 Of the Nose. 
 
 SECTION I. 
 
 Op the External Nose - 
 
 SECTION IL 
 Of the Cavities of the Nose 
 
 CHAPTER II. 
 
 Of the Mouth and the Salivary Glands. 
 
 C 7 the Mouth - = 14 
 
 Of the Salivary Glands ------ 25 
 
 CHAPTER III. 
 Of the Throat. 
 SECTION I. 
 
 Of the Isthmus of the Fauces 
 
 SECTION II. 
 
 Of the Larynx - 
 Of the Thyroid Gland - 
 
 SECTION m. 
 
 Of the Pharynx - 
 
 29 
 
 31 
 
 37 
 
 37 
 
IV 
 
 • •ox TEXTS. 
 
 PART VII. 
 
 OF THE THORAX. 
 CHAPTER I. 
 
 Of the General Cavity of the Thorax. 
 SECTION I. 
 
 Of the Form of the Cavity of the Thorax 
 
 44 
 
 SECTION II. 
 
 
 Of the Arrangement. of the Pleurae 
 Preparation of the Thorax - 
 
 45 
 
 47 
 
 CHAPTER II. 
 
 
 Of the Heart and the Pericardium, and the Great Vessels 
 connected with the Heart. 
 
 SECTION I. 
 
 
 Of the Pericardium - ■ - 
 
 49 
 
 SECTION II. 
 
 \ 
 
 
 Of the Heart ------ 
 
 50 
 
 SECTION III. 
 
 
 Of the Aorta, the Pulmonary Artery and Veins, 
 Venae Cavae at their commencement 
 
 and the 
 
 59 
 
 CHAPTER III. 
 
 
 Of the Trachea and Lungs. 
 
 
 SECTION L 
 
 
 Of the Trachea 
 
 The Black Glands on the Bronchia; 
 
 62 
 
 64 
 
 SECTION II. 
 
 
 Of the Lungs 
 
 Thorax of the Foetus 
 
 Physiological observations, &c. ... 
 
 65 
 
 69 
 
 71 
 
OOMTENTSo 
 
 V 
 
 PART VIII. 
 
 OF THE abdomen, 
 
 CHAPTER I. 
 
 A general view of the Abdomen and Pelvis , aim their Con- 
 tents ; with an Account of the Peritoneum . 
 
 SECTION I. 
 
 Construction of the Abdomen - 
 
 - 
 
 - 
 
 - 
 
 SB 
 
 Contents of the Abdomen 
 
 - 
 
 - 
 
 - 
 
 85 
 
 SECTION II. 
 
 Of the Peritoneum - 
 
 - 
 
 - 
 
 - 
 
 90 
 
 CHAPTER II. 
 
 Of the (Esophagus , the Stomach, and the Intestines . 
 
 
 SECTION I. 
 
 Of the (Esophagus 
 
 - 
 
 - 
 
 - 
 
 94 
 
 SECTION II. 
 Of the Stomach - - 
 
 
 
 ' J 
 
 96 
 
 0.f the Gastric Liquor - 
 
 - 
 
 - 
 
 ■ - 
 
 10; 
 
 SECTION III. 
 
 Of the Intestines - 
 
 
 
 
 104 
 
 Division of the Intestines 
 
 . 
 
 - 
 
 - 
 
 109 
 
 The Small Intestines - 
 
 
 . 
 
 - 
 
 110 
 
 The Duodenum - 
 
 - 
 
 . 
 
 - 
 
 111 
 
 Jejunum and lieon - 
 
 - 
 
 . 
 
 - 
 
 113 
 
 The Mesentery - 
 
 - 
 
 - 
 
 - ■ 
 
 115 
 
 Ot the Great intestines - 
 
 - 
 
 - 
 
 -> 
 
 117 
 
 The Caecum and Colon ... 
 
 
 - 
 
 - 
 
 118 
 
 The Rectum - 
 
 *, 
 
 
 • 
 
 122 
 
 The Omentum - 
 
 
 • 
 
 . 
 
 125 
 
 CHAPTER III. 
 
 Of the Liver , the Pancreas , and the Spleen. 
 SECTION I. 
 
 Of the Liver - _ „ _ , * „ iQS 
 
Vi CONTENTS. 
 
 SECTION II. 
 
 Of the Pancreas 141 
 
 SECTION III. 
 
 Of the Spleen 145 
 
 CHAPTER IV. 
 
 Of the Urinary Organs , and the Glandulse Renales. 
 SECTION I. 
 
 Of the Glandulse. Renales - - - - 154 
 
 SECTION II. 
 
 Of the Kidneys and Ureters - - - - 155 
 
 SECTION III. 
 
 Of the Urinary Bladder 162 
 
 CHAPTER V. 
 
 Of the Male Organs of Generation . 
 
 SECTION I. 
 
 Of the Testicles and their Appendages = - * 171 
 
 SECTION II. 
 
 *)f the Vesiculae Seminales and the Prostate Gland - 181 
 
 SECTION III. 
 
 Of the Penis - ■■ -184 
 
 CHAPTER VI. 
 
 Of the Female Organs of Generation. 
 
 SECTION I. 
 
 Of the External Parts of Generation - 200 
 
 SECTION II. 
 
 Of the Vagina - 203 
 
 SECTION III. 
 
 Of the Uterus, the Ovaries, and their Appendages - 205 
 
 SECTION IV. 
 
 Of the Bladder and Urethra - 
 
 213 
 
CONTENTS) Vii 
 
 PART IS. 
 
 OF THE BLOOD VESSELS. 
 
 CHAPTER I. 
 
 Of the General Structure and arrangement of the Blood Vessels, 
 SECTION I. 
 
 Of the Arteries ------- 226 
 
 SECTION II. 
 
 Of the Veins - -- -- -- - 233 
 
 CHAPTER II. 
 
 A Particular Aeeount of the Distribution of the Arteries. 
 
 SECTION I. 
 
 Of the Aorta, or the Great Trunk of the Arterial System 236 
 SECTION II. 
 
 Of the Branches which go off from the Arch of the Aorta 23S 
 SECTION III. 
 
 Of the Branches which go off between the Arch and the 
 Great Bifurcation of the Aorta - 2r2 
 
 SECTION IV. 
 
 Of the Arteries which originate at and below the Great 
 Bifurcation of the Aorta ----- 283 
 
 CHAPTER III. 
 
 Of the particular Distribution of the Veins, 
 
 SECTION I. 
 
 Of the Superior, or Descending Vena Cava, and the 
 Veins which communicate with it - 300 
 
 SECTION It 
 
 Of the Inferior Vena Cava, and the veins connected 
 with it - - - - - - 
 
 309 
 
via 
 
 CONTENl S. 
 
 PART X. 
 
 OF THE NERVES 
 
 Nerves of the Brain - 
 
 - 
 
 - 
 
 3!23 
 
 Of the Cervical Nerves - 
 
 _ 
 
 - 
 
 343 
 
 Nerves of the Diaphragm 
 
 
 
 346 
 
 Brachial Plexus - 
 
 
 - 
 
 347 
 
 Nerves of the Arm - 
 
 - 
 
 - 
 
 348 
 
 The Dorsal Nerves - 
 
 . 
 
 - 
 
 352 
 
 Of the Lumbar Nerves - 
 
 - 
 
 - 
 
 353 
 
 The Sacral Nerves - 
 
 - 
 
 - 
 
 356 
 
 Sciatic Plexus - 
 
 - 
 
 - 
 
 3 57 
 
 Great Sciatic Nerve 
 
 . 
 
 - 
 
 358 
 
 Great Sympathetic Nerve 
 
 . 
 
 - 
 
 361 
 
 Nerves of the Heart - 
 
 - 
 
 - 
 
 363 
 
 Nerves of the Abdominal Viscera - 
 
 - 
 
 - 
 
 368 
 
 PART XL 
 
 OF THE ABSORBENT VESSELS. 
 
 CHAPTER I. 
 
 k 
 
 Of the ./2b sorbents of the Lower Extremities — the Abdomen 
 and the Thorax, 
 
 SECTION I. 
 
 i" e Absorbents of the Lower Extremities - - 376 
 
 SECTION II. 
 
 The Absorbents of the Abdomen and Thorax - - 381 
 
 CHAPTER II. 
 
 Of the Absorbents of the Head and Neel', of the Upper Ex- 
 fremiti f \ and the Upper Part of the Trunk of the Body. 
 
 SECTION I. 
 
 Of the Absorbents of the Head and Neck - - 391 
 
 SECTION II. 
 
 • >f the Absorbents of the Arm, and Upper Part of the 
 
 Trunk - - - - - - SOS 
 
SYSTEM OF ANATOMY, 
 
 PART VI. 
 
 OF THE NOSE: THE MOUTH AND THE THROAT. 
 
 CHAPTER I. 
 
 OF THE NOSE. 
 
 The prominent part of the 'face, to which the 
 word nose is exclusively applied in ordinary lan- 
 guage, is the anterior covering of two cavities which 
 contain the organ of smelling. 
 
 These cavities are formed principally by the upper 
 maxillary and palate bones; and, therefore, to acquire 
 a complete idea of them, it is necessary to study these 
 bones, as well as the os ethmoides, the vomer, and 
 the ossa spongiosa inferiora, which are likewise con- 
 cerned in their formation. 
 
 In addition to the description of these bones, in 
 the account of the bones of the head, it will be use- 
 ful to study the description of the cavities of the nose 
 which follows it. See vol. I. page 64. 
 
 After thus acquiring a knowledge of the bony struc- 
 ture, the student will be prepared for a description 
 of the softer part's 
 
 Vn L , u . 1 
 
3 
 
 The External Nose, 
 
 SECTION i. 
 
 Of the External Nose. 
 
 The superior part of the nose is formed by the 
 ossa nasi, and the nasal processes of the upper max- 
 illary bones, which have been already described; (see 
 vol. I. pages 42 — 46,) hut the inferior part, which 
 is composed principally of cartilages, is much more 
 complex in its structure. 
 
 The orifice, formed by the upper maxillary and 
 nasal bones, is divided by a cartilaginous plate, 
 which is the anterior and inferior part of the sep- 
 tum, or partition between the two cavities of the 
 nose. The anterior edge of this plate projects be- 
 yond the orifice in the bones, and continues in the 
 direction of the suture between the ossa nasi. This 
 edge forms an angle with the lower edge of the same 
 cartilage, which continues from it, in a horizontal 
 direction, until it reaches the lower part of the ori- 
 fice of the nose, at the junction of the palatine pro- 
 cesses of the upper maxillary bones; where a bony 
 prominence is formed, to which it is firmly united. 
 The upper part of the anterior edge of this carti- 
 lage, which is in contact with the ossa nasi, is fiat, 
 and is continued into two lateral portions that are 
 extended from it, one on each side, and form a part 
 of the nose : these lateral portions are sometimes spo- 
 ken of as distinct cartilages: but they are really con- 
 tinuations of the middle portion or septum. ^ 
 
 Below the lower edge of these lateral portums are 
 situated the cartilages which form the orifices of the 
 nose, or the nostrils. Of these, there is one of con- 
 siderable size, and several small fragments, on each 
 side of the septum. Each of the larger cartilages 
 forms a portion of an oval ring, which is placed ob- 
 liquely on the side of the septum: so that the extre- 
 
3 
 
 Of the Nose. 
 
 jmty of the oval points downward and forward, while 
 the middle part of the oval is directed upwards and 
 backwards. The sides of this cartilage are flat, and 
 unequal in breadth. The narrowest side is internal, 
 and projects lower down than the cartilaginous sep- 
 tum ; so that it is applied to its fellow of the other 
 nostril. The external side is broader, and continues 
 backward and upward to a considerable distance. 
 
 The upper and posterior part of this oval ring is 
 deficient; but the remainder of the nostril consists 
 of several small pieces of cartilage, which are fixed 
 in a ligamentous membrane that is connected by each 
 of its extremities to the oval cartilage, and thus com- 
 pletes the orifice. 
 
 The anterior parts of the oval cartilages form the 
 point of the nose ; and the ligamentous portions, the 
 alae or lateral parts of the nostrils. 
 
 When the external integuments and muscles are 
 removed from the lower portion of the nose, so that 
 the internal membrane and these cartilages only re- 
 main, the internal membrane will be found attached 
 to the whole bony margin of each orifice, and to each 
 side of the whole anterior edge of the middle carti- 
 lage, which projects beyond the bones. This mem- 
 brane is afterwards continued so as to line the oval 
 cartilages and the elastic membrane of the ala nasi, 
 to the margin of the orifice of the nostril. 
 
 The internal portions of the oval cartilages being 
 situated without the septum, and applied to each 
 other, they form the eternal edge of the partition 
 between the nostrils, or the columna nasi ; which is 
 very moveable upon the edge of the middle carti- 
 lage. 
 
 The orifices of the nostrils, thus constructed, are 
 dilated by that portion of the muscle, called Levator 
 Labii Superior is Alseque Nasi , which is inserted 
 into the alas nasi. 
 
4 
 
 Of the Cavities of the JYose. 
 
 They are drawn down by the depressor labii supe- 
 rioris alaeque nasi. They are pressed against the sep- 
 tum and the nose by the muscle called Compressor 
 JYaris , which has however an opposite effect when 
 its upper extremity is drawn upwards by those fibres 
 of the occipito-frontalis, which descend upon the 
 nose, and are in contact with it. 
 
 The end of the nose is also occasionally drawn 
 down, by some muscular fibres which descend from 
 it, on the septum of the nose, to the orbicularis oris : 
 they are considered as a portion of this muscle by 
 many anatomists, but were described by Albinus as 
 a separate muscle, and called JYasalis Lahii Supe - 
 rioris. 
 
 When inspiration takes place with great force, the 
 alse nasi would be pressed against the septum if they 
 were not drawn out and dilated by some of the mus- 
 cles above mentioned. 
 
 SECTION II. 
 
 Of the Cavities of the JYose. 
 
 To the description of the osseous parts of the nasal 
 cavities in vol. I. page 64, it ought now to be added 
 that the vacuity in the anterior part of the osseous 
 septum is filled up by a cartilaginous plate, connect- 
 ed with the nasal lamella of the ethmoid bone above, 
 and with the vomer below. This plate sends off 
 those lateral portions already described, which form 
 the cartilaginous part of the bridge of the nose. 
 
 It should also be observed that at the back parts 
 of these cavities are two orifices called the Posterior 
 JYares, which are formed by the palate bones, the 
 vomer, and the body of the sphenoidal bone, and 
 are somewhat oval. 
 
 The nasal cavities, thus constructed, are lined by 
 a peculiar membrane, which is called pituitary front 
 
Schneiderian Membrane. 5 
 
 its secretion of mucus, or Schneiderian after an ana- 
 tomist who described it with accuracy.* 
 
 This membrane is very thick and strong, and 
 abounds with so many blood vessels, that in the liv- 
 ing subject it is of a red colour. It adheres to the 
 bones and septum of the nose like the periosteum, 
 but separates from them more easily. The surface 
 which adheres to the bones has some resemblance to 
 periosteum ; while the other surface is soft, spongy, 
 and rather villous. Bichat seems to have considered 
 this membrane as formed of two lamina, viz. perios- 
 teum, and the proper mucous membrane ; but he 
 adds, that it is almost impossible to separate them. 
 
 It has been supposed that many distinct glandular 
 bodies were to be seen in the structure of this mem- 
 brane by examining the surface next to the bones ;f 
 but this opinion is adopted by very few of the anato- 
 mists of the present day. The texture of the mem- 
 brane appears to be uniform ; and on its surface are 
 a great number of follicles of various sizes, from 
 which flows the mucous of the nose. 
 
 These follicles appear like pits, made by pushing 
 a pin obliquely into a surface which retains the form 
 of the impression. They can be seen very distinctly 
 with a common magnifying glass when the membrane 
 is immersed in water, both on the septum and on the 
 opposite surface. They are scattered over the mem- 
 brane without order or regularity, except that in a 
 few places they occur so as to form lines of various 
 lengths, from half an inch to an inch. The largest 
 of them are in the lower parts of the cavities. 
 
 It may be presumed that the secretion of mucous is 
 effected here by vessels which are mere continuations 
 of arteries spread upon a surface analogous to the 
 
 * Conrad .Schneider, a German professor, in a large work, “ De Ca- 
 tarrhis,” published about 1660. 
 t See Winslow, section X- No. 33 1 /, 
 
6 
 
 Olfactory JVerves, 
 
 exhalents, and not convoluted in circumscribed 
 masses, as in the case of ordinary glands. 
 
 The arteries of this membrane are derived from 
 various sources : the most important of them is the 
 nasal branch of the internal maxillary, which passes 
 into the nose through the spheno-palatine foramen, 
 and is therefore called the Spheno palatine Jlrtery. 
 It divides into several twigs, which are spent upon 
 the different parts of the surface of the nasal cavities. 
 Two of them are generally found on the septum of 
 the nose : one, which is small, passes forwards near 
 the middle ; the other, which is much larger, is near 
 the lower part of it. 
 
 Two small arteries called the anterior and poste- 
 rior ethmoidal, which are branches of the ophthal- 
 mic, enter the nose by foramina of the cribriform 
 plate of the ethmoidal bone. These arteries pass 
 from the orbit to the cavity of the cranium, and then 
 through the cribriform plate to the nose. In addi- 
 tion to these, there are some small arteries derived 
 from the infra orbital, the alveolar and the palatine, 
 which extend to the Schneiderian membrane ; but 
 they are not of much importance. 
 
 The veins of the nose correspond with the arteries. 
 Those which accompany the ethmoidal arteries open 
 into the ocular vein of the orbit, which terminates in 
 the cavernous sinuses of the head. The other veins 
 ultimately terminate in the external jugulars. 
 
 The nerves of the nose form an important part of 
 the structure ; they are derived from several sources ; 
 but the most important branches are those of the ol- 
 factory. 
 
 The olfactory nerves form oblong bulbs, which lie 
 on each side of the crista galli, on the depressed por- 
 tions of the cribriform plate of the ethmoid bone, 
 within the dura mater. These bulbs are of a soft con- 
 sistence, and resemble the cortical part of the brain 
 
Olfactory Nerves. 7 
 
 mixed with streaks of medullary matter. They send 
 off numerous filaments, which pass through the fora- 
 mina of the ethmoid bone, and receive a coat from 
 the dura mater as they pass through it. 
 
 These filaments are so arranged that they form two 
 rows, one running near to the septum, and the other 
 to the surface of the cellular part of the ethmoid bone, 
 and the os turbinatum : and in addition to these are 
 some intermediate filaments. 
 
 When the Schneiderian membrane is peeled from 
 the bones to which it is attached, these nervous fila- 
 ments are seen passing from the foramina of the eth- 
 moid bone to the attached surfaces : one row passing 
 upon that which covered the septum, and the other 
 to that of the opposite side ; while the intermediate 
 filaments take an anterior direction, but unite to the 
 membrane as soon as they come in contact with it. 
 
 All of these can be traced downwards on the afore- 
 said surfaces of the membrane for a considerable dis- 
 tance, when they gradually sink into the substance of 
 the membrane, and most probably terminate on the 
 internal villous surface ; but they have not been traced 
 to their ultimate termination. They ramify so that 
 the branches form very acute angles with each other. 
 On the septum the different branches are arranged so 
 as to form brushes, which lie in contact with each 
 other. On the opposite sides, the different ramifica- 
 tions unite so as to form a plexus. 
 
 Dr. Soemmering published last year some very 
 elegant engravings of the nose, representing one of 
 his dissections, which appears to have been uncom- 
 monly minute and successful.* These represent the 
 ramifications as becoming more expanded and deli- 
 cate in the progress towards their terminations, and 
 
 They are entitled, leones organovum liumanoruin olfactws. 
 
S Sphenopalatine and other Nerves of the Nose. 
 
 as observing a tortuous course, with very short mean- 
 dering flexures. 
 
 It is to be observed that the i*am ideations of the 
 olfactory nerve, thus arranged, do not extend to die 
 bottom of the cavity. On the external side, they are 
 not traced lower than the lower edge of the ethmoid, 
 or of the superior spongy bone : and on the septum, 
 they do not extend to the bottom, although they are 
 lower than on the opposite side. On the parts of the 
 membrane not occupied by the branches of the olfac- 
 tory nerves, several other nerves can be traced. The 
 nasal twig of the ophthalmic branch of the fifth pair, 
 after passing from the orbit into the cavity of the 
 cranium, proceeds to the nasal cavity on each side 
 by a foramen of the cribriform plate ; and after send- 
 ing off some fibrillse, descends upon the anterior part 
 of the septum to the point of the nose. The sphe- 
 no-palatine nerve, which is derived from the second 
 branch of the fifth pair, and enters the nose by the 
 spheno-palatine foramen, is spread upon the lower 
 part of the septum and of the opposite side of the 
 nose also, and transmits a branch through a canal in 
 the foramen incisivum to the mouth. Several small 
 branches also pass to the nose from the palatine and 
 other nerves ; but those already mentioned are the 
 most important. 
 
 A question has been proposed, whether the olfac- 
 tory nerve is exclusively concerned in the function 
 of smelling, or whether the other nerves above men- 
 tioned are also concerned in it. It seems probable 
 that this function is exclusively performed by the 
 olfactory nerve, and that the other nerves are like 
 the ophthalmic branch of the fifth pair, with respect 
 to the optic nerve. In proof of this, it is asserted 
 that the sense of smelling has entirely ceased in some 
 cases, where the sensibility to mechanical irritation 
 of every kind has remained unchanged. If the ol- 
 
9 
 
 Extent of the Schneiderian Membrane. 
 
 factory nerve alone is concerned in the function of 
 smelling, it follows, that this function must be confin- 
 ed to the upper parts of the nasal cavities ; but it 
 ought to be remembered, that the structure of the 
 Schneiderian membrane, in the lower parts of these 
 cavities, appears exactly like that which is above. 
 
 The surface of the nasal cavities and their septum, 
 when covered with the Schneiderian membrane, cor- 
 responds with the osseous surface formerly descri- 
 bed. The membrane covers the bones and cartilage 
 of the septum, so as to make one uniform regular 
 surface. From the upper part of the septum, it is 
 continued to the under side of the cribriform plate 
 of the ethmoid, and lines it ; the filaments of the 
 olfactory nerve passing through the foramina of that 
 bone into the fibrous surface of the membrane. It 
 is continued from the septum, and from the cribri- 
 form plate, to the internal surface of the external 
 nose, and lines it. It is also continued backwards to 
 the anterior surface of the body of the sphenoidal 
 bone ; and, passing through the foramina or openings 
 of the sphenoidal cells, it lines these cavities com- 
 pletely ; but in these, as well as the other cavities, 
 its structure appears somewhat changed ; it becomes 
 thinner and less vascular. 
 
 At the above mentioned foramina, in some subjects, 
 it forms a plait or fold, which diminishes the aper- 
 ture considerably. 
 
 From the upper surface of the nasal cavities, the 
 membrane is continued downwards over the surface 
 opposite to the septum. On the upper flat surfaces 
 of the cellular portions of the ethmoid, it forms a 
 smooth uniform surface. After passing over the first 
 turbinated bone, or that called after Morgagni, it is 
 reflected into the groove, or upper meatus, immedi- 
 ately within and under it ; the fold formed by the 
 membrane, as it is reflected into the meatus, is rather 
 Vol, ii. 2 
 
10 Distribution of the Schneiderian Membrane . 
 
 larger than the bone : and the edge of the fold there- 
 fore extends lower done than the edge of the bone, 
 and partly covers the meatus like a flap, consisting 
 only of the doubled membrane. This fold generally 
 continues backwards as far as the spheno-maxillary 
 foramen, which it closes; the periosteum, exterior to 
 the foramen, passing through it, and blending itself 
 with the fibrous surface of the Schneide:ian mem- 
 brane within. Here the spheno-palatine nerves and 
 arteries join the membrane. Below this meatus, it 
 extends over the middle, (formerly called the upper,) 
 turbinated bone, and is reflected or folded inwards 
 on the under side of this bone, and continued into 
 the middle meatue below it. In the middle meatus, 
 which is partly covered by the last-mentioned turbi- 
 nated bone, there are two foramina: one communi- 
 cating with the maxillary sinus ; and the other with 
 the anterior cells of the ethmoid and the frontal si- 
 nuses. The aperture into the maxillary sinuses is 
 much less in the recent head, in which th Schnei- 
 derian membrane lines the nose, than it is in the 
 bare bones. A portion of the aperture in the bones 
 is closed by the Schneiderian membrane, which is 
 extended over it : the remainder of the aperture is 
 unclosed ; and through this foramen, the membrane 
 is reflected so as to line the whole cavity. As a por- 
 tion of the foramen is covered by the membrane, and 
 this portion as well as the other parts of the cavity 
 is lined by the membrane, it is obvious that at the 
 place where the membrane is extended over the 
 foramen in the bone, it must be doubled ; or, in 
 other words, a part of the aperture of the maxillary 
 sinus is closed by a fold of the Schneiderian mem- 
 brane. 
 
 This aperture varies in size in different subjects, 
 and is often equal in diameter to a common quill. It 
 is situated in the middle of the meatus, and is covered 
 
Eustachian Tube. 
 
 11 
 
 by the middle turbinated bone : immediately above it, 
 is a prominence of the cellular structure of the eth- 
 moid bone, which has a curved or semicircular figure. 
 Near this prominence, in the same meatus, a groove 
 terminates, which leads from the anterior ethmoid 
 cells and the frontal sinuses. 
 
 From the middle meatus, the membrane proceeds 
 over the inferior turbinated bone, and is reflected 
 round and under it into the lower meatus. It appears 
 rather larger than the bone which it covers; and 
 therefore the lower edge of the bone does not extend 
 so low as the lower edge of the membrane, which of 
 course is like a fold or plait. The membrane then 
 continues and lines the lower meaiuos here it appears 
 less full than it is in the turbinated bone. In this 
 meatus, near to its anterior end, is the lower orifice 
 of the lachrymal duct : this is simply lined by the 
 Schneiderian membrane, which is continued into it, 
 and forms no plaits or folds that affect the orifice. 
 
 Orifice of the Eustachian Tube. 
 
 Immediately behind each of the nasal cavities, on 
 the external side, is the orifice of the Eustachian 
 Tube. It has an oval form, and is large enough to 
 admit a very large quill. Its position is oblique; 
 the upper extremity being anterior to the other parts 
 of the aperture, and on a line with the middle mea- 
 tus, while the centre is behind the inferior turbinated 
 bone. The lower part of the oval is deficient. This 
 tube is formed posteriorly by a cartilaginous plate. 
 It is lined by the membrane continued from the nose. 
 
 The cavities of the nose answer a twofold purpose in 
 the animal economy: they afford a surface for the 
 expansion of the olfactory nerves : and a passage 
 for the external air to the windpipe, in respiration. 
 
 The function of smelling appears to be dependent, to 
 a certain degree, upon respiration. It has been as- 
 
12 
 
 Observations respecting the Nose. 
 
 serted that unless the air passes in a stream through 
 the nose, as in respiration, the perception of odour 
 does not take place; that in persons who breathe 
 through wounds and apertures in the windpipe, the 
 function of smelling is not performed. It is rather 
 in confirmation of this proposition, that most per- 
 sons, when they wish to have an accurate perception 
 of any odour, draw in air rapidly through the nose. 
 
 Although the ultimate terminations of the olfactory 
 nerves cannot be demonstiated like those of the op- 
 tic and auditory nerves, it is probable, from the ap- 
 pearance of the fibres, while they are distinguisha- 
 ble, that they are finally arranged with great delica- 
 cy. It is certain that the impressions from whence 
 we derive the perceptions of many odours must be 
 very slight; as odorous bodies will impregnate 
 
 the aii of a large chamber for a great length of time, 
 without losing any sensible weight. 
 
 With respect to delicacy of structure and sensibility, 
 it is probable that the nose holds a middle rank be- 
 tween the eye or ear, and the tongue : and on this 
 account the mucous is necessary as a covering and 
 defence of its surface. 
 
 It has been ascertained, by the investigations of che- 
 mists, that this mucous contains the same ingredi- 
 ents as the tears already described, viz. animal mu- 
 cous and water; with muriate of soda, and soda un- 
 combined; phosphate of lime, and phosphate of soda. 
 
 The animal mucous, which is a most important ingre- 
 dient in the composition, resembles the mucilage 
 formed by some of the vegetable gums in several 
 particulars ; and differs from them in others. 
 
 The mucous of the nose, if it remain there long after 
 it is secreted, becomes much more viscid in con- 
 sistence, and changes from a whitish colour to one 
 which partakes more or less of the yellow. It is 
 probable that an incipient putrefaction may occasion 
 these changes in it. 
 
 The use of the frontal, maxillary and other sinuses, 
 communicating with the nose, has been the subject 
 of some inquiry. As there can be no stream of air 
 through them, and as the membrane lining them is 
 neither so thick, villous nor flexible as that lining 
 the nose, it may be concluded, a priori, that they 
 are not concerned in the function of smelling. This 
 
13 
 
 Use of the Sinuses of the Nose, 
 
 opinion is strengthened by the fact, that very young 
 children, in whom these sinuses scarcely exist, en- 
 joy the sense of smelling in perfection. The fol- 
 lowing fact is also in support of it. The celebrated 
 Desault attended a patient, in whom one of the 
 frontal sinuses was laid open by the destruction of 
 the bone which covered it anteriorly. This patient 
 was able to breathe a short time through the sinus 
 when the mouth and nose were closed : At the re- 
 quest of Desault he breathed in this manner when 
 a cup of some aromatic liquor was held near the 
 opening of the sinus : and had not the least percep- 
 tion of odour. This experiment was repeated se- 
 veral times. 
 
 Many physiologists believe that these sinuses have an 
 effect in modulating the voice. 
 
CHAPTER II. 
 
 OF THE MOUTH. 
 
 The general cavity of the mouth is formed ante- 
 riorly and laterally by the connexion of the lips and 
 cheeks to the upper and lower jaws : so that the teeth 
 and the alveoli of both jaws may be considered as 
 within the cavity. Above, it is bounded principally 
 by the palatine processes of the upper maxillary and 
 palate bones, and the soft palate, which continues 
 backward from them in the same direction. 
 
 Below, the cavity is completed by several muscles, 
 which proceed from almost the whole internal circum- 
 ference of the lower jaw, and, by their connexions 
 with each other, with the tongue and the os hyoides, 
 form a floor or bottom to it. The tongue is particular- 
 ly connected to this surface, and may be considered 
 as resting upon and supported by it. 
 
 To acquire an idea of the parietes of this cavity, 
 after studying the upper and lower maxillary bones, 
 the orbicularis oris and the muscles connected with it, 
 especially the buccinator, ought to be examined ; and 
 also the digastricus, the mvlo-hyoideus, genio-hyoi- 
 deus, and genio-hyoglossus. By this it will appear 
 that the lips and cheeks, and the basis or floor of the 
 mouth, are formed in a great measure by muscles. 
 Upon the internal surface of these muscles, a por- 
 tion of cellular and adipose substance is arranged, 
 as well as glandular bodies of different sizes ; and to 
 these is attached the membrane which lines the in- 
 side of the mouth. 
 
 This membrane passes from the skin of the face 
 to the lips, and the inside of the mouth; and, al- 
 though it is really a continuation of the skin, there 
 
Internal Surface of the Mouth. 15 
 
 is so great a change of structure, that it ought to be 
 considered as a different membrane. At the orifice 
 of the lips it is extremely thin, and so vascular that 
 it produces the fine florid colour which appears there 
 in health. It is covered by a cuticle, called by some 
 anatomists, Epithelium , which has a proportionate 
 degree of delicacy, and can be separated like the 
 cuticle in other parts. When this cuticle is separa- 
 ted, the lips and the membrane of the mouth appear 
 to be covered with very fine villi, which are parti- 
 cularly apparent in some preparations of the lips af- 
 ter injection and maceration.* 
 
 Under this membrane are many small glandular 
 bodies' of a roundish form, called glandulse labiales, 
 whose excretory ducts pass through it to the inner 
 surface of the mouth, for the purpose of lubrifying 
 it withjjieir secretion, which is mingled with the 
 saliva. 
 
 The membrane, which lines the inside of the lips 
 and cheeks, is somewhat different from that which 
 forms the surface of the orifice of the mouth : it is 
 not so florid ; the blood vessels in its texture are 
 larger and not so numerous. This change, however, 
 takes place very gradually, in the progress of the 
 membrane, from the orifice of the lips to the back 
 part of the cheeks. Glandular bodies, like those of 
 the lips, are situated immediately exterior to this 
 membrane of the cheeks, between it and the mus- 
 cles : their ducts open on its surface. These glands 
 are called Buccales. 
 
 This lining membrane is continued from the inter- 
 nal surface of the lips and cheeks to the alveolar por- 
 tions of the upper and lower jaws, which are in the 
 cavity of the mouth, and covers them, adhering 
 firmly to the periosteum. 
 
 * Ruysch had a fine preparation of this structure. See Thesaurus VII. 
 Tab. III. Fig. 5. 
 
16 Gums. — Surface of the Hard Palate. 
 
 The teeth appear to have passed through aper- 
 tures in this membrane, and are surrounded by it 
 closely at their respective necks. 
 
 The portion of membrane, which thus invests the 
 jaws, constitutes the gums; which have now acquired 
 a texture very different from that of the membrane, 
 from which they were continued. They are ex- 
 tremely firm and dense, and very vascular. It is 
 probable that their ultimate structure is not perfect- 
 ly understood. 
 
 In the desease called scurvy , they tumify and lose 
 the firmness of their texture ; they acquire a livid 
 colour, and are much disposed to hemorrhage. 
 
 From the alveoli of the upper jaw, the lining 
 membrane is continued upon the palatine processes 
 of the upper maxillary and palate bones, or the roof 
 of the mouth. 
 
 This membrane of the palate is not quite so firm as 
 that of the gums, and is also less florid : it adheres 
 firmly to the periosteum, and thus is closely fixed to 
 the bones. There is generally a ridge on its surface, 
 immediately under thesature between the two upper 
 maxillary bones ; and some transverse ridges are also 
 to be seen upon it. On the internal surface of this 
 membrane are small glandular bodies, whose ducts 
 open on the surface of the palate. 
 
 It is asserted, that this membrane has a limited de- 
 gree of that sensibility which is essential to the func- 
 tion of tasting ; and, that if certain sapid substances 
 are carefully applied to it, their respective tastes will 
 be perceived, although they have not been in contact 
 with the tongue. 
 
 The membrane is continued from the bones above 
 mentioned to the soft palate, or velum pendulum pa- 
 lati, which is situated immediately behind them. This 
 soft palate may be considered as a continuation of 
 the partition between the nose and mouth ; it is at- 
 
17 
 
 Soft Palate.-- Uvula. 
 
 tached to the posterior edge of the palatine processes 
 of the ossa palati, and to the pterygoid processes of 
 the sphenoidal bone. Its interior structure is mus- 
 cular. The upper surface is covered by the mem- 
 brane of the nose, the lower surface by the mem- 
 brane which lines the month. 
 
 The muscles, which contribute to the composition 
 of this structure, are the circumflexi and the le- 
 vatores palati above, and the constrictores isthmi 
 faucium and palato-pharyngei below. (See Vol. I. 
 page 190 — 191.) Thus composed the soft palate 
 constitutes the back part of the partition between 
 the nose and mouth. When viewed from before, 
 with the mouth open, it presents towards the tongue 
 an arched surface, which continues downwards on 
 each side, until it comes nearly in contact with the 
 edges of that organ. On each of the lateral parts of 
 this arch, are two pillars, or rather prominent ridges, 
 which project into the mouth. These ridges are at 
 some distance from each other below, and approach 
 much nearer above, so that they include a triangular 
 space. They are called the lateral half arches of 
 the palate. Each of them is formed by a plait or 
 fold of the lining membrane of the mouth, and contains 
 one of the two last mentioned muscles : the anterior, 
 the constrictor isthmi faucium ; the posterior, the pa- 
 lato-pharyngeus.^Tk<se muscles, of course, draw the 
 palate down toward the tongue when they contract. 
 
 From the centre of the arch, near its posterior 
 edge, is suspended the uvula, a conical body, which 
 varies in length from less than half an inch to rather 
 more than one inch. It is connected by its basis to 
 the palate ; but its apex is loose and pendulous. 
 This body is covered by the lining membrane of the 
 mouth. It contains many small glands, and a mus- 
 cle also, the azygos uvulse, which arises from the 
 posterior edge of the ossa palati, at the suture which 
 
 Vol. ii, 3 
 
18 
 
 The Tongue. 
 
 connects them to each other, and, passing posteriorly 
 upon the soft palate, extends from the basis to the 
 apex of the uvula, into which it is inserted. By the 
 action of this muscle, the length of the uvula can be 
 very much diminished ; and when its contraction 
 ceases, that body is elongated. 
 
 The pendulous part of the uvula can also be moved, 
 in certain cases, to either side. 
 
 It is commonly supposed, that the principal use of 
 this little organ is to modulate the voice ; but there 
 are good reasons for believing, that it has another 
 object. It was remarked by Fallopius, (and the ob- 
 servation has been confirmed by many surgeons since 
 his time,) that the uvula may be removed completely 
 without occasioning any alteration of the voice, or 
 any difficulty of deglutition, if the soft palate be left 
 entire. 
 
 The soft palate is so flexible, that it yields to the 
 actions of the levatores palati, which draw it up so 
 as to close the posterior nares completely. 
 
 It also yields to the circumflexi or tensores, which 
 stretch it so as to do away its arched appearance. 
 
 It is therefore very properly called the Palatum 
 Molle. It is also frequently called the Velum Pen- 
 dulum palati , from the position which it assumes. 
 
 The Tongue , 
 
 Which is a very important part of this structure, 
 is retained in its position and connected with the 
 parts adjoining it, by the following arrangements. 
 
 The os hyoides, which as its name imports, re- 
 sembles the Greek letter v, or half an oval, is situa- 
 ted rather below the angles of the lower jaw, in the 
 middle of the upper part of the neck. It is retained 
 in its position by the sterno-hyoidei muscles, which 
 connect it to the upper part of the sternum ; by the 
 coraco-hyoidei, w’hich pass to it obliquely from the 
 
19 
 
 Structure of the Tongue. 
 
 scapula ; by the thyro-hyoidei, which pass to it di- 
 rectly upward from the thyroid cartilage: all of 
 which connect it to parts below. To these should be 
 added the stylo-hyoidei, which pass to it obliquely 
 from behind and rather from above ; the mylo-hyoidei, 
 which come rather anteriorly from the lateral parts 
 of the lower jaw ; and the genio-hyoidei, which arise 
 from a situation directly anterior and superior, the 
 chin. When these muscles are at rest, the situation 
 of the os hyoides is, as above described, below the 
 angles of the lower jaw : when those, in one parti- 
 cular direction, act while the others are passive, the 
 bone may be moved upwards or downwards, back- 
 wards or forwards, or to either side. This bone may 
 be considered as the basis of the tongue ; for the pos- 
 terior extremity of that organ is attached to it ; and 
 of course the movements of the bone must have an 
 immediate effect upon those of the tongue. 
 
 The tongue is a fiat body of an oval figure, but 
 subject to considerable changes of form. 
 
 The posterior extremity, connected to the os hy- 
 oides, is commonly called its basis ; the anterior ex- 
 tremity, which, when the tongue is quiescent, is 
 rather more acute, is called its apex. 
 
 The lower surface of the tongue is connected with 
 a number of muscles, which are continued into its 
 substance. This connexion is such, that the edges of 
 the tongue are perfectly free and unconnected ; and so 
 is the anterior extremity for a considerable distance 
 from the apex towards the base. 
 
 The substance of the tongue consists principally of 
 muscular fibres intermixed with a delicate adipose 
 substance. It is connected to the os hyoides by the 
 hyoglossus muscle and also by some other muscular 
 fibres, as well as by a dense membranous substance, 
 which appears to perform the part of a ligament. 
 
20 
 
 Structure of the Tongue. 
 
 This connexion is also strengthed by the continuance 
 of the integuments from the tongue to the epiglottis 
 cartilage, to be hereafter described ; for that cartil- 
 age is attached by ligaments to the os hyoides. 
 
 The tongue is thin at its commencement at the os 
 hyoides : but it soon increases in thickness. The 
 muscular fibres in its composition have been consider- 
 ed as intrinsic, or belonging wholly to its internal 
 structure ; and extrinsic, or existing in part outside 
 of this structure. The linguales muscles are intrin- 
 sic : (Vol. I. page 189,) they are situated near the 
 under surface of the tongue, one on each side, sepa- 
 rated from each other by the genio-hyo-glossi mus- 
 cles, and extending from the basis of the tongue to 
 its apex. These muscles can be easily traced as above 
 described ; but there are also many fibres in the 
 structure of the tongue, which seem to pass in every 
 direction, and of course are different from those of 
 the linguales muscles. To these two sets of fibres 
 are owing many of the immensely varied motions of 
 the different parts of the tongue. 
 
 In addition to these, are the extrinsic muscles, which 
 originate from the neighbouring parts, and are insert- 
 ed and continued into the substance of the tongue. 
 
 Among the most important of these muscles, are 
 those which proceed from the chin, or the genio- 
 hyo-glossi. They are in contact with each other: 
 their fibres radiate from a central point on the inside 
 of the chin, and are inserted into the middle of the 
 lower surface of the tongue : the insertion commen- 
 cing at a short distance from its apex, and continu- 
 ing to its base. 
 
 As the genio-hyo-glossi muscles have a considera- 
 ble degree of thickness, they add much to the bulk of 
 the tongue in the middle of the posterior parts of it. 
 
 The hyo-glossi and the stylo-glossi, being conti- 
 
21 
 
 Papillse of the Tongue . 
 
 nued into the posterior and laternal parts, contribute 
 also to the bulk of these parts. 
 
 The tongue, thus composed and connected, lies, 
 when at rest, on the mylo-hyoidei muscles; and the 
 space between it and these muscles is divided into 
 two lateral parts by the above described genio-hyo- 
 glossi. In the space above mentioned, is a small sa- 
 livary gland, of an irregular oval form ; the greatest 
 diameter of which extends from before backwards, 
 and its edges present outwards and inwards. It has 
 several excretory ducts, the orifices of which form a 
 line on each side of the tongue. This gland is very 
 prominent under the tongue ; and when the tongue 
 is raised it is particularly conspicuous ; it is called 
 the Sublingual. 
 
 The lining membrane of the mouth continues from 
 the inside of the alveoli of the lower jaw, which it 
 covers, over the sublingual glands to the lower sur- 
 face of the tongue. In this situation it is remarkably 
 thin ; but, as it proceeds to the upper surface of the 
 tongue, its texture changes considerably ; and on this 
 surface it constitutes the organ of taste. 
 
 The upper surface of the tongue, although it is 
 continued from the thin membrane above described, 
 is formed by a rough integument which consists, like 
 the skin, of three lamina. The cuticle is very thin; 
 and under it, the rete raucosum* is thicker and softer 
 than in other places. 
 
 The true skin here abounds with eminences of va- 
 rious sizes and forms, all of which are denominated 
 Papillse. The largest of these are situated on the 
 posterior part of the tongue, and are so arranged that 
 they form an angle rather acute, with its point back- 
 
 s M. Bichat appears to have had doubts whether the real rete tnucosum 
 existed here. He says that he could only perceive a decussation of vessels 
 in the intervals of the papillse, which, as he supposes, occasioned the florid 
 colour of the tongue. 
 
22 
 
 Papillse of the Tongue. 
 
 wards. They are commonly nine in number : they 
 resemble an inverted cone ; or, are larger at their 
 head than their basis. They are situated in pits or 
 depressions, to the bottoms of which they are con- 
 nected. In many of them there are follicles, or per- 
 forations, which have occasioned them to be regard- 
 ed as glands. They are called Papillse Maximse, 
 or Capitatse. 
 
 The papillas, next in size, are denominated fungi- 
 form by some anatomists, and Medise or Semilenti- 
 cnlares by others. They are nearly cylindrical in 
 form, with their upper extremities regularly round- 
 ed. They are scattered over the upper surface of 
 the tongue, in almost every part of it, at irregular 
 distances from each other. 
 
 The third class are called conoidal or villous. 
 They are very numerous, and occupy the greatest 
 part of the surface of the tongue. Although they 
 are called conoidal , there is a great difference in their 
 form ; many of them being irregularly angular and 
 serrated, as well as conical. 
 
 Soemmering and other German anatomists consider 
 the smallest papillaj as a fourth class, which they call 
 the filiform : these lie between the others. 
 
 It is probable that these papillae are essential parts 
 of the organ of taste ; and their structure is of course 
 an interesting object of inquiry. 
 
 The nerves of the tongue have been traced to the 
 papillae, and have been compared by some anatomists 
 to the stalk of the apple, while the papillse resembled 
 the fruit ; but their ultimate termination does not ap- 
 pear to have been ascertained.* 
 
 ' In the explanation of the plates, referred to in the following sentence, 
 Soemmering observes, that when the fibrillae of the lingual nerve of the 
 fifth pair are traced to the papillae of the second class, they swell out into 
 a conical form ; and these nervous cones are in such close contact with 
 each other, that the point of the finest needle could not be insinuated into 
 the papillae without touching a nerve. 
 
Blood vessels of ike Tongue. 23 
 
 Soemmering has lately published some elegant en- 
 graved copies of drawings of these papillae, when 
 they were magnified twenty-five times ; from which 
 it appears that a very large number of vessels, parti- 
 cularly of arteries, exist in them. These vessels are 
 arranged in a serpentine direction, and are prominent 
 on the surface ; but they appear doubled, and the 
 most prominent part is the doubled end. — This ar- 
 rangement of vessels is perceptible on the sides of 
 the tongue, as well as on the papillae. 
 
 Behind the large papillae is a foramen, first de- 
 scribed by Morgagni, and called by him Foramen 
 Csecum. It is the orifice of a cavity which is not 
 deep ; the excretory ducts of several mucous glands 
 open into it. 
 
 On the upper surface of the tongue, a groove is 
 often to be seen, which is called the linea mediana , 
 and divides it into two equal lateral parts. Below, 
 the lining membrane of the mouth, as it is continued 
 from the lower jaw to the tongue, forms a plait, 
 which acts as a ligament, and is called the frsenum 
 linguse. It is attached to the middle of the tongue, 
 at some distance behind the apex. 
 
 The tongue is Well supplied with blood vessels, 
 which are derived from the lingual branch of the 
 external carotid on each side. This artery passes 
 from the external carotid, upwards, inwards, and 
 forwards, to the body of the tongue. In this course 
 it sends off several small arteries to the contiguous 
 parts, and one, which is spent about the epiglottis 
 and the adjoining parts, called the Dorsalis Linguse. 
 About the anterior edge of the hyo-glossus muscle, 
 it divides into two large branches : one of which, 
 called the Sublingual, passes under the tongue be- 
 tween the genio-hyo-glossus and the sublingual gland, 
 and extends near to the symphysis of the upper jaw ; 
 sending branches to the sublingual gland, to the 
 
24 Blood vessels of the Tongue. 
 
 muscles under the tongue, to the skin, and the lower 
 lip. The other is in the substance of the tongue, 
 on the under side near the surface, and extends to 
 the apex. 
 
 The veins of this organ are not so regular as the 
 arteries : they communicate with the external jugu- 
 lar ; and some of them are always very conspicuous 
 under the tongue : these are called ranular. 
 
 It is to be observed, that the vessels on each side 
 have but little connexion with each other ; for those 
 of one side may be injected while the others continue 
 empty. 
 
 The tongue is also well supplied with nerves, and 
 derives them from three different sources on each 
 side, viz. from the fifth, the eighth, and ninth pairs 
 of the head. 
 
 The lingual portion of the third branch of the fifth 
 pair, passing under the tongue, enters its substance 
 about the middle, and forms many minute branches, 
 which pass to the papillae of the fore part of the 
 tongue. 
 
 The glosso-pharyngeal portion of the eighth pair, 
 sending off several branches in its course, passes to 
 the tongue near its basis, and divides into many 
 small branches, which are spent upon the sides and 
 middle of the root of the tongue, and also upon the 
 large papillae. 
 
 The ninth pair of nerves are principally appro- 
 priated to the tongue. They pass on each side to 
 the most fleshy part of it, and after sending one 
 branch to the rnylo-hyoideus, and another to com- 
 municate with the lingual branch of the fifth pair, 
 they are spent principally upon the genio-glossi, and 
 linguales muscles. 
 
 The tongue answers a threefold purpose. It is 
 the principal organ of taste. It is a very important 
 agent in the articulation of words ; and it assists in 
 
Salivary Glands , 25 
 
 those operations upon our food, which are perform- 
 ed in the mouth. 
 
 The Salivary Glands. 
 
 The salivary glands have such an intimate con- 
 nexion with the mouth that they may be described 
 with it.* 
 
 There are three principal glands on each side : 
 the Parotid , the Submaxillary and the Sublingual. 
 They are of a whitish or pale flesh-colour, and are 
 composed of mauv small united masses of lobuli, 
 each of which sends a small excretory duct to join 
 similar ducts from the other lobuli, and thereby form 
 the great duct of the gland. 
 
 The Parotid is much larger than the other glands. 
 It occupies a large portion of the vacuity between 
 the mastoid process and the posterior parts of the 
 lower jaw. It extends from the ear and the mastoid 
 process over a portion of the masseter muscle, and 
 from the zygoma to the basis of the lower jaw. Its 
 name is supposed to be derived from two Greek 
 words which signify contiguity to the ear. It is of a 
 firm consistence. It receives branches from the ex- 
 ternal carotid artery and from its facial branch. 
 
 From the anterior edge of this gland, rather above 
 the middle, the great duct proceeds anteriorly across 
 the masseter muscle ; and, after it has passed over 
 it, bends inward through the adipose matter of the 
 cheek to the buccinator muscle, which it perforates 
 obliquely and opens on the inside of the cheek op- 
 posite to the interval between the second and third 
 molar teeth of the upper jaw. The aperture of the 
 duct is rather less than the general diameter of it, 
 and this circumstance has the effect of a valve. 
 When the duct leaves the parotid, several small 
 glandular bodies called socise parotidis, are often 
 
 For a general account of glands, see the appendix to this volume 
 
 Vol. ii. 4 
 
26 Parotid and Submaxillary Glands. 
 
 attached to it, and their ducts communicate with it. 
 The main duct is sometimes called after Steno, who 
 first described it. 
 
 When the mouth is opened wide, as in gaping, 
 there is often a jet of saliva from it into the mouth. 
 
 The parotid gland furnishes the largest proportion 
 of saliva. 
 
 It covers the nerve called Portio Dura , after it 
 has emerged from the foramen stylo- mastoideum. 
 
 The second gland is called the Submaxillary. It is 
 much smaller than the parotid, and rather round in 
 form. It is situated immediately within the angle 
 of the lower jaw, between it, on the outside, and the 
 tendon of the digastric muscle and the ninth pair of 
 nerves internally. Its posterior extremity is con- 
 nected by cellular membrane to the parotid gland ; 
 its anterior portion lies over a part of the mylo- 
 hyoideus muscle ; and from it proceeds the excretory 
 duct, which is of considerable length, and passes be- 
 tween the mylo-hyoideus and the genio-glossus mus- 
 cles along the under and inner edge of the sublin- 
 gual gland. In this course the duct is sometimes 
 surrounded with small glandular bodies, which seem 
 to be appendices of the sublingual gland. It termi- 
 nates under the tongue, on the side of the fraenum 
 linguae, by a small orifice which sometimes forms a 
 papilla.* 
 
 The orifice is often smaller than the duct ; in con- 
 sequence of which, obstruction frequently occurs here, 
 and produces the disease called ranula. 
 
 The sublingual gland, which has already been 
 mentioned, lies so that, when the tongue is turned 
 
 * Lassus informs us that Oribases, afterwards all the Arabians, and sub- 
 sequently Guy De Chauljac, Lanfranc, Achillini Berenger De Carpi, 
 Charles Etienne, Casserius and several others have given the description 
 of these salivary ducts, notwithstanding which Wharton, a physician of 
 London, attributed to himself the discovery of them on the bullock in 
 1656.— Ed. 
 
Sublingual Gland. — Saliva. 27 
 
 up, it can be seen protruding into the cavity of the 
 mouth, and covered by the lining membrane, which 
 seems to keep it fixed in its place. It lies upon the 
 mylo-hyoideus, by the side of the genio-hyoideus ; 
 and is rather oval 'in form and flat. Its greatest 
 length is from before backwards; its position is rather 
 oblique, one edge being placed obliquely inwards and 
 upwards, and the other outwards and downwards. 
 It has many short excretory ducts, which open by 
 orifices arranged in a line on each side : they are 
 discovered with difficulty on account of their small 
 size, and sometimes amount to eighteen or twenty in 
 number. In some few instances, this gland sends off 
 a single duct, which communicates with the duct of 
 the submaxillary gland. 
 
 The salivary fluid secreted by these glands is in- 
 odorous, insipid, and limpid, like water ; but much 
 more viscid, and of greater specific gravity. Water 
 constitutes at least four-fifths of its bulk ; and animal 
 mucus one-half of its solid contents. It also contains 
 some albumen, and several saline substances : as the 
 muriate of soda, and the phosphates of lime, of soda, 
 and of ammonia. 
 
 It is probable that this fluid possesses a solvent 
 power with respect to the articles of food. 
 
 There are small glandular bodies, situated be- 
 tween the masseter and buccinator muscles, opposite 
 to the last molar tooth of the upper jaw, whose na- 
 ture is not well understood : they are called Gland - 
 idee Molares. 
 
 The motions of the tongue are very, intelligible to a 
 person who has a preparation of the lower jaw be- 
 fore him, with the tongue in its natural situation, and 
 the muscles which influence it, properly dissected. 
 Its complicated movements will appear the neces- 
 sary result of the action of those muscles upon it, 
 and the os hyoides ; and also upon the larynx, with 
 
28 
 
 Observations on the Tongue. 
 
 which the os hyoides is connected. The muscular 
 fibres of the tongue itself are also to be taken into 
 this view, as they act a very important part. 
 Although tiie tongue appears very necessary in a me- 
 chanical point of view, to the articulation of many 
 words, yet there are cases where it has been entire- 
 ly deficient, in which the parties thus aft'ected, have 
 been able to speak very well in general, as well as 
 to distinguish different tastes.* 
 
 The tongue is also a very delicate organ of touch — 
 We can perceive the form of the teeth, and the state 
 of the surface of the mouth, more accurately by the 
 application of the tongue than of the fingers. 
 
 On the three nerves which go to the tongue, it is ge- 
 nerally supposed that the Ungual portion of the third 
 branch of the fifth pair is most immediately con- 
 cerned in the function of tasting, as it passes to the 
 front part of the surface of the tongue. The glos- 
 so-phuryngeal are probably concerned in the same 
 function on the posterior part, while the ninth pair 
 of nerves seems principally spent upon the muscu- 
 lar parts of the organ. 
 
 It is obvious that the tongue is most copiously supplied 
 with nerves. This probably accounts for the great 
 facility of its motions, and the power of continu- 
 ing them. 
 
 * There is a very interesting paper on this subject, in the Memoirs of 
 the Academy of Sciences for the year 1718, by Jussieu; in which he de- 
 scribes the case of a female, fifteen years old, examined by himself, who 
 was bom without a tongue . In this paper he refers to another case, de- 
 scribed by Rolland, a surgeon of Saumur, of a boy nine years old, whose 
 tongue was destroyed by gangrene. In each of these cases the subject was 
 able to articulate very well, with the exception of a few letters; and also 
 enjoyed the sense of taste. 
 
CHAPTER III. 
 
 OF THE THROAT. 
 
 To avoid circumlocution, the word throat is used 
 as a general term to comprehend the structure which 
 occurs behind the nose and mouth, and above the 
 (Esophagus and trachea. This structure consists, 
 
 1st. Of the parts immediately behind the- mouth, 
 which constitute the Isthmus of the Fauces : 
 
 2nd. Of the parts which form the orifice of the 
 windpipe, or the Larynx ; — and 
 
 3d. Of the muscular bag, which forms the cavity 
 behind the nose and mouth that terminates in the 
 (Esophagus, or the Pharynx, 
 
 SECTION I, 
 
 Of the Isthmus of the Fauces. 
 
 In the back part of the mouth, on each side, are to 
 be seen the two ridges or half arches, passing from 
 the soft palate of the root of the tongue, mentioned 
 in page 17, and said to be formed by plaits of the 
 skin containing muscular fibres. The anterior plait, 
 which contains the muscle called Constrictor Isthmi 
 Faucium , passes directly from the side of the root of 
 the tongue to the palate, and terminates near the 
 commencement of the uvula. The posterior plait 
 runs from the palate obliquely downwards and back- 
 wards, as it contains the palato-pharyngeus muscle, 
 which passes from the palate to the upper and poste- 
 rior part of the thyroid cartilage. 
 
 In the triangular space between these ridges is 
 situated a glandular body, called the Tonsil Jimyg- 
 
30 
 
 Tonsils — Epiglottis. 
 
 dala. This gland has an oval form, its longest dia- 
 meter extending from above downwards. Its surface 
 is rather convex, its natural colour is a pale red. On 
 its surface are the large orifices of many cells of con- 
 siderable size, which exist throughout the gland. 
 These cells often communicate with each other, so 
 that a probe can be passed in at one orifice and out 
 at the other. 
 
 Into these cells open many mucous ducts, which 
 discharge the mucus of the throat, for the purpose 
 of lubricating the surface, and facilitating the trans- 
 mission of food. 
 
 Tiie epiglottis, or fifth cartilage of the larynx, is 
 situated at the root of the tongue, in the middle, 
 between the tonsils. The part which is in sight is 
 partly oval in form, and of a whitish colour. Its 
 position, as respects the tongue, is nearly perpendi- 
 cular, and its anterior surface rather convex. 
 
 The membrane continued from the tongue over 
 the epiglottis is sn arranged that it forms a plait, 
 which extends from the middle of the root of the 
 tongue along the middle of the anterior surface of 
 the epiglottis, from its base upwards. 
 
 On each side of this plait, or frzenum, at the junc- 
 tion of the surfaces of the tongue and of the epiglot- 
 tis, there is often a depression, in which small por- 
 tions of food sometimes remain; and a small frsenum, 
 similar to that above described, is sometimes seen on 
 the outside of each of these cavities. 
 
 The epiglottis is situated immediately before the 
 opening into the larynx. 
 
 The above described parts can be well ascertained 
 in the living subject, by a person who has a general 
 knowledge of the structure. Thus, looking into the 
 mouth, with the tongue depressed, the uvula and soft 
 palate are in full view above, and the epiglottis is 
 very perceptible below ; while the two ridges or la- 
 
Of the Larynx. 31 
 
 tera] half arches can be seen on each side, with the 
 tonsil between them. 
 
 SECTION II. 
 
 Of the Larynx . 
 
 In this structure are five cartilages, upon which 
 its form and stength depends, viz. the Cricoid , the 
 Thyroid, the two Arytenoid , and the Epiglottis. 
 These cartilages are articulated to each other, and 
 are supplied with muscles by which certain limited 
 motions are effected. 
 
 The basis of the structure is a cartilaginous ring, 
 called the cricoid cartilage, which may be considered 
 as the commencement of the windpipe. 
 
 It may be described as an irregular section of a 
 tube : its lower edge, connected with the windpipe, 
 being nearly horizontal when the body is erect ; and 
 the upper edge very oblique, sloping from before, 
 backwards and upwards : in consequence of this, it 
 has but little depth before, but is eight or nine lines 
 deep behind. 
 
 The Thyroid cartilage is a single plate, bent in such 
 manner that it forms an acute angle with two similar 
 broad surfaces on each side of it. It is so applied to 
 the cricoid cartilage, that the lower edge of the angu- 
 lar part is at a small distance above the front part of 
 that cartilage, and connected to it by ligamentous 
 membrane : while its broad sides are applied to it 
 laterally, and thus partially enclose it. 
 
 The upper edge of the angular part of the thyroid 
 cartilage forms a notch ; and the natural position of 
 the cartilage is such, that this part is very prominent 
 in the neck : it is called the Pomum JLdami . 
 
 Both the upper and lower edges of the thyroid 
 cartilage terminate posteriorly in processes, which 
 
32 Arytenoid Cartilages and Ligaments . 
 
 are called Cornua. The two uppermost are longest : 
 they are joined by ligaments to the extremities of the 
 os hyoid es. The lower and shorter processes are 
 fixed to the cricoid cartilage. The thyroid cartilage, 
 therefore, partly rests upon the cricoid cartilage be- 
 low, and is attached to the os hyoides above. It is 
 influenced by the muscles which act upon the os 
 hyoides, and also by some muscles which are insert- 
 ed into itself. It is moved obliquely downwards and 
 forwards, in a slight degree, upon the cricoid cartil- 
 age by a small muscle, the crico-thyroideus, which 
 arises from that cartilage and is inserted into it. 
 
 The Arytenoid cartilages are two small bodies of a 
 triangular pyramidal form, but slightly curved back- 
 wards. They are placed upon the upper and poste- 
 rior edge of the cricoid cartilage, near to each other; 
 and their upper ends, taken together, resemble the 
 mouth of a pitcher or ewer; from which circum- 
 stance their name is derived. Their bases are broad ; 
 and on their lower surfaces is a cavity, which cor- 
 responds with the convex edge of the cricoid cartil- 
 age, to which they are applied. At these places, a 
 regular moveable articulation is formed, by a capsu- 
 lar ligament between each of these cartilages and the 
 cricoid, in consequence of which they can be incli- 
 ned backward or forward, inward or outward. 
 
 From the anterior part of each of these cartilages, 
 near the base, a tendinous cord passes forward, in a 
 direction which is horizontal when the body is erect, 
 to the internal surface of the angle of the thyroid. 
 These ligaments are not perfectly parallel to each 
 other ; for they are nearer before than behind. The 
 aperture between them is from two to five lines wide 
 when the muscles are not in action ; and this aperture 
 is the orifice of the windpipe : for the exterior space, 
 between these ligaments and the circumference of 
 the thyroid, is closed up by membrane and muscle. 
 
33 
 
 Epiglottis. 
 
 At a small distance above these ligaments are two 
 others, which also pass from the arytenoid to the 
 thyroid cartilages. They are not so tendinous and 
 distinct as the first mentioned, and cannot be drawn 
 so tense by the muscles of the arytenoid cartilages. 
 They are also situated at a greater distance from each 
 other, and thus form a large aperture. 
 
 On the external side of the upper extremity of 
 each of the arytenoid cartilages, and nearly in con- 
 tact with it, is a small cartilaginous body, not so large 
 as a grain of wheat, and nearly oval in form. These 
 are connected firmly to the arytenoid cartilages, and 
 are called their appendices. Being in the margin of 
 the aperture of the larynx, they have an effect upon 
 its form. 
 
 The arytenoid cartilages are the posterior parts 
 of the larynx : the Epiglottis , which has already 
 been mentioned, is the anterior. When this carti- 
 lage is divested of its membrane, it is oval in its 
 upper extremity, and rather angular below, termi- 
 nating in a long narrow process, which is like the 
 stalk of a leaf. It is firmly attached to the internal 
 surface of the angular part of the thyroid by this 
 lower process ; and, being placed in a perpendicular 
 position, one of its broad surfaces is anterior towards 
 the tongue, and the other posterior, towards the open- 
 ing of the windpipe. 
 
 It is attached to the os hyoides by dense cellular 
 texture or ligament, and to the tongue by those plaits 
 of the membrane of the mouth, which have been al- 
 ready described. 
 
 It is elastic, but more flexible than the oth*f car- 
 tilages ; being somewhat different in its structure.— 
 Its surface is perforated by the orifices of many mu- 
 cus ducts. 
 
 There is a small .space between the lower part of 
 this cartilage, and the upper part of the thyroid and 
 Vol. ii„ 5 
 
34 
 
 liima Glottidis. — Glottis. 
 
 the ligamentous membrane passing from it to the os 
 hyoides. In this is a substance, which appears to 
 consist of glandular and of adipose matter. It is sup- 
 posed that some of the orifices on the lower part of 
 the epiglottis communicate with this substance. 
 
 In the erect position of the body, the epiglottis is 
 situated rather higher up than the arytenoid carti- 
 lages, and at the distance of ten or twelve lines from 
 them. 
 
 The membrane which covers the epiglottis, is ex- 
 tended from each side of it to the arytenoid carti- 
 lages ; and being continued into the cavity of the la- 
 rynx, as well as upon the general surface of the 
 throat, it is necessarily doubled : this doubling forms 
 the lateral margins of the orifice of the cavity of the 
 larynx. In these folds of the membrane are seen 
 very delicate muscular fibres, called the Aryteno- 
 epiglottidei. 
 
 The membrane continues down the cavity of the 
 larynx, and, covering the upper ligaments, pene- 
 trates into the vacuity between them and the lower 
 ligaments, so as to form a cavity on each side of the 
 larynx, opening between the two ligaments, which 
 is called the Ventricle of Morgagni. The shape of 
 these cavities is oblong. Its greatest length extends 
 from behind forward, on each side of the opening 
 into the windpipe formed by the two lower or prin- 
 cipal ligaments; so that when the larynx is removed 
 from the subject, upon looking into it from above, 
 ytri perceive three apertures : one in the middle, 
 formed by the two lower ligaments ; and one on 
 each ode of it, between the lower and upper liga- 
 ment, Vvfiich is the orifice of the ventricle of Mor- 
 gagni. 
 
 The apertore between the two lower ligaments is 
 called the Uinta, Gloitidis, or Chink of the Glottis $ 
 the upper aperture, formed by the fold of the mem- 
 
35 
 
 Arteries and jXerves of the Larynx . 
 
 brane extending from the epiglottis to the arytenoid 
 cartilages, may be termed Glottis. 
 
 If the windpipe is divided near the larynx, and 
 the larynx inverted, so that the rima glottidis, may 
 be examined from below, the structure appears still 
 more simple : it resembles a septum fixed abruptly 
 in the windpipe, with an aperture in it of the figure 
 of the rima glottidis. . 
 
 The anterior surface of the two arytenoid cartila- 
 ges is concave. This concavity is occupied in each 
 by a glandular substance, which lies between the car- 
 tilage and the lining membrane ; and extends itself 
 horizontally, covered by the upper ligament of the 
 glottis. The nature of these bodies is not perfectly 
 understood j but they are supposed to secrete 
 mucus. 
 
 The membrane, which lines the cavity of the glot- 
 tis being continued from the mouth and throat, re- 
 sembles the membranes which invest those parts. In 
 some places, where it is in close contact with the car- 
 tilages, it appears united with the perichondrium, 
 and acquires more firmness and density. 
 
 The general motions of the larynx are very intel- 
 ligible to those who are acquainted with the muscles 
 which are connected with the thyroid cartilage, and 
 which move the os hyoides They take place par- 
 ticularly in deglutition, and in some modifications of 
 the voice ; and also in vomiting. 
 
 The motions of the particular cartilages on each 
 other can also be well understood, by attending to 
 the origin and insertion of the various small muscles 
 connected with them. The most important of these 
 muscles are the crico-arytenoidei postici and late- 
 rales, the thyreo-arytenoidei, the arytenoidei obliqui, 
 and the arytenoideus transversus. The effects of 
 their actions appear to be the dilating or contracting 
 
36 
 
 Arteries and JYerves of the Larynx. 
 
 the rima glottidis, and relaxing or extending the li- 
 gaments which form it. 
 
 The arteries of the larynx are derived from two 
 sources, viz. the superior thyroid, or laryngeal 
 branch of the external carotid ; and the thyroid 
 branch of the subclavian. 
 
 The nerves of the larynx also come to it in two 
 very different directions on each side. It receives 
 two branches from the par vagum ; one which leaves 
 that nerve high up in the neck, and is called the 
 Superior Laryngeal branch ; and another which 
 proceeds from it after it has passed into the cavity 
 of the thorax, and is called from its direction the 
 Recurrent. 
 
 The extreme irritability of the glottis is unequivocally 
 demonstrated by the cough which is excited when a 
 drop of water, or any other mild liquid, or a crumb 
 of bread enters it. Notwithstanding' this, a flexi- 
 ble tube, or catheter, has several times been passed 
 into the windpipe through the rima glottidis, and 
 been endured by the patient a considerable time. 
 
 The cough, which occurs when these parts are irritated, 
 does not appear to arise exclusively from the irrita- 
 tion of the membrane within the glottis ; for, it it 
 were so, mucilaginous substances, when swallowed 
 slowly, could not suspend it. Their effect in reliev- 
 ing cough is universally known ; and as they are only 
 applied to the surface exterior to the glottis, it is evi- 
 dent that the irritation of this surface must also pro- 
 duce coughing. 
 
 Several curious experiments have been made to deter- 
 mine the effect of dividing the different nerves which 
 go to the larynx ; by which it appears that the re- 
 current branches supply parts which are essentially 
 necessary to the formation of the voice, whilst the 
 laryngeal branches supply parts which merely in- 
 fluence its modulation, or tone. See Mr. Haighton’s 
 Essay on this subject : Memoirs of the Medical So- 
 ciety of London, Vol. III. 
 
The Thyroid Gland. — The Pharynx. 37 
 
 The Thyroid Gland 
 
 May be described here, although a part of it is 
 situated below the larynx. 
 
 This body consists of two lobes, which are united 
 at their lower extremities by a portion which extends 
 across the anterior part of the windpipe. Each lobe 
 generally rises upwards and backwards from the se- 
 cond cartilaginous ring of the windpipe over the cri- 
 coid cartilage and a portion of the thyroid. It lies 
 behind the sterno-hyoidei and sterno-tliyroidei mus- 
 cles. It is of a reddish-brown colour, and appears 
 to consist of a granulous substance ; but its ultimate 
 structure is not understood. It is plentifully suppli- 
 ed with blood, and receives two arteries on each side : 
 one from the laryngeal branch of the external caro- 
 tid : and the other from the thyroid branch of the 
 subclavian. 
 
 Notwithstanding this large supply of blood, there 
 is no proof that it performs any secretion ; for al- 
 though several respectable anatomists have supposed 
 that they discovered excretory ducts passing to the 
 windpipe, larynx, or tongue, it is now generally 
 agreed that such excretory ducts are not to be found. 
 Several instances have however occurred, in which 
 air has been forced, by violent straining, from the 
 windpipe into the substance of this gland.* 
 
 * There are two membranous expansions in the neck which should be 
 noticed in its dissection. The first called Fascia Superficialis lies imme- 
 diately beneath the skin, may be considered as a continuation of the fascia 
 superficialis abdominis, and is strongly connected to the base of the lower 
 jaw, being also spread over the parotid gland. It is not very distinct in all 
 subjects. The second is called the Fascia Profunda Cervicis; it extends 
 from the larynx and thyroid gland to the upper part of the sternum and 
 first ribs, the great vessels, &c. of the superior mediastinum are placed 
 immediately below it. — E d. 
 
38 
 
 Structure of the Pharynx . 
 
 SECTION III. 
 
 Of the Pharynx. 
 
 The pharynx is a large muscular bag. which forms 
 the great cavity behind the nose and mouth that ter- 
 minates in the oesophagus. 
 
 It has been compared to a funnel, of which the 
 oesophagus is the pipe : but it differs from a funnel 
 in this respect, that it is incomplete in front, at the 
 part occupied by the nose and mouth and larynx. 
 
 It is connected above, to the cuneiform process of 
 the occipital bone, to the pterygoid processes of the 
 sphenoidal, and to both the upper and lower maxil- 
 lary bones. It is in contact with the cervical verte- 
 brae behind ; and, opposite to the cricoid cartilage, 
 it terminates in the oesophagus. 
 
 If the pharynx and oesophagus be carefully dissect- 
 ed and detached fi om the vertebrae, preserving the 
 connexion of the pharnx with the head ; and the head 
 then be separated from the body, by dividing the 
 articulation of the atlas and the os oceipitis, and cut- 
 ting through the soft parts below the larynx ; the 
 resemblance to a funnel will be very obvious. 
 
 In this situation, if an incision be made from 
 above downwards though the whole extent of the 
 posterior part of the pharynx, the communication of 
 the nose, mouth, and windpipe, wdth this cavity, 
 will be seen from behind at one view. 
 
 The openings into the nose, or the posterior nares, 
 appear uppermost. Their figure is irregularly oval 
 or oblong ; they are separated from each other by a 
 thin partition, the vomer. Immediately behind, on 
 the external side of each of these orifices, is the 
 Eustachian tube. 
 
 The soft palate will appear extending from the 
 Jow r er boundary of the posterior nares, obliquely 
 
Structure of the Pharynx . 39 
 
 backwards and downwards, so as nearly to close the 
 passage into the mouth. The uvula hangs from it ; 
 and, on each side of the uvula, the edge of the palate 
 is regularly concave. 
 
 Below the palate, in the isthmus of the fauces, are 
 the ridges or half-arches, and the tonsils between 
 them. The half-arch which presents first, in this 
 view, runs obliquely downward and backward, and 
 not parallel to the other. 
 
 Close to the root of the tongue is the epiglottis 
 erect ; and, immediately adjoining it, is an aperture 
 large enough to admit the end of a middle-sized 
 finger. This aperture is widest at the extremity 
 next to the epiglottis, and rather narrower at the 
 other extremity : it is the glottis or opening of the 
 windpipe. When the larynx is elevated, the epi- 
 glottis can be readily depressed so as to cover it 
 completely. 
 
 The extremities of the arytenoid cartilages, and 
 their appendices, may be recognised at the posterior 
 edge of the glottis. At a short distance below this 
 edge, the (Esophagus begins. 
 
 The Pharynx is composed of the membrane con- 
 tinued from the nose and mouth internally, and of a 
 stratum of muscular fibres externally. The internal 
 membrane is very soft and flexible, and perforated 
 by many muciferous ducts. The surface which it 
 forms is rather rough, owing to the mucous glands 
 which it covers. It has a red colour, but not so deep 
 as that of some other parts. It is connected to the 
 muscular stratum by a loose cellular membrane. 
 
 The muscular coat consists of three different por- 
 tions, which are considered as so many distinct mus- 
 cles. 
 
 The fibres of each of these muscles originate on 
 each side, and run in an oblique direction to meet in 
 
40 Structure of the Pharynx. 
 
 the middle, thus forming the posterior external sur- 
 face of the dissected pharynx. 
 
 The fibres of the upper muscle originate from the 
 cuneiform process of the occipital bone, from the 
 pterygoid processes of the os sphenoides, and from 
 the upper and lower jaws, near the last dentes mo- 
 lares, on each side. They unite in a middle line in 
 the back of the pharynx. 
 
 The fibres of the middle muscle originate princi- 
 pally from the lateral parts of the os hyoides, and. 
 from the ligaments which connect that bone to the 
 thyroid cartilage. The superior fibres run obliquely 
 upwards, so as to cover a part of the first mentioned 
 muscle, and terminate in the cuneiform process of the 
 occipital bone; while the other fibres unite with 
 those of the opposite side in the middle line. 
 
 The fibres of the lower muscles arise from the thy- 
 roid and the cricoid cartilages, and terminate also in 
 the middle line. Those which are superior, running 
 obliquely upwards ; the inferior, nearly in a trans- 
 verse direction. 
 
 It is obvious, from the origin and insertion of 
 these fibres, that the pharynx must have the power 
 of contracting its dimensions in every respect ; and, 
 particularly, that its diameter may be lessened at 
 any place ; and that the whole may be drawn up- 
 wards. 
 
SYSTEM OF ANATOMY. 
 
 PART VII. 
 
 OF THE THORAX. 
 
 Before the thorax is described, it will be in or- 
 der to consider the 
 
 Mammse ; 
 
 Or those glandular bodies, situated on the anterior 
 part of it, which, in females, are destined to the se- 
 cretion of milk. 
 
 These glands lie between the skin and the pecto- 
 ral muscles, and are attached to the surfaces of those 
 muscles by cellular membrane. 
 
 They are of a circular form ; and consist of a 
 whitish firm substance, divisible into small masses or 
 lobes, which are composed of smaller portions or lo- 
 buli. Between these glandular portions a great deal 
 of adipose matter is so diffused, that it constitutes a 
 considerable part of the bulk of the mammse. 
 
 The gland, however, varies greatly in thickness in 
 the same person at different periods of life. 
 
 The mammas become much enlarged about the 
 age of puberty. They are also very large during 
 pregnancy and lactation ; but after the period of 
 child-bearing, they diminish considerably. They 
 are supplied with blood by the external and internal 
 
 VOLv II. © 
 
42 
 
 Mammae. 
 
 maniary arteries, the branches of which enter them 
 irregularly in several different places. 
 
 The veins correspond with the arteries. 
 
 From the small glandular portions that compose 
 the mamma, fine excretory tubes arise, which unite 
 together and form the great lactiferous ducts of the 
 gland. These ducts proceed in a radiated manner 
 from the circumference to the centre, and terminate 
 on the surface of the nipple.*' 
 
 They are commonly about fifteen in number, and 
 vary considerably in size : the largest of them being 
 more than one-sixth of an inch in diameter. 
 
 They can be very readily injected by the orifices 
 of the nipple, from a pipe filled with mercury, in 
 subjects who have died during lactation or pregnan- 
 cy; but they are very small in subjects of a differ- 
 ent description. 
 
 It has been asserted by respectable anatomists, that 
 these ducts communicate freely with each other ; but 
 they do not appear to do so : each duct seems to be 
 connected with its proper branches only.f 
 
 Haller appears to have entertained the remarkable 
 sentiment , that some of the ducts originated in the 
 adipose matter about the gland, as well as in the glan- 
 dular substance.;}: 
 
 The papilla, or nipple, in which these ducts ter- 
 minate, is in the centre of the mamma : it consists of 
 a firm elastic substance, and is nearly cylindrical in 
 form. It is rendered tumid by irritation, and by 
 certain emotions. 
 
 The lactiferous ducts terminate upon its extremi- 
 ty. When it is elongated they can freely discharge 
 
 * Described in the 16th century, by Charles Etienne, Vesalius and Pos- 
 thuis, but their uses were unknown. — Ed. 
 
 t See Edinburgh Medical Commentaries, vol. 1. page 31 — a paper by 
 Meckel. Ed. 
 
 t Elemeuta Physiologise, Tom. 7, Pars 11, page 7. 
 
Mammas. 43 
 
 their contents ; but when it contracts, this discharge 
 is impeded. 
 
 The skin immediately around the nipple is of a 
 bright red colour in virgins of mature age. In preg- 
 nant women it is sometimes almost black ; and in 
 women who have borne children it is often brownish. 
 It abounds with sebaceous glands, which form small 
 eminences on its surface. 
 
 This gland exists in males, although it is very 
 small. In boys, soon after birth, it has often been 
 known to tumefy and become very painful, in conse- 
 quence of the secretion and accumulation of a whitish 
 fluid, which can be discharged by pressure. It also 
 sometimes swells and is painful, in males at the age 
 of puberty. 
 
 There have been some instances in which it has 
 secreted milk in adult males ; and a few instances 
 also in which it has been affected with cancer, in the 
 same sex. 
 
 The mamma is plentifully supplied with absorbent 
 vessels, which pass from it to the lymphatic glands 
 in the axilla. 
 
 Its nerves are principally derived from the great 
 plexus formed by the nerves of the arm. 
 
CHAPTER I. 
 
 OF THE GENERAL CAVITY OF THE THORAX. 
 
 SECTION I. 
 
 Of the form of the Cavity of the Thorax. 
 
 The osseous structure of the thorax is described 
 in vol. i. page 94. The cavity is completed by the 
 intercostal muscles, which dose the vacuities between 
 the ribs; and by the diaphragm, which fills up the 
 whole space included within its lower margin. 
 
 If we except the apertures of the diaphragm, 
 which are completely occupied by the aor ta, the vena 
 cava, and the oesophagus, &c. the only outlet of this 
 cavity is above : it is formed by the upper ribs, the 
 first dorsal vertebra, and the sternum. The figure 
 of this aperture is between that of the circle and the 
 oval ; but it is made irregular by the vertebra, and 
 by the upper edge of the sternum. 
 
 When the superior extremities and the muscles 
 appropriated to them are removed, the external figure 
 of the thorax is conical ; but the cavity formed hy it 
 is considerably influenced by the spine, which pro- 
 trudes into it ; while the ribs, as they proceed from 
 the spine, curve backwards, and thus increase its 
 prominency in the cavity. 
 
 The diaphragm has a great effect upon the figure 
 of the cavity of the' thorax. It protrudes into it from 
 below , with a convexity of such form that it has been 
 compared to an inverted bowl ; so that, although it 
 arises from the lower margin of the thorax, the cen- 
 tral parts of it are nearly as high as the fourth rib. 
 
Pleurse. 
 
 45 
 
 The position of the diaphragm is also oblique. 
 The anterior portion of its margin, being connected 
 to the seventh and eighth ribs, is much higher than 
 the posterior portion, which is attached to the eleventh 
 and twelfth. 
 
 In consequence of the figure and position of the 
 diaphragm, the form of the cavity of the thorax re- 
 sembles that of the hoof of the ox when its posterior 
 part is presented forwards. 
 
 SECTION II. 
 
 Of the arrangement of the Plearse. 
 
 The thorax contains the two lungs and heart, as 
 well as several very important parts of smaller size. 
 
 The lungs occupy the greatest part of the cavity; 
 and to each of them is appropriated a complete sac, 
 called Pleura , which is so arranged that it covers 
 the surface of the lungs, and is continued from it to 
 the contiguous surface of the thorax, which it hues. 
 After covering the lung, it is extended from it to the 
 spine posteriorly, and the sternum anteriorly : so 
 that in tracing the pleura in a circular direction, if 
 you begin at the sternum, it proceeds on the inside 
 of the ribs to the spine ; at the spine it leaves the 
 surface of the thorax, and proceeds directly forwards 
 towards the sternum. In its course from the spine 
 to the sternum, it soon meets with the great branch 
 of the windpipe and the blood vessels, which go to 
 the lung : it continues on these vessels and round the 
 lung until it arrives at the anterior side of the ves- 
 sels, when it again proceeds forwards untii it arrives 
 at the sternum. Each sac being arranged in the 
 same way, there is a part of each extended from the 
 spine to the sternum. These two lamina, form the 
 great vertical septum of the thorax, called Mediasti- 
 num. They are situated at some distance from each 
 
46 
 
 Mediastinum. 
 
 other ; and the heart, with its investing membrane or 
 pericardium, is placed between them. 
 
 The pericardium is also a complete sac or blad- 
 der, which, after covering perfectly the surface of 
 the heart, is extended from it so as to form a sac, 
 which lies loose about it, and appears to contain it. 
 This loose portion adheres to those parts of the la- 
 mina of the mediastinum with which it is contigu- 
 ous ; and thus three chambers are formed within the 
 cavity of the thorax : one for each lung, and one for 
 the heart. 
 
 The two lamina of the pleura, which constitute 
 the mediastinum, are at different distances from each 
 other, in different places. At the upper part of the 
 thorax, they approach each other from the internal 
 edges of the first l ibs ; and, as these include a space 
 which is nearly circular, the vacuity between these 
 lamina is necessarily of that form, at its commence- 
 ment above. 
 
 Here, therefore, is a space between them above, 
 which is occupied by the great transverse vein that 
 carries the blood of the left subclavian and the left 
 internal jugular to the superior cava ; by the trachea; 
 by the oesophagus ; and by the subclavian and caro- 
 tid arteries, as they rise from the curve of the aorta. 
 This space is bounded below by the above mentioned 
 curve of the aorta. 
 
 The heart and pericardium are so placed that 
 there is a small distance between them and the ster- 
 num : in this space the two lamina of the mediasti- 
 num are very near to each other ; and cellular sub- 
 stance intervenes between them. This portion of the 
 mediastinum is called the Anterior Mediastinum. 
 
 Posteriorly, the heart and pericardium are also at 
 a small distance from the spine ; and here the lami- 
 na of the mediastinum are at a greater distance from 
 each other, and form a long narrow cavity which 
 
47 
 
 Preparation of the Thorax. 
 
 extends down the thorax in front of the vertebrae : 
 this is called the Posterior Mediastinum. It con- 
 tains a considerable portion of the aorta as it de- 
 scends from its curve, the oesophagus, the thoracic 
 duct, and the vena azygos. The aorta is in contact 
 with the left lamen, and can often be seen through 
 it when the left lung is lifted up. 
 
 The oesophagus, is in contact with the right la- 
 men : in its progress downwards, it inclines to the 
 left side and is advanced before the aorta. 
 
 The vena azygos appears posterior to the oesopha- 
 gus ; it proceeds upwards until it is as high as the 
 right branch of the windpipe : here it bends forward, 
 round that branch, and opens into the superior cava, 
 before that vein opens into the right auricle. 
 
 The thoracic duct proceeds upwards from below, 
 lying in the space between the aorta and the vena 
 azygos, until the beginning of the curve of the aorta, 
 when it inclines to the left, proceeding towards the 
 place of its termination. 
 
 The formation of the mediastinum, and the arrangement 
 of the pleura, as well as the connexion of these mem- 
 branes with the parts contained in the thorax, may be 
 studied advantageously, after the subject has been pre- 
 pared in the manner now to be described. 
 
 Take away, from each side, the five ribs which are situ- 
 ated between the first and last true ribs, by separating 
 their cartilages from the sternum, and their heads from 
 the spine ; so that the great cavities of the thorax may 
 be laid open. 
 
 The precise course of the mediastinum is thus rendered 
 obvious ; and the sternum may now be divided with a 
 saw throughout its whole length in the same direction ; 
 so that the division of the bone may correspond with 
 the space between the lamina of the mediastinum. 
 
 Separate the portion of the sternum cautiously, so as to 
 avoid lacerating the lamina of mediastinum; and keep 
 them separate, while the trachea is dissected from the 
 neck into the cavity of the thorax ; the great transverse 
 vein and the descending cava are dissected to the pe= 
 
48 
 
 Preparation of the Thorax . 
 
 ricardium ; and tire left carotid artery, with the right 
 subclavian and carotid, are dissected to the curve of 
 the aorta, taking care not to destroy the lamina of the 
 mediastinum. 
 
 After this preparation the upper space between the la- 
 mina of the mediastinum can be examined ; and the 
 relative situation of the trachea and the great vessels 
 in it can be understood. The anterior mediastinum 
 can also be studied : the root of each lung, or its con- 
 nexion with the mediastinum, may be seen perfectly ; 
 and the precise situation of the lung, in its proper ca- 
 vity, may be well conceived. 
 
 After this, while the portions of the sternum are separa- 
 ted, the pericardium may be opened, and the heart 
 brought into view: the attachment of the pericardium, 
 and to the mediastinum, and to the diaphragm, may 
 be seen with advantage in this situation. The por- 
 tions of the sternum may now be detached from the 
 ribs, with which they remain connected ; and further 
 dissection may be performed to examine the posterior 
 mediastinum and its contents, and the parts which 
 constitute the roots of the lungs. 
 
CHAPTER II. 
 
 OF THE HEART AND THE PERTCARDIUM, AND THE 
 
 GREAT VESSELS CONNECTED WITH THE HEART. 
 
 SECTION I. 
 
 Of the Pericardium . 
 
 The heart is enclosed by a membranous sac, 
 which, upon a superficial view, seems only con- 
 nected with its great vessels : but which, in fact, 
 adheres closely to the whole of its surface. From 
 this surface it is extended to those vessels ; from 
 which it proceeds, after the manner of the reflected 
 membranes, and forms an enclosure that lies loosely 
 about the heart. If it were dissected from the heart, 
 without laceration or wounding, it would be an en- 
 tire sac. 
 
 The pericardium, thus arranged, is placed between 
 the two lamina of the mediastinum, and adheres firm- 
 ly to them where they are contiguous to it : it also 
 adheres firmly to the diaphragm below, and thus pre- 
 serves the heart in its proper position. 
 
 The figure of the pericardium, when it is distend- 
 ed, is somewhat conical; the base being on the dia- 
 phragm. The cavity formed by it is larger than the 
 heart after death, but it is probable that the heart 
 nearly fills it during life ; for, when this organ is dis- 
 tended by injection, it often occupies the whole ca- 
 vity of the pericardium. 
 
 The pericardium is composed of two lamina, the 
 internal of which covers the heart, as has been al- 
 ready described : while the external merely extend^ 
 over the loose portion of the other, and blends 
 
 Vol. ii. 7 
 
50 Of the Heart. 
 
 with the mediastinum, where that membrane invests 
 the great vessels. 
 
 The interna] surface of the pericardium is very 
 smooth and polished ; and in the living subject is 
 constantly moistened* with a fluid, which is probably 
 effused from the exhalent vessels on its surface. 
 
 The quantity of this fluid does not commonly ex- 
 ceed two drachms ; but in cases of disease it some- 
 times amounts to many ounces.* It is naturally trans- 
 parent, but slightly tinged with red in children, and 
 yellow in old persons. It is often slightly tinged 
 with red in persons who have died by violence. 
 
 SECTION II. 
 
 Of the Heart. 
 
 The great organ of the circulation consists of mus- 
 cular fibres, which are so arranged that they give it 
 a conical form, and compose four distinct cavities 
 within it. 
 
 Two of these cavities, which are called Auricles, 
 receive the contents of the veins ; the other two com- 
 municate with the arteries, and are called Ventricles. 
 
 The auricles form the basis of the cone ; the ven- 
 tricles the body and apex. 
 
 The structure of the auricles is much less firm 
 than that of the ventricles, and consists of a smaller 
 proportion of muscular fibres. They appear like ap- 
 pendages of the heart, while the ventricles compose 
 the body of the viscus. 
 
 The ventricles are very thick, and are composed 
 of muscular fibres closely compacted. 
 
 * The pericardium has been so distended, by effusion in dropsy, that it 
 '•*as forrne ) a tumour,, protruding on the neck from under the sternum. This 
 tumour h ac i a strong pulsating motion. It disappeared completely when 
 the o^f hydropic symptoms were relieved. 
 
51 
 
 Connexions of the Heart, 
 
 The figure of the heart is not regularly conical : for 
 a portion of it, extending from the apex to the base, 
 is flattened ; and in its natural position, this flat part 
 of the surface is downwards. 
 
 It is placed obliquely in the body ; so that its base 
 presents backward and to the right, and its apex 
 forward and to the left. 
 
 Notwithstanding this obliquity, the terms right 
 and left are applied to the different sides of the heart, 
 and to the different auricles and ventricles ; although 
 they might, with equal propriety, be called anterior 
 and posterior. 
 
 The two great veins, called Venae Ccwas, which 
 bring the blood from every part of the body, open 
 into the right auricle from above and below ; the 
 right auricle opens into the right ventricle ; and from 
 this ventricle arises the artery denominated Pulmo- 
 nary, which passes to the lungs. 
 
 The Pulmonary veins, which bring back the blood 
 from the lungs, open into the left auricle ; this auri- 
 cle opens into the left ventricle ; and from this ven- 
 tricle proceeds the Aorta , or great artery, which 
 carries blood to every part of the body. 
 
 The heart is preserved in its position, 1st, by the 
 vense cavse, which are connected to all the parts to 
 which they are contiguous in their course ; 2d, by 
 the vessels which pass between it and the lungs, 
 which are retained in a particular position by the 
 mediastinum ; 3d, by the aorta, which is attached to 
 the mediastinum in its course downwards, after mak- 
 ing its great curve ; and 4th, by the pericardium, 
 which is attached to the great vessels and to the me- 
 diastinum. By these different modes the basis of the 
 heart is fixed, while its body and apex are perfectly 
 free from attachment, and only contiguous to the pe- 
 ricardium. 
 
52 
 
 Right Auricle. 
 
 The external surface of the heart, being formed by 
 the pericardium., is very smooth : under this surface 
 a large quantity of fat is often found. 
 
 The two auricles are contiguous to each other at 
 the base, and are separated by a partition which is 
 common to both. 
 
 The Right Auricle originates from, the junction of 
 the two vense cavge. These veins are united at some 
 distance behind the right ventricle,* and are dilated 
 anteriorly into a sac or pouch, which is called the 
 Sinus, and extends to the right ventricle, to which 
 it is united. 
 
 The upper part of this poueh, or sinus, forms a 
 point with indented edges, which is detached from 
 the ventricle, and lies loose on the right side of the 
 aorta. This point has some resemblance to the ear 
 of a dog, from which circumstance the whole cavity 
 has been called auricle ; but by many persons the 
 cavity is considered as consisting of two portions : the 
 Auricle, strictly speaking ; and the Sinus Venosus , 
 above described : they however form but one cavity. 
 
 This portion of the heart, or Right Auricle, is of 
 an irregular oblong figure. In its posterior surface, 
 it is indented ; for the direction of the two cavge, 
 at their junction, is not precisely the same ; but they 
 form an angle, which causes this indentation. The 
 anterior portion of the auricle, or that which appears 
 like a pouch between the ventricle and the veins, is 
 different in its structure from the posterior part, 
 which is strictly a portion of the veins. It consists 
 simply of muscular fibres, which are arranged in fas- 
 ciculi that cover the whole internal surface : this is 
 also the case with the point, or that part which is 
 strictly called auricle. 
 
 * In this description the heart is supposed to be in its natural position. 
 
53 
 
 Right Ventricle . 
 
 These fasciculi are denominated Musculi Pecti- 
 nati, from their resemblance to the teeth of a comb. 
 
 That part of the internal surface, which is formed 
 by the septum, is smooth ; and the whole is covered 
 by a delicate membrane. 
 
 On the surface of the septum, below the middle, 
 is an oval depression, which has a thick edge or 
 margin : this is called the Fossa Ovalis. In the foe- 
 tal heart, it was the Foramen Ovale, or aperture 
 which forms the communication between the two 
 auricles. 
 
 Near this fossa is a large semilunar plait, or valve, 
 with its points and concave edge uppermost, and 
 convex edge downwards. It was described by Eu- 
 stachius, and, therefore, is called the Valve of Eu- 
 stachius. 
 
 Anterior to this valve, and near the union of the 
 auricle and ventricle, is the orifice of the proper 
 vein of the heart, or the conorary vein. This ori- 
 fice is covered by another semilunar valve, which is 
 sometimes reticulated. 
 
 The aperture, which forms the communication be- 
 tween the right auricle and right ventricle, is about 
 an inch in diameter, and is called ostium venosum. 
 From its whole margin arises a valvular ring, or du- 
 plicature of the membrane lining the surface : this 
 circular valve is divided into three angular portions, 
 which are called Valvulse Tricuspides. From their 
 margins proceed a great number of fine tendinous 
 threads, which are connected to a number of distinct 
 portions of muscular substance, which arise from the 
 ventricle. 
 
 The right Ventricle , when examined separately 
 from the other parts of the heart, is rather triangular 
 in its figure. It is composed entirely of muscular 
 fibres closely compacted ; and is much thicker than 
 the auricle, although not so thick as the other ven- 
 
54 
 
 Right Ventricle. 
 
 tricle. Its internal surface is composed of bundles 
 or columns of fleshy fibres, which are of various 
 thickness and length. Some of these columns arise 
 from the ventricle, and are connected with the ten- 
 dinous threads, which are attached to the margin of 
 the tricuspid valves : the direction of them is from 
 the apex of the heart towards the base. Others of 
 the columns arise from one part of the surface of the 
 ventricle, and are inserted into another part. A 
 third species are attached to the ventricle through- 
 out their whole length, forming ridges or eminences 
 on it. The columns of the two last described species 
 are very numerous. They present an elegant reti- 
 culated surface when the ventricle is laid open, and 
 appear also to occupy a considerable portion of the 
 cavity of the heart, which some of them run across 
 in every direction near the apex. They are all 
 covered by a membrane continued from the auricle 
 and the tricuspid valves ; but this membrane appears 
 more delicate and transparent in the ventricle than 
 it is in the auricle. 
 
 A portion of the internal surface of the ventricle, 
 which is to the left, is much smoother and less fasci- 
 culated than the rest : it leads to the orifice of the 
 pulmonary artery, which arises from it near the ba- 
 sis of the ventricle. This artery is very conspicu- 
 ous, externally, at the basis of the heart. 
 
 It is very evident, upon the first inspection of the 
 heart, that the valvules tricuspides will permit the 
 blood to flow from the auricle to the ventricle ; but 
 must rise and close the orifice, and thereby prevent 
 its passage back again, when the ventricle contracts. 
 
 The use of the tendinous threads, which connect 
 the valves to the fleshy columns, is also very evi- 
 dent; the valve is supported by this connexion, 
 and prevented from yielding to the pressure and 
 opening a passage into the auricle. The blood. 
 
Left Auricle . a 5 
 
 therefore', upon the contraction of the ventricle, is 
 necessarily forced into the pulmonary artery ; the 
 passage to which is now perfectly free. Into this 
 artery the membrane lining the ventricle seems con- 
 tinued ; but immediately within the orifice of the 
 artery it is formed into three semicircular folds, 
 each of which adheres to the surface of the artery 
 by its circumference, while the edge constituting its 
 diameter is loose. 1 In the middle of this loose edge, 
 is a small firm tubercle, called Corpusculum Arantii,* 
 which adds to the strength of the valve. Each of 
 these valves, by its connexion with the artery, forms 
 a sac or pocket, the orifice of which opens forward 
 towards the course of the artery, and the bottom of 
 it. presents towards the ventricle. Blood will, there- 
 fore, pass from the ventricle in the artery, and along 
 it, without filling these sacs ; and on the contrary, 
 in this course, will compress them and keep them 
 empty. If it moves in the artery towards the heart, 
 it will necessarily fill these sacs, and press the se- 
 micircular portions from the sides of the artery 
 against each other ; by this means a partition or sep- 
 tum, consisting of three portions, will be formed be- 
 tween the artery and the heart, which will always 
 exist when the artery compresses, (or acts upon,) its 
 contents. It is demonstrable, by injecting wax into 
 the artery, in a retrograde direction, that these valves 
 do not form a flat septum, but one which is convex 
 towards the heart, and concave towards the artery ; 
 and that this convexity is composed of three distinct 
 parts, each of which is convex. At the place where 
 these valves are fixed, the artery bulges out when 
 distended by a retrograde injection. The enlarge- 
 ments thus produced are called the Sinuses of Val- 
 salva , after the anatomist who first described them. 
 
 After Arantius, a professor at Bologna, who first described it. 
 
i36 
 
 Left Ventrical. 
 
 The valves are called Semilunar; and, although they 
 are formed by a very thin membrane, they are very 
 strong. 
 
 The Left .'thtricle is situated on the left side of the 
 basis of the heart. It originates from the junction of 
 the four pulmonary veins ; two of which come from 
 each side of the thorax, and appear to form a large 
 part of it. It is nearly of a cubic form ; but has also 
 an angular portion, which constitutes the proper au- 
 ricle, that proceeds from the upper and left part of 
 the cavity, and is situated on the left side of the pul- 
 monary artery. 
 
 This auricle is lined by a strong membrane, from 
 which the valves between it and the ventricle ori- 
 ginate ; but it has no fleshy columns or musculi pec- 
 tinati, except in the angular process properly called 
 auricle. 
 
 These valves, and the orifice communicating with 
 the ventricle, resemble those which have been al- 
 ready described between the right auricle and ven- 
 tricle ; but with this difference, that the valvular 
 ring is divided into two portions only, instead of 
 three, which are called Vulvulx Mitrales. The ten- 
 dinous threads, which are connected to the muscular 
 columns, are also attached to these valves, as in the 
 ease of the right auricle. 
 
 These valves admit the passage of blood from the 
 auricle into the ventricle, but completely prevent its 
 return when the ventricle contracts. One of them is 
 so situated that it covers the mouth of the aorta 
 while the blood is flowing into the ventricle, and 
 leaves that orifice open when the ventricle contracts, 
 and the passage to the auricle is closed. 
 
 The Left Ventricle is situated posteriorly, and to 
 the left of the Right Ventricle : its figure is differ- 
 ent, for it is rather conical, and it is also longer. 
 
 The internal surface of this ventricle resembles 
 
57 
 
 Muscular Fibres of the Heart. 
 
 that of the right ventricle ; but the eolumnse carneaa 
 are stronger and larger. 
 
 On the right side of this ventricle is the mouth of 
 the aorta. The surface of the ventricle near this 
 opening is smooth and polished to facilitate the pas- 
 sage of the blood. 
 
 The mouth of the aorta is furnished with three 
 semilunar valves, after the manner of the pulmonary 
 artery, but the former are stronger ; the corpuscula 
 arantii are better developed in them. Indeed Mr. 
 Hunter does not admit of their existence in the pul- 
 monary artery. The sinuses of Valsalva are about 
 the same size in both arteries. 
 
 The cavity of this ventricle is supposed to be 
 smaller than that of the right ; but the amount of the 
 difference has not been accurately ascertained. 
 
 This ventricle must have much more force than the 
 right, as its parietes are so much thicker. Their 
 thickness often exceeds half an inch. 
 
 The difference in the strength of the two ventricles 
 probably corresponds with the difference between the 
 extent of the pulmonary artery and the aorta. 
 
 The thickness of the septum between the ventri- 
 cles is thicker than the sides or parietes of the right 
 ventricle, and less thick than those of the left. 
 
 The muscular fibres of the heart are generally less 
 florid than those of the voluntary muscles ; they are 
 also more closely compacted together. The direc- 
 tion of many of them is oblique or spiral ; but this 
 general arrangement is very intricate : it is such, 
 however, that the cavities of the heart are lessened, 
 and probably completely obliterated, by the contrac- 
 tion of these fibres.* 
 
 Mr. Home has given a precise description of the muscular hbres oi 
 the heart in his Croonian Lecture. London Philosopher! for 
 
 1795, part I. page 215. 
 
 VOL. II. 
 
 8 
 
58 Coronary Vessels , $c. 
 
 The external surface of the heart is covered by 
 that portion of the pericardium which adheres to it. 
 Adipose matter is often deposited between this mem- 
 brane and the muscular surface ; being distributed 
 irregularly in various places. 
 
 This membrane is continued from the surface of the 
 ventricles over that of the auricles. When it is dis- 
 sected off from the place of their junction, these 
 surfaces appear very distinct from each other. 
 
 The proper blood vessels of the heart appear to be 
 arranged in conformity to the general laws of the 
 circulation, and are very conspicuous on the surface. 
 There are two arteries which arise from the aorto im- 
 mediately after it leaves the heart, so that their orifices 
 are covered by two of the semilunar valves. One of 
 these passes from the aorta between the pulmonary 
 artery and the right auricle, and continues in a cir- 
 cular course in the groove between the right auricle 
 and the right ventricle, and sends off its principal 
 branches to the right side of the heart. 
 
 The other artery of the heart passes between the 
 pulmonary artery and the left auricle. It divides into 
 two branches : one, which is anterior, passes to a 
 groove on the surface, corresponding to the septum 
 between the two ventricles, and continues on it to the 
 apex of the heart, sending off branches in its course; 
 another, which is posterior and circumflex, passes be- 
 tween the left auricle and ventricle. 
 
 The great vein of the heart opens into the under 
 side of the right auricle, as has been already mention- 
 ed : the main trunk of this vein passes for some dis- 
 tance between the left auricle and ventricle.* 
 
 * It was asserted by Vieussens at an early period, in the last century, 
 and\<jon afterwards by Thebesius, a German Professor, that there were a 
 numbbypf small orifices in the texture of the heart, which opened into the 
 different > a vities or. both sides of it. 
 
 > This assu^ion of «. fact so difficult to reconcile with the general prin- 
 ciples of the drculation. was received with great hesitation : and although 
 
The Great Vessels . 
 
 59 
 
 From the coarse of these different vessels round 
 the basis of the ventricles of the heart, they are ge- 
 nerally called Coronary Vessels: the arteries are 
 denominated, from their position, Right and Left 
 Coronary. 
 
 The nerves of the heart come from the cardiac 
 plexus, which is composed of threads derived from 
 the intercostal or great sympathetic nerves, and the 
 nerves of the eighth pair. 
 
 SECTION III. 
 
 Of the Aorta , the Pulmonary Artery and Veins , 
 
 and the Vense Cavse ; at their commencement . 
 
 The two great arteries, which arise from the heart, 
 commence abruptly, and appear to be extremely dif- 
 ferent in their composition and structure from the 
 heart. 
 
 They are composed of a substance, which has a 
 whitish colour and very dense texture, and is very 
 elastic as well as firm and strong. 
 
 When the pericardium is removed, these arteries 
 appear to proceed together from the upper part of the 
 basis of the heart : the pulmonary artery being placed 
 
 it was confirmed by some very respectable anatomists of the last century, 
 it was denied by others. Some of the anatomists of the present day have 
 denied the existence of these orifices, and some others have neglected 
 them entirely. 
 
 The subject has lately been brought forward in the London Philoso- 
 phical Transactions for 1798, Part I by a very respectable anatomist, Mr. 
 Abernethy, who states that he has often passed a coarse waxen injection 
 from the proper arteries and veins of the heart into all the cavities of that 
 organ, and particularly into the Left Ventricle. But it was only in sub- 
 jects with diseased lungs that this was practicable. 
 
 The existence of this communication between the coronary vessels and 
 the great cavities of the heart seems therefore to be proved. The easy 
 demonstration in such subjects is ingeniousl) referred by Mr. Abernethv. 
 to the obstruction of the circulation in the lungs : and he regards the com- 
 munication as a provision enabling the coronary vessels to unload them- 
 selves, when the coronary vein cannot dtscha-ge freely into the right 
 auricle. 
 
60 Pulmonary Artery and Veins and Vense Cause. 
 
 to the left of the aorta with the left auricle on the left 
 side of it, and the right auricle on the right side of 
 the aorta. The pulmonary artery arises from the 
 most anterior, and left part of the basis of the right 
 ventricle, and proceeds obliquely backwards and up- 
 wards ; inclining gradually to the left side for about 
 eighteen or twenty lines ; when it divides into two 
 branches which pass to the two lungs. 
 
 The aorta arises from the left ventricle, under the 
 origin of the pulmonary artery, and immediately pro- 
 ceeds to the right, covered by that vessel, until it 
 mounts up between it and the right auricle : it then 
 forms a great curve, or arch, which turns backward 
 and to the left, to a considerable distance beyond the 
 pulmonary artery. In this course, it crosses the 
 right branch of the pulmonary artery ; and, turning 
 down in the angle between it and the left branch, 
 takes a position on the left side of the spine. 
 
 The course of this artery, from its commencement 
 at the ventricle, to the end of the great curve or 
 arch, is extremely varied. 
 
 The uppermost part of the curve is in the bottom 
 of the chamber formed by the separation of the la- 
 mina of the mediastinum when they join the first 
 rib on each side. 
 
 From this part of the curve three large branches 
 go off, viz. one, which soon divides into the carotid 
 and the subclavian arteries of the right side ; a se- 
 cond, somewhat smaller, which is the left carotid ; 
 and a third, which is the left subclavian artery. 
 
 When the heart and its great vessels are viewed 
 from behind, (after they have all been filled with 
 injection ; and the pericardium, mediastinum, and 
 windpipe have been removed,) the aorta appears 
 first, descending behind the other vessels ; the pul- 
 monary artery then appears, dividing so as to form 
 an obtuse angle with its two great branches, each of 
 
Pulmonary Artery and Veins and Verne Cavse. 61 
 
 which divides again before it enters the lung to which 
 it is destined. 
 
 Under the main trunk of the pulmonary artery is 
 the left auricle : its posterior surface is nearly of a 
 square form, and each of the pulmonary veins pro- 
 ceeds from one of its angles. These veins ramify in 
 the substance of the lungs, at a very short distance 
 from the auricle : the two uppermost of them are si- 
 tuated rather anterior to the branches of the pulmo- 
 nary artery. 
 
 In this posterior view, the pulmonary vessels of 
 the right side cover a great part of the right auricle, 
 as it is anterior to them. The lower portion of the 
 auricle, with the termination of the inferior cava, is 
 to be seen below them. Above them the superior 
 cava appears ; and in that part of it which is imme- 
 diately above the right branch of the pulmonary ar- 
 tery, is the orifice of the vena azygos. 
 
 In its natural situation in the thorax, the superior 
 cava is connected by cellular membrane to the right 
 lamen of the mediastinum, and supported by it. At 
 a small distance below the upper edge of the ster- 
 num, it receives the trunk formed by the left subcla- 
 vian and internal jugular vein, which passes oblique- 
 ly across the sternum below its inner edge, in the 
 upper space between the lamina of the mediastinum. 
 
CHAPTER III. 
 
 OF THE TRACHEA AND THE LUNGS. 
 
 Although the principal part of the windpipe is 
 situated in the neck above the cavity of the thorax., 
 it is so intimately connected with the lungs, that it is 
 necessary to describe them together, 
 
 SECTION I. 
 
 Of the Trachea. 
 
 Trachea is the technical name for. the windpipe, 
 or tube which passes from the larynx to the lungs. 
 
 This tube begins at the lower edge of the cricoid 
 cartilage, and passes down the neck in front of the 
 oesophagus as low as the third dorsal vertebra, when 
 it divides into two branches called Bronchia , one of 
 which goes to the right and the other to the left lung 
 and ramifies very minutely in them. 
 
 There is in its structure a number of flat cartila- 
 ginous rings placed at small distances from each oth- 
 er, the edges of which are connected by membrane 
 so that they compose a tube. 
 
 These cartilaginous rings are not complete, for they 
 do not form more than three-fourths or four-fifths of 
 a circle ; but their ends are connected by a mem- 
 brane which forms the posterior part of the tube. 
 
 They are not alike in their size or form ; some of 
 them are rendered broader than others, by the union 
 of two or three rings with each other, as the upper- 
 most. The lowermost also is broad, and has a form 
 which is accommodated to the bifurcation of the tube. 
 Their number varies, in different persons from fif- 
 teen to twenty. 
 
63 
 
 Structure of the Trachea . 
 
 These rings may be considered as forming a part 
 of the first proper coat of the trachea ; which is com- 
 posed of them, and of an elastic membrane that occu- 
 pies all the interstice between them ; so that the car- 
 tilages may be regarded as fixed in this membrane. 
 
 A similar arrangement of rings exists in the great 
 branches of the bronchia ; but after they ramify in 
 the lungs, the cartilages are no longer in the form of 
 rings : they are irregular in their figures, and are so 
 arranged in the membrane that they keep the tube 
 completely open. These portions of cartilage do not 
 continue throughout the whole extent of the ramifi- 
 cations ; for they become smaller, and finally disap- 
 pear, while the membranous tube continues without 
 them, ramifying minutely, and probably forming the 
 air cells of the lungs. 
 
 This membrane is very elastic : the lungs are very 
 elastic also ; and it is probable that their elasticity 
 is derived from this membrane. 
 
 On the inside of this coat of the trachea is an ar- 
 rangement of muscular fibres, which may be called 
 a muscular coat. It is best seen by peeling off or 
 removing the internal coat to be next described. 
 
 On the membranous part of the trachea, where the 
 cartilaginous rings are deficient, these muscular 
 fibres run evidently in a transverse direction : in the 
 spaces between the cartilages their direction is lon- 
 gitudinal. There is some reason to doubt whether 
 these longitudinal fibres are confined altogether to 
 the spaces between the cartilaginous rings, and at- 
 tached only to their edges, because their is a fleshy 
 substance on the internal surface of the rings, which 
 appears to be continued from the spaces between 
 them. 
 
 The internal coat of the trachea is a thin and de- 
 licate membrane, perforated with an immense num- 
 
64 Black Glands of the Bronchise. 
 
 ber of small foramina; which are the orifices of mu- 
 cous ducts. 
 
 On the surface of this membrane there is an ap- 
 pearance of longitudinal fibres which are not distri- 
 buted uniformly over it, but run in fasciculi in some 
 places, and appear to be deficient in others. These 
 fasciculi are particularly conspicuous in the ramifica- 
 tions of the bronchia in the lungs. 
 
 On the posterior membranous portion of the tra- 
 chea, where the cartilages are deficient, a consider- 
 able number of small glandular bodies are placed, 
 which are supposed to communicate with the mucous 
 ducts that open on the internal surface. If these 
 bodies are removed from the external surface of this 
 portion, and the muscular fibres are also removed 
 from the internal, a very thin membrane only re- 
 mains, which is very different from that which is left 
 between the rings, when the fleshy substance is re- 
 moved from that situation. 
 
 The reason of the deficiency in the rings, at this 
 posterior part, is not very obvious.* It continues 
 in the bronchia until the form of their cartilages is 
 changed in the lungs : if it were only to accommo- 
 date the oesophagus, during the passage of food, 
 there would be no occasion for its extension to the 
 bronchia. 
 
 At the bifurcation of the trachea, and on the 
 bronchia, are a number of black coloured bodies, 
 which resemble the lymphatic glands in form and 
 texture. They continue on the ramifications of the 
 bronchia some distance into the substance of the 
 lungs. Their number is often very considerable ; 
 and they vary in size from three or four lines in dia- 
 
 * Doctor Physic has advanced the opinion that it enables a person to ex- 
 pel the raucous of the lungs by contracting the size of the trachea, and con- 
 sequently increasing the velocity or impetus of the air.— Ed. 
 
65 
 
 Root of the Lungs. 
 
 meter to eighteen or twenty. As lymphatic vessels 
 have been traced to and from them during their course 
 to the thoracic duct, they are considered as lympha- 
 tic glands. 
 
 SECTION II. 
 
 Of the Lungs. 
 
 There are two of these organs: each of which oc- 
 cupies one of the great cavities of the thorax. 
 
 When placed together, in their natural position, 
 they resemble the hoof of the ox, with its back part 
 forward ; but they are at such a distance from each 
 other, and of such a figure, that they allow the medi- 
 astinum and heart to intervene; and they cover every 
 part of the heart anteriorly, except a small portion 
 at the apex. 
 
 Each lung fills completely the cavity in which it 
 is placed, and every part of its external surface is in 
 contact with some part of the internal surface of the 
 cavity ; but when in a natural and healthy state, it is 
 not connected with any part except the lamina of the 
 mediastinum. One great branch of the trachea and 
 of the pulmonary artery passes from the mediastinum 
 to each lung, and enters it at a place which is rather 
 nearer to the upper rib than to the diaphragm, and 
 much nearer to the spine than the sternum : at this 
 place also the pulmonary veins return from the lungs 
 to the heart. 
 
 These vessels are enclosed in a membrane, which 
 is continued over them from the mediastinum, and 
 extended from them to the lung. Thus covered, 
 they constitute what has been called the Root of the 
 Lung. 
 
 When their covering, derived from the mediasti- 
 num, is removed, the situation of these vessels ap- 
 pears to be such that the bronchia are posterior, 
 
 Vol. ii. 9 
 
66 
 
 Colour of the Lungs. 
 
 the branches of the pulmonary artery are rather above 
 and before, and the veins below and before them. 
 
 Each of these vessels ramifies before it enters into 
 the substance of the lungs: the bronchia and the 
 branches of the pulmonary artery send each a large 
 bianch downward to the inferior part of the lungs, 
 from which the lower pulmonary veins pass in a di- 
 rection nearly horizontal. In general, each of the 
 smaller ramifications of the bronchia in the lungs is 
 attended by an artery and a vein. 
 
 Each lung is divided, by very deep fissures, into 
 portions which are called Lobes. The right lung is 
 composed of three of these lobes, and the left lung 
 of two. 
 
 The lungs are covered as has been already stated, 
 with the reflected portion of the pleura continued 
 from the mediastinum, which is very delicate and al- 
 most transparent. They have, therefore, a very 
 smooth surface, which is kept moist by exudation 
 from the arteries of the membrane. 
 
 The Colour of the Lungs is different in different 
 subjects. In children they are of a light red colour; 
 in adults they are often of a light grey ; owing to 
 the deposition of a black pigment in the substance 
 immediately under the membranes which form their 
 external surface. Their colour is often formed by a 
 mixture of red and black. In this case they are more 
 loaded with blood, and the vessels of the internal 
 membranes being distended with it, the red colour 
 is derived from them. 
 
 The black pigment sometimes appears in round 
 spots of three or four lines in diameter : under the ex- 
 ternal membrane it is often in much smaller portions, 
 and sometimes is arranged in lines in the interstices 
 of the lobuli, to be hereafter mentioned. It is also 
 diffused in small quantities throughout the substance 
 of the lungs. 
 
Structure of the Lungs . 67 
 
 The source of this substance, and the use of it, are 
 unknown. 
 
 The lungs are of a soft spongy texture ; and, in 
 animals that have breathed, they have always a con- 
 siderable quantity ol air in them. 
 
 They consist of cells, which communicate with the 
 branches of the trachea that ramify through them in 
 every part. These cells are extremely small, and 
 the membranes which compose them are so thin and 
 delicate that if they are all filled by an injection of 
 wax, thrown into the trachea, the whole cellular 
 part of the lung will appear like a mass of wax. If 
 a corroded preparation be made of a lung injected 
 in this manner with force, the wax will appear like 
 a concretion. 
 
 These effects of injections prove that the membranes 
 of which the cells are formed are very thin ; and, of 
 course, that their volume is very small when compar- 
 ed with the capacity of the cells. 
 
 In those corroded preparations, in which the ra- 
 mifications of the broncnia are detached from the wax 
 of the cells, these ramifications become extremely 
 small indeed. 
 
 If the lungs of the human subjects, or of animals 
 of similar construction, be examined when they are 
 inflated, their cellular structure will be very obvious, 
 although, their cells are so small that they cannot 
 commonly be distinguished by the naked eye. Each 
 of the extreme ramifications of the bronchia appears 
 to be surrounded by a portion of this cellular sub- 
 stance, which is gradually distended when air is blown 
 into the ramification. 
 
 This celiular substance is formed into small por- 
 tions of various angular figures, which are denomi- 
 nated Lobuli : these can be separated to a consider- 
 able extent from each other. They are covered by 
 the proper coat of the lungs, which is extremely de= 
 
68 
 
 Structure of the Lungs. 
 
 licate, and closely connected to the general covering 
 derived from the pleura. Between the lobuli, where 
 they are in contact with each other, there is a por- 
 tion of common cellular substance, which is easily 
 distinguished through the membrane covering the 
 lungs. This is very distinct from the cellular struc- 
 ture which communicates with the ramifications of 
 the bronchia, and contains air ; for it has no com- 
 munication with the air, unless the proper coat of 
 the lungs be ruptured. If a pipe be introduced by 
 * a puncture of the external coat of the lungs, and 
 this interstitial cellular membrane be inflated, it will 
 compress the lobuli. This cellular membrane is al- 
 ways free from adipose matter : it may be easily ex- 
 amined in the lungs of the bullock. 
 
 Upon the membranes which compose the air cells, 
 the pulmonary artery and vein ramify most minutely; 
 and it seems to have been proved within the last thirty 
 years, by the united labours of chemists and physio- 
 logists, that the great object of respiration is to effect 
 a chemical process between the atmospheric air, when 
 taken into the air cells, and the blood which circu- 
 lates in these vessels. 
 
 In addition to the blood vessels which thus pass 
 through the substance of the lungs, there are several 
 smaller arteries denominated Bronchial , which arise 
 either from the upper intercostal, or from the aorta 
 itself: they pass upon the bronchia, and are distri- 
 buted to the substance of the lungs. The veins 
 which correspond with these arteries terminate ulti- 
 mately in the vena azygos. 
 
 The nerves of the lungs are small in proportion to 
 the bulk of these organs. They are derived princi- 
 pally from the par vagum and the intercostal nerves. 
 
 The elasticity of the air cells of the lungs and of 
 the ramifications of the bronchia which lead to them, 
 appears by their rapid contraction after distention, 
 
69 
 
 The Thorax of the Foetus. 
 
 and by the force with which they expel the air which 
 is used to inflate them when taken out of the thorax. 
 
 The Thorax of the Foetus. 
 
 In the cavity between the lamina of the medias- 
 tinum, where they approach each other from the first 
 ribs, is situated a substance which is denominated 
 the 
 
 Thymus Gland. 
 
 This substance gradually diminishes after birth, so 
 that in the adult it is often not to be found : and when 
 it exists it is changed in its texture, being much firmer, 
 as well as greatly diminished. 
 
 In the foetus it is of a pale red colour ; and during 
 infancy it has a yellowish tinge. It generally ex- 
 tends from the thyroid gland, or a little below it, to 
 the pericardium. From its superior portion two la- 
 teral processes are extended upwards : below, it is 
 formed into two lobes, which lie on the pericardium. 
 
 If an incision be made into its substance, a fluid 
 can be pressed out, which has a whitish colour, and 
 coagulates upon the addition of alcohol. 
 
 Although it is called a gland , no excretory duct 
 has ever been found connected with it. 
 
 The blood vessels of this body are derived from 
 the thyroid branches of the subclavians, from the in- 
 ternal mammaries, and the vessels of the pericardium 
 and mediastinum. 
 
 The Heart , 
 
 And the great arteries which proceed from it, have 
 some very interesting peculiarities in the foetus. 
 
 In the septum between the two auricles, is a fora- 
 men of sufficient size to permit the passage of a large 
 quill, which inclines to the oval form, with its long- 
 est diameter vertical when the body is erect. On 
 the left side of the septum, a valve, formed by the 
 lining membranes, is connected to this foramen ; and 
 
70 
 
 The Thorax of the Foetus. 
 
 allows a free passage to a fluid moving from the right 
 auricle to the left, but prevents the passage of a fluid 
 from the left to the right. This structure is evidently 
 calculated to allow some of the blood which flows 
 into the right auricle from the two venae cavse to 
 pass into the left auricle of the heart instead of going 
 into the right ventricle. As the contents of the left 
 auricle pass into the left ventricle, and from thence 
 into the aorta, it is obvious that the blood, which 
 passes from the right auricle into the left through 
 this foramen, must be transmitted from the sys- 
 tem of the vena cava to the system of the aorta 
 without going through the lungs, as it must necessa- 
 rily do in subjects who do not enjoy the foetal struc- 
 ture. 
 
 The Pulmonary Artery and the Aorta 
 
 Have a communication in the foetus, which is very 
 analogous to the communication between the auricles 
 of the heart. 
 
 From the pulmonary artery, where it divides into 
 the two great branches, another large branch conti- 
 nues, in the direction of the main trunk, until it joins 
 the aorta ; with which it communicates at a small 
 distance below the origin of the left subclavian artery. 
 In the young subject that has never respired, it ap- 
 pears as if the pulmonary artery was continued into 
 the aorta, and sent off' in its course, a branch on each 
 side, much smaller than itself, to each lung. In 
 subjects that have lived a few days, these branches 
 to the lungs are much larger ; and then the main 
 pulmonary artery appears to have divided into three 
 branches : one to each lung, and one to the aorta ; 
 but that which continues to the aorta is larger than 
 either of the others. 
 
 In the course of time, however, this branch of the 
 aorta is contracted, so that no fluid passes through it; 
 
General Observations. 
 
 71 
 
 and it has the appearance of a ligament, in which 
 slate it remains. 
 
 The course of the blood from the right ventricle, 
 through the pulmonary artery, to the aorta below its 
 curve, is more direct than that from the left ventricle 
 to the same spot, through the aorta at its commence- 
 ment. The column of blood in the aorta below its 
 curve is evidently propelled by the force of both ven- 
 tricles : and this circumstance, although it seems to 
 proceed merely from the state of the foetal lungs, is 
 particularly calculated for the very extensive circula- 
 tion which the foetus carries on, by means of the um- 
 bilical arteries and vein in the placenta. 
 
 The Lungs of the. Foetus 
 
 Differ greatly from those of the adult. They appear 
 solid, as if they were composed of the parenchymatous 
 substance which constitutes the matter of glands, 
 rather than the light spongy substance of the lungs 
 of adults. They differ also in colour from the lungs 
 of older subjects, being of a dull red. 
 
 They have greater specific gravity than water ; 
 but if air be once inspired, so much of it remains in 
 them that they ever afterwards float in that fluid. 
 
 The nature of the process of respiration, and its ef- 
 fects upon the animal economy, particularly upon 
 the action of the heart, appear to be much better un- 
 derstood at this time than they were before the dis- 
 covery of the composition of the atmosphere, by Dr. 
 Priestly and by Mr. Scheele. The publications upon 
 this subject, which have appeared since that period, 
 viz. 1774, are therefore much more interesting to 
 the student of medicine than those which preceded 
 them. Two of these publications ought to be parti- 
 cularly noticed by him : viz, an essay, by Dr. Ed- 
 ward Goodwyn, entitled, “ The Connexion of life 
 
72 Cases of Malformation. 
 
 with respiration;” and — the “ Physiological Re- 
 searches of M. Bichat upon Life and Death. Part 
 Second.* 
 
 The general doctrines respecting the oxygenation or 
 decarbonation of the blood, and the absolute necessi- 
 ty that it should take place to a certain degree in or- 
 der to preserve life, are confirmed by a number of 
 cases of malformation of the heart or the great ves- 
 sels, in which the structure was such that a consider- 
 able portion of venous blood passed from the right 
 side of the heart to the aorta, without going through 
 the lungs. In these different cases, notwithstanding 
 the structure was somewhat varied, the symptoms 
 produced were very much alike ; differing in the re- 
 spective patients in degree only, and not in kind. 
 
 The symptoms indicating this structure are blue 
 colour of the face, (such as generally accompanies 
 suffocation.) extending more or less over the whole 
 body, and particularly apparent under the nails of 
 the fingers and toes ; anxiety about the region of the 
 heart; palpitation; laborious respiration; sensations 
 of great debility, &c.: all of which are greatly aggra- 
 vated by muscular exertion. These effects have gen- 
 erally appeared to be proportioned to the quantity 
 of venous blood admitted into the aortic system. t 
 When these appearances take place immediately 
 after birth, it is probable that they depend entirely 
 upon malformation of the heart or great vessels; but 
 when they commence at a subsequent period, they are 
 
 * The student will derive much information respecting the publications 
 on this subject, prior to 1804, from Dr. Bostock’s Essay on Respiration — 
 Since the publication of that essay several interesting papers on respira- 
 tion have appeared, viz. Two memoirs by the late Abbe Spalanzani ; — 
 “ An Enquiry into the Changes induced on Atmospheric Air by the Ger- 
 mination of Seeds,” &c. by Ellis ; — two very important communications by 
 Messrs. Allen and Pepys in the Transactions of the Royal Society of Lon- 
 don for 1808 and 1809; — and “ Further Enquiries into the Changes induced 
 on Atmospheric Air.” Also by Ellis. 
 
 f Cases of this kind are related in several of the periodical publications 
 on medical subjects. Two of them were described by the late Dr. Wil- 
 liam Hunter in the sixth volume of Medical Observations and Enquiries, 
 by a Society of Physicians in London ; one, (quoted by Dr. Goodwyn,) is 
 in the Observationes Anatomicse of Sandifort ; and another, by Dr J. S. 
 Dorsey, has lately been published in the first oumber of the New England 
 Journal of Medicine and Surgery. 
 
Cases of Malformation. 73 
 
 commonly the effect of a diseased alteration in the 
 lungs. They sometimes occur near the termination 
 of fcital cases of pneumonia or catarrh ; but a . diffe- 
 rent cause, which has not latterly been suspected, 
 appears to have produced them in the following case 
 related by Dr. Marcet, in the first volume of the 
 Edinburgh Medical and Physical Journal. 
 
 The blue colour occurred in a young woman, twen- 
 ty-one years of age, in whom it had never been ob- 
 served before. — It came on during an affection of 
 the breast, and was attended with great prostration 
 of strength and difficulty of breathing ; as well as 
 cough, oedema of the hands and feet, and several 
 other symptoms. About seven weeks after the com- 
 mencement of these symptoms she died $ when it 
 was ascertained by dissection, that there was no 
 unnatural communication whatever between the ca- 
 vities of the heart, and that its valves were all in 
 a perfect and natural state . The lungs were free 
 from tubercles, or any other appearance of disease. 
 Their substance seemed more compact than usual, 
 especially the left lung, although it did not sink in 
 water 5 but they adhered every where to the inner 
 surface of the thorax, to the diaphragm , and to the 
 pleura covering the pericardium . — This case is the 
 more remarkable, because numberless instances 
 have occurred in which very large, portions of the 
 external surface of the lungs have been found upon 
 dissection to adhere to the internal surface of the 
 thorax without the occurrence of such symptoms 
 during life. 
 
 It may be inferred, from a statement published by M. 
 Dupuytren, in a late volume of the Proceedings of 
 the National Institute of France, that the oxygena- 
 tion or decarbonation of the blood is much affected, 
 in respiration, by an influence exercised by the 
 nerves which are appropriated to the lungs. From 
 his account it appears, that although the complete 
 division of the eighth pair of nerves produces death 
 after some time ; yet in the horse whose nerves are 
 thus divided, life continues, and respiration goes 
 an, from half an hour to ten hours ; but his arterial 
 blood is in a state of great disoxygenation. or corbo- 
 nation, during this time. This fact is more rem sxka- 
 
 Vol, II„ W 10 
 
74 Effects of Venous Blood on the Heart. 
 
 hie, because venous blood, contained in a bladder 
 exposed to the open air, will become oxygenated or 
 decarbonated. 
 
 It is also asserted in another Memoir, read to the 
 National Institute by Dr. J. M. Provem^al, that ani- 
 mals in whom the eighth pair of nerves has been 
 divided, do not consume so much oxygen, or produce 
 so much carbonic acid, by a considerable degree, as 
 they did before the division of these nerves ; and 
 that their temperature is considerably reduced.* 
 
 The fact, that venous blood occasions death, when it is 
 admitted into the left ventricle of the heart, and the 
 aorta, is truly important. Dr. Goodwin explained it 
 by suggesting that this blood was not sufficiently sti- 
 mulating to produce the necessary excitement of the 
 heart ; but on this occasion one of his friends propo- 
 sed to him the following question: Why does venous 
 blood affect the left side of the heart in this injurious 
 manner, when it appears to exert no noxious effects 
 whatever on the right side of tbatorgan ? His reply 
 may be seen in a note at the 8 2d page of his Essay, 
 in the first edition. Bichat has offered a solution 
 which completely resolves this difficulty, viz. “ The 
 effect of Venous blood upon the heart is produced by 
 the presence of this blood in the proper, or coronary 
 arteries of that organ, and not in its great cavities.” 
 For the animation of the heart, like that of the other 
 parts of the body, depends upon the state of the blood 
 in the arteries which penetrate its fexture.t And 
 while the heart acts, the blood of the coronary arte- 
 ries will be the same with that of the left ventricle. 
 See Bichat’s Researches, P. II. art. 6. § 2. 
 
 The French Anatomists appear to entertain some pecu- 
 liar opinions respecting the course of the blood in 
 the foetus, which have a particular relation to the sub- 
 ject last mentioned. Winslow, who paid great at- 
 tention to the valve of Eustachius in the right auricle 
 of the heart, was of opinion, that this valve was cal- 
 
 These Memoirs are republished in the Eclectic Repertory of Phila- 
 delphia for April and October, 1811. 
 
 f It is probable that the contents of the great cavities of (.lie heart have 
 no more effect upon its animation than the contents of the stomach and. 
 bowels love upon the animation of those organs,. 
 
Sentiments of Sabatier , fyc. 75 
 
 dilated for some important purpose in the fetal eco- 
 nomy.* 1 Although his hypothesis respecting its par- 
 ticular use has not been retained by his countrymen, 
 many of them have adopted his general sentiment $ 
 and among others Sabatier. That learned anatomist 
 believed that this valve, in the fetal state, serves 
 to direct the blood of the inferior cava , after its ar- 
 rival in the right auricle , through the foramen ovale 
 into the left auricle ; while the blood of the upper 
 cava passes directly into the right ventricle. His 
 opinion seems to be supported to a certain degree. 
 
 1. By the direction in which the two columns of 
 blood enter the auricle from the two vense cavse. 
 
 2. By the position of the Eustachian valve. 
 
 3. By the foramen ovale, when its valve is com- 
 . plete ; as the passage through it, from the right to the 
 
 left, is at that time oblique, and from below upwards. 
 
 The theory of Sabatier appears to be this : the um- 
 bilical vein brings from the placenta blood which has 
 a quality essential to the animation of the fetus. If 
 there were no particular provision to the contrary, a 
 large portion of this blood, after passing from the 
 umbilical vein by the inferior cava into the right 
 • auricle of the heart, would proceed by the right ven- 
 tricle, though the pulmonary pretry and arterial ca- 
 nal, into the aorta, below the origins of the carotid 
 and subclavian arteries ; and consequently none of 
 it would pass to the head and upper extremities, but 
 a considerable part would return again by the umbi- 
 lical arteries to the placenta, without circulating 
 through the body : while on the other hand, the 
 blood which passed by the carotid and subclavian 
 arteries to the head and upper extremities, return- 
 ing from them to the heart by the superior cava, 
 might pass from the right auricle to the left auricle 
 and ventricle and the aorta, and so to the head and 
 upper extremities again, without passing through 
 the placenta. But by means of tins valve, the blood 
 of the Sower cava, and of course of the umbilical 
 vein, is directed to the left auricle and ventricle 
 and the aorta, by which a considerable portion of 
 it will necessarily pass to the head and upper ex- 
 tremities : while the blood which returns from these 
 
 See Memoirs of the Academy of Sciences for 1717 and 1725. 
 
76 
 
 Sentiments of Sabatier , 
 
 parts by the superior cava, must consequently pass 
 from the right auricle into the right ventricle ami 
 pulmonary artery ; from whence a large portion of it 
 will proceed through the arterial canal into the aorta 
 beyond the carotids and subclavians, and of this por- 
 tion a considerable part will go to the placenta by the 
 umbilical atteries. Sabatier compares the course of 
 the blood in the foetus to the course of afluidin a tube 
 which has the form of the numeral character 8.* — If 
 this doctrine be true, the progress of the blood in the 
 foetus and placenta is very analogous to that of the 
 double circulation of the adult; the character 8 an- 
 swering equally well in the description of either sub- 
 ject. 
 
 According to Sabatier, the blood of the placenta 
 takes this peculiar course through the heart, in order 
 that some of it may be carried to the head and upper 
 extremities. But an additional reason may be sug- 
 gested, which appears to be of great importance ; 
 viz. the supplying of the coroijary or proper xesse\s 
 of the heart with some of the same blood. 
 
 The heart of the adult, as has been before stated, 
 cannot act without its proper or coronary arteries are 
 supplied with arterial blood. The heart of the foetus 
 performs a more extensive circulation than that of the 
 adult, and therefore is probably in greater need of 
 such blood. But unless the blood of the placenta pas- 
 ses through the foramen ovale into the left auricle and 
 ventricle , and so to the aorta , it cannot enter the coro- 
 nary arteries which originate at the commencement 
 of the aorta; for the b.lood which flows from the 
 right side of the heart through the arterial canal, 
 passes into the aorta at so great a distance from the 
 orifices of the coronary arteries, that it certainly 
 cannot enter them. 
 
 The whole of this doctrine seems to be supported by 
 a fact, very familiar to accoucheurs, viz. the occur- 
 rence of death in the foetus whenever the circulation 
 through the umbilical cord issuspendedduringfifteen 
 or twenty minutes: for as the placenta imparts to the 
 foetal blood a quality essential to life, some arrange- 
 ment seems necessary to provide for the equal distri- 
 bution of the blood which comes from this organ, and 
 
 " See Sabatier’3 Paper on this subject in the Memoirs of the Academy 
 of Sciences, for 3774. 
 
Unusual Cases of Malformation . 77 
 
 especially for carrying the requisite proportion of it 
 to the substance of the heart. 
 
 Life has existed for some time with a structure very 
 different indeed from that which is natural. In the 
 series of elegant engravings relating to morbid ana- 
 tomy, published by Dr. Baillie, is the representa- 
 tion of a heart, in which the venae cavae opened 
 into the right auricle, aftd the pulmonary veins into 
 the left auricle, in the usual manner ; but the aorta 
 arose entirely from the right ventricle, and the pul- 
 monary artery as completely from the left. The 
 canalis arteriosus, howevdr, passed from the pulmo- 
 nary artery to the aorta, and the foramen ovale ex- 
 isted. In this case it is evident that the pulmona- 
 ry artery must have carried back to the lungs the 
 arterial blood which came from them by the pulmo- 
 nary veins, with a small quantity of venous blood 
 that passed into the left auricle through the foramen 
 ovale; add that the aorta must have returned to the 
 body, the venous blood which just before had been 
 brought from it by the venae cavae, with a small ad- 
 dition of arterial blood that passed through the 
 ductus arteriosuss Yet, with this structure, the 
 child Ijjved two months after its birth, 
 
 A case, which had a strong resemblance to the 
 foregoing, occurred lately in Philadelphia, and was 
 examined by the author of this work. The venae 
 cavae terminated regularly in the right auricle, and 
 the pulmonary veins in the same regular manner in 
 the left ; but the pulmonary artery arose from the 
 left ventricle, and the aorta from the right. There 
 was no communication between these vessels by a ca- 
 nalis arteriosus ; but a large opening existed in the 
 septum between the auricles. 
 
 It is very evident, that in this case also the pul- 
 monary artery must have returned to the lungs the 
 arterial blood as it came from them, and the aorta 
 must have carried back to the general system the 
 venous blood brought to the heart by the cavae ; ex- 
 cepting only those portions of the arterial and 
 venous blood which must have flowed reciprocally 
 from one*auricle into the other, and thus changed 
 their respective situations. 
 
78 
 
 Foramen Ovale . 
 
 The subject was about two years and a half old. 
 Tiie heart was nearly double the natural size, and 
 the foramen, or opening in the septum between the 
 auricles, was eight or nine lines in diameter. The 
 pulmonary artery was larger in proportion than the 
 aorta or the heart. 
 
 With this organization the child lived to the age 
 above specified. His countenance was generally 
 rather livid ; and this colour was always much in- 
 creased by the least irregularity of respiration. His 
 nails were alivays livid. He sometimes appeared 
 placid, but more frequently in distress. He never 
 walked, and seldom, if ever, stood on his feet. 
 When sitting on the floor, he would sometimes push 
 himself about the room; but this muscular exertion 
 always greatly affected his respiration. He attain- 
 ed the size common to children of his age, and had 
 generally a great appetite. For some weeks before 
 death his legs and feet were swelled. 
 
 It is probable that the protraction of life depend- 
 ed upon the mixture of the blood in the two auri- 
 cles ; and that they really were to be considered as 
 one cavity, in this case. 
 
 There seems reason to -believe, thai^n adults of the 
 common structure, there is no passage of blood from 
 one auricle to the other, when the foramen ovale 
 has remained .open ; because in several persons in 
 whom it was found by dissection to have remained 
 open, there were no appearances during life that in- 
 dicated the presence of disoxygenated blood in the 
 aortic system. It is probable, that the small size 
 of the foramen ovale, the valvular structure which 
 generally exists there, and the complete occupation 
 of the left auricle by the blood flowing from the pul- 
 monary veins, prevent the passage of blood from the 
 right auricle to the left, in such persons ; whereas, 
 in the case in question, the opening between the 
 auricles was very large indeed, and there was no 
 appearance of a valve about it. 
 
 Although it be admitted, that* in adults with the 
 foramen ovale pervious, there is no transmission of 
 
On the Source of the motion of the Heart. 79 
 
 blood from the right to the left auricle ; there is 
 every reason to believe that this transmission goes 
 on steadily in the fetus. To the arguments, 
 derived from the structure and the nature of the 
 case, it may be added, that the pulmonary veins, in 
 the fetal state, carry to the left auricle a quantity 
 of blood, not sufficient .to fill it; while the venae 
 cavse carry to the right auricle not only the whole 
 blood of the body, but of the umbilical cord and 
 placenta : some of which must flow into the unfilled 
 
 • .left auricle, when the right auricle becomes fully 
 
 distended. 
 
 The question how far the functions of the heart and 
 lungs are dependent upon the brain is very impor- 
 tant, and has often been agitated with great zeal. 
 In favour of the opinion that the motions of the 
 heart are independent of the brain, may be stated 
 
 • the numerous cases in which the brain has been de- 
 ficient in children, who have notwithstanding lived 
 the full period of utero-gestation, and even a short 
 time after birth, and have arrived at their full size, 
 with every appearance of perfect vigour and action 
 in the heart. In support of the doctrine, that the 
 action of the heart is immediately dependent upon 
 the brain, it may be observed, that no organ of the 
 body appears to be so much influenced by passions 
 and other mental affections as the heart. These 
 contradictory facts have occasioned this question to 
 be considered as undecided, if not incapable of so- 
 lution ; although Cruikshank and Bichat* have stated 
 circumstances very favourable to the opinion that 
 the motions of the heart are independent of the 
 brain. 
 
 This question seems now to be settled by the ex- 
 periments of Dr. Legallois, a physician of Paris, 
 
 * See Cruikshank’s Experiments on the Nerves anc! Spinal Marrow of 
 living animals ; London Philosophical Transactions for 1795. The eighth 
 experiment has a particular relation to this subject. 
 
 Bichat’s researches, part 2, article 9. 
 
 The Abbe Fontana has considered this subject in bis Treatise on the 
 Venom of the Viper, vol. ii. page 194, English translation ■ and also in 
 same of his other works. 
 
80 Humboldt and others on Legallois* Paper . 
 
 which prove, that in animals who have suffered de- 
 capitation , the action of the heart does not cease as 
 an immediate consequence of the removal of the 
 head ; but its cessation is an indirect effect , induced 
 by the suspension of respiration. That respiration 
 is immediately affected by decapitation, and depends 
 upon the influence.of the brain transmitted through 
 the eighth pair of nerves. That the action of the 
 heart will continue a long time after decapitation, 
 * if inflation of the lungs, or artificial respiration, be 
 performed ; but, on the contrary, if the spinal mar - 
 ' row be destroyed, the action of the heart ceases ir- 
 recoverably. 
 
 The inference from these experiments seems very 
 conclusive, that the Spinal Marrow , and not the 
 brain, is the source of the motions of the heart. 
 
 It appears also by some of the experiments, that 
 the power of motion in the trunk of the body is de- 
 rived from the spinal marrow; and that when this or- 
 gan is partially destroyed, the parts which receive 
 nerves from the destroyed portion soon cease to live. 
 By particular management of the spinal marrow, 
 one part of the body can be preserved alive for 
 some time after the other parts are dead. 
 
 These experiments of Dr. Legallois commenced in 
 1806 or 1807, and were communicated to the Im- 
 perial Institute of France in 1811. The committee 
 of that body to whom they were referred, viz. 
 Messrs. Humboldt, Halle and Percy, reported that 
 the experiments had been repeated before them, at 
 threfe different meetings of several hours each ; and 
 that' to allow themselves sufficient time for reflec- 
 tion, they suffered an interval of a week to take 
 place between the meetings. The committee be- 
 lieve these experiments to have proved, 
 
 1st. That the principle upon which all the move- 
 ments of inspiration depend, has its seat about that 
 part of the medulla obiongatafrom which the nerves 
 of. the eighth pair arise. 
 
 2d. That the principle which animates each part of 
 the trunk of the body is seated in that portion of the 
 spinal marrow from which the nerves of the part arise. 
 
 3. That the source of the life and strength of 
 the heart is also in the spinal marrow; not in any 
 distinct portion, but in the whole of it. 
 
Brodie on the Source of the Motion of the Heart . 81 
 
 4th. That the great sympathetic nerve is to be consi- 
 dered as originating in the spinal marrow, and that the 
 particular character of this nerve is to place each of 
 the parts to which it is distributed under the immedi- 
 ate influence of the whole nervous power. 
 
 The interesting memoir of Dr. Legal lois is confirmed to 
 a certain degree by a communication of B. C. Brodie 
 to the Royal Society of London in 1810, in which are 
 detailed many very interesting experiments which in- 
 duced the author to conclude, — 
 
 That the influence’ of the brain is not directly ne- 
 cessary to the action of the heart ; and 
 
 That when the brain is injured or removed, the action 
 of the heart ceases, only because respiration is under its 
 influence ; and if under these circumstances respira- 
 tion is artificially produced, the circulation will still 
 continue. 
 
 These various experiments apply particularly to the cases 
 in which the brain is deficient. The effects of mental 
 agitations on the heart are likewise reconcilable to the 
 theory which arises out of them. But they throw no 
 light on the question why the motions of the heart are 
 so perfectly free from the influence of the will : and 
 although they seem to prove incontestibly that the mo- 
 tion of the heart is independent of the brain, it ought 
 to be remembered that in certain diseased states of 
 the brain, where that organ appears to be compressed, 
 the action of the heart- is often very irregular, and its 
 contractions less frequent than usual. 
 
 VOL. II. 
 
 11 
 
SYSTEM OF AX ATOMY. 
 
 PART VIII. 
 
 OF THE ABDOMEN. 
 
 The lowermost of the two great cavities of the 
 trunk of the body is called Abdomen. The pelvis 
 may be considered as a chamber of this cavity, al- 
 though its structure is very different. 
 
 CHAPTER I. 
 
 A GENERAL VIEW OF THE ABDOMEN AND PELVIS AND 
 
 THEIR CONTENTS, WITH AN ACCOUNT OF THE PE- 
 RITONEUM. 
 
 , SECTION I. 
 
 Of the Abdomen. 
 
 This great cavity occupies more than half of the 
 space enclosed by the ribs, and all the interior of the 
 trunk of the body below the thorax. 
 
 It is formed by the diaphragm, supported by the 
 lower ribs ; by a portion of the spine ; by the vari- 
 ous muscles which occur between the lower margin 
 of the thorax and the upper margin of the ossa in- 
 nominata ; and by the ossa innominata, which con- 
 tribute, for the purpose, the costas of the ossa ilia, 
 as well as the pelvis. 
 
S3 
 
 Construction of the Abdomen. 
 
 The general figure of this cavity partakes of the 
 figure of the lower part of the trunk of the body ; 
 with these exceptions, that the diaphragm makes it 
 arched or vaulted above, that the spine and psose 
 muscles, &e. are rather prominent on the posterior 
 surface, and that the lower part corresponds with the 
 costas of the ossa ilia and with the pelvis. 
 
 To acquire a precise idea of this cavity, it is ne- 
 cessary first to study the bones concerned in its 
 structure, in their natural situation in the skeleton ; 
 and then the muscles, which form so large a part 
 of it. 
 
 The arrangement of the tendons of some of these 
 muscles, with a view to complete the cavity, is par- 
 ticularly interesting ; as that of the external oblique 
 where it forms the crural arch.* The ligaments of 
 the pelvis and the levatores ani muscles, as they also 
 contribute to the formation of the cavity, and have 
 an influence upon its figure, should likewise be at- 
 tended to. 
 
 In the walls of the cavity, thus constructed, there 
 are many foramina by which the viscera and other 
 contained parts communicate externally ; but few of 
 them pass directly into the cavity ; for like the tho- 
 rax, there are no vacuities in- it exterior to the con- 
 tained organs. 
 
 Three of these foramina are in the diaphragm. 
 One for the transmission of the aorta, another for the 
 vena cava, and a third for the oesophagus. Below, 
 there is an aperture at each of the crural arches, for 
 the transmission of the great femoral vessels ; in each 
 of the ligamentous membranes, which close the fora- 
 men thyroideum, for the obturator vessels and nerve; 
 and at the sacro sciatic notches, for nerves and blood 
 vessels. 
 
 * See the account of this tendon, vol. i. in the description of the “ Ob* 
 liquus Decendens Externus.” 
 
84 
 
 Construction of the Abdomen, 
 
 There are also two apertures at the bottom of the 
 pelvis, for the orifice of the rectum and of the ure- 
 thra. In the tendons of the external oblique mus- 
 cles are two orifices, covered by the integuments, for 
 the spermatic cords ; and, in the foetal state, one for 
 the umbilical cord. 
 
 The apertures in the tendons, and under their 
 edges, for the transmission of the spermatic cords, 
 and the blood vessels, &c. are not to be considered 
 as simple perforations made abruptly; but the edges 
 of these foramina are formed by tendinous mem- 
 branes turned inwards and continued so as to com- 
 pose a cylindrical tube, which becomes gradually so 
 thin that it cannot be readily distinguished from the 
 cellular membrane with which it is connected.* The 
 blood vessels, &c. pass along this tube before they go 
 through the apertures. 
 
 It is evident from the construction of this cavity 
 that it is essentially different from the thorax. It 
 has no power of spontaneous dilatation whatever : it 
 yields passively to the distention of the stomach and 
 intestines, during deglutition, and when air is extri- 
 cated from the aliment, &c. ; but it is particularly 
 calculated for compressing its contents by the con- 
 traction of the muscles* which compose it. The di- 
 minution of its capacity, which is thus effected, not 
 only takes place to a great degree, but occasionally 
 with great force. The diaphragm and the abdomi- 
 nal muscles may be considered in some measure as 
 antagonists of each other. When the diaphragm 
 descends, if the abdominal muscles are passive, they 
 are distended by the contents of the abdomen, which 
 are forcibly pressed from above ; but if the abdomi- 
 nal muscles act at the same time, an effort to dimi- 
 
 * The [student of anatomy, ■when engaged with this subject, will be 
 gratified by the examination of Mr. Astley Cooper’s plates relating to 
 hernias. 
 
Contents of the Abdomen. 85 
 
 msh the cavity in every direction takes place, and the 
 contained parts are compressed with more or less force 
 according to the exertion made. This will be very 
 evident upon examining the situation of the diaphragm 
 and of the abdominal muscles. When their force is 
 considered it will also be very obvious that the vari- 
 ous outlets of the cavity are constructed most advan- 
 tageously ; otherwise hernia or protrusion of its con- 
 tents would be a daily occurrence. 
 
 The abdomen contains, 1st. The Stomach and the 
 whole Intestinal Tube, consisting of the small and 
 the great intestines. 
 
 2d. The Assisting Ckylopoietic Viscera , — the 
 Liver, the Pancreas and the Spleen. 
 
 3d. The Urinary Organs , — the Kidneys, the 
 Ureters, and the Bladder. To which should be add- 
 ed the Glandulae Renal es. 
 
 4. The Organs of Generation in part: those of 
 the female sex being almost wholly included in the 
 pelvis ; and those of the male being situated partly 
 within and partly without it. 
 
 5th. The Peritoneum and its various processes. 
 The Mesentery, Omentum, &c. 
 
 6th. A portion of the Aorta, and almost the 
 whole of the Inferior Cava, and their great ramifi- 
 cations ; with such of' their branches as are appro- 
 priated to the Viscera of the Abdomen and Pelvis. 
 
 7th. Those portions of the Par Vagum and In- 
 tercostal Nerves which are appropriated to the cavi- 
 ty ; and portions of some of the nerves destined to 
 the lower extremities. 
 
 . 8th. The lower part of the Thoracic Duct, or 
 the Great Trunk of the Absorbent System, with the 
 large branches that compose it, and the glands con- 
 nected with them ; and also those absorbent vessels 
 called Lacteals, and their glands. 
 
 As the cavity of the abdomen has no natural divi- 
 
86 Regions of the Abdomen . 
 
 sions, anatomists have divided it by imaginary lines 
 into various regions, with a view to precision in their 
 accounts of the situation of the different contained 
 parts. Thus, 
 
 They have, very generally, agreed to apply two 
 transverse lines to form three great divisions ; viz. 
 the Upper , Middle, and Lower : and they have also 
 agreed that each of these divisions shall be subdivid- 
 ed into three regions. 
 
 The three regions of the uppermost division are 
 defined with some precision. Those on each side, 
 which are called the Right and Left Hypochondriac 
 regions, occupy the spaces immediately within the 
 lower ribs and their cartilages ; while the middle 
 space, included within the margins of these cartila- 
 ges, and a line drawn from the lower edge of the 
 thorax on one side to that on the other, is denomi- 
 nated the Epigastric region. 
 
 The boundaries of the regions below are less pre- 
 cisely defined. 
 
 Many anatomists have fixed the two transverse 
 lines above mentioned at an arbitray distance above 
 and below the umbilicus : some choosing for this pur- 
 pose two inches, and others a hand’s breadth. As 
 these distances will occupy different proportions of 
 the cavity in persons of different stature, other ana- 
 tomists, with a view to avoid this inconvenience, have 
 proposed to connect these lines With certain fixed 
 points of the skeleton. 
 
 It is of importance that the boundaries of these 
 regions should be fixed, and therefore the proposi- 
 tion of Sabatier may be adopted ; viz. To draw the 
 upper transverse line from the most inferior part of 
 the lower margin of the thorax, on one side, to the 
 corresponding part on the opposite side ; and the 
 lower transverse line from the uppermost part of the 
 
87 
 
 Regions of the Abdomen. 
 
 spine of one ilium to the same part of the other. 
 These lines will mark the three great divisions. If 
 then two parallel lines are drawn directly upwards, 
 one from each of the superior anterior spinous pro- 
 cesses of the ilium until it touches the lower margin 
 of the thorax, they will divide each of the two lower 
 divisions of the abdomen into three regions. The 
 centre of the middle division is the umbilical, and 
 on each side of it is the right and left lumbar region. 
 The middle of the lower division is the hypogastric ; 
 and on each side of it the right and left iliac region. 
 
 It is true, that the three middle regions of the ab- 
 domen will be made very small by the vicinity of the 
 transverse lines to each other ; but the advantages 
 derived from a principle which is similar in its ap- 
 plication to all subjects fully compensates for this in- 
 convenience. 
 
 There are therefore nine of these regions : viz. 
 The Epigastric and the two Hypochondriac: the Um- 
 bilical, and the two Lumbar : the Hypogastric, and 
 the two Iliac regions.* And it should be added, 
 that the space immediately around the end of the ster- 
 num is sometimes called the Scrobiculus Cordis ; 
 and the space immediately within the os pubis, the 
 Regio Pubis. 
 
 These different regions are generally occupied in 
 the following manner. The liver fills nearly the 
 whole of the right hypochopdriac region, and ex- 
 tends through the upper part of the epigastric region 
 into the left hypochondriac. The stomach occupies 
 the principal part of the epigastric region, and a 
 considerable portion of the left hypochondriac. The 
 spleen is also situated in the left hypochondriac re- 
 
 * It is to be observed that the lateral regions of the middle and lower di- 
 visions of the abdomen are named differently bv different writers. 
 
38 
 
 Situation of the Viscera, 6,'C. in the 
 
 gion. That portion of the intestinal tube, which is 
 composed of small intestines, is generally found in 
 the umbilical, the hypogastric, and the iliac regions ; 
 and when the bladder is empty, in the pelvis. But 
 the duodenum, or first of the small intestines, which 
 proceeds immediately from the stomach, is situated 
 in the epigastric and umbilical regions. The great 
 intestine commences in or near the right, iliac region, 
 and ascends through the right lumbar* to the right 
 hypochondriac region. It then crosses the abdomen, 
 passing through the lower part of the epigastric, 01 s 
 upper part of the umbilical to the left lumbar region ; 
 from this it continues into the left iliac region, and 
 curves in such a manner that it finally arrives at the 
 middle of the upper part of the os sacrum, when it 
 descends into the pelvis, and, partaking of the cur- 
 vature of the last mentioned bone, continues to the 
 termination of the os coccygis. 
 
 In the back part of the epigastric region, and very 
 low down in it, is situated the pancreas. The kid- 
 neys lie in the most posterior parts of the lumbar re- 
 gions, and from each of them is continued a tube or 
 duct, called Ureter, that passes into the pelvis to con- 
 vey the urine to the bladder. This viscus, in males, 
 is in contact with the last portion of the great intes- 
 tine called the Rectum, and with it occupies almost 
 all the cavity of the pelvis ; while in females, the 
 uterus and its appendages are situated between this 
 intestine and the bladder. 
 
 In the posterior part of the abdomen, in contact 
 with the spine is the aorta. This great blood ves- 
 sel passes from the thorax between the crura of the 
 diaphragm, and continues down the spine until it 
 approaches towards the pelvis, when it divides into 
 two great branches called the Iliac Arteries. Each 
 of these great branches divides again, on the side 
 
89 
 
 Cavity of the Abdomen. 
 
 of the pelvis, into two ; viz. the External Iliac , 
 which passes under the crural arch to the thigh, and 
 the Internal Iliac, or Hypogastric , which descends 
 into the cavity of the pelvis. 
 
 Soon after the arrival of the aorta in the abdomen 
 it gives off two large branches. The first, which is 
 called the Cceliac, is distributed to the liver, the sto- 
 mach, and the spleen : the second, called the Supe- 
 rior Mesenteric, is spent upon the intestines. Lower 
 down, in the abdomen, it also sends off a small 
 branch for the intestines, called Inferior Mesen- 
 teric. Besides these vessels for the chylopoietic vis- 
 cera, the aorta sends off a large branch, called Emul- 
 gent, to each kidney. 
 
 The inferior or ascending vena cava is situated 
 on the right of the aorta, in front of the spine. It is 
 formed below by the union of the iliac veins, and in 
 its progress upwards it receives the emulgent veins, 
 which correspond to the arteries of the kidneys ; but 
 it receives in its course no veins which correspond 
 directly with the cceliac and mesenteric arteries. 
 The smaller veins, that answer to the branches of 
 these arteries, unite and form one large vein, which 
 goes to the liver, and is called, (from the part of that 
 viscus at which it enters,) Vena Portarum. From 
 the liver three large veins pass into the vena cava, 
 and deposit there the blood of the vena portarum, 
 after it has furnished materials for the secretion of 
 bile. The vena cava, in its passage upwards, is in 
 close contact with the posterior .thick edge of the 
 liver : it often passes along a deep groove in this 
 edge, and sometimes it is completely surrounded by 
 the liver in its course. The veins of the liver enter 
 the vena cava at this place, and of course they are 
 not to be seen without dissection. Immediately af- 
 ter leaving the liver the vena cava passes through an 
 
 Vol. ii. 12 
 
90 
 
 The Peritoneum. 
 
 aperture in the tendinous centre of the diaphragm 
 to unite itself to the right auricle of the heart. 
 
 SECTION II. 
 
 Of the Peritoneum. 
 
 The abdomen, thus constructed and occupied, is 
 lined by a thin firm membrane called Peritoneum , 
 which is extremely smooth on its internal surface, 
 and is immediately connected with the cellular sub- 
 stance exterior to it. This membrane adheres close- 
 ly to the anterior, lateral, and superior portions of the 
 surface of the abdomen ; and is extended from the 
 posterior surface so as to cover, more or less com- 
 pletely, the viscera of the cavity. Those viscera 
 which are in close contact with the posterior surface 
 of the abdomen, as some portions of the large intes- 
 tine, are covered only on their anterior surfaces, and 
 are fixed in their precise situation by the peritone- 
 um ; which extends from them to the contiguous 
 surface of the cavity, and adheres where it is in con- 
 tact, so as to produce this effect. 
 
 Other viscera, which are not in close contact, but 
 moveable to a distance from the posterior surface of 
 the abdomen, are covered by this membrane, which 
 is extended to them from the surface ; and this ex- 
 tended portion forms an important part of the con- 
 nexion between the viscus and the cavity in which it 
 lies. This connecting part is called Mesentery , 
 when it thus passes to the small intestines; Mesoco- 
 lon ., when it goes to the colon, one of the larger in- 
 testines ; and Ligoment , when it passes to some of 
 the other viscera. 
 
 The peritoneum is a complete but empty sac, 
 which is fixed in the abdomen anterior to the viscera. 
 The anterior portion of this sac forms the lining to 
 the anterior and lateral parts of the surface of the 
 
The Peritoneum. 
 
 91 
 
 abdomen : the posterior portion covers the viscera,, 
 and forms the mesentery, mesocolon, and ligaments 
 above described. * 
 
 It necessarily follows that the mesentery and the 
 other similar processes are mere plaits or folds of the 
 sac, which invests the viscera ; and that they must 
 consist of two lamina ; and as the blood vessels, 
 nerves, and absorbents, are all posterior to the peri- 
 toneum, they naturally pass between these lamina of 
 the mesentery. 
 
 Some of the viscera are much more completely in- 
 vested with the peritoneum than others. The sto- 
 mach, liver, and spleen, are almost completely 
 surrounded by it ; and it is said to form a coat for 
 each of these viscera. That portion of the smaller 
 intestinal tube, which is called jejunum and ileum, 
 and the transverse portion of the large intestine, call- 
 ed the arch of the colon, are invested by it in the 
 same way. But a considerable portion of the duo- 
 denum and the pancreas is behind it. The lateral 
 portions of the colon are in close contact with the 
 posterior surface of the abdomen, and the peritone- 
 um only covers that portion of their surfaces which 
 looks anteriorly towards the cavity of the abdomen, 
 and is not in contact with its posterior surface. 
 
 The urinary organs are not much connected with 
 the peritoneum. The kidneys appear exterior to it, 
 and behind it: the bladder of urine is below it, and 
 has but a partial covering from it, on its upper por- 
 tion. 
 
 The peritoneum, which covers the stomach, is ex- 
 tended from the great curvature of that organ so as 
 to form a large membrane, which descends like an 
 apron before the intestines. This process of perito- 
 neum is composed of two lamina, so thin and deli- 
 cate as to resemble cellular membrane, which, after 
 extending downwards to the lower part of the abdo- 
 
92 
 
 The Peritoneum. 
 
 men, are turned backwards and upwards, and pro- 
 ceed in that direction until they arrive at the colon, 
 which they enclose, and then continue to the back of 
 the abdomen, forming the mesocolon. The part of 
 this process which is between the stomach and the 
 colon, is called Epiploon or Omentum. 
 
 This extension of a membrane, from the surface 
 of a cavity, which it lines to the external surface of 
 a viscus in that cavity, is called, by some anatomists, 
 “ reflection and the technical term reflected mem- 
 brane is therefore applied to a membrane distributed 
 like the peritoneum. 
 
 It must be evident that this distribution of the pe- 
 ritoneum is very complex, and that* it is not easy to 
 form an accurate conception of it from description, 
 but it can be readily understood by demonstration ; 
 therefore no further account of its arrangement will 
 now be attempted, but each of its processes will be 
 considered with the organs to which they are parti- 
 cularly subservient. 
 
 That portion of the peritoneum which lines the 
 abdomen and covers the viscera, is thin and delicate, 
 but very firm. It yields to distension, as in preg- 
 nancy, ascites, &c. and again recovers its dimen- 
 sions. It was formerly thought to be composed of two 
 lamina, but this cannot be proved. The internal 
 surface of this membrane is very smooth, and highly 
 polished ; and from it exudes a liquor which is well 
 calculated for lubrication, and barely sufficient to 
 keep the surface moist during health ; but sometimes 
 it is very abundant, and occasions the aforesaid dis- 
 ease — ascites. This fluid appears to exude from 
 
 the surface of the peritoneum when it is compressed 
 in a living animal, or in one recently dead. It is 
 probably efl'used from the extremities of arteries, for 
 an effusion takes place when water is injected into 
 these vessels. 
 
The Peritoneum . 
 
 93 
 
 The peritoneum abounds with absorbent vessels, 
 and therefore possesses the power of absorption to a 
 great degree. This power may be inferred, not only 
 from the spontaneous removal of the fluid of ascites, 
 but if milk and water be introduced into the abdomen 
 of a living animal, through a puncture, it will also 
 disappear. 
 
 The blood vessels of the peritoneum are derived 
 from those which supply the neighbouring parts. 
 Nerves have not yet been traced into it, and it has 
 little or no sensibility. 
 
 This membrane supports the viscera of the abdo- 
 men in their proper situations ; and also forms a sur- 
 face for them, and for the cavities which contains 
 them, so smooth and lubricated, that no injury can 
 arise from their friction. 
 
 The cellular substance, by which the peritoneum 
 is connected to the contiguous parts, is very different 
 in different places. It is very short indeed between 
 this membrane and the stomach and intestines, and 
 also between it and the tendinous centre of the dia- 
 phragm. Between the peritoneum and the muscles 
 generally, it is much longer. When it covers the 
 kidneys and the psoas muscles it is very lax and 
 yielding. About the kidneys a large quantity of 
 adeps very commonly collects in it. On the psoas 
 muscle it yields with but little resistance to the pas- 
 sage of pus, or any other effused fluid, as in the case 
 of the psoas abscess. 
 
CHAPTER II. 
 
 OF THE OESOPHAGUS, THE STOMACH, AND THE IN- 
 TESTINES. 
 
 SECTION I. 
 
 Of the (Esophagus . 
 
 The (Esophagus is a muscular tube which passes 
 from the pharynx to the stomach, and is so intimate- 
 ly connected with the stomach, that it will be advan- 
 tageous to the student to attend to its structure im- 
 mediately before he engages in the examination of 
 that important organ. 
 
 The pharynx has been lately described* as com- 
 posed of a varied stratum of muscular fibres, lined by 
 a membrane which is continued from the internal sur- 
 face of the nose and mouth. From the pharynx the 
 oesophagus passes downwards between the trachea 
 and the vertebrae. After the bifurcation of the tra- 
 chea, it proceeds in contact with the spine, between 
 the lamina of the mediastinum, to the diaphragm, 
 which it passes through, and then terminates in the 
 stomach. 
 
 The oesophagus is a flexible tube, which, when 
 distended, is nearly cylindrical. It consists of a 
 muscular coat externally, and an internal tunic evi- 
 dently continued from that of the pharynx. These 
 coats are connected by a cellular substance called 
 the Nervous Coat , which is remarkably loose, and 
 allows them to move considerably upon each other. 
 The muscular coat which is very distinguishable 
 from that of the pharynx, consists of two substantial 
 strata of fibres ; the exterior of which is nearly lon- 
 
 * See page 37. 
 
The (Esophagus. 95 
 
 • 
 
 gitudinal in its direction, and the interior circular or 
 transverse. 
 
 The internal coat of the oesophagus, resembling 
 that of the fauces, is soft and spongy. It is covered 
 with a very delicate cuticle, which Haller supposed 
 to be to tender to confine the matter of variolous 
 pustules, as he had never found these extending into 
 the oesophagus. It is very vascular, and abounds 
 with the orifices of mucous follicles, from which is 
 constantly poured out the mucous that is spread over 
 this surface. When the oesophagus is not distended, 
 many longitudinal plaits are found in this membrane 
 by the contraction of the circular or transverse fibres 
 exterior to it. These plaits are calculated to admit 
 readily of the distention which is requisite in deglu- 
 tition. This tunic is continued from the lining mem- 
 brane of the pharynx above, and terminates below in 
 the villous coat of the stomach ; from which, howev- 
 er, it is very different. 
 
 The blood vessels of the oesophagus come from 
 those which are in the vacinity. The nerves are 
 derived from the eighth pair. The lymphatic ves- 
 sels are very abundant. 
 
 In the neck, the oesophagus inclines rather to the 
 left of the middle line. As it proceeds down the 
 back between the lamina of the mediastinum, it pre- 
 serves the same course to the fourth dorsal vertebra, 
 when it assumes the middle portion and proceeds 
 downwards, with the aorta to its left, and the peri- 
 cardium before it. About the ninth dorsal vertebra 
 it inclines again rather to the left, and somewhat for- 
 ward, to arrive at the aperture in the diaphragm 
 through which it passes. 
 
 Throughout this course it is connected by cellular 
 membrane to the contiguous parts ; and this investi- 
 ture of cellular membrane has been called its Ex- 
 ternal Coat, 
 
96 
 
 Form of the Stomach. 
 
 While the oesophagus is in the posterior mediasti- 
 num, it is in contact with several small absorbent 
 glands, especially when it first assumes a situation 
 to the right of the aorta. These glands were for- 
 merly believed to be particularly connected with 
 this tube, but they are now considered as belonging 
 to the absorbent system. They are sometimes great- 
 ly enlarged. 
 
 SECTION II. 
 
 Of the Stomach. 
 
 This most important organ which occasionally 
 exerts a powerful influence upon every part of the 
 body, appears very simple in its structure. 
 
 It is a large sac, which is so thin when much in- 
 flated that at first view it seems membranous, but 
 upon examination is found to be composed of several 
 lamina or coats, each of a different structure. It is 
 of considerable length, but incurvated. It is much 
 larger at one extremity than the other, and changes 
 so gradually in this respect, that it would appear 
 conical if it were straight. It is not, however, strictly 
 conical, unless it is greatly distended ; for when 
 moderately distended, a transverse section is rather 
 oval than circular. It is therefore considered as hav- 
 ing two broad sides or surfaces, and two edges, 
 which are the curvatures. It has been compared by 
 the anatomists of different nations to the wind sac 
 of the musical instrument called the bagpipe.* The 
 orifice in which the oesophagus terminates is at a 
 small distance from its largest extremity, and is 
 called Cardia. The orifice which communicates 
 
 * The student ought not to attempt to acquire an idea of the form of 
 the stomach without demonstration, for a view of one moment will be 
 more serviceable than a long description. 
 
Position of the Stomach . 97 
 
 with the intestines is at the termination of its small 
 incurvated extremity, and is called the Pylorus, 
 
 The two ends of the stomach being thus very dif- 
 ferent in size, are denominated the great and small 
 extremities. The two curved portions of the surface 
 are also called the great and small curvatures. The 
 two flat portions of the surface, or the broadsides, 
 are called the anterior and posterior surfaces. 
 
 The situation of the stomach in the abdomen is 
 nearly transverse : it lies principally in the left hy- 
 pochondriac and epigastric regions, immediately be- 
 low the liver. The great extremity of the stomach 
 is in the left hypochondriac region, and the lesser 
 extremity in the epigastric region, under the left 
 lobe of the liver. The upper orifice, or Cardia, is 
 nearly opposite to the body of the last dorsal ver- 
 tebra ; and owing to the curved form of the stomach, 
 the other orifice, or Pylorus , is situated at a small 
 distance to the right of that bone, and rather lower 
 and more forward than the cardia ■: both orifices be- 
 ing in the epigastric region. The position of the 
 stomach is oblique in two respects ; it inclines in a 
 small degree from above downwards, from the left 
 to the right ; and it also inclines downwards and 
 forwards, from behind. Its two orifices are situated 
 obliquely with respect to each other ; for, if the sto- 
 mach, when placed with its small curvature upwards, 
 were divided into two equal parts by a vertical plane 
 passing lengthways through it, they would be found 
 on different sides of the plane. 
 
 As the oesophagus terminates in the stomach im- 
 mediately after it has passed through an aperture of 
 the diaphragm, it is evident that the stomach must 
 be somewhat fixed at that place ; but it is more move- 
 able at its other orifice ; for the extremity of the duo- 
 denum, into which it is continued, is moveable. 
 
 Vol. ix. 13 
 
98 External Coat of the Stomach. 
 
 The stomach is connected to the concave surface 
 of the liver by the reflexion or continuation of the 
 peritoneum which forms the lesser omentum. This 
 membrane, after extending over each surface of the 
 stomach continues from its great curve in the form 
 of the large omentum, and connects it to different 
 parts, especially to the colon. There are likewise 
 folds of the peritoneum, as it passes from the dia- 
 phragm and from the spleen to the stomach, which 
 appear like ligaments. 
 
 Notwithstanding these various connexions, the 
 stomach undergoes considerable changes in its posi- 
 tion. When it is nearly empty, and the intestines 
 are in the same situation, its broad surfaces are pre- 
 sented forwards and backwards ; but when it is dis- 
 tended, these surfaces are presented obliquely up- 
 wards and downwards, and the great curvature for- 
 wards. When its anterior surface is presented up- 
 wards, its urifices are considerably influenced in their 
 direction, and the oesophagus forms an angle with the 
 plane of the stomach. 
 
 The stomach is composed of four dissimilar lamina, 
 which may be demonstrated by a simple process of 
 dissection. 
 
 There is first a coat or external covering conti- 
 nued from the peritoneum : within this, and connect- 
 ed to it by delicate cellular substance, is a coat or 
 stratum of muscular fibres : contiguous to these fibres, 
 internally, is a layer of dense cellular substance, call- 
 ed a nervous coat ; and last is the internal coat of the 
 stomach, called villous or fungous, from the structure 
 of its surface. 
 
 The external or first coat of the stomach, as has 
 been already stated, is continued from the concave 
 surface of the liver to the lesser curve of the sto- 
 mach in two delicate lamina, which separate when 
 they approach the stomach, and pass down, one on 
 
 i 
 
Muscular and Nervous Coats of the Stomach . 99 
 
 each side of it, adhering firmly to it in their course : 
 at the opposite curve of the stomach they again unite 
 to form the great omentum. The stomach is there- 
 fore closely invested by the peritoneum on every part 
 of its surface except two strips, one at the lesser and 
 the other at the greater curvature. These strips or 
 uncovered places are formed by the separation of the 
 lamina above mentioned, which includes a triangular 
 space bounded by the stomach and these two lamina. 
 In these triangular spaces, at each curvature of the 
 stomach, are situated the blood vessels which run 
 along the stomach in those directions, and also the 
 glands which belong to the absorbent vessels of this 
 viscus. The peculiar arrangement of the lamina at 
 this place is particularly calculated to permit the dila- 
 tation of the stomach. When it is dilated the lamina 
 are in close contact with its surface, and the blood 
 vessels being in the angle formed by the adhesion of 
 the two lamina to each other, are so likewise : when 
 it contracts, the blood vessels appear to recede from 
 it, and the lamina are then applied to each other. 
 
 Where the peritoneum thus forms a coat to the sto- 
 mach, it is stronger and thicker than it is between 
 the liver and stomach. In a recent subject it is very 
 smooth and moist, but so thin that the muscular fibres, 
 blood vessels, &c. appear through it. If it is care- 
 fully dissected from the muscular coat, it appears 
 somewhat flocculent on that surface which adhered 
 to the muscular fibres. It seems to be most abundant- 
 ly furnished with serous vessels ; but it has been as- 
 serted by Mascagni and Soemmering, that a large 
 proportion of its texture consists of absorbent ves- 
 sels. The cellular substance which connects this to 
 the muscular coat appears no way different from or- 
 dinary cellular membrane. 
 
 The Muscular Coat of the stomach has been de- 
 scribed very differently by respectable anatomists ; 
 
a 00 Internal Coat of the Stomach. 
 
 some considering it as forming three strata of fibres? 
 and others but two. If the stomach and a portion of 
 the oesophagus attached to it be moderately distended 
 with air, and the external coat carefully dissected 
 away, many longitudinal fibres will appear on every 
 part of it, that evidently proceed from the oesophagus; 
 these fibres are particulary numerous and strong on 
 the lesser curvature of the stomach. — Beside the lon- 
 gitudinal fibres there are many that have a circular 
 direction, and these are particularly numerous to- 
 wards the small extremity ; but it has been doubted 
 whether there are any fibres in the muscular coat of 
 the stomach that go directly round it. The whole sur- 
 face of the stomach, when the peritoneal coat is re- 
 moved, appears at first view to be uniformly covered 
 by muscular fibres ; but upon close examination, 
 there are interstices perceived, which are occupied 
 with firm cellular membrane. 
 
 In contact with the internal surface of the mus» 
 cular coat is the cellular stratum , which has been 
 called the JYervous Coat of the stomach. It is dense 
 and firm, of a whitish colour, resembling condensed 
 cellular membrane. It was considered as different 
 from ordinary cellular membrane ; but if air be in- 
 sinuated into its texture, by blowing between the 
 muscular and villous coats, while it connects them to 
 each other, it exhibits the proper appearance of cel- 
 lular substance. It however adds greatly to the ge- 
 neral strength of the stomach, and the vessels which 
 terminate in the villous coat ramify in it. 
 
 The internal coat of the stomach in the dead sub- 
 ject is commonly of a whitish colour, with a tinge of 
 red. It is named villous, from, its supposed resem- 
 blance to the surface of velvet. It has also been 
 called fungous, because the processes analogous to 
 the villi are extremely short, and its surface has a 
 
Gastric Liquor. 101 
 
 granulated appearance 5 differing in these respects 
 from the internal surface of the intestines. It is con- 
 tinued from the lining membrane of the oesophagus, 
 but is very different in its structure. Many very 
 small vessels seem to enter into its texture, which 
 are derived from branches that ramify in the nervous 
 coat. It is supposed by several anatomists of the 
 highest authority, to have a cuticle or epithelium ; 
 and it is said that such a membrane has been sepa- 
 rated by disease. It ought however, to be remem- 
 bered, that the structure of the villous coat of the 
 stomach and intestines, is essentially different from 
 the structure of the cuticle. 
 
 The internal coat of the stomach is generally found 
 covered, or spread over, with mucous, which can be 
 readily scraped off. This mucous is certainly effus- 
 ed upon it by secreting organs, and it has been sup- 
 posed that there were small grandular bodies exte- 
 rior to the villous coat, which furnished this secre- 
 tion ; but the existence of such bodies is very doubt- 
 ful, as many skilful anatomists have not met with 
 any appearance that could be taken for glands, ex- 
 cept in a very few instances, which would not be the 
 case if those appearances had been natural. Pores, 
 perhaps the orifices of mucous follicles, and also of 
 exhalent vessels, are very numerous, but no proper 
 glandular masses are attached to them. Glands, as 
 have been already said, are found in the triangular 
 spaces between the lamina of the peritoneum at the 
 great and small curvatures of the stomach, but these 
 evidently belong to the absorbent system. Besides 
 the mucous above mentioned, a large quantity of a 
 different liquor, the proper Gastric Juice , or fluid of 
 the stomach, is effused from its surface. It nas been 
 supposed that this fluid is furnished by the small 
 glandular bodies believed to exist between the coats 
 
102 
 
 The Pylorus. 
 
 of this origin ; but, admitting the existence of these 
 glands, they are not sufficiently numerous to produce 
 so much of it as is found, and it is therefore probable 
 that this fluid is discharged from the orifices of ex- 
 halent vessels in the internal surface. 
 
 Much information respecting the gastric liquor 
 has been obtained within a few years past by the 
 researches of physiologists, and they are generally 
 agreed that it is the principal agent in the effects 
 produced by the stomach upon alimentary substan- 
 ces.* - 
 
 As the muscular coat of the stomach frequently 
 varies its dimensions, trie villous and nervous eoats, 
 which have no such power of contraction, cannot ex- 
 actly fit it. They therefore generally appear larger, 
 and of course are thrown into folds or rugae. These 
 folds are commonly in a longitudinal direction ; but 
 at the orifices of the stomach they are arranged in a 
 radiated manner, and sometimes they are observed 
 in a transverse direction. They depend upon the 
 contraction of the muscular fibres, and disappear en- 
 tirely when the stomach is laid open and spread out. 
 
 At the lower orifice is a circular fold, which is 
 permanent, and constitutes the valve denominated 
 
 * On this subject the student may consult with advantage. 
 
 M. Reaumur. In the Memoirs of the Academy of Sciences for 1752. 
 
 John Hunter. London Philosophical Transactions for 1772 ; and also 
 his observations on the Animal Economy, 1786. 
 
 Dr. Edward Stevens. Inaugural Thesis de Alimentorum Concoctione. 
 Edinburgh, 1777. 
 
 The Abbe Spalanzani. Dissertations relative to Natural History, Szc. 
 The first volume of the English translation contains the author’s disserta- 
 tions on digestion, and also the first paper of Mr. Hunter, and the Thesis 
 of Dr. Stevens, as well as an account of the experiments of Mr. Gosse of 
 Geneva. 
 
 In addition to these, there are several interesting essays in the French, 
 German, and Italian languages, a compilation of which is to be found in 
 Johnson’s “ History of the progress and present state of Animal Chemistry.” 
 See Vol. I. page 180. 
 
Lymphatics and Nerves of the Stomach. 1Q3 
 
 Pylorous. It appears like a circular septum with a 
 large foramen in its centre, or like a flat ring. The 
 villous and nervous coats of the stomach contribute 
 to this, merely by forming the circular fold or ruga ; 
 and within this fold is a ring of muscular fibres, evi- 
 dently connected with the circular fibres of the mus- 
 cular coat of the stomach, the diameter of which at 
 this place is not larger than that of an intestine : the 
 fibres of this ring seem a part of the muscular coat 
 projecting into the cavity of the stomach and duode- 
 num. If a portion of the lesser extremity of the sto- 
 mach and the adjoining part of the duodenum be de- 
 tached, and laid open by a longitudinal incision, and 
 then spread out upon a board, the internal coat can be 
 very easily dissected from the muscular, and the py- 
 lorous will- then appear like a ridge or narrow bundle 
 of muscular fibres, which runs across the extended 
 muscular membrane. It is evident that when the 
 parts are replaced so as to form a cylinder, this nar- 
 row fasciculus will form a ring in it. Thus arrang- 
 ed, the circular fibres can readily close the lower ori- 
 fice of the stomach. 
 
 The pylorus separates the stomach from the intes- 
 tine duodenum ; and this separation is marked exte- 
 riorly by a small circular depression, which corres- 
 ponds exactly with the situation of the pylorus. 
 
 The arteries of the stomach are derived from the 
 Coeliac, the first branch which the aorta sends off to 
 the viscera of the abdomen. This great artery, im- 
 mediately after it leaves the aorta, is divided into 
 three branches, which are distributed to the stomach, 
 the liver, and the spleen, and are called the Superior 
 Cm'onary or Gastric, the Hepatic , and the Splenic. 
 Beside the first mentioned branch, which is distri- 
 buted principally to the neighbourhood of the cardia 
 and to the lesser curvature, the stomach receives a 
 considerable, branch from the hepatic, which passes 
 
104 The Intestines in general. 
 
 along the right portion of its great curvature, and 
 has been called the right gastro-epiploic, and another 
 from the spleen, which passes along the left portion 
 of the great curvature, and has been called the left 
 gastro-epiploic. In addition to these branches, the 
 splenic artery, before it enters the spleen, sends off 
 several small arteries to the great extremity of the 
 stomach, which are called vasa brevia. 
 
 These vasa brevia generally arise from the main 
 trunk of the splenic artery, but sometimes from its 
 branches. 
 
 •The veins which receive the blood from these ar- 
 teries have similar names, and pursue corresponding 
 courses backwards ; but they terminate in the vena 
 portarum. 
 
 The absorbent vessels of the stomach are very nu- 
 merous and large : they pass to the glands which are 
 on the two curvatures, and from thence to the thoracic 
 duct. It is an important fact relative to the history 
 of digestion, that there are good reasons for doubting 
 whether chyle commonly passes through them, not- 
 withstanding their number and size.* 
 
 The nerves of the stomach are derived principally 
 from the two great branches of the par vagum, which 
 accompany the oesophagus and are mostly spent upon 
 this organ. It also receives branches from several 
 plexus, which are derived from the splanchnic por- 
 tions of the intercostal nerves. 
 
 SECTION III. 
 
 Of the Intestines. 
 
 The intestines form a Continued canal from the 
 pylorus to the anus, which is generally six times 
 
 ' Sabatier, however, in one subject observed white lines on the stomach, 
 which he suspected to be lacteals, See his account of the absorbents of 
 the stomach. 
 
105 
 
 Villous Coat of the Intestines, 
 
 the length of the subject to which they belong. Al- 
 though the different parts of this tube appear some- 
 what different from each other, they agree in their 
 general structure. The coats or lamina of which they 
 are composed, are much like those of the stomach, 
 but the peritoneum which forms their external coat 
 does not approach them in the same manner ; nor is 
 it continued in the form of omentum from the whole 
 tube, there being only a certain portion of intestine, 
 viz. the colon, from which such a process of perito- 
 neum is continued. 
 
 The Muscular Coat, like that of the stomach, 
 consists of two strata, the exterior of which is com- 
 posed of longitudinal fibres, which adhere to the 
 external coat, and do not appear very strong. The 
 other stratum, consisting of circular or transverse 
 fibres, is stronger, as the fibres are more numerous. 
 It is observable that they adhere to the longitudinal 
 fibres: and they seldom if ever form complete cir- 
 cles. 
 
 The cellular substance immediately within the 
 muscular fibres resembles the 'nervous coat of the 
 stomach in its firmness and density. It is likewise 
 so arranged as to form many circular ridges on its in- 
 ternal surface, which support to a certain degree the 
 permanent circular plaits of the internal coat, called 
 valvulze conniventes. 
 
 The inner surface of the internal coat has been 
 commonly compared to that of velvet, and the coat 
 is therefore called villous ; but there is certainly a 
 considerable difference between these surfaces ; for 
 if a portion of the small intestine be inverted, and 
 then suspended in perfectly transparent water, in a 
 clear glass, and examined with a strong light, it will 
 appear like the external surface of the skin of a 
 peach, on which the down or hair-like processes are 
 not so close as those on velvet. On this surface, 
 
 Vol* ii. 14 
 
106 Lieberkuhn on the Villous Coat. 
 
 between the villi, there are many orifices of mucous 
 follicles and of exhaling vessels.* Exterior to the 
 villous coat, many very small glandular bodies are 
 sometimes found, which are called after their descri- 
 bers Glandulse Brunneri and Peyeri. 
 
 The internal coat of the upper portion of the in- 
 testinal tube is arranged so as to form a great num- 
 ber of transverse or circular folds or plaits^ called 
 Valvulse Conniventes, which do not generally extend 
 round the intestine, but are segments of circles; they 
 are so near each other that their internal edges, 
 which are very moveable, may be laid upon the folds 
 next to them, like tiles or shingles. It is evident 
 that this arrangement of the internal coat must add 
 greatly to its length. This coat is extremely vascu- 
 lar, so that in the dead subject it can be uniformly 
 coloured by a successful injection. The minute struc- 
 ture of it has been the subject of very diligent inquiry. 
 There can be no doubt but that an immense number 
 of exhaling and of absorbent vessels open upon it; 
 but there are many different opinions respecting the 
 termination of one set of vessels and the commence- 
 ment of the other. 
 
 A very interesting account of the Villous Coat was 
 published in 1744, by Lieberkuhn, who was con- 
 sidered by his contemporaries as a most expert prac- 
 tical anatomist, and was also very skilful in micro- 
 scopical examinations, for which he was particularly 
 calculated, as his natural powers of vision were un- 
 commonly strong. In his essay he refers to his 
 preparations, which were at Berlin, and which ap- 
 pear to have excited great surprise in the minds of 
 
 * It appears clearly, from the account of Lieberkuhn, that the ori- 
 fices or terminations of the arteries on the intestines, are distinct from 
 the follicles ; for he forced injection from the arteries into the cavity of 
 the intestines, and found the follicles still filled with mucous. He then 
 urged the injection further, and filled the follicles, or forced the mucous 
 out of tfeeat. 
 
Hewson and others on the Villi. 107 
 
 the members of the Academy of Sciences of Prussia, 
 at a time when one of the first anatomists of Europe, 
 the celebrated Meckel, was of their number. 
 
 According to this account, the internal surface of 
 the small intestines abounds with villi, and with the 
 orifices of follicles. These villi are ^about the fifth 
 part of a line in breadth. In each of them is a cavity 
 filled with a soft spungy substance, which has one 
 or more orifices communicating with the intestines, 
 and from which also proceeds a lacteal vessel. On 
 the membrane which forms this cavity, blood vessels 
 are most minutely ramified. This cavity he calls an 
 ampullula, and supposes it to constitute the principal 
 part of the villous. By injecting the arteries of the 
 intestine, he was able to pass a fluid through the 
 ampufluia into the cavity of the gut ; he kept a 
 stream of air in this way passing through the am- 
 pullula until it was nearly dry and stiff, and then 
 laid it open with a fine instrument. From the ap- 
 pearances which then presented, he inferred that the 
 cavity of the ampullula was occupied with a spongy 
 or cellular substance. Around each villus he found 
 a number of mucous follicles, which often were filled 
 with a tenacious mucous: and distinct from these 
 must be the exhalent orifices, which discharged a 
 fluid injected by the arteries without passing through 
 the mucous follicles. 
 
 Lieberkuhn died early, and left but one essay on 
 this subject, which was originally published in Hol- 
 land, in 1744, but has been republished by the Aca- 
 demy of Berlin, in their Memoirs ; and also by Mr. 
 John Sheldon, of London. 
 
 This account of Lieberkuhn appears to have 
 been admitted by Haller ; but it has been rigidly 
 scrutinized by some of the anatomists of London, 
 who were particularly interested with the subject; 
 as they had paid great attention to the absorbent 
 
108 Fyfe and others on the Villi . 
 
 system, and were very successful in the investiga- 
 tion of it. 
 
 The late Mr. Hewson, whose opinion is entitled to 
 the greatest respect, rejected the idea of the ampul- 
 lula, and believed that the villi are composed of net- 
 works of lacteals, as well as arteries and veins ; al- 
 though he added that (i this is the only circumstance 
 concerning these parts in which he should differ from 
 this very acute observer.”* 
 
 Mr. Sheldon agrees with Lieberkuhn : but Mr. 
 Cruikshank asserts, that, “ in some hundred villi, 
 be has seen the lacteals originate by radiated 
 branches, w hose orifices were distinct, on the surface 
 of the villus.” The villus being transparent, when 
 the intestine was immersed in water, these branches, 
 filled w ith chyle could be seen passing into the lac- 
 teal. Mr. Cruikshank therefore supposes that Lie- 
 berkuhn was mistaken, and that the spongy cavity, 
 or ampullula, was the common cellular membrane, 
 connecting together all the arteries, veins, nerves, 
 and lacteals. 
 
 It seems probable, from Mr. Cruikshank’s state- 
 ment, that Dr. William Hunter held the same 
 opinion with himself. And there is also reason to 
 believe that Monro the second, who studied anato- 
 my at Berlin, held a different opinion from Lieber- 
 kuhn. 
 
 Mr. Fyfe, who has bedn much employed in the 
 investigation of the absorbent system, and must be 
 perfectly acquainted with the'preparations of Monro, 
 asserts that each lacteal takes its rise upon one of 
 the villi by numerous short radiated branches, and 
 each branch is furnished with an orifice for imbibing 
 chyle. 
 
 bieveral of the late French writers adopt the opi- 
 
 * See Hewson’s Experimental Inquiries, vol, 2, page 171. 
 
109 
 
 Division of ihe Intestines „■ 
 
 nion of Lieberkuhn ; but his countryman Soemmer- 
 ing gives a different account of the subject. He says, 
 that,, besides the blood vessels, each villus consists of 
 a fine net-work of absorbent vessels, whose orifices 
 may be distinctly recognised ; and that from six to 
 ten of these orifices are sometimes discovered. 
 
 Mascagni, who has published the most extensive 
 work upon the absorbent system that has yet appear- 
 ed, supposes Lieberkuhn to have been mistaken, and 
 confirms the description of Hewson : but he also 
 agrees with Hewson in his opinion of the general ac- 
 curacy of Lieberkuhn. 
 
 Notwithstanding their differences respecting the 
 origin of thelacteals, all these observers have agreed, 
 that the orifices which communicate with the lacteals 
 are on the villi ; and that these villi contain also 
 very fine ramifications of blood, vessels. They have 
 also agreed, that the surface of the intestines in the 
 intervals of the villi seems occupied with the orifices 
 of duets or of exhalent vessels.* 
 
 Division of the Intestines . 
 
 Although there is a considerable degree of uni- 
 formity in the structure of the intestinal canal, dif- 
 ferent parts of it are very distinguishable from each 
 other by their exterior appearance, by their size, 
 their investments, and their position. 
 
 The first division is into two great portions, which 
 are very different from each other in their diameter 
 and length, as well as their situation : the first por- 
 tion being much smaller in diameter, and near four 
 times the length of the other. 
 
 * On this subject the student will consult with advantage, Hewson’s 
 Experimental Inquiries, vol. 2 ; Sheldon’s History of the Absorbent 
 System, part 1st ; Cruikshank on the Anatomy of the Absorbing Ves- 
 sels ; and the Historia Yasorum Lymphaticorum Corporis Hvtmani, of 
 Mascagni. 
 
110 Division of the Intestines. 
 
 These portions are therefore known by the names 
 of Great, and Small Intestines , and the line of sepa- 
 ration between them is very strongly marked ; for they 
 do not gradually change into each other, but the al- 
 teration in size and in exterior appearance is very 
 abrupt, and their communication is not perfectly di- 
 rect. A considerable portion of the Great Intestine 
 is fixed immoveably in the abdomen, while a large 
 part of the Small Intestine is very moveable. 
 
 Each of these great portions of the intestinal tube 
 is subdivided into three parts. Thus, in the Small 
 Intestine , there is a piece at the commencement call- 
 ed Duodenum , a great part of which has no coat from 
 the peritoneum, and is immoveably fixed in one situa- 
 tion ; while all the remainder of the small intestine 
 has a uniform covering from the peritoneum, and is 
 very moveable. This last piece, notwithstanding 
 its exterior uniformity, is considered as forming two 
 parts. The uppermost two-fifths form one part* 
 which is called Jejunum ; and the remainder is 
 called Ileum. The Great Intestine commences in 
 the lower part of the right side of the abdomen, and 
 after proceeding up that side crosses over to the 
 left, along which it descends to the lower part again, 
 when by a peculiar flexure it proceeds to the cen- 
 tre of the posterior margin of the pelvis, from which 
 it passes down to the anus. A short portion of this 
 intestine, which is above its junction with the ileum, 
 is called Cxcum ; the part which proceeds from this, 
 round the abdomen, is called Colon ; and the por- 
 tion which is in the pelvis is called Rectum. 
 
 Of the Small Intestines. 
 
 Previous to the description of the small intestines, 
 it is necessary to observe, that the Mesocolon, or 
 process of the peritoneum connected to the trans- 
 verse portion of the colon, forms a kind of moveable 
 
Commencement of the Small Intestines . til 
 
 and incomplete septum, which divides the abdomen 
 into an upper and lower apartment. Above this sep- 
 tum are the stomach, with the commencement of the 
 duodenum, the liver, and the spleen ; below it. that 
 portion of the small intestine which is called jejunum 
 and ileum, makes its appearance. The portion of 
 the intestine which passes from the stomach to the 
 jejunum, and is called Duodenum , is so much in- 
 volved by the mesocolon, that the greatest part of it 
 cannot be seen without dissecting the mesocolon from 
 its connexion with the back of the abdomen. — For 
 the duodenum proceeds backwards from the pylorus, 
 and passing down behind the peritoneum, enters a 
 vacant space between the two lamina of the mesoco- 
 lon ; it proceeds for some distance in this space, and 
 then emerges on the lower side of the mesocolon. 
 Here the duodenum terminates, and the small intes- 
 tine then is invested by the peritoneum in such man- 
 ner as to form the mesentery, which continues with it 
 throughout its whole course to the great intestine. 
 This portion of the intestine, although very uniform 
 in its exterior appearance, as has been observed be- 
 fore, is divided into Jejunum and Ileum : the jeju- 
 num being the upper’ portion, which begins at the 
 mesocolon ; and the ileum the lower portion, which 
 opens into the great intestine. '> 
 
 Of the Duodenum. 
 
 The length of this intestine is equal to the breadth 
 of twelve fingers, and hence its name. It is very 
 different from the rest of the small intestine, not only 
 as respects its position and investment by the perito- 
 neum, but on account of its connexion with the liver 
 and pancreas, by means of their excretory ducts, 
 which open into it. From this connexion with these 
 glands, probably, all the peculiarities of its position 
 are to be deduced. 
 
112 Situation of the Duodenum. 
 
 When the stomach is in its natural situation, the 
 pylorus is at some distance from the back of the 
 abdomen. The duodenum proceeds backwards 
 from this point, and passes near the neck of the 
 gall-bladder, being here connected with the small 
 omentum ; it then curves downwards, and descends 
 before the right kidney, sometimes as low as the 
 lower part of it; then it curves again, and passes 
 over to the left: after it has arrived at the left side 
 of the spine, at the second or third lumbar vertebra, 
 it projects forwards and downwards to form the je- 
 junum. The only portion of this intestine which is 
 moveable, is that which is in sight as it proceeds 
 immediately from the pylorus, being about an inch 
 and a half or two inches in length. The remain- 
 der is connected to the back of the abdomen, and lies 
 between the two lamina of the mesocolon. In its 
 progress its passes before the aorta and the vena cava, 
 but the principal branch of the vena portarum is be- 
 fore it. 
 
 The duodenum is larger in diameter than any other 
 part of the small intestines, and has a stronger mus- 
 cular coat. Its general situation admits of great dilata- 
 tion, and it has been called a second stomach. Its in- 
 ternal coat is strictly villous, in the anatomical sense 
 of the word ; and its folds, the valvulse conniventes, 
 begin at a small distance from the pylorus. The ori- 
 fices of many mucous ducts are to be seen on its sur- 
 face. It is supposed that some of these are the ter- 
 minations of ducts from the glands of Brunner, which 
 sometimes appear in the villous coat, or very close to 
 it exteriorly ; being small flat bodies, with a depres- 
 sion in the centre, and a foramen in the depression. 
 They are sometimes very numerous at the upper ex- 
 tremity of this intestine, and diminish gradually to- 
 wards the other extremity. 
 
 The biliary and pancreatic ducts open posteriorly 
 
113 
 
 Jejunum and Ileum . 
 
 into the duodenum, rather above the middle of it. 
 The orifice of these ducts is generally surrounded by 
 a small tubercle, which is oblong, somewhat rounded 
 at one extremity, and pointed at the other. Some- 
 times this orifice is in a plait, like one of the valvulse 
 conniventes. Most commonly the two ducts unite 
 before they perforate the coat, so as to form but one 
 orifice ; and sometimes they open separately, but al- 
 ways very near to each other. 
 
 Absorbent vessels, which contain chyle, are found 
 on the duodenum. 
 
 The Jejunum and Ileum 
 
 Are situated in the abdomen very differently from 
 the duodenum. When the cavity is opened, and the 
 omentum raised, they are in full view ; and every 
 portion of them, except the two extremities and the 
 parts near them, can readily be moved. This free- 
 dom of motion is owing to the manner in which they 
 are invested by the peritoneum ; or in the technical 
 language of anatomy, to the length of their mesen- 
 tery. They agree in their structure with the general 
 description of the small intestines, but their muscular 
 coat is rather weaker than that of the duodenum. The 
 valvulze conniventes are very numerous and large in 
 the upper part of the tube, or the jejunum ; and gra- 
 dually diminish in number, until they finally disap- 
 pear, in the lower part of the ileum. The villous 
 coat is in perfection in the jejunum, the villi being 
 more conspicuous there than in any other part of the 
 intestinal tube. There are frequently found, exterior 
 to this coat, but intimately connected with it, many 
 small glandular bodies of a roundish form, which are 
 often clustered together at that part of the intestine 
 which corresponds with the interstice of the lamina 
 of the mesentery. They are called Peyer’s glands, 
 Vol. ii, 15 
 
114 Distinction between Jejunum and Ileum 
 
 after the anatomists who first described them ; and are 
 supposed, like the glands of Brunner, to secrete mu- 
 cus. If a portion of the jejunum be inverted, and 
 moderately distended with air, these bodies appear 
 very distinctly in it, dispersed at small distances from 
 each other. In the ileum they appear in small clus- 
 ters, which often have the appearance of disease. 
 
 No natural line of separation for distinguishing the 
 jejunum and ileum from each other, is to be found; 
 but these names are still retained ; and therefore a 
 rule laid down by Winslow is generally adopted, 
 viz. to name the first two-fifths of the tube jejunum, 
 and the remainder ileum. There are, however, some 
 important differences between these portions of the 
 intestine. 
 
 In the jejunum, the valvulae conniventes are so nu- 
 merous, that they lie in contact with each other, as 
 shingles on the roof of a house ; in the ileum they 
 gradually diminish in number, and finally disappear. 
 In the jejunum the villi are much stronger than they 
 are in the ileum. 
 
 It is very difficult to acquire a precise idea of the 
 arrangement of this part of the intestinal tube, while 
 it is in the abdomen, especially if it be much distend- 
 ed ; but if it be separated at each extremity from the 
 intestine with which it is connected, and the mesen- 
 tery cut off from the back of the abdomen, and the 
 whole then spread out upon a flat surface, it will 
 appear, as has been already said, that the intestine 
 is arranged so as to form a semicircle or large 
 curve; the concavity of which is opposite to the 
 back of the abdomen, while the convexity presents 
 forward. It will also appear, when thus placed 
 upon a table, that the intestine, while connected 
 with the mesentery, is laid into many folds. It has 
 been supposed, that the middle portion of the mesen- 
 tery, and the intestine connected with it, is generally 
 
Construction of 'the Mesentery . 115 
 
 itn the umbilical region ; and the two portions on the 
 sides of it are in the iliac regions ; but their situation 
 in the abdomen varies considerably at different times. 
 When the viscera of the pejvis are empty, a large 
 portion of the small intestine is in the pelvis; but 
 when those viscera are filled, the intestine is in the 
 general cavity of the abdomen. 
 
 The Mesentery 
 
 Is a process of the peritoneum, which is formed in 
 the manner of a plait or fold, and of course consists 
 of two lamina. These lamina proceed from the back 
 part of the abdomen, and are so near to each other, 
 that they compose one substantial process ; having 
 cellular and adipose substance, blood vessels and 
 nerves, with absorbent or lacteal vessels and their 
 glands, between them. 
 
 The form of this process, when it is separated 
 from the back, and the intestines are detached from 
 it, is somewhat semicircular : that portion of its mar- 
 gin or edge which corresponds to the diameter of the 
 semicircle, is connected to the back of the abdomen, 
 and called the root of the mesentery; the edge, which 
 is the circumference of the semicircle, is connected 
 with the intestine. The edge connected with the 
 back of the abdomen is commonly about five or six 
 inches in length -. the semicircular edge, instead of ex- 
 tending fifteen or eighteen inches, the ordinary pro- 
 portion, is attached to a portion of intestine some- 
 times twenty-four feet in length. The mesentery on 
 account of this great difference between its diameter 
 and circumference, has been compared to the ruffle of a 
 shirtsleeve; its roots being taken for the plaited edge 
 of the ruffle, and the circumference for its loose edge. 
 But the comparison is not precisely accurate; for the 
 mesentery is not plaited at its root, but perfectly 
 
116 Root of the Mesentery . 
 
 smooth, and free from every kind of fold. It begins 
 to enlarge towards its circumference, and enlarges to 
 that degree, that it falls into plaits or folds : precisely 
 such as would exist in a semicircular piece of mem- 
 brane about six inches in diameter, if a number of 
 simple incisions, of about an inch and a half in length, 
 were made in a radiated direction from its circumfer- 
 ence, and if portions like a sextant or quadrant were 
 taken from a circular membrane three inches in di- 
 ameter, and united by their edges to these incisions, 
 so that their circumference might be continuous with 
 the circumference of the large semicircular piece. In 
 this case, the portions like quadrants or sextants 
 would assume a folded position like the edge of the 
 mesentery, while the middle of the semicircular piece 
 would preserve its regular form without folds ; as is 
 the case with the mesentery at some distance within 
 its circumference. By many additions of this kind, 
 the circumference of a membrane, which was original- 
 ly a semicircle of five or six inches, may be extended 
 so as to exceed greatly that of the mesentery. It 
 seems of course impossible to form an accurate mo- 
 del of the mesentery with a single piece of membrane 
 or paper ; but it may be easily made with clay, or 
 any ductile substance. A model of this kind must 
 necessarily be folded after the manner of the mesen- 
 tery ; and its circumference, like the mesentery, would 
 appear as if formed of portions of the circumference 
 of smaller circles united to each other.* 
 
 The root of the mesentery commences with the 
 jejunum on the lower side of the mesocolon, at the 
 left of the spine, and extends downwards near to 
 the right iliac region $ crossing the spine obliquely. 
 
 * A model, upon the plan first mentioned, was invented by Dr. J. G. 
 Shippen. It has been proposed, I believe by M. Gavard, to make one 
 with a single piece of buckskin, of a semicircular form f by stretching it at 
 the circumference! 
 
Appearances of the C cecum and Coton. 117 
 
 When it is examined in its natural situation, the peri- 
 toneum is found continued from the back of the ab- 
 domen to the intestine ; it then surrounds the intes- 
 tine, and continues from it to the back of the abdo- 
 men again. There must therefore be two lamina of 
 peritoneum in the mesentery, and there must be a 
 small portion of intestine answering to the interstice 
 between these lamina, which is not covered by the 
 peritoneum. The blood vessels, and absorbent or 
 lacteals, pass most commodiously to the intestines 
 between these lamina ; for they are connected with 
 large trunks that lie on or near the spine, and the 
 root of the mesentery commences there. 
 
 The glands connected with the lacteals or absorb- 
 ents are very conspicuous in the mesentery, and are 
 commonly called mesenteric glands. They are of 
 different sizes, from more than half an inch to one or 
 two lines in diameter. They are very numerous, 
 and scattered irregularly, but are seldom observed 
 very near to the intestine. They are often enlarged 
 in consequence of disease, especially in children. 
 
 The nerves of the small intestines which are de- 
 rived principally from the superior mesenteric plex- 
 us, are also to be found here. 
 
 The adipose matter between the lamina of the me- 
 sentery is very often in a large quantity, but varies, 
 in proportion to the general quantity of adeps in the 
 subject. 
 
 OF THE GREAT INTESTINES. 
 
 The Ceecum and Colon 
 
 Are very different from the small intestines in 
 many respects. They are much larger in diameter. 
 Their external surface is marked by three longitudi- 
 nal bands of a light colour, which extend the great- 
 est part of their length, and are placed nearly at 
 
118 Position of the Caecum, 
 
 equal distances from each other. The spaces be- 
 tween these bands are marked by transverse inden- 
 tations, which pass from one band to the other at 
 short but unequal distances. At these indentations 
 the coats of the intestine are pressed inwards, as if a 
 fine thread had been drawn round it externally? 
 while the spaces between them are full and tumid? 
 and on this account are called cells. 
 
 The great intestine, with these appearances? be- 
 gins, as has been already observed, in the right iliac 
 region, by a rounded end which rests on the fossa 
 or concave surface formed by the costa of the ileum ; 
 from this it is continued upwards in the right lum- 
 bar region, anterior to the kidney, until it arrives 
 near the liver, when it forms a curve? and passes 
 directly across the abdomen to the left side. In this 
 course it approaches so near to the under side of 
 the liver, that it is often in contact with it, and with 
 the gall-bladder, which, after death, tinges it with a 
 yellow colour. On the left side it passes dowm the 
 lumbar region, before the kidney, to the left iliac 
 region ; here it is curved so as to resemble the 
 Roman letter S, inverted ; this curve generally car- 
 ries it to the right side of the spine, and then brings 
 it back to the centre of the sacrum. Here the in- 
 testine changes its course, and passing into the 
 pelvis, continues downward, in contact with the 
 sacrum and coccygis, and partaking of the curvature 
 of those bones, until it terminates at the anus, where 
 it is connected with the sphincter and levator ani 
 muscles. 
 
 About two inches from the commencement of the 
 great intestine the ileum opens into it laterally ; and 
 all that portion which is between its commencement 
 and the insertion of the ileum is termed. Caecum, or 
 the blind intestine: that part of the great tube? 
 which is included in its course from the insertion of 
 
119 
 
 Structure of the Colon . 
 
 the ileum to the posterior part of the brim of the 
 pelvis, is called Colon ; and the remainder, or the 
 part which is contained in the pelvis, is termed i?ee- 
 turn. 
 
 The Csecurn is nearly as wide as it is long ; it is 
 fixed in the right iliac fossa by the peritoneum, 
 which invests it so that the great body of the intes- 
 tine projects from the surface of the fossa covered 
 by the peritoneum ; but a portion is in close con- 
 tact with the surface, and connected to it by celhi" 
 lar membrane. Its external surface, covered by the 
 peritoneum, is marked by two of the bands or 
 stripes before mentioned, which proceed on it length- 
 ways. These bands are in full view, but the third 
 band is generally on that part of the intestine which 
 rests on the iliac fossa, and is therefore out of sight. 
 At the rounded extremity of the csecurn, situated 
 anteriorly and internally, is a small process resem- 
 bling an earth-worm in form and size : this is there- 
 fore called Jippendicula Vermiformis. It is hollow 
 and communicates with the cavity of the csecurn at 
 the place of junction ; and like the csecurn, has its 
 other extremity closed up. It is composed of the 
 same number of coats and has the same structure as 
 the great intestine : its length varies from two to four 
 inches. 
 
 The longitudinal bands above mentioned commence 
 at the junction of this appendix with the csecurn, and 
 continue throughout the extent of the colon. They 
 appear to be formed by some of the longitudinal fibres 
 of the muscular coat, which are arranged close to each 
 other. These fibres seem to be shorter than the coats 
 of the intestine, and the interior coats adhere firmly 
 to them. Thus are produced the indentations and 
 cells ; for if the bands are divided transversely, the 
 indentations disappear, and the surface of the intes- 
 
120 
 
 Valve of the Colon. 
 
 tine becomes uniform. One of these bands is cover* 
 ed by the mesocolon. 
 
 The circular or transverse fibres of the muscular 
 coat of the csecum and colon are very delicate, and 
 not numerous. 
 
 The internal coat differs materially from that of the 
 small intestines, although at first view they seem to 
 resemble each other : for if a portion of the ileum and 
 of the colon be inverted and suspended in water, no 
 villi can be seen with the naked eye on the internal 
 coat of the colon, while those of the ileum are very 
 visible. The glands exterior to this coat are larger 
 than those on the small intestines. 
 
 Instead of valvulse conniventes, are the ridges made 
 by the indentations or depressions above described, 
 which separate the incomplete cells from each other. 
 These ridges differ essentially from the valvular con- 
 niventes, because all the coats of the intestine are con- 
 cerned in their formation, whereas the valvulse conni- 
 ventes are formed by the villous coat only ; they also 
 project into the cavity of the intestine, while the val- 
 vulse are laid on its surface. They pass only from 
 one longitudinal band to another, and, in consequence 
 of this, the cells are small, and the position of each 
 band is very evident when the intestine is laid open. 
 
 The communication of the ileum with the great 
 intestine has been already stated to be on the left 
 side of it, about two inches from its commencement. 
 The aperture is so constructed, that it is considered 
 as a valve, and is called the Valve of Bauhin, or of 
 Tulpius, after the anatomists who have described 
 it.* The appearance of the aperture is as follows: 
 If the csecum, with a small portion of the ileum and 
 
 * Posthius in 1566; Vidus Vidius about 1569; Alberti in 1581, and Varo- 
 lius who died in 1575, each lay claims to the discovery of it. Bauhin’s 
 claims are in 1579. Em 
 
Structure of the Valve of the Colon. • 121 
 
 of the colon, be separated from the other intestines, 
 and kept in an inflated state until it be so dry as to 
 preserve its form when opened, and then if the cae- 
 cum and colon be laid open opposite to the aperture 
 of the ileum, a large transverse ridge, resembling 
 some of the ridges or folds just described, will be 
 seen projecting into the cavity of the intestine. In 
 the internal edge of this fold is a long slit or opening, 
 which forms the communication between the two in- 
 testines. It is obvious that the form of this fold must 
 be that of a crescent ; and that its two surfaces with 
 the slit between them, must have the appearance of 
 two lips, which would readily permit a fluid or sub- 
 stance of soft consistence to pass from the ileum into 
 the great intestines, but must impede, if not prevent, 
 its passage back ; especially if the large intestines 
 were distended, as then the lips would be pressed 
 against each other. 
 
 When the peritoneal coat is dissected from each 
 of the intestines at their place of junction, and this 
 structure is then examined from without , it appears 
 as if a transverse or half circular indentation had 
 been formed by the villous coat of the great intestine, 
 and that the internal coat of the extremity of the 
 ileum was pressed into this indentation, and united 
 to the internal coat of the great intestine which form- 
 ed it; while there was a slit, both in. the indentation 
 and in the end of the ileum, which formed a commu- 
 nication between the eavityof the great intestine and 
 the ileum. The longitudinal fibres of both intestines, 
 as well as their external coats, seemed to be united, 
 so as to form a common cover for them ; while the 
 circular fibres were blended in the two portions of 
 the indentation which form the lips of the orifice. 
 
 This orifice is, of course, transverse with respect 
 to the intestine. It has been observed, that there 
 was a difference in the thickness and strength of the 
 
 VoLj ii, 16 ' 
 
122 Position of the Rectum . 
 
 two lips or valves ; that the lower valve was the 
 strongest, and appeared to have the largest propor- 
 tion of muscular fibres in its composition. At the 
 extremities of the orifice, and near each end of the 
 fold or ridge, are tendinous fibres, which give 
 strength to the structure ; they are called the Reti- 
 nacula of Morgagni, as they were first described by 
 that anatomist. 
 
 There is great reason for believing that this valve 
 cannot prevent the retrograde motion of the contents 
 of the intestines in all cases ; for in some instances 
 of hernia and of colic, matter perfectly stercoraceous 
 has been vomited, and the probable inference from 
 such a state of the ejected matter is, that this matter 
 has been in the large intestines. It is also said, that 
 suppositories and enemata have been discharged by 
 vomiting. 
 
 On the right and left sides of the abdomen, the 
 colon is in close contact with the posterior surface of 
 the cavity. The peritoneum, which covers this sur- 
 face, extends over the intestine also, and thus retains 
 it in its position . The great arch of the colon, which 
 is loose and moves far from the back of the abdomen, 
 is invested by the two lamina of the omentum, which, 
 after surrounding it, unite again and form the meso- 
 colon. Connected with the exterior surface of the 
 colon are many processes, composed of adipose mem- 
 brane, varying in length from half an inch to an inch 
 and a half : these appear, to be of the nature of the 
 omentum, and are therefore generally denominated 
 Appendices Epiploicsc. 
 
 The Rectum. 
 
 After forming the sigmoid flexure, the colon ter- 
 minates; and the rectum begins opposite to the lower 
 Surface of the last lumbar vertebra, and nearly in 
 contact with it ; from this it proceeds downwards, 
 
123 
 
 Structure of the Rectum. 
 
 forming a curve like the sacrum, until it terminates 
 at the anus, where it is invested with the muscles 
 called the sphincter, and levator ani. It is called 
 rectum, because in this course it is supposed not to 
 incline to either side ; but it is often found on one 
 side of the middle line.* 
 
 This intestine being in contact with the posterior 
 surface of the pelvis, is covered, on its anterior sur- 
 face only, by the peritoneum which lines the poste- 
 rior surface of the pelvis ; and it is fixed in this situ- 
 ation by the peritoneum, as the colon is on the right 
 and left sides of the abdomen, but more loosely; and 
 therefore the term Mesorectum has sometimes been 
 applied to that portion of the peritoneum which is 
 analogous to the mesentery and. mesocolon. The pe- 
 ritoneum does not extend to the end of th'e rectum ; 
 for it is reflected at the lower part of the pelvis from 
 the rectum to the bladder, or uterus, and does not 
 line the bottom of the pelvis ; so that the lower part 
 of this intestine, as well as of the other viscera of 
 the pelvis, is below the peritoneum, and not connect- 
 ed with it. 
 
 The muscular coat of the rectum is much thicker 
 and stronger than that of any other intestine. The 
 strata of longitudinal and circular fibres which com- 
 pose it are very distinct from each other. The lon- 
 gitudinal fibres are most numerous, and terminate at 
 the insertion of the fibres of the levator ani muscle. 
 The lower circular fibres are intimately connected 
 with the sphincter ani. 
 
 The internal coat is very vascular, but the villous 
 structure is not apparent. Mucous follicles are also 
 very numerous; and there are likewise some distinct 
 glandular bodies exterior to this coat, which vary in 
 size in different subjects. 
 
 * Morgagni and Haller supposed it to be commonly on the left of the 
 middle line: and Sabatier on the right. 
 
124 Absorbents and JYerves of the Intestines. 
 
 The quantity of mucous discharged from the rec- 
 tum in certain cases of disease, is sometimes very 
 great. The internal coat, in consequence of the con- 
 traction of the circular fibres exterior to it, some- 
 times forms longitudinal folds, which have been 
 called its columns ; these often disappear when the 
 intestine is opened lengthways and spread out. By 
 the contraction of the longitudinal fibres, the internal 
 coat is often thrown into folds or doublings, that 
 must assume a transverse or circular direction ; they 
 occasionally pass down through the sphincter, and 
 form the prolapsus ani. The rectum is most plenti- 
 fully supplied with blood vessels, to be described 
 hereafter; and it may be observed, that, on the low- 
 er part of the internal coat, the veins are particular- 
 ly numerous. 
 
 The internal coat of the rectum terminates ab- 
 ruptly just within the anus, and is united to a pro- 
 duction of the skin, which, like the covering of the 
 lips, is very delicate and vascular, and has an epi- 
 thelium, or very thin cuticle* spread over it. The 
 levator and sphincter ani muscles, with which the 
 termination of the rectum is invested, are described 
 in the first volume. , 
 
 The Absorbents of the Intestines are commonly 
 denominated Lacteals .* They originate on the in- 
 ternal surfaces of these viscera, as has been already 
 described. After passing through the lymphatic 
 glands, which are so numerous on the mesentery, 
 they generally unite and form one of the great trunks 
 which compose the thoracic duct. It is asserted, 
 that some of the absorbent vessels of the lower in- 
 testines unite to the lymphatics of the loins. 
 
 * The lacteals were first observed by Erasistratus and Herophilus, of 
 the school of Alexandria, during the reign of the Plotemies ; and subse- 
 quently by Aselli, of Pavia, in 1622, the knowledge of them having been 
 lost for 1900 years. — E d. 
 
Origin and Arrangement of the Omentum. 125 
 
 The Nerves of the Intestines are principally de- 
 rived from the intercostals, or great sympathetics 
 From each of these nerves, while they are in the tho- 
 rax, an important branch, called the ramus splanch- 
 nieus, arises. These splanchnic branches pass through 
 the diaphragm, and are the chief contributors to the 
 ganglions and plexuses formed in the abdomen. A 
 plexus, derived from this source surrounds the supe- 
 rior mesenteric artery, and another the inferior me- 
 senteric ; and from these proceeds the nerves of the 
 intestines. 
 
 The Omentum 
 
 Requires a separate description, although several 
 circumstances connected with its structure have been 
 already noticed. It often varies in its position; but 
 when it is rendered firm by a quantity of adipose mat- 
 ter, it is spread over the intestines like an apron, ex- 
 tending from the lower edge, or great curvature of 
 the stomach, towards the bottom of the abdomen. 
 
 As has been already said, it is an extension of the 
 peritoneum, in two lamina, from the concave surface 
 of the liver to the lesser curvature of the stomach ; 
 and these lamina, after surrounding the stomach, 
 come in contact with each other near its great curva- 
 ture. From this portion of the stomach, from the 
 commencement of the duodenum, and also from the 
 spleen, the Omentum , composed of two lamina de- 
 scends over the colon and the small intestines more 
 or less low into the abdomen ; it is then folded back- 
 wards and upwards, and is continued. until it meets 
 the great arch in the colon : here the lamina again 
 separate and enclose that portion of the intestine, on 
 the posterior side of which they again approach each 
 other, and form a membrane like the mesentery, of 
 two lamina, which passes from the concave or pos- 
 terior surface of the colon to the back of the abdo- 
 
126 Origin and Arrangement of the Omentum . 
 
 men, where it is continued into the membrane which 
 lines that surface. This last portion is the Mesoco- 
 lon: the portion between the liver and stomach is 
 called the Omentum of Winslow , or the lesser 
 omentum; and the great portion between the sto- 
 mach and colon is called the Great Omentum , or the 
 omentum gastro colicum. There is also a process 
 of peritoneum continued from that portion of the 
 colon which is on the right side of the abdomen, and 
 from the caecum, which extends to some distance ; 
 it is formed of two lamina, that compose a cavity of 
 an angular form. This has been called the Omen- 
 tum Colicum. 
 
 The great and small omentum, with a portion of 
 the peritoneum on the back of the abdomen, form a 
 sac, which encloses a distinct cavity in the abdomen. 
 The anterior part of this sac is composed of two 
 lamina, and between these lamina are the stomach 
 and the great arch of the colon. This cavity, form- 
 ed by the two omenta, communicates with the gene- 
 ral cavity of the abdomen by a foramen of a semicir- 
 cular form, called the Foramen of Winslow, which 
 is behind the great cord of the vessels that go to the 
 liver. 
 
 The omentum is so delicate in structure, that 
 when free from fat, it is very liable to laceration 
 merely by adhering to the fingers, if they are dry. 
 Winslow therefore advised that some unctuous sub- 
 stance should be rubbed on the hands, before they 
 were applied to it. 
 
 The appearance of the great omentum is very dif- 
 ferent in different persons. In the emaciated, it 
 appears like a delicate transparent membrane ; in 
 the corpulent, it is like a broad mass of adeps, which 
 sometimes is very thick. When it is thus loaded 
 with adeps, it is most commonly spread over the 
 small intestines : when it is free from fat, it is often 
 
Varieties in the Appearance of the Omentum. 127 
 
 compressed together, so as to form a small mass near 
 the arch of the colon, on the left side. 
 
 The principal blood vessels of the omentum are 
 derived from those of the stomach, and are called gas- 
 tro epiploic arteries and veins. 
 
 The use of this membrane in the animal economy 
 has not been ascertained with certainty. It seems 
 probable that one of its principal objects is to protect 
 the small intestines, and lessen the friction consequent 
 upon their motion ; but it has been supposed to an- 
 swer several other important purposes.* 
 
 * See Halleri Elementa Physiologic, vol. vi. page 381. 
 
 Gavard. Traite de Splanchnologie, page 350. 
 
 Dr. James Rush’s Inquiry into the use of the Omentum. 
 
CHAPTER III. 
 
 OF THE LIVER, THE PANCREAS, AND THE SPLEEN. 
 
 SECTION L 
 
 Of the Liver. 
 
 This largest viscus of the abdomen, when in a 
 healthy condition, is of a reddish-brown colour. If it 
 is taken out of the subject, and laid on a flat surface, 
 it is flat, but in the abdomen it is convex and concave. 
 
 It is situated in the right hypochondriac region, 
 which it occupies entirely ; and extends through the 
 upper portion of the epigastric into the left hypochon- 
 driac region. Being placed immediately under the 
 diaphragm, and in close contact with it, as well as with 
 the inner surface of the right hypochondriac region, 
 it partakes of their form, and is convex above and 
 concave below. When thus situated, it is of an irre- 
 gular figure, between the circular and the oval, but it 
 is broader at the right extremity than at the left, and 
 very irregular in thickness. The edge or margin 
 which is in contact with the posterior part of the right 
 hypochondriac region, is very thick. It gradually be- 
 comes thinner towards the left, and also towards the 
 front; so that the right margin, and a large portion 
 of the posterior margin, is very thick, while the left 
 and the anterior margin is thin. 
 
 The upper convex surface of the liver, when in 
 its natural situation, is smooth : the lower concave 
 surface is marked by several grooves or fissures and 
 eminences. One of these, called the Umbilical or 
 the great fissure, commences at a notch in the ante- 
 
129 
 
 Lobes and Fissures of the Liver. 
 
 rior edge of the liver, to the left of the middle, and 
 continues to the posterior edge. At the commence- 
 ment of this fissure the umbilical ligament enters ; 
 and at the termination, or near it, the vena cava is 
 situated. Opposite to this fissure, on the upper or 
 convex surface, is a ligament passing from the dia- 
 phragm to the liver, which is called the falciform. 
 The fissure and the ligament divide the liver into its 
 two great lobes, the Right and Left . 
 
 Another great fissure , called the transverse or 
 principal, commences in the right lobe and extends 
 to the left, crossing the first mentioned fissure at 
 right angles, and extending a very short distance 
 beyond it. It is very deep, and rather nearer to 
 the posterior than the anterior edge of the liver. In 
 this fissure, near to its right extremity, the great 
 vein, called vena portarum, and the hepatic artery 
 enter, and the excretory duct of the liver, commonly 
 called the hepatic duct, comes out. About the mid- 
 dle of the fissure are two prominences, one on each 
 side ; these were called the portae, or gates of the 
 liver, and hence the great vein was called vena por- 
 tarum. This vein has two very large rectangular 
 branches, which constitute what is called the sinus 
 of the vena portarum, and they occupy the principal 
 extent of the fissure. 
 
 The liver is in close contact with the vena cava 
 behind; and there is either a groove in it for the pas- 
 sage of the vein, or this great vessel is completely en- 
 closed by it. There is also an excavation on the 
 lower surface of the liver, which is occupied by a 
 portion of the gall bladder. 
 
 Besides the great lobes above mentioned, there 
 are also two or three prominent parts on the concave 
 surface, which are denominated lobes. One of these, 
 called Lohulus Spigelii, is oblong, with two sides, 
 and an angle continued along its whole length, 
 Vol, II. 17 
 
130 
 
 Ligaments of the Liver „ 
 
 which extends from the transverse fissure to the pos- 
 terior margin of the liver. It is situated between 
 the posterior part of the transverse fissure, or ductus 
 venosus, and the vena cava. 
 
 The anterior extremity of this lobe, which forms 
 one of the margins of the transverse fissure, is some- 
 what bifurcated, and has been called lobulus caudatus. 
 The largest portion of the bifurcated end forms a pro- 
 cess like a papilla, and is one of the portae. 
 
 Between the umbilical fissure and the depression 
 for the gall bladder is a protuberant space, which 
 varies from an inch and a quarter to two inches in 
 breadth. This has also been called a lobe, Lobulus 
 Quarlus or Anonymous , its posterior point opposite 
 the papilla of the lobulus spigelii forms the other 
 porta of the liver. 
 
 The peritoneum is extended from the surface of 
 the abdomen to the surface of the liver, in such man- 
 ner as to cover it, and to form ligaments, which have 
 a great effect in retaining it in its proper situation. 
 The whole posterior edge of the liver is in contact 
 with the back of the abdomen. The peritoneum 
 above the liver is reflected to the upper surface of it, 
 and the peritoneum below it to the lower surface ; 
 so that two lamina of the peritoneum pass from the 
 lower part of the diaphragm at the back of the abdo- 
 men to the posterior edge of the liver. These pro- 
 cesses of the peritoneum are considered as forming 
 two ligaments, which are called the right and left 
 lateral ligaments. A portion of the posterior surface 
 of the liver, uncovered by the peritoneum, is often in 
 contact with a portion of the tendon of the diaphragm, 
 also uncovered by peritoneum : around this place of 
 contact, the peritoneum is extended from the dia- 
 phragm to the liver, and thus forms what has been 
 called the coronary ligament of the liver. 
 
 The peritoneum of the right side of the diaphragm, 
 and of the abdominal muscles, as far down as the 
 
131 
 
 Mode of supporting the Liver, 
 
 umbilicus, is extended to the liver, and joins it on 
 the convex surface immediately opposite to the um- 
 bilical fissure. The peritoneum from the left side of 
 these parts does the same j and as these reflections 
 ©f the peritoneum are continued from so low a part 
 as the umbilicus, they are extended not only to the 
 convex surface of the liver, but also to the great 
 notch, and along the umbilical fissure. 
 
 From the umbilicus proceeds a round cord-like lig- 
 ament, which in the foetal state was a vein, that 
 passes to the great fissure of the liver, and along it. 
 The process of the peritoneum above mentioned is 
 so connected with this cord, that it encloses it in its 
 lower edge, and the whole is called the falciform 
 ligament of the liver. The cord, when named se- 
 parately, is the umbilical or the round ligament : and 
 the membrane or lamina of the peritoneum forms the 
 suspensory ligament. Besides these, the peritoneum 
 on the lower side of the liver is so arranged, that it 
 not only extends to the stomach, but to the duodenum 
 and the colon. 
 
 By these ligaments the position of the liver must 
 be fixed to a great degree ; and there is one additional 
 connexion, which must have a great effect in retain- 
 ingit in its proper situation. The vena cava receives 
 two or three great veins from the liver, at the place 
 where it is in contact with the posterior edge of that 
 viscus : these veins of course pass directly from the 
 substance of the liver into the cava, and connect if to 
 that vessel. As the cava is supported by the heart, 
 and also by the diaphragm, it must afford a consider- 
 able support to the liver. 
 
 When the stomach and intestines are distended, 
 they must also contribute in a considerable degree to 
 the support of the liver. 
 
 The liver has a strong tendency, when we are 
 erect, to change its situation % and some considerable 
 
132 Acini of the Liver. — Proper Coat of the Liver , 
 
 support is necessary to counteract this tendency. It 
 would move to the right, when we lie on the right 
 side, if it were not in contact with the ribs ; and it 
 inclines to the left, for want of such support, when 
 we lie on the left side. 
 
 It has been computed, that the liver descends 
 about two inches, when the position of the subject is 
 changed from the horizontal to the erect. As it is 
 in contact with the diaphragm, it is obvious that it 
 must be influenced by the motions of that muscle, 
 and that it must descend when the diaphragm con- 
 tracts. 
 
 The liver is composed of a substance which has 
 some firmness of consistence, although it is yielding; 
 and is also somewhat brittle or friable.* When cut 
 into, the sections of many tubes, or vessels of dif- 
 ferent diameters, appear on the cut surface. When 
 the texture of this substance is more closely ex- 
 amined, it appears somewhat granulated, or com- 
 posed of very small bodies, which were called acini 
 by the anatomists who first described them. The 
 whole substance is enclosed by the peritoneum, which 
 is extended to it from the surface of the abdomen in 
 the manner that has been already described. It has 
 also a proper coat or capsule ; and on the posterior 
 edge, where the lamina of the lateral ligaments pass 
 from the diaphragm to the liver, at some distance 
 from each other, a portion of the liver, covered by 
 this coat and by cellular substance, is in contact with 
 the diaphragm. The same thing occurs likewise at 
 the coronary ligament, f 
 
 The liver holds the first place among the glands 
 
 * It has been fractured in the living body by external violence. 
 
 f Many anatomists deny the existence of this coat ; but if one of the 
 lamina of the ligaments be carefully peeled off from the surface of a 
 liver which is slightly affected by putrefaction, it will be apparent, al- 
 though very thin. It was described by M. Laennec, in Le Journal de 
 Medecine for 1803. 
 
Vessels of the Liver.-— Hepatic Artery „ 133 
 
 of the body for size, but it is still more remarkable 
 for some other circumstances in its economy. In 
 addition to an artery, which passes to it as arteries 
 do to other glands, there is a large vein which also 
 enters it as an artery; and after ramifying through- 
 out the liver, communicates, as does the artery, with 
 other veins, which carry the blood from this gland 
 into the vena cava and the general circulation. 
 There are therefore three species of blood vessels in 
 the liver; and with these are found the vessels which 
 carry out of the gland the fluid secreted by it, or the 
 bile. 
 
 The artery of the liver is denominated the Hepa~ 
 tic Artery. The vein which goes to the liver is call- 
 ed the Vena Portarum , from the place at which it 
 enters. The veins which carry to the vena cava the 
 blood brought to the liver by the hepatic artery and 
 the vena portarum, are called the Hepatic Veins ; 
 and the duct through which the bile flows out of the 
 liver, is called the Hepatic Duct. Three of these 
 vessels, the Hepatic Artery , the Vena Portarum , 
 and the Hepatic Duct , enter the liver at the great 
 fissure, at the spot where the prominences exist call- 
 ed the porta 2 ; hence the name vena portarum was 
 applied to the vein. 
 
 These vessels ramify in the manner presently to be 
 described; and it is ascertained by minute anatomical 
 investigation, that the liver is entirely composed of the 
 ramifications of these vessels and of the hepatic veins, 
 with absorbent vessels and nerves, which are connect- 
 ed together by cellular membrane. 
 
 It has been already observed, that the first great 
 branch sent off by the aorta in the abdomen, the Cce- 
 liac, divides into three branches, which go respective- 
 ly to the stomach, the liver, and the spleen. 
 
 The Hepatic is generally the largest of these 
 branches. In its progress towards the liver it sends 
 
134 
 
 Vena P or forum - 
 
 off an artery to the stomach, called the gastrica dex- 
 tra. At the great fissure it divides into two branches"; 
 the right branch, which supplies the right lobe of the 
 liver, is of course the largest. Tins branch sends off 
 oat to the gall-bladder, which is called the cystic ar- 
 tery ; and also some smaller branches : it passes un- 
 der the hepatic duct, and ramifies through the great 
 lobe of the liver. The left branch is distributed 
 through the left lobe of the viseus. It can be proved 
 by injection, that the hepatic artery communicates not 
 only with the hepatic veins, but with the biliary duct, 
 and the vena portarum also. It has been disputed 
 whether the size of this artery is greater than would 
 he requisite for the nourishment and animation of the 
 liver- 
 
 The Vena Portarum , the great peculiarity of the 
 liver, originates from all the chylopoietic viscera ex- 
 cept the liver, and is of course formed by the union 
 of the veins which correspond to all the branches of 
 the coeliae and mesenteric arteries, as they are dis- 
 tributed to the stomach and intestines, the spleen, 
 the pancreas, and the omentum. The veins from 
 the intestines generally form two great trunks, which 
 are denominated the greater and lesser mesenteric 
 veins. The great mesenteric vein is situated to the 
 right, and rather before the mesenteric artery.— 
 After it has approached the origin of the artery it 
 separates from it, and passes behind the pancreas i 
 at this place, nearly in front of the spine, it is joined 
 by the great vein of the spleen, which forms almost 
 a right angle with it, and these constitute the great 
 trunk of the vena portarum- The lesser mesenteric 
 vein, which corresponds to the inferior mesenteric 
 artery, and brings blood from the pelvis and from 
 the left part of the colon, becomes finally a large 
 vessel, and commonly unites with the splenic about 
 an inch and a half before its junction with the supe- 
 
135 
 
 Vena For iarum . —Hepatic Duct . 
 
 sior mesenteric vein. The vena portarum, thus 
 formed, proceeds towards the liver, inclining to the 
 right, and is generally about three inches in length: 
 in its course it sometimes receives small veins, which 
 in other cases pass to its splenic and mesenteric 
 branches. When it has arrived at the great trans- 
 verse sinus of the liver, it divides into two large 
 branches, each of which forms nearly a right angle 
 with it. Their size is so great, that, when distend- 
 ed with injection, they appear like an independent 
 vessel, into which the vena portarum enters ; and on 
 this account they are called the great Sinus of the 
 vena portarum. They do not adhere firmly to the 
 glandular substance of the liver, but are united to it 
 by cellular membrane. The right branch is the 
 widest and shortest. It generally divides into three 
 branches; an anterior, a posterior, and a lateral 
 branch; which ramify minutely, and extend them- 
 selves in the right lobe. The left branch is much 
 longer, and continues to the extent of the transverse 
 fissure. Near its termination it is joined by the urn- 
 bilical ligament, which has been already mentioned. 
 This branch is generally in contact with a branch of 
 the hepatic artery and of the hepatic duct ; and ra- 
 mifies, like the right branch, into the contiguous parts 
 of the liver. 
 
 The Hepatic or excretory duct originates, by very 
 small vessels, from the acini or corpuscles of which 
 the liver is composed, and into which the minute ra- 
 mifications of the vena portarum and hepatic artery 
 extend. They accompany these vessels, increasing 
 as they increase, although the fluid they contain moves 
 in an opposite direction ; and two large branches 
 which they ultimately form are situated at the portae 
 of the liver, in contact with the great branches of the 
 vena portarum and the hepatic artery. 
 
 These three vessels are in contact with each other 
 
136 Hepatic Veins. — Nerves of the Liver . 
 
 before they enter the liver. The biliary duct is an-^ 
 terior, the vena portarmn posterior, and the artery to 
 the left of them. They are accompanied by nerves 
 and lymphatic vessels, and are surrounded by a con-\ 
 siderable quantity of cellular substance, and thus ar- 
 ranged are partially covered with peritoneum. The 
 cellular substance which invests them continues with 
 them into the liver, and is more particularly con- 
 nected with the vena portarum. It is called Glis- 
 son’s Capsule, and was supposed to have some con- 
 tractile power, which assisted the circulation of the 
 vena portarum ; but that idea is now altogether aban- 
 doned, The hepatic veins, which receive the blood 
 of the hepatic artery and the vena portarum, open 
 into the anterior part of the vena cava, where it is 
 in contact with the liver. Generally there are three 
 of these veins, but sometimes there are only two ; 
 in which case one of them is formed by two others, 
 which unite immediately before they open into the 
 vena cava. It is to be observed, that the various 
 branches of these veins do not accompany those 
 branches of the vena portarum or hepatic artery to 
 which they correspond, but form very large angles 
 with them. This is probably owing merely to 
 their termination in a part so distant from that in 
 which the artery and the vena portarum originate ; 
 but it is very different from what occurs in other 
 glands. 
 
 The Nerves of the Liver are derived from the 
 sisnilunar ganglions of the splanchnic nerves. From 
 these many nerves proceed, which form a net-work 
 denominated the solar plexus. From this plexus 
 many threads are sent off, which form a net-work 
 that is divided into the right and left hepatic plexus. 
 These plexuses surround the hepatic artery and the 
 vena portarum, and accompany them in their ramifi- 
 cations throughout the liver, being enclosed by Glis- 
 
Lymphatics . 137 
 
 son's capsule. They receive some threads from the 
 stomachic plexus, formed by the par vagum. A1- 
 though the number of nervous fibres is very conside- 
 rable, their bulk, compared with that of the liver, is 
 very small. 
 
 The Lymphatics of the Liver are extremely nu- 
 merous; and those in that portion of the peritoneum 
 which invests the liver may easily be rendered con- 
 spicuous : for by pressure the injected fluid can be 
 forced from the trunks and large branches into the 
 smtll ramifications, in opposition to the valves. When 
 all the surface is injected in this manner, it has the 
 colour of the substance injected; as is the case with 
 parts which are very vascular, when the blood ves- 
 sels are injected. 
 
 The deep-seated lymphatics are also very numer- 
 ous in the liver, and communicate freely with the su- 
 perficial. 
 
 The superficial lymphatics which are on the upper 
 surface, proceed through the diaphragm into the tho- 
 rax in their course to the thoracic duct. Those which 
 are deep-seated emerge from the liver at the portae, 
 where the great vessels enter, and unite with the tho- 
 racic duct in the abdomen, after passing through se- 
 veral glands. The lymphatics of the lower surface 
 unite with the deep-seated. 
 
 The glandular or parenchymatous substance of the 
 liver is of a reddish-brown colour, and moderately 
 firm consistence. When it is cut into, the cut surface 
 exhibits the sections of the branches of the different 
 blood vessels above mentioned, and of the excretory 
 ducts. These vessels are often distinguishable from 
 each other. The section of the biliary duct appears 
 the thickest ; that of the artery next ; the vena por- 
 tarum is next in order ; and, last of all, the vense 
 hepatic^o 
 
 VOL. n. 
 
 18 
 
138 Glandular Substance of the Liver. 
 
 The branches of the vena portarum are surrounded 
 by cellular substance, or Glisson’s capsule ; and there- 
 fore adhere less to the substance of the liver than the 
 branches of the hepatic veins. The sections of the 
 hepatic ducts have often bile in them, and are there- 
 fore termed pori biliarii. The branches of the arte- 
 ry are also very distinguishable. 
 
 When the internal substance of the liver is brought 
 into view, and examined accurately, it appears to be 
 formed of small bodies, or acini, which are distin- 
 guishable from each other. If the liver happens to 
 be torn or lacerated, the lacerated surfaces are rough 
 and irregular, owing to the separation of these acini 
 from each other. 
 
 It is asserted by several microscopical observers, 
 that a minute branch of each of the aforesaid vessels 
 can be traced into each of the aeini. It is also de- 
 clared, that if each of these vessels be injected sepa- 
 rately with mercury, oil of turpentine coloured, or a 
 saturated aqueous solution of gutta gamba, there is no 
 part of the glandular mass as large as a grain of mus- 
 tard seed in which these vessels will not be found. 
 
 Several anatomists of the first character have like- 
 wise declared, that a fluid properly injected into one 
 of these vessels, will occasionally pass into all of 
 them. Thus an injection will not only pass from the 
 vena portarum to the biliary duct, but to the hepatic 
 artery and veins also. It will likewise pass, in a re- 
 trograde course, from the biliary ducts to the vena 
 portarum, and to the hepatic artery and the hepatic 
 veins ; or from any one of the four orders of vessels 
 into the three others.* 
 
 The great peculiarity of the liver is, that venous 
 blood, instead of arterial, is brought to it for the 
 purpose of secretion. Thus, the great vein of the 
 
 * I have tried the experiment and find the assertion to be correct— E d. 
 
Peculiarity of the Liver. — Gall Bladder. 139 
 
 ehylopoietic viscera, instead of passing to the cava, 
 enters the liver by the transverse fissure, and takes 
 on the office of an artery ; its coats, on this account, 
 being much thicker and stronger than those of the 
 hepatic veins.* 
 
 The Biliary or Hepatic Duct is formed of very 
 minute vessels, which originate in the acini above 
 described ; these unite together like veins until they 
 form considerable branches, which finally compose 
 the great ramifications of the biliary duct. This 
 duct is very strong and firm, and on its internal sur- 
 face are the orifices of many mucous follicles or 
 ducts. It passes from the transverse fissure of the 
 liver, with the hepatic artery, as before described, 
 and at the distance of an inch and a half or two 
 inches from the fissure, it unites with a duct from the 
 gall bladder, which is called the Cystic Duct. This 
 duct is nearly equal in length to the hepatic, and af- 
 ter running almost parallel to it, at length unites so 
 as to form an acute angle with it. The cystic duct 
 is smaller than the hepatic, and they unite much like 
 two branches of an artery. 
 
 The Gall Bladder , from which the cystic duct 
 arises, has the shape of a pear, with a very long 
 neck, curved in a way to be hereafter described. It 
 is situated in a superficial pit or cavity in the con- 
 cave surface of the right lobe of the liver ; and its 
 fundus, or basis, often projects a small distance be- 
 yond the anterior edge of the viscus. Its position 
 is such, that it extends from before backwards, and 
 inclines rather to the left ; of course, therefore, when 
 the subject lies on his back, the bottom of the blad- 
 
 * A case is related by Mr. Abernethy, in the London Philosophical 
 Transactions, in which the vena portarum terminated in the vena cava be- 
 low the liver, without commmunicating with it. The hepatic artery was the 
 only vessel which carried blood to the organ, and was unusually large; the 
 liver being nearly of the natural size. Some bile was in the gall bladder, 
 but it was less acrid tha» usual. 
 
140 
 
 Gall Bladder. 
 
 der is the uppermost part of it ; when he lies on the 
 left side, it is also higher than the neck ; and when 
 he lies on the right side it is the lowermost. 
 
 The gall bladder consists of an internal coat, and 
 one that is cellular or nervous, and has somewhat of 
 a fibrous appearance. This coat connects the gall 
 bladder to the surface of the pit nr cavity in which 
 it lies. The peritoneal coat of the liver is extended 
 from the surface of the viscus over that part of the 
 surface of the gall bladder which is not in contact 
 with it. 
 
 The internal coat has a peculiar structure, with a 
 faint resemblance to that of the villous membrane. 
 It is so arranged as to form very fine folds, which 
 have various directions : in some places they make 
 a net-work ; in others, as the neck of a bladder, they 
 are longitudinal. Many mucous follicles exist on its 
 internal surface. 
 
 The neck of the gall bladder is suddenly bent down 
 or curved upon itself, and twisted, so that it resem- 
 bles the neck of the swan, when the head of that bird 
 is applied to one side of its breast. 
 
 A branch of the hepatic artery, which leaves it be- 
 fore it enters the liver, is appropriated to the gall 
 bladder, and is therefore denominated the cystic artery. 
 The veins corresponding to this artery empty them- 
 selves into the vena portarum .* The lymphatic ves- 
 sels are united to those which are found on the lower 
 surface of the liver, and the nerves are derived from 
 the hepatic plexus. 
 
 The gall bladder appears to be merely a reservoir, 
 into which bile passes through its duct in a retro- 
 grade direction. If air be blown through the hepa- 
 tic duct from the liver, it will pass to the gall blad- 
 der almost as freely as it passes to the duodenum. 
 
 * It has been justly observed by John Bell, that the veins would not ter- 
 minate thus, if bile were secreted by the gall bladder. 
 
Ductus Communis Choledochus.— The Bite . 141 
 
 The biliary duct from the liver, after receiving the 
 duct from the gall bladder, takes the name of Ductus 
 Communis Choledochus. It is wider than either of 
 the other ducts, and near three inches in length. It 
 passes down before the vena portarum, and on the 
 right of the hepatic artery, to the posterior surface 
 of the right extremity of the pancreas. It passes 
 through a small portion of that gland, and then per- 
 forates the muscular coat of the duodenum ; after 
 which it proceeds from half an inch to an inch be- 
 tween this coat and the villous, and opens into the 
 cavity of the intestine. The orifice forms a tubercle 
 which extends lengthways of the intestine, and is 
 rounded above and pointed below, with a slit in it. 
 While this duct is in contact with the pancreas, a 
 duct from that gland generally opens into it, so that 
 the biliary and pancreatic fluids enter the duodenum 
 by the same orifice ; but sometimes the pancreatic 
 duct opens into the duodenum, by a distinct orifice, 
 very near to that of the biliary duct. 
 
 The Bile, or fluid secreted by the liver, appears to an- 
 swer a two-fold purpose in the animal economy. It 
 produces a chemical effect upon the alimentary mix- 
 ture which passes from the stomach through the intes- 
 tines ; and it increases the peristaltic motion of those 
 important organs. 
 
 By an inverted action of the duodenum, some of this 
 fluid is frequently carried upwards into the stomach : 
 it then often produces only slight derangement of the 
 functions and sensations connected with that viscous; 
 but sometimes violent vertigo, and even convulsions , 
 seem to have arisen merely from the presence of a 
 large quantity of bile in the stomach : for they have 
 gone off completely upon the discharge of bile by 
 vomiting. 
 
 Notwithstanding these effects of bile in certain 
 cases, in which a great deal of it exists in the sto- 
 mach, it is often carried into the mass of blood in 
 large quantities, and appears to be mixed with the 
 
142 
 
 The Pancreas. 
 
 serum, and to circulate through the body, without pro- 
 ducing any very sensible effect : thus many persons 
 who are deeply tinged by bile in their blood, experi- 
 ence but few effects that can be imputed to the mixture 
 of it with the circulating fluids : and neither the brain 
 nor the heart appear to be much influenced by the cir- 
 cumstance. 
 
 Bile is miscible with water and with alcohol, and 
 also with oily substances ; and it often assumes a green 
 colour, when mixed with acids. The colour of the 
 alvine discharges is derived from the bile, and they 
 are therefore sometimes very green, when the acetous 
 fermentation takes place in the contents of the sto- 
 mach and bowels. 
 
 It is asserted by some chemists, that ten parts in 
 eleven of the human bile consists of water ; that albu- 
 minous matter composes about one forty-sixth part of 
 it ; and that there is nearly an equal quantity of re- 
 sinous matter in it. There is also a small quantity, 
 (one part in 244,) of uncombined soda dissolved in it, 
 and a smaller quantity of neutral salts, consisting of 
 soda combined with the phosphoric, sulphuric and mu- 
 riatic acids. In addition to these is a very small 
 quantity of phosphate of lime and of oxide of iron, 
 and some yellow insoluble matter. 
 
 The bile in the Gall Bladder is generally more 
 viscid than that which is found in the Hepatic Duct . 
 
 SECTION II. 
 
 Of the Pancreas. 
 
 The pancreas is a glandular body, which has a 
 strong resemblance to the salivary glands in seve- 
 ral particulars. It is seven inches in length, and 
 is irregularly oblong in its form, one extremity 
 being much larger than the other. Its large extre- 
 mity is in contact with the duodenum, and it ex- 
 tends from this intestine in a transverse direction to 
 the spleen, to which it is connected by the omentum 
 and by blood vessels. It is not invested by the 
 peritoneum, but is situated in the space which exists 
 
The Pancreas . 
 
 143 
 
 between the two lamina of the mesocolon, as they 
 proceed from the back of the abdomen, before they 
 come in contact with each other. It is anterior to 
 the aorta and vena cava, and to the mesenteric vein, 
 or main branch of the vena portarum ; being connect- 
 ed to these parts by cellular membrane. At the right 
 extremity, which is connected with the duodenum, is 
 a process of the gland that extends downwards in 
 close contact with the intestine. — This is called the 
 head of the pancreas, or the lesser prancreas. 
 
 The position of the pancreas is such, that one of 
 its surfaces looks forwards and rather upwards, and 
 the other backwards and downwards ; one edge is 
 of course posterior and superior, and the other ante- 
 rior and inferior. The posterior of these edges is 
 much thicker than the other, and has a groove or 
 excavation which is occupied by the splenic blood 
 vessels. 
 
 This gland differs from the other large glands of 
 the abdomen, inasmuch as it has not a large artery 
 particularly appropriated to it ; but instead of this, 
 it receives branches from the contiguous arteries. 
 
 The arterial blood of this gland is partly supplied 
 by the splenic artery, which, in its course from the 
 main trunk of the cceliac to the spleen, while it is in 
 the groove at the edge of the pancreas, sends off into 
 the gland one considerable branch called the great 
 pancreatic, and a number of small branches, which 
 go off in succession. In addition to these, the pan- 
 creas receives vessels from one of the branches of 
 the hepatic artery, before it sends off its great rami- 
 fications, as well as small twigs from several other 
 contiguous arteries. The veins correspond with the 
 arteries, but ultimately are discharged into the vena 
 portarum. 
 
 The pancreas resembles the salivary glands in 
 
144 
 
 Pancreatic Duct . 
 
 colour, and also in texture ; for it it of a dull white 
 colour with a tinge of red, and it appears to consist 
 of small bodies of a granulated form, which are so 
 arranged as to compose small masses or lobes that 
 are united to each other by cellular membrane. — , 
 Each of these granulated bodies receives one or 
 more small arterial twigs, and from it proceeds not 
 only a vein but a small excretory duct, which, 
 uniting with similar ducts from the adjoining granu- 
 lated portions or acini, forms a larger duct in each 
 lobe or mass; these open into the great duct of the 
 gland, which proceeds through it lengthwise from 
 the left extremity, in which it commences, to the 
 right. 
 
 This duet is situated in the body of the gland, 
 which must be dissected to bring it into view. It is 
 thin and transparent, like the ducts of the salivary 
 glands, and is rather larger in diameter than a crow’s 
 quill. In its progress towards the right extremity 
 of the gland it gradually enlarges, and commonly 
 receives a branch from the part called the lesser 
 pancreas. It most commonly unites with the biliary 
 duct before it opens into the duodenum : sometimes 
 these ducts open separately, but very near to each 
 other. They penetrate the coats of the intestine 
 rather obliquely, and between four and five inches 
 from the pylorus. This canal is sometimes called 
 Dustus Virsungii , after an anatomist who published 
 a plate of it. 
 
 The pancreas has an irregular surface, and no coat 
 which covers it uniformly. It is invested by cellular 
 membrane, which also connects its different lobes to 
 each other. Absorbent vessels and nerves are traced 
 into it. 
 
 The portion called the lesser pancreas adheres to 
 the duodenum, and when it is enlarged by disease., 
 
145 
 
 Size of the Spleen. 
 
 the passage of aliment through that intestine is much 
 impeded, and sometimes completely obstructed.* 
 
 It is now generally believed that the fluid secreted 
 by the pancreas is similar to that which is produced 
 by the salivary glands. 
 
 SECTION III. 
 
 Of the Spleen. 
 
 The Spleen is a flat body of a bluish colour, and 
 an irregular oblong form, with thick edges, which are 
 indented in some places. 
 
 It is various in different subjects, both in size and 
 form. Its most common size is between four and five 
 inches in length, and about three or four inches in 
 breadth ; but it has often been found of more than 
 four times this size ; and it has also been seen not 
 much longer than an inch. Its ordinary weight is be- 
 tween six and nine ounces ; but it has varied in dif- 
 ferent subjects from eleven pounds to one ounce. It 
 is supposed, by many physiologists, that it frequent- 
 ly varies in size in the same individual. 
 
 It is situated in the left hypochondriac region, in 
 contact with the diaphragm, below the eighth rib. 
 The position of the spleen is somewhat oblique,— 
 one extremity being directed downwards and rather 
 forwards, and the other upwards and backwards ; 
 but when the stomach is distended, the lower end of 
 it is pushed forward by the great extremity of that 
 viscus. 
 
 In general it is so deeply seated in the left hypo- 
 
 * In several cases where examination after death evinced that the pan- 
 creas had become enlarged and indurated, particularly at the right ex- 
 tremity, the principal symptoms wer e jaundice; great uneasiness after ta° 
 ing food; vomiting some time after eating , but not immediately ; extreme 
 acidity of the matter rejected 
 
 Vol. lie- " 19 
 
146 Enlargement of the Spleen 
 
 chondriac region, that it is out of view when the sub- 
 ject is opened in the ordinary way : but in some 
 cases of enlargement, after the intermitting fever, it 
 has extended downwards, nearly as low as the 
 pelvis ; and towards the right side beyond the um- 
 bilicus. 
 
 The external surface of the spleen is convex, in 
 conformity to the surface of the diaphragm, with 
 which it is in contact. The internal surface of the 
 spleen is irregularly concave, having a longitudinal 
 fissure which divides it into two portions. 
 
 The spleen is invested by the peritoneum, one 
 process of which is often extended from the dia- 
 phragm, above and behindit, in the form of ligament. 
 Another process of the same membrane is extended 
 to it from the great extremity of the stomach. The 
 peritoneum is also continued from the spleen in the 
 form of omentum. 
 
 Within this peritoneal covering is the proper coat 
 of the spleen, which is so closely connected to it, that 
 many anatomists have considered them as one mem- 
 brane : they are, however, very distinct at the great 
 fissure, but the external coat is extremely thin. 
 
 The proper coat of the spleen is not very thick : 
 it is dense and firm, and somewhat elastic* but not 
 much so. Iris partly transparent. 
 
 The spleen has a large artery, which is one of the 
 three great branches of the cceliac. This vessel runs 
 in an undulating manner, in a groove in the upper 
 edge of the pancreas, and in this course sends off 
 many small branches to supply that gland. The 
 splenic artery, before it arrives at the spleen, divides 
 into five or six branches, which are also undulating 
 in their progress, and penetrate into the body of the 
 viscus at the above mentioned fissure. These branches 
 are distributed to every part of the viscus, and ram- 
 ify minutely. 
 
147 
 
 Vessels of the Spleen , 
 
 From these branches, or from the main trunk be- 
 fore it ramifies, three or four smaller branches pro- 
 ceed to the left extremity of the stomach. They are 
 called vasa brevia or arterise breves. 
 
 The arteries which enter the spleen are accom- 
 panied by veins that emerge from it, and unite to 
 form a great trunk. This trunk observes a course 
 corresponding to that of the splenic artery, and re- * 
 ceives veins from the stomach and pancreas, which * 
 correspond with the arterial branches sent to those 
 organs. The splenic vein is one of the principal 
 branches of the vena portarum. 
 
 The splenic artery is very large in proportion to 
 the viscus to which it is sent, and the vein is unusu- 
 ally large in proportion to the artery. The vein is 
 also very tender and delicate in its structure. 
 
 The absorbent vessels of the spleen are very nu- 
 merous. It has been asserted, that when those of 
 the external coat of the spleen are injected, they are 
 sufficient to form a fine net-work on it. The absorb- 
 ents of the deep-seated parts unite to the superficial 
 at the*fissure where the blood vessels enter. They 
 terminate in the thoracic duct, after passing through 
 several lymphatic glands. 
 
 The nerves of the spleen are derived from the 
 solar .plexus : they form a plexus round the vessels 
 and accompany them through the viscus. 
 
 The spleen consists of a substance which is much 
 softer than that of any other viscus of the abdomen. 
 This substance is made up either wholly or in great 
 part of the ramifications of the splenic artery and 
 vein, which are demonstrated by injections to be very 
 minute and numerous in this body. There are also 
 many fine white cords, like threads, which pass from 
 the internal surface of the inner coat of the spleen 
 into its soft substance, in which some of them ramify. 
 These cords connect the substance of the spleen 
 
148 Malpighi on the Structure of the Spleen „ 
 
 pretty firmly to its coat, and they seem to have the 
 effect of rendering the exterior part of the substance 
 more firm and dense than the internal. They are 
 particularly conspicuous if the spleen be immersed 
 in water, and the coat pulled off while it is in that 
 situation. 
 
 The spleen has a strong resemblance to the glan- 
 dular organs, but has no excretory duct, and its par- 
 ticular function is not very obvious : for these reasons 
 the structure of this organ is a subject of very inte- 
 resting inquiry. 
 
 Malpighi, who took the lead in researches of this 
 nature, before injections of the blood vessels with 
 wax were in use, after investigating the structure of 
 the spleen by long maceration, by boiling, by infla- 
 tion, by the injection of ink or coloured fluids, and 
 by examination with microscopes, declared that its 
 structure was cellular ; that the cells communicated 
 more freely with the veins than the arteries ; and 
 that they might be considered as appendices of the 
 veins. He also asserted, that a large number of 
 white bodies or vesicles were to be found in those 
 cells and throughout the whole substance of the 
 spleen, which were in bunches like grapes, and pre- 
 served their whitish colour although the vessels 
 around them were injected with a coloured fluid. 
 This description of Malpighi appears to have been 
 admitted by some of the very respectable anatomists 
 who were cotemporary with him ; but it was most 
 zealously opposed by Ruysch, who exhibited the 
 spleen so completely injected with wax, that it ap- 
 peared to be composed entirely of vessels.* 
 
 Ruysch appears to have paid great attention to 
 
 * Two plates, taken from drawings of these preparations, are published 
 in Ruysch’s works. One is attached to Epistola Problematica Quarta, in 
 the second volume ; and the other to Thesaurus Septimus, in the third 
 volume. 
 
149 
 
 De La Sone on the Spleen „ 
 
 this subject, and to have made many preparations of 
 the spleen. From these he derived the opinion, that 
 the substance of this organ was entirely composed of 
 arteries, veins, absorbent vessels and nerves ; and 
 that if it were properly injected before it was dis- 
 sected, no other structure would be found. He 
 stated, that the minute ramifications of the blood 
 vessels appeared to have acquired a peculiar quality, 
 and were so soft and delicate, that their texture was 
 destroyed by the least friction ; and that by the 
 slightest degree of putrefaction they appeared to be 
 reduced to a fluid state. He also denied the exist- 
 ence of cells, or of the whitish bodies described by 
 Malpighi. 
 
 The question thus at issue between these great 
 masters of their art, was very carefully examined by 
 M. De La Sone, a French physician, whose observa- 
 tions are published in the Memoirs of the Academy 
 of Sciences for 1754. After repeating the proces- 
 ses of each of these anatomists, and instituting some 
 others in addition, he adopted the opinion that there 
 was in the texture of the spleen a pulpy substance 
 which was not a mere coagulum, but which, howev- 
 er, could not be injected. 
 
 He derived his opinion from this fact among others. 
 After macerating the spleen a considerable time, and 
 injecting water into the vessels until it returned co- 
 lourless, he injected ink, and confined it some time in 
 the vessels by tying them : he then allowed the ink 
 to flow out of the vessels, and made various sections 
 of the spleen, but no ink appeared in the pulpy sub- 
 stance, although it was visible in many small vessels 
 which ramified in that substance. He observes that 
 this could not have been the case, if the pulpy sub- 
 stance had been composed entirely of vessels, as was 
 supposed by Ruyseh. 
 
 He also examined the spleen after it had been in- 
 
150 Haller and the French Anatomists on the Spleen . 
 
 jected with wax, according. to the manner of Ruyseh, 
 and believed not only that the pulpy matter remain- 
 ed uninjected, but that Ruyseh himself, in his own 
 preparations, removed this substance, supposing it to 
 exist for the mere purpose of connecting the vessels 
 to each other. 
 
 To see the blood vessels in the same state of de- 
 tention in which they were during life, he tied the 
 splenic vessels in a living animal, and removed the 
 spleen with the ligatures on the vessels. In this 
 situation he boiled it, and then examined the ap- 
 pearance of the vessels and the pulpy substance. — 
 From these, as well as his other observations, he 
 decided, that the pulpy substance did not consist en- 
 tirely of vessels, but was an additional and different 
 structure. 
 
 He also suggested, that as the brain and the mus- 
 cular fibres were so covered by blood vessels in the 
 injected preparations of Ruyseh, that they appeared 
 to be composed entirely of vessels, when in fact they 
 consisted of a different substance, so the pulpy sub- 
 stance of the spleen was covered ar obscured by the 
 blood vessels which passed through it, without con- 
 stituting its whole substance. 
 
 He confirms the account of Malpighi respecting the 
 Whitish Vesicles or Follicles ; and states, that, in a 
 majority of cases they are not to be discovered with- 
 out a particular preparation ; but that they are gene- 
 rally made obvious by long maceration of the spleen 
 in water. In his opinion they are the most essential 
 part of the organ. 
 
 Notwithstanding these investigations of M. De La 
 Sone, the question respecting the structure of the 
 spleen remains not completely decided even to this 
 day. 
 
 Haller, who was perfectly well acquainted with 
 the subject, inclined to the opinion of Ruyseh ; 
 
151 
 
 British Anatomists on the Spleen, 
 
 while Sabatier adopted completely the opinion of De 
 La Sone; 
 
 It appears from the statement of Gavard, that De- 
 sault did not admit the existence of the transparent 
 bodies; although he believed that the pulpy substance 
 of the spleen, consisted of cells which resembled 
 those of the cavernous bodies of the penis. 
 
 Boyer, whose descriptions of the animal structure 
 appear to have been formed with scrupulous exacti- 
 tude, admits the existence of transparent bodies; 
 sometimes so small as to be scarcely visible, and 
 sometimes as large as the head of a pin.’ He ob- 
 serves, that the best method of examining them is to 
 place a very thin slice of the spleen between the eye 
 and a strong light, when the transparency of these 
 bodies occasions the slice of the spleen to appear as 
 if perforated. 
 
 As to the general structure of the pulpy substance, 
 he avows himself unable to decide respecting if; but 
 observes, that upon examining the cut surface of the 
 spleen, you perceive black liquid blood flow from 
 the vessels ; if you then scrape this surface, you may 
 express easily a species of sanies different from that 
 which flows from the vessels, which, after exposure, 
 becomes red, and resembles coagulated blood ; whe- 
 ther this is contained in the capillary vessels, or in 
 the cavities of this organ, he acknowledges himself 
 unable to determine. 
 
 Notwithstanding the sentiments of these French 
 gentlemen, many of the British Anatoihists, who are 
 entitled to great attention on account of their skill in 
 minute injections, have adopted the ideas of Ruysch. 
 Among these are to be mentioned the late Dr. F, 
 Nicholls, and many of- the anatomists of London, as 
 well as the second Professor Monro, of Edinburgh. 
 There are, however, two remarkable exceptions to 
 this account of the British anatomists* The late 
 
152 British Anatomists on the Spleen* 
 
 Mr. Faleonar, who wrote a dissertation on the situa- 
 tion and structure of the spleen, which contains the 
 sentiments of the late truly respectable Mr. Hewsoq,* 
 after stating that the organ was extremely vascular, 
 so that when injected it appeared like a mere conge- 
 ries of vessels, makes this unequivocal assertion — 
 that there are innumerable cells dispersed through- 
 out the whole substance of it, which are so small that 
 they are only to be discovered by the aid of a micro - 
 scope ; and are to be seen after steeping a thin piece 
 of spleen, the blood vessels of which have been mi- 
 nutely injected, in clear water during a day, and 
 changing the water frequently. He also adds, that 
 the ultimate branches of the arteries and veins form a 
 beautiful net-work on each cell ; and that these cells 
 are sufficiently distinguished from the irregular inter- 
 stices of the cellular substance, by their round figure 
 and their great regularity. 
 
 Mr. Everard Home, in his papers on the structure 
 and uses of the spleen, confirms the account of the ve- 
 sicles in this organ ; and adds that these vesicles are 
 occasionally seen in a distended and in a contracted 
 state. That when distended they are twice as large 
 as when contracted, and are distinguishable by the 
 naked eye ; whereas, when contracted, they require 
 a magnifying glass to be distinctly seen. These ob- 
 servations appear to have been made upon quadru- 
 peds.! 
 
 Professor Soemmering appears to unite in the ge~ 
 neral sentiment of the British anatomists, that the 
 spleen is simply vascular. He says, that the tuber- 
 culi which sometimes appear in it, when examined 
 with a magnifying glass appear to be composed en- 
 tirely of vessels. 
 
 * See Experimental Inquiries, voi. iii. 
 
 f See the London Philosophical Transactions for 1808. 
 
Questions relating to the Structure of the Spleen. 153 
 
 There are therefore two questions not perfectly de- 
 cided respecting the spleen. 
 
 First. Whether its general structure is simply vas- 
 cular, or whether there is any other structure either 
 cellular or more substantial, which composes its ge- 
 neral bulk. 
 
 Second. Whether the small transparent vesicles, 
 originally described hy Malpighi, are to be regarded 
 as essential parts of the structure of the spleen. 
 
 With respect to the first question, the injections of 
 Ruysch, and of the British Anatomists in general, 
 and even of Mr. Hewson, as well as of Haller and 
 Soemmering, seem to afford positive facts in opposi- 
 tion to those of a negative kind adduced by M. De 
 La Sorie, and render it highly probable that the ge- 
 neral structure is simply vascular. 
 
 But the second question stands on differentgrounds* 
 The existence of small transparent vesicles, although 
 denied by Ruysch, and neglected by the British Ana- 
 tomists in general, was asserted as a positive fact by 
 Malpighi and De La Sone ; and their assertions have 
 been confirmed, not only by most of the French Ana- 
 tomists, but also by Hewson and Home among the 
 British. 
 
 The sentiments of physiologists respecting the func- 
 tions of the spleen, are more discordant than those of 
 anatomists respecting its structure ; although the sub- 
 ject has been considered by many authors of great in- 
 genuity.^ 
 
 * See M. Lieutaud. Elementa Physiologic?, 
 
 Hewson’s Experimental Inquiries, 'vol. iii. 
 
 Dr. Rush. Medical Museum, vol. iii.' 
 
 Haller. Elementa Pbysiologis, tom. vi. page'414. 
 
 Yol, n» 
 
 20 
 
CHAPTER IV* 
 
 OF THE URINARY ORGANS AND THE GLANDULE 
 RENALES. 
 
 The urinary organs consist of the Kidneys, which 
 are situated in the lumbar regions ; of the Bladder, 
 which is in the pelvis ; of the Ureters, which are 
 flexible tubes or canals that pass from the kidneys to 
 the bladder; and of the Urethra, or tube through 
 which the urine is discharged from the bladder. 
 
 These organs have but little connexion with the 
 peritoneum. The kidneys are behind it ; and a con- 
 siderable quantity of cellular membrane is placed 
 between them and it. The ureters are also behind it; 
 and but a part of the bladder is invested with it. 
 
 The Glandulx Benales are described with the uri- 
 nary organs, on account of their contiguity to'the kid- 
 neys : and to avoid a derangement of the natural or- 
 der of description they are considered first. 
 
 The urethra pertains to the organs of generation 
 as well as to the urinary organs, and can be descri- 
 bed most advantageously with them. 
 
 SECTION I. 
 
 Of the Glandulx Benales . 
 
 These are two small bodies, situated on the psoas 
 muscles, one on each side of the spine, behind the 
 peritoneum and above the kidney, being in contact 
 with its upper and anterior edge. They have an ir- 
 regular semilunar figure with three sides, one of 
 
The Kidneys and Ureters . 155 
 
 which is accommodated to the convexity of the kid- 
 ney. Their colour is commonly a dull yellow. 
 
 The appearance and texture of these bodies have 
 some resemblance to those of glands, and hence their 
 name, but they have no excretory duct. 
 
 When they are laid open by an incision, a cavity 
 often appears, which is somewhat triangular, and 
 from the lower part of it a small thin ridge arises.^ 
 
 A small quantity of fluid is generally found in it, 
 which has a very dark colour in adults, is yellowish 
 in young subjects, and red in infants. 
 
 These bodies have not a single artery appropriated 
 to them, as the spleen has, but receive small branches 
 from several contiguous sources ; viz. from the arte- 
 ries of the diaphragm, from the coeliac artery or the 
 aorta, and from the arteries of the kidneys. There 
 is generally one principal vein, as well as some 
 that are smaller, belonging to each of these bodies : 
 the large vein on the right side generally opens into 
 the vena cava, and on the left into the left eraulgent 
 vein. 
 
 These bodies were first described by Eustachius, 
 and have been regarded with attention by many ana- 
 tomists since that period. They exist in a great num- 
 ber of animals ; but their nature and functions are 
 altogether unknown. 
 
 SECTION II. 
 
 Of the Kidneys and Ureters. 
 
 The kidneys are two glandular bodies which se- 
 crete the urine. They are of a dull red colour, and 
 their form has a strong resemblance to that of the 
 bean which bears their name. They have a peeu- 
 
 * The cavity in these bodies has sometimes been sought for in vain. 
 Haller found it in sixteen cases out of nineteen. 
 
156 
 
 The Kidneys . ' 
 
 liar texture, which is uniform, and not granulated 
 or composed of acini ; and they are covered by a thin 
 delicate tunic, which has no connexion with the pe- 
 ritoneum. 
 
 They are situated in the lumbar regions of the ab- 
 domen, one on each side of the spine. They are 
 opposite to the two last dorsal and the two first lum- 
 bar vertebrae. They rest principally upon the psoas 
 and quadratus lumborum muscles, and their posi- 
 tion is oblique ; the concave edge presenting inwards 
 and forwards, the convex edge backwards, and the 
 upper extremity approaching nearer to the spine than 
 the lower. 
 
 The Right Kidney is situated rather low'er than 
 the left : it is below the posterior part of the right 
 lobe of the liver, and behind the duodenum and the 
 colon. The Left Kidney is below the spleen, and 
 behind the descending portion of the colon. Each 
 of the kidneys is below' and very near to one of the 
 glandulae renales. 
 
 They are surrounded with a large quantity of lax 
 adipose membrane, which in corpulent persons forms 
 a very large mass of adeps around them ; while in 
 the emaciated they are surrounded with a membrane 
 almost free from fat. Each kidney has two broad 
 sides, two extremities, and two edges. The side or 
 surface which is posterior, when the kidney is in its 
 natural situation, is rather broader than the other. 
 The upper extremity, or portion, is also broader 
 and larger than the lower. The edge which is pos- 
 terior and external is regularly convex ; the anterior 
 edge is concave ; but the concave edge, or margin, 
 is not very regular. In the middle it is largely in- 
 dented ; in this indentation is a deep fissure, which 
 separates the two broad surfaces or sides of the 
 gland from each other; and here the breadth of the 
 posterior surface is evidently greater than the anterior. 
 
157 
 
 . The Kidneys. 
 
 Each of the kidneys receives a large artery, which 
 proceeds immediately from the aorta, nearly in a 
 rectangular direction. A vein, which opens into the 
 vena cava, accompanies the artery. It is obvious, 
 from the situation of the kidneys with respect to the 
 great vessels, that the artery on the right side must 
 be longer than that on the left, and that the reverse 
 of this must be the case with the veins; the veins are 
 also anterior to the arteries. At the great fissure these 
 vessels divide into several branches, w T hich enter the 
 kidney at that place. The branches of the vein are 
 before and above ; those of the artery are below, and 
 in the middle. Surrounded more or less by the 
 branches of those vessels, is a membranous sac, the 
 breadth of which extends from above downwards. 
 This sac terminates in a tube that proceeds from the 
 lower part of the fissure down to the bladder. The 
 sac is denominated the pelvis of the kidney, and the 
 tube a ureter: each of these parts will soon be more 
 particularly described. 
 
 The substance of the kidney, as has been already 
 said, is uniform in its texture, and of a reddish brown 
 colour. When it is divided by an incision made 
 lengthways, and from its convex to its concave edge, 
 there appears to be a small difference in the different 
 parts of it. The exterior part, which is called corti- 
 cal, is rather more pale in colour and softer in con- 
 sistence than the internal part. It varies in thickness, 
 so that some writers have described it as equal to two 
 lines, and others to one-third of the kidney. In a 
 majority of subjects it will be. found between the two 
 statements. 
 
 The interior part is called medullary 7 , or tubular, 
 and appears to be composed of very fine tubes. 
 These tubes are so arranged, that a number of pa- 
 pillae or cones are formed by their convergence, and 
 project into the fissure of the kidney. These pa- 
 
158 
 
 The Kidneys . 4 
 
 pillae have been supposed to consist of a substance 
 different from either of the two above mentioned, 
 but they appear to be formed merely by the tubular 
 part. 
 
 The arteries, accompanied by corresponding veins, 
 and by nerves and absorbent vessels, after ramifying 
 in the fissure of the kidney, proceed into its substance, 
 and continue their aborescent ramifications until they 
 have arrived very near the exterior surface. They 
 are so uniformly distributed to the different parts of 
 the organ, that when the blood vessels are injected 
 with wax, and the substance of the kidney is removed 
 from the injected matter, as is the case in corroded 
 preparations, the injection exhibits accurately the 
 form of the kidney. 
 
 The large branches of the blood vessels occupy 
 the vacuities between the papillae in the fissure of 
 the kidney. When they penetrate the substance of 
 the kidney, they are enclosed by sheaths which are 
 derived from the cqat of the gland, and are sur- 
 rounded by membrane, which frequently contains 
 adeps. 
 
 There are commonly ten or twelve papillae in the 
 fissure of each kidney, but there are sometimes more 
 and sometimes less than this number. These pa- 
 pillae are surrounded by a membranous sac of a cor- 
 responding form ; the papilla being a cone, and the 
 sac resembling the upper part of a funnel. The 
 sac is therefore called an infundibulum, or calyx. 
 Sometimes there are two papillae in each infundibu- 
 lum, and then the form of the sac is not so regular. 
 The infundibulum adheres to the base of the papilla, 
 but lies loose about the other parts of it. Each in- 
 fundibulum communicates, at its apex, with the pel- 
 vis of the kidney. 
 
 The Pelvis, as has been already mentioned, is a 
 membranous sac which terminates in the ureter, ex- 
 
Cortical and Tubular Portions of the Kidney . 159 
 
 terior to the kidney. This sac generally divides it- 
 self, in the fissure of the kidney, into three large ir- 
 regular branches, each of which very soon terminates 
 in three or four of the infundibula above described. 
 That portion of the sac which terminates in the ure- 
 ter is exterior to the kidney. 
 
 When the interior parts of the kidney are exposed, 
 to view, by the section above mentioned, after the 
 arteries and veins have been minutely injected, the 
 cortical part will be found to consist almost entirely 
 of the minute ramifications of these vessels. Among 
 them are. some small bodies, which are dispersed 
 through the substance, like berries on a bush : these 
 are asserted also to be composed of vessels. 
 
 The tubular part certainly proceeds from this vas- 
 cular cortical substance : for Ruysch, and after him 
 several other injectors, have filled these tubes with 
 injection thrown into the arteries. 
 
 The tubuli, of which this part is composed, seem 
 to arise obscurely from the cortical part. They soon 
 assume somewhat of a radiated direction, and are 
 finally arranged so as to form the papillae or, cones 
 above described. 
 
 On these papilla or cones some of them can be 
 traced, uniting with each other, to form larger tubes, 
 which terminate on the surfaces of the papillae, in 
 orifices large enough to be seen distinctly. From 
 these orifices urine may be forced out by compress- 
 ing the papillae. On this account the tubes have been 
 called tubuli uriniferi. , 
 
 In the foetal state the kidney is formed of a num- 
 ber of distinct lobuli, each of which consists of a 
 papillae with the cortical matter connected to its 
 base. Soon after birth these lobuli coalesce ; and 
 in two or three years the substance of the kidney 
 appears uniform, as above described. In some ani- 
 mals this lobulated structure continues during life ; 
 
160 Nerves and Lymphatics.— Coat of the Kidney. 
 
 in them, and also in the foetus, each lobe appears 
 like a distinct organ. Although in the adult kidney 
 this structure has disappeared, the papillae and the 
 tubular part connected with them are somewhat de- 
 tached from each other, in a manner corresponding 
 to their original arrangement. . 
 
 The Nerves of the Kidneys originate from the se- 
 milunar ganglion, formerly mentioned. They form 
 a plexus round the blood vessels, and go with them 
 into the gland. 
 
 The kidneys have internal and external absorbent 
 vessels, although the external vessels are very small. 
 These absorbents pass through glands in the lum- 
 bar region to the thoracic duct. 
 
 The proper coat of the kidney is said, by some 
 anatomists, to consist of two lamina ; but this can- 
 not be shown in common cases. It appears simple 
 in its structure, and very flexible. It is but slightly, 
 connected to the glandular substance which it en- 
 closes, and may be easily peeled off. It is reflected 
 inwards at the fissure of the kidney, and can be 
 traced inwardly to some distance, forming sheaths 
 for the vessels. In this internal situation it is very 
 thin. 
 
 The Ureters. 
 
 The pelvis of the kidney terminates exteriorly in 
 the Ureter , which is a membranous cylindrical tube, 
 rather flattened, and between three and five lines in 
 diameter, with some variations in this respect. 
 
 The Ureters descend from the pelvis of the kid- 
 ney so as to pass obliquely across the psoas muscle 
 and the great iliac vessels. They are behind the 
 peritoneum, but in contact with it. They approach 
 the pelvis near the junction of the os ilium with the 
 sacrum, and thence descend forwards and inwards, 
 surrounded with loose cellular membrane, to the 
 
Structure of the Ureters. 161 
 
 lower part of the bladder, into which they are in- 
 serted at its external and posterior part. They first 
 penetrate obliquely the muscular coat, and then pro- 
 ceed between the muscular and internal coats, from 
 half an inch to an inch, in an oblique direction, from 
 without inwards and forwards, when they terminate 
 by small orifices in the internal coat, each of which 
 is at an equal distance, (rather more than an inch,) 
 from the orifice of the urethra, thus forming a triangle 
 with it. 
 
 The ureters are said to have three coats. The ex- 
 terior appear to be derived from the cellular sub- 
 stance : within it is another, which has been regarded 
 very differently by different anatomists ; some consi- 
 dering it as merely membranous, and others as mus- 
 cular. If the ureter be laid open and the internal 
 coat peeled off, the muscular structure of this coat is 
 often very perceptible. 
 
 The internal coat is called villous, or mucous, and 
 is continued from the internal coat of the bladder. 
 Over this coat mucous is constantly spread, which 
 defends it from the acrimony of the urine. It is 
 very difficult to separate the two last mentioned coats 
 from each other. 
 
 The ureters receive blood vessels and nerves from 
 those of the neighbouring parts. Their internal 
 coat is very vascular, and is also very sensible of ir- 
 ritation. The passage of a small urinary calculus 
 can be traced from the pelvis of the kidney to the 
 bladder, by the exquisite pain and the spasmodic af- 
 fections which it often excites. 
 
 Vol, II. 
 
 21 
 
162 
 
 Situation of the Bladder . 
 
 SECTION III. 
 
 Of the Urinary Bladder. 
 
 The urinary bladder is a large sac, of a muscular 
 and membranous structure, which occupies the ante- 
 rior part of the cavity of the pelvis, immediately 
 within the ossa pubis. 
 
 The size of the bladder is in a continued state of 
 variation, according to the quantity of urine secreted. 
 When moderately distended, it is of an irregular 
 oval form, but rather more flat at its lower extremity 
 than above. It varies in form according to the dif- 
 ferent circumstances of the pelvis to which it has been 
 subjected. 
 
 It is fixed firmly and immoveably to the pelvis 
 immediately within the symphysis pubis ; so that it 
 is always to be found there of a larger or smaller 
 size. This fixture is produced by the attachment of 
 the lower portion of fundus of the bladder to the 
 parts beneath it, but principally by the anterior liga- 
 ments of the bladder which proceed one on each side 
 from the lateral surfaces of the prostate gland, and are 
 inserted into the pubis of the corresponding side at 
 the lower part of the symphysis. These ligaments 
 are in fact the extension of a membrane, (called by 
 the French Anatomists, the pelvic aponeurosis,) which 
 proceeds from the upper part of the pelvis to the 
 side of the prostate gland and bladder, and which 
 may be seen by turning off the peritoneum from the 
 levator ani muscle.* It is sometimes completely 
 empty, and occupies no more space than the thickness 
 
 * See Thesis on Femoral Hernia, &c. by Gilbert Breschet. Paris, April, 
 1819. Colies’ Surgical Anatomy, Dublin, 1811, for a more minute account 
 of this membrane. Ed-. 
 
163 
 
 Situation of the Bladder. 
 
 of its coats requires. When moderately distended, 
 it occupies a considerable portion of the pelvis : 
 when distention increases, it presses the parts poste- 
 rior to it against the sacrum, and extends itself above 
 the brim of the pelvis into the general cavity, rising 
 not only to the umbilicus, but in some eases to? the 
 epigastric region. 
 
 In males the relative situation of the bladder and 
 rectum is such, that the upper and middle part of 
 the rectum is behind the bladder ; but the lower 
 part of the rectum, following the curve of the os 
 sacrum and coccygis, is below the posterior part of 
 the bladder. 
 
 In females the vagina and uterus are situated be- 
 tween the bladder and rectum ; so that the connex- 
 ion of these last mentioned parts is very different in 
 the two sexes. 
 
 The peritoneum is reflected at the anterior part of 
 the brim of the pelvis from the abdominal muscles, 
 which it lines, to the upper part of the bladder, 
 which is generally contiguous to the brim of the pel- 
 vis. It continues over to the posterior side of the 
 bladder, and passes down upon it some distance to- 
 wards the lower part ; but before it has arrived at 
 the bottom, it is reflected towards the sacrum. 
 
 In males it extends from the bladder to the rectum, 
 and in females to the vagina and uterus ; so that there 
 is a considerable portion of the lower part of the 
 bladder which is not invested by the peritoneum. It 
 also follows that when the bladder is extended into 
 the abdomen, and rises above the brim of the pelvis, 
 that part of it which presents anteriorly, and is in 
 contact with the abdominal muscles, is without a co- 
 vering of peritoneum, being below it. 
 
 The bladder is composed of a coat consisting of 
 muscular fibres, of a stratum of cellular substance 
 immediately within this, and of an internal lining 
 
1 64 Muscular Coal of the Bladder. 
 
 membrane, which lias been called villous, but, as 
 there are no villi perceptible on it, may be more 
 properly denominated mucous. 
 
 It should be observed, that, in addition to these 
 coats, the bladder has a peculiar investment of the 
 peritoneum, as has been already described; and 
 also of the common cellular membrane, which is 
 placed between it and every part to which it is con- 
 tiguous. 
 
 The Muscular Coat of the Bladder consists of 
 fibres which are not spread over it of a uniform thick- 
 ness, but are thin in some places, and in others are 
 collected in fasciculi. They run in every direction: 
 some appear longitudinal, others circular, and some 
 oblique ; and there are interstices between them 
 which are occupied by cellular membrane. The 
 longitudinal fibres originate from the lower part of 
 the bladder ; and as this is the fixed part of that 
 viscus, it is the place from which these fibres must 
 necessarily act. These fibres are generally exterior. 
 There is no arrangement of muscular fibres to which 
 the term of sphincter can properly be applied ; but 
 many anatomists have thought that the fibres near 
 the neck of the bladder, by their separate contrac- 
 tion, might prevent the escape of urine ; this senti- 
 ment, however, is contrary to that of several very 
 respectable writers. 
 
 The direction of the fibres, taken collectively, is 
 such, that, when they all contract, the cavity of the 
 bladder is completely obliterated. 
 
 The cellular substance between the muscular and 
 internal coats is dense. It yields in a remarkable 
 manner to distension, and recovers its original dimen- 
 sions very easily. From its analogy to a similar 
 coat in the intestines, it is called the Nervous Coat. 
 
 The Internal Coat of the bladder is of a light co- 
 lour in the dead subject, when it has been free from 
 
165 
 
 Internal Coat of the Bladder . 
 
 disease. It had been called villous improperly ; for 
 the villous structure is not apparent upon its surface. 
 Being continued from the integuments of the body 
 which are extended along the urethra, it has been in- 
 ferred, that the surface of this coat was formed by the 
 epidermis; and some respectable authors have sup- 
 posed that they had seen cases in which portions of 
 the epidermis of the bladder had separated and been 
 discharged ; but these appearances are very equivo- 
 cal, and it is by no means certain that an epidermis 
 exists there.* 
 
 The fasciculi of fibres of the muscular coat occasion 
 this coat to appear very irregular, but these irregula- 
 rities correspond exactly with the arrangement of the 
 fibres of the muscular coat. 
 
 When the internal coat is separated by dissection 
 from the muscular, its surface is very smooth and 
 uniform. In the recent subject, when no disease 
 has previously existed, it is always spread over with 
 mucous of a light colour, but nearly transparent, 
 which can be easily scraped off. This mucous is 
 spread upon the surface so uniformly, that it must 
 be derived from sources which are situated upon 
 every part of the surface ; but these sources are not 
 very obvious. On the membrane of the nose the 
 orifices of many mucous ducts are very visible, but 
 such orifices are not to be seen on this surface. — • 
 Haller mentions that he has seen mucous glands 
 near the neck of the bladder; and it is stated by the 
 pupils of Desault, that, in one of his courses, he 
 pointed out a number of these glands, in a subject 
 who had been afflicted with a catarrhal affection of 
 the bladder. 
 
 * In the fauces and the follicles of the tonsils an effusion of coagulable 
 matter, in consequence of inflammation, often forms crusts, that may be 
 mistaken for sloughs of the integuments, although those integuments re- 
 main entire. 
 
166 Mucous of the Bladder. 
 
 Notwithstanding that the sources of this mucous 
 are obscure, the quantity of it is sometimes immense. 
 In some cases, where the secretion is increased by 
 the irritation of a calculus in the bladder, the urine 
 is rendered somewhat viscid and white coloured by 
 the mucous mixed with it ; which, after the urine has 
 been allowed to remain for some time, subsides in 
 such quantities as demonstrates that many ounces 
 must be secreted in the course of the twenty-four 
 hours. The same circumstances occur, without the 
 irritation of calculus, in the disease called catarrhus 
 vesica}.* 
 
 It is probable that, in healthy persons, a great deal 
 of it passes ofF unperceived, being dissolved or dif- 
 fused in the urine. From the quantity and the regu- 
 lar diffusion of this mucous on the surface of the 
 bladder, there is the greatest reason for believing 
 that is is effused from every part of the surface; and 
 it is a question that has not been decided whether it 
 is discharged from glandular ducts too small to be 
 perceived, or from the exhalent extremities of the 
 blood vessels. It is probable that the use of it is to 
 defend the internal coat of the bladder from the acri- 
 mony of the urine. 
 
 The symptoms of a stone in the bladder, as well as 
 of several other diseases, evince that this coat is en- 
 dued with a great degree of sensibility. 
 
 It is evident that the essential parts in the general 
 structure of the bladder are the muscular coat and 
 the internal coat last described : but in addition to 
 the account of them, there are some other important 
 circumstances to be noted in the description of this 
 organ, It has been already stated, that the form of 
 the bladder was an irregular oval, although it was 
 
 * In some cases this mucous soon becomes putrid, and during the putre- 
 factive process deposits a substance which appears to be calcareous. 
 
167 
 
 Orifice of the Urethra. 
 
 somewhat varied in different persons. The oval form 
 is not much altered at the part called the neck of the 
 bladder, where the urethra passes off from it. The 
 orifice of the urethra is situated anteriority at the low- 
 ermost part of the bladder. On the lower surface of 
 the urethra, at its commencement, and on the bottom 
 of the bladder, immediately connected with the 
 urethra, is situated the Prostate Gland, (to be here- 
 after described with the organs of generation,) which 
 is a firm body, that adheres strongly both to the 
 bladder and urethra. This circumstance gives par- 
 ticular firmness and solidity to that part of the blad- 
 der. It has also been observed, that the bladder is 
 attached firmly to the ossa pubis, at its neck, about 
 the origin of the urethra. Each of these circum- 
 stances have an effect upon the orifice of the urethra ; 
 and when the bladder is opened, and this orifice is 
 examined from within, it appears to be kept open by 
 the connexion of the bladder with the prostate, and 
 has been very justly compared to the opening of 
 the neck of a bottle into the great cavity of that 
 vessel.* 
 
 The orifices of the two ureters are at equal dis- 
 tances from the orifice of the urethra, and form with 
 it the angles of a triangle. That part of the internal 
 surface of the bladder which is within this triangu- 
 lar space, is more smooth than the remainder of the 
 same surface, probably in consequence of the adhe- 
 sion of the bladder to the prostate, and to other parts 
 exterior to it. 
 
 * The late Mr. Lieutaud, and after him the French anatomists of the 
 present day, have described a small tubercle at the lower and posterior 
 part of the orifice of the urethra, which resembles the uvula in form. It 
 has not been noticed here; and M. Boyer states, that it is often scarcely 
 perceptible. He, however, makes a remark which is very worthy of at- 
 tention, viz. that it is very subject to enlargement in old people, forming a 
 tumour which impedes the discharge of urine. Sabatier has also made the 
 same observation. 
 
168 Ligaments and Vessels of the Bladder. 
 
 That part of the bottom of the bladder which is 
 immediately behind the triangular space, is rather 
 lower than this space; and but a small portion of cel- 
 lular membrane exists between it and the rectum in 
 males, and the vagina in females. 
 
 The upper part of the bladder is connected with 
 the umbilicus by means of a ligament, which passes 
 between the peritoneum and the abdominal muscles. 
 This ligament consists of three cords. One of these, 
 which is in the middle, arises from the coats of the 
 bladder, and was, in the foetus, the duct called ura- 
 chus; the other two, which are connected to the 
 bladder principally by cellular membrane, were ori- 
 ginally the umbilical arteries.* The middle cord is 
 of a light colour and fibrous structure ; it is thickest 
 at the bladder, and gradually diminishes as it ap- 
 proaches the umbilicus. In a few instances it has 
 been found to be hollow. In its progress to the umbi- 
 licus it becomes more or less blended with the linea 
 alba or the tendons of the abdominal muscles. The 
 other cords are generally solid. After passing from 
 the umbilicus to the bladder, they continue on the 
 sides of that viscus, and finally terminate at the hy- 
 pogastric or internal iliac artery. 
 
 In the very young subject these cords are invested 
 by distinct processes of the peritoneum, but their 
 position is exterior to the peritoneum. 
 
 As the bladder is situated very near most of the 
 large ramifications of the hypogastric artery in the 
 pelvis, it receives branches from several of them; 
 viz. from the umbilical arteries before they termi- 
 nate ; from the pubic ; from the obturators, &c. These 
 branches ramify in the cellular membrane exterior 
 to the muscular coat, and also in the cellular sub- 
 stance between the muscular and internal coats. It 
 
 * See the accounts of these parts in the description of the Abdomen of 
 
 the Foetus. 
 
General Obsei'vations. 
 
 169 
 
 has been conjectured, that their terminations in ex- 
 halents on the surface of the bladder are remarkably 
 numerous. 
 
 The veins correspond with the arteries, but they 
 are very numerous on the lower and lateral parts of 
 the bladder, and by uniting with the veins of the 
 rectum form a remarkable plexus. 
 
 The Lymphatic Vessels of this organ do not appear 
 more numerous than those of other parts. They pass 
 on each side the bladder in the course of its blood 
 vessels, and unite with the larger lymphatics, and 
 the glands which lie upon the great blood vessels on 
 the sides of the pelvis. 
 
 The JYerves of the bladder are derived both from 
 the intercostal nerve and from the nerves of the me- 
 dulla spinalis, which pass off through the sacrum ; 
 and therefore the bladder is more affected than the 
 viscera of the abdomen, by injuries of the medulla 
 spinalis. 
 
 The action of the muscular fibres of the bladder in ex- 
 pelling urine, and the effect of those fibres which are 
 situated near the orifice of the urethra in retaining it, 
 can be considered with more advantage after the struc- 
 ture of the urethra and the muscles connected with 
 that canal have been described. 
 
 It has been stated, that the internal coat of the blad- 
 der is very sensible ; but it may be added, that in 
 consequence of disease about the neck of the bladder, 
 the natural sensibility appears most inordinately in- 
 creased. When the intensity of pain which accom- 
 panies these complaints, the frequent recurrence of 
 paroxysms, and their duration, are taken into view, 
 there seems reason to believe that none of the painful 
 affections of the human race exceed those which arise 
 from certain diseases of the bladder Happily these 
 diseases are not very common. 
 
 The functions of the kidneys is to secret urine, :nd 
 that of the bladder to retain it, until the proper time 
 for evacuation. 
 
 Voi.. xr, 22 
 
170 
 
 General Observations. 
 
 The urine may be regarded as an excrementitious 
 fluid, which contains many substances in solution that 
 are constantly found in it, and many others that are 
 occasionally in it, which are taken as aliment or me- 
 dicine, and pass to the bladder with little, if any, 
 change. The odour of the rose leaf, the colour of 
 rhubarb, &c. are occasionally perceived in urine. 
 
 The substances constantly found in urine are nume- 
 rous. THe chemical account of the subject is so long, 
 that it cannot be detailed here ; but the student ought 
 to make himself acquainted with it, and he will read 
 with great advantage Johnson’s History of Animal 
 Chemistry, vol. 2d, page 363 ; and also Thompson’s 
 Elements of Chemistry, page 333. 
 
CHAPTER V. 
 
 OF THE MALE ORGANS OF GENERATION. 
 
 These organs consist, 1st, of the Testicles, and 
 their appendages. 
 
 2d. Of certain parts denominated the Vesiculse 
 Seminales and the Prostate Gland , which are situ- 
 ated near the commencement of the urethra, and are 
 subservient to the purposes of generation. 
 
 3d. Of the Penis. 
 
 SECTION I. 
 
 Of the Testicles and their Appendages „ 
 
 The Testicles are two bodies of a flattened oval 
 form. Each of them has a protuberance on its upper 
 and posterior part called Epididymis , and is connect- 
 ed to parts within the cavity of the abdomen by a 
 thick cord, which proceeds to it through the abdo- 
 minal ring. Each testicle also appears to be contain- 
 ed in a sac, which is suspended by this cord and co- 
 vered by the common integuments. 
 
 That portion of the common integuments which 
 forms the external covering of the testicles, is deno- 
 minated 
 
 The Scrotum . 
 
 The skin of the scrotum, although it is very often 
 in a state of corrugation, has the same structure with 
 that on other parts of the body, except that it is 
 
3 *2 Structure of the Scrotum . 
 
 lather thiner and more delieate. The superior deli- 
 cacy of this portion of the skin is evinced by the great 
 irritation produced by the application of stimulating 
 substances, and the desquamation of the cuticle, which 
 seems to be the effect of irritation. There are many 
 sebaceous follicles in this portion of skin ; and after 
 puberty there are often a few long hairs growing out 
 of it, the bulbs of which are often very conspicuous. 
 There is a small raised line in the middle of this 
 skin, which commences at the root of the penis, and 
 proceeds backwards, dividing it into two equal parts: 
 this line is denominated Raphe. 
 
 The corrugation which so- often takes place in the 
 skin of the scrotum, appears to be occasioned by the 
 contraction of certain fibres, which are in the cellu- 
 lar substance immediately within it. This cellular 
 substance appears to be attached in a particular way 
 to the skin ; and it also invests each testicle in such 
 a manner, that when they are withdrawn a cavity is 
 left in it. It has long been observed, that no adipose 
 matter is found in this cellular substance ; but it is 
 often distended with water in hydropic diseases. 
 As the contraction and corrugation of the scrotum 
 has been imputed to this substance, it has been ex- 
 amined with particular attention by anatomists, and 
 very different sentiments have been entertained re- 
 specting it. While some dissectors have asserted 
 that muscular fibres could be seen in it, which they 
 have denominated the Dartos Muscle ,* others have 
 said that this substance was simply cellular, and 
 without any muscular fibres. This difference of sen- 
 timent may possibly have arisen from the different 
 conditions of this part in different subjects ; for in 
 some cases there are appearances which seem to jus- 
 tify the assertion that muscular fibres exist in this 
 structure. 
 
 After the testicles are removed, so as to leave the 
 
173 
 
 Action of the Dartos Muscle . 
 
 cellular substance connected with the skin, if the scro- 
 tum be inverted, and this substance examined in a 
 strong light, many fibres will appear superadded to 
 the common cellular structure ; and sometimes their 
 colour can be distinguished to be red. It is not as- 
 serted that this will be uniformly the case ; but cer- 
 tainly it has often been observed in this way. 
 
 The existence of an organ which possesses the 
 power of contraction, within the skin of the scrotum 
 and connected to it, is evinced by the corrugation 
 which takes place when the scrotum is suddenly ex- 
 posed to cold, after having been very warm. This 
 corrugation occurs in a very sudden and rapid man- 
 ner, in some cases, in which the wounded scrotum 
 is thus exposed for the purpose of dressing : for ex- 
 ample, upon removing an emollient poultice from 
 this part some days after the operation for the cure 
 of hydrops testis, by incision, if the air of the cham- 
 ber be cool, a motion of the scrotum will take place, 
 almost equal to the peristaltic movements of the in- 
 testines. 
 
 The Arteries of the scrotum are derived from two 
 sources. One or two small arteries, which arise from 
 the femoral artery, between Poupart’s ligament and 
 the origin of the profunda, are spent upon it. These 
 are called the external pudic arteries. It also re- 
 ceives some small branches from the internal pudic 
 artery. 
 
 The Nerves of the scrotum are principally derived 
 from the lumbar nerves. 
 
 The Spermatic Cord. 
 
 The cord which proceeds to the testicle through 
 the abdominal ring, appears at first view like a bun- 
 dle of muscular fibres ; but it consists of an artery 
 and veins, with many lymphatic vessels and nerves, 
 and also the excretory duct of the testicle, connected 
 
174 Cremaster Muscle. —Blood vessels of the Testicle . 
 
 to each other by cellular substance, and covered by 
 an expansion of muscular fibres which are derived 
 from the lower edge of the internal oblique muscle of 
 the abdomen, and continue from it to the upper part 
 of the testicle. These fibres constitute the Cremas- 
 ter Muscle. 
 
 The artery above mentioned is called the Sperma- 
 tic. It commonly arises from the front of the aorta, 
 very near its fellow, at a small distance below the 
 emulgents : and is not much larger than a crow’s 
 quill. It proceeds downwards behind the perito- 
 neum and before the psoas muscle and ureter. — 
 While it is in contact with the psoas muscle, it joins 
 the ramifications of the vein. It afterwards meets 
 the vas deferens, and proceeds through the abdomi- 
 nal ring to the back part of the testis. Before it ar- 
 rives at the testis it divides into several branches, 
 two of which generally go to the epididymis, and the 
 others penetrate the tunica albuginea on the upper 
 and back of the testicle, and ramify very minutely 
 on the fine membranous partitions which exist in that 
 body. 
 
 In addition to the spermatic artery, there is a small 
 twig from the umbilical branch of the hypogastric* 
 which passes to the spermatic cord along the vas de- 
 ferens. 
 
 The branches of the spermatic vein are much larg- 
 er than those of the artery: several of them proceed 
 from the testicle so as to correspond with the arterial 
 branches ; and in addition to these there are many 
 smaller, which also arise from the testicle and epidi- 
 dymis. In their course up the cord they ramify, 
 and again unite, so as to form a considerable plexus, 
 which is called the Corpus Pampiniforme , and con- 
 stitutes a considerable part of the volume of the sper- 
 matic cord. 
 
 As they proceed upwards they unite into a few 
 
Lymphatics and Nerves of the Spermatic Cord. 175 
 
 larger veins ; and finally, on the psoas muscle, they 
 generally form one trunk, which continues upwards 
 so as to unite with the vena cava on the right side, 
 and the emulgent vein on the left. 
 
 Sometimes, but not often, there are several sper- 
 matic veins on each side. 
 
 The Lymphatic Vessels of the testicle are very nu- 
 merous, considering the size of the organ. Six or 
 eight, and sometimes more, large trunks have been 
 injected, running upon the cord, and continuing to 
 the glands on the back part of the abdomen. 
 
 The JYerves of the testicle are derived from those 
 which supply the viscera of the abdomen, and are to 
 be found in the cord although they can scarcely be 
 traced to the testicle. A small plexus, called the 
 spermatic, is formed by fibres from the renal plexus 
 and from the sympathetic nerve. These fibres ac- 
 company the spermatic vessels, and in all probability 
 enter the body of the testis and the epididymis. The 
 spermatic cord and cremaster muscle receive filaments 
 from the second lumbar nerve. 
 
 In addition to these vessels, the Vas Deferens, 
 which is much firmer than either of them, is always 
 to be distinguished in the back part of the cord. 
 
 They are all covered in front and on the sides by 
 the cremaster muscle, which passes with them from 
 the lower margin of the internal oblique, through the 
 abdominal ring, and continues to the upper part of 
 the external coat of the testicle, which is a sac appa- 
 rently containing that organ, and upon this sac it is 
 spread out and terminates. 
 
 The Tunica Vaginalis . 
 
 The External Coat of the testicle, which is com- 
 monly called the Tunica Vaginalis , is a complete 
 sac which encloses the testicle as the pericaridum 
 encloses the heart. It covers the body of the testicle 
 
176 
 
 Coals of the Testicle . 
 
 and epididymis, and adheres closely to them. It is 
 then reflected from them so as to form a loose sac, 
 which appears to contain them. The cavity of the 
 tunica vaginalis commonly extends above the body of 
 the testis up the cord, and is oval or pyriform. — This 
 sac is so reflected from the body of the testicle that 
 there is a place on the upper and back part of that 
 body, at which the blood vessels enter it, without 
 penetrating the sac. 
 
 It resembles the peritoneum and other serous mem- 
 branes in texture, and is therefore thin and delicate. 
 It always contains a quantity of moisture, sufficient to 
 lubricate the surface which it forms. 
 
 When the tunica vaginalis is lain open, the testicle 
 appears as if it were contained in the posterior part 
 of its cavity. 
 
 The testicles, as has been already stated, are of a 
 flattened oval form. Their position is somewhat 
 oblique, so that their upper extremities look upwards 
 and forwards, their lower extremities downwards 
 and backwards, and their edges present forwards and 
 backwards. 
 
 The body of the testicle is very firm, in conse- J 
 quence of its enclosure in a very firm coat called Tu- 
 nica Albuginea. Upon the upper and posterior part 
 of it is the protuberant substance, called Epididymis , 
 which is less firm, being exterior to the tunica albu- 
 ginea. The blood vessels of the testicle pass into it 
 on the posterior edge, at some distance below the 
 upper end. 
 
 The Tunica Albuginea , 
 
 In which the body of the testicle is completely 
 enclosed, is firm and dense ; and upon this coat its 
 particular form depends. It is of a whitish colour, 
 and has a smooth external surface. It is thick as 
 well as strong. The epididymis is exterior to it. 
 
Form and Connexions of the Epididymis . 177 
 
 It is only perforated by the blood vessels, lympha- 
 tics and nerves, and by the vasa efferentia, which 
 carry out the secretion of the testis. One portion of 
 the tunica vaginalis adheres very closely to it, and 
 the other appears to contain it. The portion which 
 adheres to it is with difficulty separated, but it is a 
 distinct membrane. 
 
 The Epididymis. 
 
 Differs in colour from the testicle, being more or 
 less reddish. It commences at the upper and ante- 
 rior extremity of the testicle, and passes down the 
 posterior edge to the lower end. 
 
 At the commencement the epididymis is somewhat 
 rounded in form, and its upper part, or head, has 
 been called the globus major : as it descends it 
 lessens, and about the middle of the testicle it is 
 flatfish. 
 
 It is firmly attached to the body of the testicle, at 
 the upper end, where the vasa efferentia pass to it ; 
 and it is also attached to it below ; but at the middle 
 it appears nearly detached from it. It has therefore 
 been compared to an arch resting with its two extre- 
 mities on the back of the testis ; it is, however, in 
 contact with it at its middle ; but about the middle 
 it only adheres by one of its edges to the body of 
 the testis, and generally by its internal edge. It has 
 a coat which is less firm than the tunica albuginea of 
 the testicle, described on the last page. The tunica 
 vaginalis of the testicle is so reflected as to cover a 
 great part of the epididymis which is not in contact 
 with the testicle, and also those surfaces of the epi- 
 didymis and testis which are in contact with each 
 other and do not adhere. 
 
 The Body of the Testicle. 
 
 When the tunica albuginea is cut through, and 
 the substance of the testicle examined, it appears 
 
 Vol, iio 23 
 
178 Tubuli, Septa and Bloodvessels of the Testicle » 
 
 to consist of a soft pulpy substance of convoluted 
 threads, of a yellowish brown colour, which is divi- 
 ded into separate portions by very delicate septa, at- 
 tached to the internal surface of the tunica albuginea 
 at the posterior part of the testicle. After macera- 
 tion, by using a fine needle to detach them from the 
 cellular substance, these threads may be drawn out to 
 a great length. In some animals they are larger than 
 in the human species ; in them, it is said, they are 
 evidently hollow, and that very small blood vessels 
 appear in their Goats. When mercury is injected 
 into the vas deferens, or excretory duct of the testis, 
 in a retrograde course, it can be perceived in these 
 ducts in the human subject. 
 
 These delicate septa, or partitions, are united to 
 the internal surface of the tunica albuginea at the 
 posterior part of the testicle, at which place there is 
 a body called Corpus Highmorianum, which has 
 been regarded very differently by different anato- 
 mists. It is a long whitish substance* which extends 
 lengthwise on the posterior part of the testis ; and 
 was supposed by Haller to resemble one of the sali- 
 vary ducts. It is now, however, generally agreed to 
 be of a cellular structure, and to contain and support 
 the ducts which pass from the substance of the testi- 
 cle to the epididymis. 
 
 The blood vessels pass into the body of the testi- 
 cle upon these septa, and are continued from them to 
 the filaments or tubes of which the body of the testi- 
 cle consists. As in some animals blood vessels are 
 distinguished on these tubes, there is the greatest 
 reason to believe that a direct communication sub- 
 sists between them, without the intervention of any 
 other structure, no other structure having been dis- 
 covered : but at the same time it ought to be obser- 
 ved, that these tubes have not yet been injected from 
 the blood vessels. Some ingenious anatomists have 
 
Blood vessels and Structure of the Testicle, fyc. 179 
 
 injected the artery going to the testicle so success- 
 fully, that the injection has passed from it into the 
 veins coming out of the testicle ; but it is not now 
 said by any of them, that they have filled the tubes 
 in this manner. 
 
 Mercury will pass into these vessels from the ex- 
 cretory duct of the testicle ; and by means of an in- 
 jection in that way, the structure of the testiele can 
 
 be unravelled. 
 
 'this structure is as follows : The cavity formed 
 by the tunica albuginea is divided into a number of 
 apartments by the very thin septa, or partitions, 
 above mentioned. From the filamentary or tubular 
 matter which fills each of these chambers, proceeds 
 a number of small tubes or vessels, which observe a 
 straight course ; they are therefore called Vasa Recta . 
 These vasa recta unite with each other and form a 
 net-work on the back of the testis, within the tunica 
 albuginea, which is called Rete Testis. From this 
 net-work other vessels, from twelve to eighteen in 
 number, denominated Vasa Ejferentia , proceed 
 through the albuginea to the epididymis. These 
 vessels are convoluted in such a manner as to form 
 bundles of a conical form, which are called Coni 
 Vasculosi. The number of these corresponds with 
 the number of the vasa efferentia, and they com- 
 pose about one third of the epididymis, viz. all the 
 upper part of it. The single tubes which form each 
 of these cones, successively unite into one duct, which 
 is convoluted so as to form all the remainder of the 
 epididymis. The lower part of the epididymis is 
 turned upwards on the back of the testicle, the tube 
 gradually enlarges and is less convoluted, and finally 
 becomes straight : it then takes the name of Vas De- 
 ferens , and continues on the back of the testicle and 
 
ISO Course of the Vas Deferens. 
 
 at the inner side of the epididymis to the spermatic 
 cord.*f 
 
 A small solitary vessel or duct, has been observed 
 by Haller, Monro, and several other anatomists, to 
 proceed from the upper part of the epididymis : 
 sometimes it Unites to the epididymis below, and 
 sometimes it proceeds upwards. The nature of- this 
 vessel has not been ascertained with certainty. 
 
 The Vas Deferens 
 
 Is a very firm tube about one line in diameter, 
 which is not perfectly cylindrical exteriorly, although 
 the cavity formed by it is so. This cavity is so small 
 in diameter, that it will only admit a fine bristle. 
 The coats of the duct have, of course, a considera- 
 ble thickness. The internal coat forms a soft sur- 
 face, analogous to that of the mucous membranes : 
 the external is firm, and its texture resembles that 
 of cartilage. Owing to the small size of the cavity, 
 the internal coat has not been separated from the ex- 
 ternal. 
 
 * De Graff appears to have been the first anatomist who made much 
 progress in the successful investigation of the structure of the testicle ; 
 and Haller ought to be mentioned next to him, on account of the plate ex- 
 hibiting this structure, and the explanation of it, which he published in the 
 Philosophical transactions of London, for 1749. This plate has been re- 
 published by the second Monro, in the Literary and Physical Essays of 
 Edinburgh, and also in his Inaugural Thesis. Haller has likewise repub- 
 lished it in his Opera Minora. It represents not only the vasa efferentia 
 and the cones formed by their convolutions, but also the rete testis and the 
 vasa recta. Haller could inject no further than this ; but Monro and 
 Hunter soon after succeeded so as to fill a considerable portion of the body 
 of the testicle with mercury, injected by the vas deferens. 
 
 f In Mr. Charles Bell’s Anatomical collection in London, there is a pre- 
 paration by his assistant, Mr. Shaw, in which the tubuli testis are com- 
 pletely injected with quicksilver and unravelled. I saw also in Leyden, 
 one nearly as successfully executed by Professor Sandifort.' — E d. 
 
181 
 
 Course of the Vas Deferens. 
 
 It passes upwards in the posterior part of the 
 spermatic cord, and continues with it through the 
 abdominal ring, under and exterior to the perito- 
 neum ; soon after this it leaves the cord and dips 
 down into the cavity of the pelvis, forming a curve 
 on the side of the bladder, and proceeding back- 
 wards, downwards and inwards. In this course it 
 crosses the ureter, and passes between it and the 
 bladder. On the lower part of the bladder the two 
 vasa deferentia approach each other so gradually, 
 that they appear to be nearly parallel. They pro- 
 ceed forward between the vesiculse seminales, which 
 are two bodies irregularly convoluted, that are placed 
 in a converging position with respect to each other, 
 and communicate with the vasa deferentia. The 
 vasa deferentia finally terminate almost in contact 
 with each other in the posterior part of the prostate 
 gland, where they perforate the urethra. At the 
 distance of about two inches and a half from their 
 termination they enlarge in diameter, and become 
 somewhat convoluted. At the posterior margin of 
 the prostate they, come in contact with the anterior 
 extremities of the vesiculse seminales, and unite with 
 them. After this union they diminish in size, and 
 become conical ; and passing a short distance through 
 the substance of the prostate, during which they ap- 
 proach each other more rapidly, they penetrate the 
 urethra, so as. to open in it on each side of a small 
 tubercle, called the Caput Gallinaginis } seon to be 
 described. 
 
 SECTION II, 
 
 . Of the Vesiculse Seminales and the Prostate Glands 
 
 The Vesiculse Seminales are two bodies of a 
 whitish colour, and irregular form, being broad and 
 flat at their posterior extremities, and terminating in 
 
182 Structure of the Vesiculse Siminaies , 
 
 a point at the other. Their surfaces are so convo- 
 luted, that they have been compared to those of the 
 brain. They are situated between the rectum and 
 bladder, and are connected to each by cellular mem- 
 brane. 
 
 When the vesiculse seminales are laid open by an 
 incision, they appear to consist of cells of a consider- 
 able size, irregularly arranged ; but when they are 
 carefully examined exteriorly, and the cellular mem- 
 brane about them is detached and divided, they ap- 
 pear to be formed by a tube of rather more than two 
 lines diameter, and several inches in length, which 
 terminates, like the caecum, in a closed extremity.? — * 
 From this tube proceed from ten to fifteen short 
 branches, which are closed in the same manner.-— 
 All these tubes are convoluted so as to assume the 
 form of the visiculm seminales above described ; and 
 they are fixed in this convoluted state by cellular 
 membrane, which firmly connects their different parts 
 to each other. It is obvious, that tubes thus convo- 
 luted, when cut into, will exhibit the appearance of 
 cells, as in the present instance. 
 
 This convoluted tube composing the vesiculse se- 3 
 minales, terminates in a very short duct, which is 
 nearly of the same diameter with the vas deferens, 
 and this duct joins the vas deferens so as to form an' 
 acute angle. 
 
 From the union of the vesicylss seminales with the 
 vas deferens on each side, a canal, which seems to 
 be the continuation of the vas deferens, proceeds i 
 through part of the prostate to the urethra, which it 
 perforates. These canals are from eight to twelve 
 lines in length ; they are conical in form, their 3 
 largest extremity being equal to the vas deferens at ' 1 
 that part. 
 
 If air or any other fluid be injected through the 
 vas deferens into the urethra, it will pass at the same 
 
Function of the Vesieulse Seminales . 183 
 
 time into the vesieulse seminales, and distend them. 
 It has been observed, that a fluid passes in this man- 
 ner much more readily from the vasa deferentia into 
 the vesieulae seminales, than it does from these last 
 mentioned organs into the duct. 
 
 These organs were generally regarded as reservoirs 
 of semen, and analogous to the gall bladder in their 
 functions, until the late Mr. J. Hunter published his 
 opinion that they were not intended to contain semen, 
 but to secrete a peculiar mucous subservient to the 
 purposes of generation. 
 
 He states the following facts in support of his opin- 
 ion. 
 
 A fluid, very different from semen, is found after 
 death in the vesieulse seminales. 
 
 In persons who have lost one testicle, a consider- 
 able time before death, the vesieulse seminales on 
 each side are equally distended with this peculiar 
 fluid. In the case of a person who had a deficiency 
 of the epididymis on one side and of the vas deferens 
 on the other, the vesieulse were filled with their pe- 
 culiar fluid S 
 
 The sensation arising from redundance of the se- 
 cretion of the testes, is referred to the testes, and 
 not to the vesieulse seminales. 
 
 In some animals there is no connexion between 
 the vasa deferentia and the vesieulae seminales. 
 
 See Observations on certain parts of the Animal 
 Economy, by John Hunter*. 
 
 The Prostate Gland. 
 
 Is situated on the under and posterior part of the 
 neck of the bladder, so as to surround the urethra. 
 Its form has some resemblance to that of the ches- 
 nut, but it has a notch on the basis like that of the 
 figure of the heart on playing cards, and it is much 
 larger than the chesnufc of this part of America,, 
 
184 Prostate Gland.* — The Penis. 
 
 The basis of this body is posterior, and its apex an- 
 terior; its position is oblique, between the rectum and 
 the symphisis pubis. Below there is in some cases a 
 small furrow, which, in addition to the notch above, 
 gives to the gland an appearance of being divided into 
 two lobes. By turning away the vesicul® seminales 
 and vasa deferentia from the under surface of the 
 bladder we bring into view a small tubercle at the 
 upper part of the base of the prostate, called by Sir 
 Everard Home the third lobe. When diseased it 
 projects into the cavity of the bladder. 
 
 It adheres to the urethra and neck of the bladder. 
 Its consistence is very firm and dense, resembling the 
 induration of scirrhus rather more than the ordinary, 
 texture of glands. 
 
 This gland receives small branches from the neigh- 
 bouring blood vessels, and has no artery of consider- 
 able size exclusively appropriated to it. 
 
 As it lies in close contact with the urethra, the 
 ducts which pass between it and the urethra are not 
 to be seen separate from these bodies ; but ducts can 
 be seen in the substance of the gland, which perfo- 
 rate the urethra, and open on the sides of the caput 
 gallinaginis to the number of five or six on each side. 
 By pressure a small quantity of a whitish fluid can 
 be forced from these orifices, which is rather viscid, 
 and coagulable in alcohol. 
 
 The particular use of this fluid is not known. 
 
 SECTION III. 
 
 Of the Penis . 
 
 The penis, when detached from the bladder, and 
 the bones, to which it is connected, and divested of 
 the skin which covers it, is an oblong body, which 
 is rounded at one extremity and bifurcated at the 
 
 other. 
 
Perns. 1&5 
 
 It is composed of three parts, viz two oblong bo- 
 dies, called Corpora Cavernosa , which, at their com- 
 mencement, form the bifurcated portions, and then 
 unite to compose the body of the organ ; and a third 
 part, of a spongy texture, which is connected to these 
 bodies where they unite to each other, on the under 
 side, and continues attached to them during the whole 
 extent of their union, terminating in an expanded 
 head which covers the anterior extremities of the 
 corpora cavernosa. The urethra passes from the 
 neck of the bladder, on the under side of the penis, 
 to its anterior extremity, invested by this third body, 
 which is therefore called Corpus Spongiosum Ure- 
 thrae . 
 
 The two bifurcated extremities are attached each 
 of them to one of the crura of the pubis and ischium ; 
 and they unite to form the body of the penis imme- 
 diately anterior to the symphisis pubis, to which the 
 lower part of it is also attached ; so that the penis is 
 firmly connected to the middle of the anterior part of 
 the pelvis. The urethra proceeds from the neck of 
 the bladder, between the crura of the ischium and 
 pubis and the crura of the penis, to join the body of 
 the penis at its commencement, and near this place 
 its connexion with the corpus spongiosum begins; so 
 that there is a small portion of the urethra between 
 the neck of the bladder and the commencement of the 
 corpus spongiosum, which is not covered by the cor- 
 pus spongiosum. This is called the membranous part 
 of the urethra. 
 
 The penis, therefore, consists of two oblong bo- 
 dies of a cellular structure, which originate separate- 
 ly, but unite together to form it ; and of the urethra, 
 which joins these bodies immediately after their 
 union, an$ is invested by a spongy covering, which 
 by its expansion forms the anterior extremity not 
 . only of the urethra but of the whole penis. These 
 
 Vol, ii. 24 
 
186 Corpora , Cavernosa Penis . 
 
 three bodies, thus arranged and connected, are cover* 
 ed by cellular membrane and skin in a manner to be 
 hereafter described. 
 
 The Corpora Cavernosa , 
 
 Which compose the body of the penis, are two ir- 
 regular cylinders, that are formed by a thick dense 
 elastic membrane, of a whitish ligamentous appear- 
 ance and great firmness. They are filled with a sub- 
 stance of a cellular structure, which is occasionally 
 distended with blood. The crura of these cylindri- 
 cal bodies, which are attached to the crura of the 
 ischium and pubis, are small and pointed at the com- 
 mencement, and are united to the periosteum of the 
 bones. In their progress upwards they enlarge, and 
 at the symphisis of the pubis they unite so as to form 
 an oblong body, which retains the appearance of a 
 union of two cylinders applied to each other length- 
 ways ; for above there is a superficial groove passing" 
 in that direction, which is occupied by a large vein : 
 and below there is a much deeper groove, in which 
 the urethra is placed. Between these grooves is a 
 septum which divides one side of the penis from the 
 other. It appears to proceed from the strong mem- 
 brane which forms the penis, and is composed of 
 bundles of fibres, which pass from one groove of the 
 penis to the other, with many intervals between them, 
 through which blood or injection passes very freely. 
 Sometimes these bundles of fibres, with their inter- 
 vals, are so regularly arranged, that they have been 
 compared to the teeth of a comb. This septum ex- 
 tends from the union of the two crura to their termi- ;i 
 nation. 
 
 Each of these cylinders is penetrated by the main 
 branch of the pudic artery, which is about equal in 
 size to a crow’s quill. These arteries enter the cor- 
 pora cavernosa near their union, and continue 
 
181 
 
 Cells of the Corpora Cavernosa „ 
 
 through their whole extent, sending off branches in 
 their course ; the turgeseence and erection of the penis 
 is unquestionably produced by the blood which flows 
 through these vessels into the penis. 
 
 The interior structure of the penis, when examined 
 in the recent subject, is of a soft spongy nature, and 
 seems stained with blood. If any fluid be injected 
 through the arteries this substance appears cellular, 
 and may be completely distended by it. When air 
 is injected, and the structure becomes dry, the penis 
 may be laid open ; the cellular structure then appears 
 as if formed by a number of lamina and of filaments, 
 which proceed from one part of the internal surface 
 of the penis to another, and form irregular cells. It 
 has been compared to thq lattice-work in the interior 
 of bones j "and it is suggested by M. Roux, that the 
 fibres of which the structure consists resemble those 
 of the strong elastic coat of the penis.* If these cells 
 are filled with coloured wax, injected by the artery, 
 and the animal substance is then destroyed by placing 
 the preparation in a corroding liquor, the wax which 
 remains shows that the membranes forming the cells 
 are very thin. 
 
 These cells communicate freely with tfeaeh other ; 
 and therefore, if a pipe be passed through the strong 
 coat of the penis, the whole of them can be filled from 
 it by the ordinary process of injection. 
 
 * Mr. John Hunter says on this subject, “ That the cells of the corpora 
 cavernosa are muscular, although no such appearance is to be observed in 
 men ; for the penis in erection is not at all times equally distended. Tke 
 penis, in a cold day, is not so large in erection as in a warm one : which 
 probably arises from a kind of spasm, that could not act if it were not mus= 
 eular. 
 
 In the horse, the parts composing the cells of the penis appear evident- 
 ly muscular to the eye, and in a horse just killed, they contract upon being 
 stimulated.”— E d. 
 
188 
 
 Corpus Spongiosum.— Bulb, 
 
 The Urethra. 
 
 Is a membranous canal, which extends from the 
 neck of the bladder to the orifice at the extremity of 
 the penis ; and for a very great part of its length is 
 invested by a spongy structure, called the corpus 
 spongiosum urethrae. It proceeds from the neck of 
 the bladder along the upper part of the prostate; 
 from the prostate it continues between the crura of 
 the penis until their junction: it then occupies the 
 great groove formed by the corpora cavernosa on the 
 lower side of the penis, and continues to the orifice 
 above mentioned. At a small distance from the pros- 
 tate gland the spongy substance which invests it com- 
 mences, and continues to its termination. After this 
 spongy substance has arrived at the termination of 
 the corpora cavernosa, it expands and forms a body 
 of a particular figure which covers the extremities 
 of the corpora cavernosa, and is denominated the 
 Gians Penis. 
 
 The Corpus Spongiosum begins at the distance of 
 eight or ten lines from the anterior part of the pros- 
 tate.* It is much larger at its commencement than at 
 any other part except the glans, and this enlarged 
 part is called the Bulb. It surrounds the whole of 
 the urethra, and with the exception Of the bulb and 
 the glans penis, is of a cylindrical figure. It is form- 
 ed by a membrane which has some resemblance to the 
 coat of the penis, but is much thinner, and by a pe- 
 culiar spongy substance, which occupies the space be- 
 tween the internal surface of this membrane and the 
 external surface of the canal of the urethra. The 
 membrane and the spongy substance, form a coat to 
 the urethra, which, with the exception of the enlarge- 
 ment before mentioned, is about one line thick. After 
 this spongy substance has arrived at the termination,, 
 its coat adheres firmiy to the coat of the penis. 
 
Structure of the Corpus Spongiosum. 189 
 
 The Bulb, or first enlargement of the corpus spon- 
 giosum, is oblong, and rather oval in form ; it is mark- 
 ed by a longitudinal depression in the middle, which 
 is very superficial. It consists entirely of the spongy 
 substance above mentioned. 
 
 The Gians Penis is also composed of the same 
 spongy substance, but the coat which covers it is 
 more thin and delicate than that of the other parts of 
 the urethra. The lower surface of the glans is fitted 
 to' the extremities of the corpora cavernosa, but it is 
 broader than the corpora cavernosa, and therefore 
 projects over them on the upper and lateral parts of 
 the surface of the penis. The edge of the promi- 
 nent part is regularly rounded, and is denominated 
 the Corona Glandis. 
 
 Several small arteries pass to this spongy structure. 
 The pudic artery, as it passes on each side to the cor- 
 pora cavernosa, sends a branch to the bulb of the 
 urethra. The same vessel in the substance of the 
 penis, also sends branches to the urethra : and the 
 artery on the back of the penis terminates in small 
 branches, which penetrate the substance of the glans. 
 
 By these vessels blood is carried to the spongy 
 substance of the urethra, which is occasionally dis- 
 tended in the same manner that the cavernous bodies 
 of the penis are distended during the erection of that 
 organ. But the cellular structure, of this organ is 
 not so unequivocal as that of the corpora cavernosa ; 
 for if it be injected with coloured wax, and corroded 
 in the usual manner, the injected matter will exhibit 
 an appearance which has the strongest resemblance 
 to a convoluted vessel, like the vas deferens in the 
 epididymis.* 
 
 * Mr. Hunter says, “ that the corpus spongiosum urethrse and glans 
 penis are not spongy or cellular, but made up of a plexus of veins. This 
 structure is discernible in the human subject ; but is much more distinctly 
 sees, in many animals, as the horse,” &e — - Ep. 
 
190 
 
 Internal Surface of the Urethra . 
 
 The Canal of the Urethra , 
 
 Which conveys the urine from the bladder, is a very 
 important part of the urinary organs. It consists of 
 a vascular membrane with a smooth surface, which is 
 perforated by the qrifices of many mucous follicles, 
 some of which are of considerable size. It is ex- 
 tremely sensible, and has so much power of contrac- 
 tion, that some persons have supposed muscular 
 fibres to exist in its structure. 
 
 It is dilferently circumstanced in different parts of 
 its course. While surrounded with the prostate it ad- 
 heres firmly to that body, seeming to be supported by 
 it ; and here its diameter is larger than it is farther 
 forward. On the lower or posterior side of this por- 
 tion of the urethra, is an oblong eminence, called 
 Verumontanum, or Caput Cfallinaginis , which com- 
 mences at the orifice of the urethra, and continues 
 throughout the whole portion that is surrounded by 
 the prostate gland, terminating at the point of that 
 body. The posterior extremity of this tubercle begins 
 abrupt^, and soon becomes thick and large ; ante- 
 riorly it gradually diminishes to a line, which is some- 
 times perceptible for a considerable distance in the 
 urethra, in a straight forward direction. In the upper 
 edge or top of this body is a groove, which ‘is produced 
 by a mucous follicle ; on the lateral surfaces, anterior 
 to the middle, are the orifices of the common ducts of 
 the vesiculse seminales and vasa deferentia, (see page 
 182,) which are sufficiently large to receive a thick 
 bristle. N ear these, on each side, are five or six smaller 
 orifices of the excretory ducts of the prostate gland. 
 At the distance of an inch before the extremity of the 
 bulb of the urethra, in the lining membrane, are the 
 openings of two ducts, one on each side, that lead to 
 small glandular bodies called Cowper’s glands, which 
 are situated on each side of the urethra below the bulb, 
 but are covered bv the accelerator es urinse muscles. 
 
 v <• 
 
191 
 
 Mucous Ducts of the Urethra. 
 
 The diameter of the urethra lessens after it leaves 
 the prostate. That portion of the canal which is be- 
 tween this gland and the bulb, without investment, 
 and therefore called the membranous part, is the 
 smallest in diameter. 
 
 After it is invested with the spongy substance, it 
 has a small enlargement, and then continues nearly 
 of one size, until it arrives near the glans penis, when 
 it again enlarges and alters its form, being no longer 
 cylindrical but flattened. Its broad surfaces have 
 now a lateral aspect. 
 
 From the bulb of the corpus spongiosum to this 
 last enlargement, the appearance of the inner surface 
 of the urethra is uniform. The membrane is thin 
 and delicate, and in a healthy subject, who has been 
 free from disease of these parts, is of a whitish co- 
 lour ; but blood vessels are very perceptible in it. 
 When it is relaxed, it appears to be thrown into 
 longitudinal wrinkles; but it admits of considerable 
 extension, being somewhat elastic : when extended, 
 its surface, appears smooth, as if it were covered 
 with an .epithelium. Mr. Shaw, of London, has 
 described a set of vessels immediately below the in- 
 ternal membrane of the urethra, which, when empty, 
 are very similar in appearance to muscular fibres.— 
 He says he has discovered that these vessels form 
 an internal spongy body, which passes down to the 
 membranous .part of the urethra, and forms even a 
 small bulb there. His preparation with a quicksilver 
 injection of the part is certainly a very satisfactory 
 proof of its existence.* Throughout the whole ex- 
 tent of this part of the' urethra, are the orifices of a 
 great many mucous ducts or sinuses, which pass 
 obliquely backwards. Many of these are so small 
 that they cannot be penetrated by a bristle, or probe 
 
 * Sea Sled, Clururg—Tfansactions of Londca— vol 10th. 
 
192 Mucous Dads of the Urethra a 
 
 of that size; but some are larger. It has not been 
 observed that any glandular body immediately sur- 
 rounds them, although they secrete the mucous with 
 which the urethra is lubricated. — On the lower side 
 of the urethra, near the commencement of the glans 
 penis, there is one or more of them, so large that 
 their orifices sometimes admit the point of a small 
 bougie.* 
 
 These organs, when inflamed, secrete the puriform 
 discharge which takes place in gonorrhoea. — In a na- 
 tural state they produce 'the mucous which is con* 
 stantly spread over the surface of the urethra, to de- 
 fend it from the acrimony of the urine, and which 
 passes away with that fluid unperceived. 
 
 The surface of the urethra is endued with great 
 sensibility, and is therefore liable to great irritation 
 from contact with any rough body or any acrid sub- 
 stance. Irritation, thus excited, induces a state of 
 contraction, which is particularly remarkable, as no 
 muscular fibres are to be seen in its structure. — When 
 a bougie has been passed into the urethra for a consi- 
 derable distance, if it cannot proceed the whole way, 
 it sometimes happens that the instrument will be dis- 
 charged by a steady uniform motion, which seems to 
 proceed from a progressive contraction of the urethra, 
 beginning very low down. At particular times, after 
 the urethra has been much irritated, it will not receive 
 a bougie, although at other times a bougie of equal 
 size may be passed to the bladder without opposition. 
 This cannot depend upon that elasticity which was 
 noticed before. f 
 
 * They were discovered by Plazzoni, of Padua, in 1621. Their number, 
 according to Loder, amounts to about 65 — See his plates. Ed. 
 
 f Sir Everard Home, whose professional opinions are of' great weight, 
 has lately described in the Transactions of the Royal Society, the appear- 
 ance of the lining membrane of the Urethra, when viewed through a 
 
Contractile Power of the Vrethra . 19J 
 
 Upon the two crura of the penis, or the beginning 
 of the corpora cavernosa, are fixed the muscles call- 
 ed Ereetores Penis, which are described in the first 
 volume.* These muscles cover the crura of the 
 penis from their origin to their junction, and not 
 only compress them, but also influence the motion oi 
 the penis when it is distended. 
 
 The bulb of the urethra is covered by a muscular 
 coat, called the Accelerator Urinse * which has the 
 effect of driving forwards any fluid contained in the 
 cavity of the urethra, and also of giving the same 
 direction to the blood in that part of the corpus 
 spongiosum. There is also the Transversus Perinei 
 on each side, that passes transversely from the tube- 
 rosity of the ischium to the bulb of the urethra.— 
 Finally the lower part of the sphincter ani muscle, 
 which is nearly elliptical in form is inserted by its 
 anterior point into the muscular covering of the bulb 
 of the urethra. Upon removing the integuments, 
 these muscles are in view ; and the course of the 
 urethra from the bladder is concealed, particularly 
 by the anterior point of the sphincter ani. When 
 the sphincter ani is dissected away from its anterior 
 connexions, and the cellular and adipose substance, 
 which is sometimes very abundant, is also removed, 
 the lower surface of the membranous part of the 
 urethra may be brought into view, as it proceeds 
 from the prostate gland to the balb of the corpus 
 spongiosum.f 
 
 microscope of great powers. From this paper it seems that he is full/ 
 convinced of its muscular structure. — E d. 
 
 * See description of “ Muscles about the Male Organs of Generation,' 
 Vol. I. Part II. Chap. II. 
 
 t The natural situation of the membranous part of the urethra, and of 
 the prostate gland, as well as their relative position with respect to the 
 sphincter ani, rectum, &c. can be best stadied by a lateral view of the 
 
 Tol, ii, 25 
 
194 Contractile Power of the Urethra . 
 
 When the accelerator u rinse is removed from the 
 bulb of the urethra, there will appear two bodies, 
 which have some resemblance to flattened peas. 
 They lie one on each side of the urethra, in contact 
 or nearly so with its bulb, and from each gland pro- 
 ceeds an excretory duct of an inch and a quarter in 
 length, between the corpus spongiosum and the lining 
 membrane of the canal of the urethra, and opens into 
 the latter. Its orifice is found with some difficulty, 
 but is large enough to admit a bristle. These are 
 Cowper’s glands.^ 
 
 The penis is connected to the symphisis pubis by 
 a ligamentous substance, which proceeds from the 
 back or upper surface of the organ to the anterior 
 part of the symphisis, and connects these parts firm- 
 ly to each other. 
 
 Thus constructed, of the corpora cavernosa and 
 the urethra with its corpus spongiosum, and attach- 
 ed to the pelvis as above mentioned, the penis is in- 
 vested with its integuments in the following man- 
 ner, f 
 
 contents of the pelvis ; which is to be obtained by removing carefully 
 one of the ossa innominata, and dissecting the parts which were enclosed 
 by it. 
 
 * These glands were discovered by Mery, in 1684, and described by 
 Cowper, in 1699. A third gland, smaller than the preceding, connected 
 with the curve of the urethra under the symphisis pubis, was discovered by 
 Cowper, and Morgagni speaks of having observed a fourth. — Ed. 
 
 t There are several fasciae and ligaments about the perineum which 
 should be connected with the account of its viscera. Immediately beneath 
 the skin of the perineum is the Perineal Fascia, a thin but strong mem- 
 brane, which extends from bone to bone, occupying the space between 
 the anus and the posterior part of the scrotum. It is rather better seen in 
 lean subjects than in fat ones, for in the latter it is converted in part into 
 adipose membrane. When a rupture occurs in the posterior part of 
 the urethra, this fascia prevents the urine from showing itself immedi- 
 ately in the perineum, and drives it into the cellular structure of the 
 scrotum. 
 
 Immediately beneath the perineal faseia are placed the muscles ; when 
 they are removed the bulb of the urethra may be seen very advantage- 
 ously; extending in the middle of the perineum almost to the anus. It is 
 
Integuments of the Penis . 
 
 195 
 
 Integuments of the Penis . 
 
 The glans penis, the structure of which has been 
 already described, is covered by a continuation of 
 the skin, which appears altered in its texture so as 
 to resemble in some respects the skin of the lips, and 
 in like manner is covered by a delicate production 
 of cuticle. 
 
 Around the corona of the glans, especially on its 
 upper part, there are whitish tubercles, which are of 
 different sizes in different persons, but always very 
 small. The skin adheres firmly to the whole extent 
 of the corona of the glans, and is very delicate in its 
 structure as it continues from the glans upon the 
 body of the penis ; but it gradually changes so as to 
 assume the appearance and structure of a common 
 skin, and continues in this state over the penis. The 
 adhesion of the skin to the ligamentous coat of the 
 corpora cavernosa also becomes more loose, owing 
 to the quantity and texture of the cellular substance 
 which connects them. The skin thus connected to 
 the penis, has commonly more length than that or- 
 gan, even in its extended state. In consequence of 
 this greater length, and of its adhering firmly around 
 the corona glandis, it necessarily forms a circular 
 
 not loose and pendulous, but is attached by its pelvic surface to the trian- 
 gular ligament of the urethra. This ligament is a septum between the 
 perineum and the pelvis, and connects itself to the pelvic or internal 
 edges of the rami of the pubis and ischii as far down as the organs of the 
 crura penis. It extends from the arch of the pubis to the line mentioned, 
 and fills up all the space between the bones of the opposite sides. It 
 consists of two lamina, and Cowper’s glands are placed between them. 
 About an inch below the symphisis pubis a perforation is made in this lig- 
 ament for the passage of the membranous part of the urethra. 
 
 Just below the symphisis pubis, between the two lamina of the triangu- 
 lar ligament, is placed a much stronger ligament called the pubic, which is 
 about half an inch broad, its lower edge is thick and rounded. For further 
 detail on the subject of the:fasciae of the pelvis see Lessons in Practical 
 Anatomy by the present editor.— Ep. 
 
A 96 Integuments of the Penis, 
 
 fold or plait, which varies in size according to the 
 length of the skin. This fold is generally situated at 
 the commencement of the firm attachment of the skin 
 to the body of the penis, or around the glans; but it 
 may be formed any where upon the body of the penis 
 by artificial management. 
 
 This duplicature, or fold of the skin, when it takes 
 place so as to cover the glans, is called the Prepuce ; 
 and the skin which is very tender and delicate for 
 some distance from the glans, form that surface of the 
 prepuce which is in contact with the glans when it 
 covers that body. 
 
 There is also a small fold of the skin, which is 
 longitudinal in its direction, that commences at the 
 orifice of the urethra, and extends backwards, on the 
 lower surface of the penis. It is unvarying in its 
 position, and is called the Frenum. 
 
 It is a general observation, that adeps is not found 
 in the cellular substance which connects the skin to 
 the body of the penis ; but this cellular substance is 
 distended with water in some hydropic cases. 
 
 From the skin immediately below the glans, and 
 from small follicles on each side of the frenum, is 
 secreted an unctuous fluid, which, when allowed to 
 continue, becomes inspissated, and acquires a caseous 
 consistence and colour, as well as a peculiar odour. 
 It sometimes also acquires an acrimony which produ- 
 ces inflammation on the surface with which it is in 
 contact, as well as the copious seeretion of puriform 
 fluid. 
 
 The distribution of the pudic artery in the penis, 
 has already been mentioned; and a further account 
 of its origin and progress to its destination, will be 
 found in the general account of the arteries. Some- 
 times small branches of the external pudic arteries, 
 which originate from the femoral, are extended to 
 the penis; and it has been asserted, that branches of 
 
Blood Vessels and Absorbents of the Penis . 19/ 
 
 the middle hsemorrhoidal artery have also been found 
 there, but this does not often occur. 
 
 The Veins of the penis are of two kinds : those 
 which originate in the corpora cavernosa, accompany 
 the corresponding branches of the pudic artery, but 
 communicate more or less with the plexus of veins 
 on the lower and lateral part of the bladder. There 
 is also a great vein, which occupies the groove on 
 the back of the penis, between the corpora caver- 
 nosa, that appears particularly appropriated to the 
 corpus spongiosum urethrae ; for it originates in the 
 glans penis, and receives branches from the urethra 
 as it proceeds backwards. There are often two of 
 these veins, one in the groove, and the other more 
 superficial : they generally unite near the root of the 
 penis. The common trunk then passes between the 
 body of the penis and the symphisis pubis, and ter- 
 minates in a plexus of veins at the neck of the blad- 
 der, which is connected to the plexus above men- 
 tioned on the lower and lateral parts of the same 
 viscus. 
 
 The Absorbent Vessels of the penis take two differ- 
 ent directions on each side. Those which arise from 
 the integuments generally, unite so as to form a few 
 trunks on the back of the penis, which divide near 
 the root of the organ, and proceed to the glands of 
 the groin. Those which originate from the interior 
 parts of the penis, accompany the blood vessels, and 
 terminate in the plexus of lymphatics in the pelvis. 
 
 It ought to be noted, that the superficial lympha- 
 tics generally enter the upper inguinal glands. 
 
 The JYerves of the penis are principally derived 
 from the lower secral nerves, which unite in the 
 plexus that forms the great ischiatic. From these 
 nerves a branch on each side originates, which passes 
 like the pudic artery, between the sacro-sciatic liga- 
 ments. In this course it divides into two branches, one 
 
198 
 
 JVerves. -^General Observations. 
 
 of which passes below to the museles of the penis and 
 urethra, and to the contiguous parts ; and some of 
 its branches seem finally to terminate in the dartos : 
 the other branch proceeds along the crura of the pu- 
 bis and ischium, and passing between the symphisis 
 pubis and the body of the penis, arrives at the upper 
 surface or dorsum of the penis, along which it conti- 
 nues on the outside of the veins to the glans, in which 
 it terminates. In this course it sends off several 
 branches, some of which terminate in the integuments 
 of the penis. 
 
 After an examination of the relative situation of the mus- 
 cles and blood vessels of the male organs of genaration, 
 there appears reason to doubt, whether the erection of 
 the penis can be referred to pressure upon the veins 
 which return from that organ. Albinus has written on 
 this subject. See Academicarum Annotationum, lib. 
 ii. caput xviii. Haller has also considered it, and 
 stated the opinions of several anatomists, in bis Ele- 
 menta Physiologiae, tom. vii. page 555. 
 
 The manner in which the urine is confined in the blad- 
 der does not appear to be clearly understood. The 
 connexion of the neck of the bladder with the prostate, 
 and the appearance of the contiguous parts of the blad- 
 der, do not render it probable that these parts act like 
 a sphincter. The late J. Hunter, who paid great at- 
 tention to the functions of these organs, was very de- 
 cided in his opinion that the contraction of the urethra 
 
 I iroduced the effect of a sphincter of the bladder. He 
 las published some very ingenious observations respect- 
 ing the manner in which urine is discharged from the 
 bladder, in his Treatise on the Venereal Disease, part 
 III. chapter IX. 
 
 Mr. Hunter also long since asserted, that the vascular 
 convoluted appearance of the corpus spongiosum ure- 
 thrae was more distinct in the horse than the man. In 
 the fifth volume of the Lemons d’Anatomie Comparee 
 of Cuvier, the very learned and ingenious author con- 
 firms the declaration of Hunter, respecting the vascu- 
 lar convolutions of the corpus spongiosum of the horse. 
 He states, that the corpora cavernosa of the penis of 
 the elephant appear to be filled in a great degree with 
 
General Observations . 
 
 199 
 
 the ramifications of veins, which communicate with each 
 other by such large and frequent anastomoses, that they 
 have a cellular appearance. A similar structure exists 
 in the horse, camel, bullock, deer, &c. and in them all 
 these communicating branches can be distinguished 
 from those which extend the whole length of the penis. 
 
 The corpus spongiosum urethrae, according to M. Cu- 
 vier, is constructed in a similar manner. From these 
 facts he is induced to believe that this structure per- 
 vades the whole class of mammalia. 
 
CHAPTER VL 
 
 OF THE FEMALE ORGANS OF GENERATION, 
 
 The female organs of generation consist of the 
 Uterus and Ovaries , with their appendages ; and of 
 the Vagina , with the structure which surrounds its 
 external orifice. The uterus is situated in the pelvis, 
 between the bladder and rectum ; and the ovaries 
 are on each side of it. The vagina is a very large 
 membranous canal, which passes from the uterus 
 downwards and forwards, also between the bladder 
 and rectum, and opens externally. 
 
 Connected with the orifice of the vagina are seve- 
 ral bodies, which are called the external parts of 
 generation , in order to distinguish them from the 
 uterus and ovaries, and their appendages, and also 
 from the canal of the vagina ; which are called the 
 internal parts. 
 
 The bladder of urine lies above and in contact with 
 the vagina : the urethra is also intimately connected 
 with it. The description of the bladder and urethra 
 is therefore placed at the end of this chapter. 
 
 SECTION I. 
 
 Of the External Parts of Generation. 
 
 The adipose membrane, immediately anterior to 
 the symphisis pubis, and on each side of it, forms a 
 considerable prominence in females, which, at the age 
 of puberty, is covered with hair, as in males. This 
 prominence is denominated the Mons Veneris. 
 
 The exterior orifice commences immediately be- 
 low this. On. each side of this orifice is a nronfib 
 
Labia Externa. — Clitoris. 2gi 
 
 uence continued from the mons veneris, which is 
 largest above, and gradually diminishes as it descends. 
 These prominences have some hair upon them. They 
 are called the Labia Externa. Their junction be 
 low is denominated the Fourchette. The space be- 
 tween the place of their junction and the anus is ra- 
 ther more than an inch in extent, and is denominated 
 the Perineum. 
 
 As the skin which forms the labia is continued in- 
 ternally, it becomes more thin and soft, and is cover 
 ed by a more delicate cuticle. It is also more or less 
 florid, and secretes a peculiar mucous. 
 
 In the upper angle, formed by the labia externa, 
 is the upper extremity and glans of the clitoris. 
 
 The Clitoris is a body which has a very strong 
 resemblance to the penis, but there is no urethra at 
 taehed to it. It has two crura of considerable length, 
 which originate, like those of the penis, from the 
 crura of the pubis and ischium, and unite at the 
 symphisis of the pubis so as to form a body, which 
 is not much more than an inch in length, and is 
 broad in proportion. The extremity of this organ, 
 called the Gians of the Clitoris , forms a small tu- 
 bercle, which is covered above and on the sides by a 
 small plait or fold of the skin, denominated the Pre- 
 puce. These parts are lubricated by a secretion 
 similar to that which is observed round the glans 
 penis. 
 
 The crura of the clitoris have muscles similar to 
 the erectores penis. The interior structure of the 
 Clitoris is very similar to that of the corpora caver- 
 nosa of the penis, or the corpus spongiosum of the 
 urethra. It appears constructed for a similar disten- 
 tion, and is endued with the same sensibility as the 
 penis. The two lateral parts are also separated from 
 each other by a septum, resembling that of the penis. 
 It is united to the symphisis pubis by a ligament 
 Vol.'h, " 26 
 
^02 JVyniphse .* — Hymen , 
 
 The Prepuce of the clitoris lias a semicircular 
 form : below its extremities two folds or plaits com 
 mence, one on each side, which are situated obliquely 
 with respect to each other, so as to form an angle. 
 These folds are denominated the Nymphsc. 
 
 The Nymphse extend from the clitoris downwards 
 nearly as far as the middle of the orifice of the vagina. 
 They are situated within the external labia, and are 
 formed by the skin after it has become more delicate 
 in its texture. Their surface however.is often some- 
 what corrugated. There are many blood vessels in 
 their internal structure, and it is supposed they are 
 occasionally somewhat tumid. They are flat, and 
 their exterior edge is convex; so that they are nar- 
 row at their extremities, and broad in the middle. 
 Their breadth is very variable, and in some instances 
 is great. In a majority of cases, it is equal to one- 
 fourth of their length. Their colour in young sub- 
 jects is of a bright red; in women advanced in years 
 and who have had many children, they are of a brown 
 red, and sometimes of a dark colour. 
 
 The use of these parts is not very evident. They 
 have been supposed to regulate the course of the 
 urine as it flows from the urethra, but their effect in 
 tliis respect is not great. They have also been sup- 
 posed to favour the necessary enlargement of the 
 parts in parturition. 
 
 The orifice of the urethra is situated about an inch 
 and one quarter further inward than the clitoris. It A 
 is often rathe® less than the diameter of the urethra, 
 and is somewhat protuberant. The orifices of mu- 
 cous ducts arq to be perceived around it. 
 
 The orifice of the urethra is at the commencement 
 of the Canal of the vagina. Immediately within 
 this orifice is situated the membrane denominated f 
 Hymen . 
 
 The Hymen is an incomplete septum, made by a * 
 
203 
 
 The Vagina. 
 
 fold op duplicature of the membrane which forms 
 the surface contiguous to it. Sometimes it is circu- 
 lar, with an aperture in the centre. Sometimes it 
 has a resemblance to the crescent, the aperture be- 
 ing at the upper part of it. The hymen has fre- 
 quently been found without a perforation, and has 
 therefore prevented the discharge of the menstrual 
 evacuation. It is generally ruptured in the first in- 
 tercourse of the sexes ; and some small tubercles, 
 which are found on the surface of the vagina near the 
 spot where it was situated, are supposed to be the 
 remains of it. These tubercles are called Car unci din 
 Mi/rtiformes. 
 
 ' SECTION 11 . 
 
 Of the Vagina. 
 
 The canal of the vagina, commencing at the hy- 
 men and the orifice of the urethra, is rather more 
 narrow at its beginning than it is further inward.— 
 From this place it extends backwards and upwards, 
 and partakes in a small degree of the curve of the 
 rectum : while the bladder, which is above it, and 
 rests upon it, increases the curvature of the anterior 
 part. It is much larger in women who have had 
 children than in those who have not. 
 
 The membrane which lines the vagina resembles 
 to a certain degree, the membranes which secrete 
 mucous in different parts of the body. Its surface 
 appears to consist of very small papillae ; and at the 
 anterior extremity of the vagina it forms a great 
 number of rugEe, which are arranged in a transverse 
 direction, both on the part of the vagina connected 
 to the bladder, and on that part which is connected to 
 the rectum, while the lateral parts of the vagina are 
 
204 Corpora Cavernosa . — Sphincter Vaginx. 
 
 smooth. These rugae are most prominent in the mid- 
 tile ; so that a raised line appears to pass through 
 them at right angles. This line extends from with- 
 out inwards. The rugae on the part next to the blad- 
 der are the strongest. 
 
 This arrangement of the surface of the vagina does 
 not extend beyond the external half of the canal : on 
 the internal half part, or that nearest the uterus, the 
 
 surface is smooth. 
 
 The rugae are considerably diminished in women 
 who have had children. 
 
 Throughout this surface are to be seen, in some 
 cases with the naked eye, the orifices of mucous fol- 
 licles or ducts, which occasionally discharge conside- 
 rable quantities of mucous. 
 
 Exterior to this lining membrane of the vagina is 
 a dense cellular structure, which has not yet been 
 completely investigated : it is of a lightish colour, and 
 has some resemblance to the texture of the body of 
 the uterus. It is very vascular, and appears to be of 
 a fibrous structure. It may be very much distended, 
 and seems to have a contractile power. 
 
 At the anterior extremity of the vagina, on each 
 side of it, there is superadded to this, a cellular, or 
 vascular substance, from eight lines to an inch in 
 breadth ; which, when cut into, resembles the cor- 
 pora cavernosa, or the corpus spongiosum of the pe- 
 nis. These bodies commence near the body of the 
 clitoris, and extend downwards on each side of the 
 vagina. They have been called Plexus Eeteformis, 
 and Corpora Cavernosa Vaginx , and are supposed 
 to be occasionally distended with blood, like the cli- 
 toris and penis. 
 
 These corpora eavernosa are covered by muscular 
 fibres, which pass over them on each side from the 
 sphincter ani to the body of the clitoris ; to each of 
 which organs they are attached. These fibres con- 
 
Unimpregnated Uterus , 205 
 
 stitute the sphincter vagina muscle, and contract the 
 diameter of the vagina at the place where they are 
 situated. 
 
 The transversus perinei muscles also exist in the 
 female. They pass from the tuberosities of the ischia, 
 and are* inserted into a dense whitish substance in 
 the perineum, to which the anterior extremity of the 
 sphincter ani is likewise attached. 
 
 The vagina is in contact with the rectum behind 5 
 the bladder lies upon it and anterior to it. A small 
 portion of peritoneum, to be reflected to the rectum, 
 is continued from the uterus upon the posterior part • 
 of it. TJie lateral portions of it are invested with 
 eellular substance. The anterior extremity of the 
 uterus, which is called the Os Tinea}, projects into 
 
 it from above. 
 
 * 
 
 SECTION III. 
 
 Of the Uterus , the Ovaries and their Appendages, 
 The Uterus 
 
 Has been compared to a pear with a long neck.— 
 There is of course a considerable difference between 
 the body and neck ; the first being twice as broad as 
 the last. Each of these parts is somewhat flattened,* 
 
 In subjects of mature age, who have never been 
 pregnant, the whole of the uterus is about two inches 
 and a half in length, and more than one inch and a 
 half in breadth at the broadest part of the body : it 
 is also near an inch in thickness. 
 
 .It is generally larger than this in women who 
 have lately had children. 
 
 The uterus is situated in the pelvis between the 
 bladder and rectum, and is enclosed in a duplicature 
 or fold of the peritoneum, which forms a loose septum 
 that extends from one side of the pelvis to the other, ^ 
 and divides it into an anterior and posterior cham 
 
2(>o Ligaments of the Uterus. 
 
 her. The posterior surface of this septum is oppo- 
 sed to the rectum, and the anterior to the bladder. 
 The two portions of this septum, which are between 
 the uterus and the lateral parts of the pelvis, are 
 called the Broad Ligaments. 
 
 On the. posterior surface, the Ovaries are, situated 
 on each side of the uterus, being enclosed by a pro- 
 ct&&of the ligament or septum. Above them, in the 
 upper edge of the septum, are the Fallopian Tubes , 
 which are ducts that commence at the upper part of 
 the uterus on each side, and proceed, in a lateral di~ 
 : *iion for some distance, when they form an angle 
 and incline downwards to the ovaries. These ducts 
 are enclosed between the two lamina of the septum 
 for the greater part of their length. 
 
 The peritoneum, which forms the septum, is re- 
 flected from it, posteriorly, to the rectum and the 
 posterior surface of the pelvis, and anteriorly, to the 
 bladder. In its progress, in each direction, it forms 
 small plaits or folds ; two of which extend from the 
 uterus to the rectum posteriorly, and two more to the 
 bladder anteriorly : these are called the Anterior 
 and Posterior Ligaments of the Uterus. 
 
 The other ligaments, which proceed more imme- 
 diately from the uterus, are called the Bound Liga- 
 ments. These arise from each side of the uterus, at 
 a small distance before and below the origins of the 
 fallopian tubes, and proceed in an oblique course to 
 the abdominal rings. These ligaments are also in- 
 vested by the peritoneum. They pass through the 
 rings and soon terminate. 
 
 In the body of the uterus is a cavity, which ap- 
 proaches to the triangular form ; and from which a 
 canal proceeds through its neck. This cavity is so 
 small that its sides are almost in contact, and the ca- 
 nal is in proportion ; so that this organ is very thick 
 in proportion to its bulk. 
 
Structure and Cavity of the Uterus. 20 7 
 
 The substance of which the uterus consists is very 
 firm and dense : it is of a whitish colour, with a slight 
 tinge of red. There are many blood vessels, with 
 nerves and absorbent vessels, in its texture. The 
 nature and structure of this substance has not yet 
 been precisely ascertained. It appears very different 
 indeed from muscle ; but the uterus occasionally con- 
 tracts, with great force, during labour. It is not ren- 
 dered thin by its enlargement during pregnancy, and 
 the blood vessels in its texture are greatly enlarged 
 at that time. 
 
 Exteriorly, the uterus is covered by the peritone- 
 um, as ha;? already been mentioned. Internally it is 
 lined with a delicate membrane that has. some resem- 
 blance to those which secrete mucous, and is gener- 
 ally of a whitish colour, abounding with small orifi- 
 ces that can be seen with a magnifying glass. This 
 membrane is so intimately connected to the substance 
 of the uterus that some anatomists have supposed it 
 was merely the internal surface of that substance, but 
 this opinion is now generally abandoned. It is sup- 
 posed that the colour of this membrane is more florid 
 about the period of menstruation. 
 
 The cavity of the uterus, as has been observed be- 
 fore, is triangular in form. When the organ is in its 
 natural position, the upper side of this triangle is 
 transverse with respect to the body, and the other 
 * sides pass downwards and inwards. In each of the 
 upper angles are the orifices of the fallopian tubes, 
 which are of such size as to admit a hog’s bristle. 
 
 The two lower lines of the triangle are slightly 
 curved outwards at their upper extremities ; so that 
 the upper angles of the triangle project outwards,, 
 and the orifices of the fallopian tubes are nearer to 
 the external surface than they otherwise would be. ’ 
 
 The lower angle of the cavity of the uterus is oc-' 
 
208 Structure and Cavity of the Uterus . 
 
 cupied by the orifice of the canal, which passes 
 through the neck of the organ ; this orifice is from 
 three to four lines in diameter. The canal is about 
 an inch, in length, and is rather wider in the middle 
 than at either end. On the anterior and posterior 
 portions of its surface are many small ridges which 
 have an arborescent arrangement, one large ridge 
 passing internally from the commencement of the 
 canal, from which a number of other ridges go off in 
 a transverse direction. These ridges extend nearly 
 the whole length of the canal. In the grooves, be- 
 tween the ridges, are the orifices of many mucous 
 ducts. There are also on this surface a tnumber of 
 transparent bodies of a round form, equal in bulk to 
 a middle sized grain of sand the nature and use of 
 which is unknown. They have been called Qvida 
 JYabothi, after a physiologist, who published some 
 speculations respecting their use, about the com- 
 mencement of the last century. 
 
 The canal of the neck of the uterus is very dif- 
 ferent from other ducts, for it seems to he a part of 
 the cavity to which it leads, and when the cavity of 
 the uterus becomes enlarged in the progress of preg- 
 nancy, this canal is gradually converted into a part of 
 that cavity. 
 
 The lower extremity of the neck of the uterus is 
 irreglarly convex and tumid. The orifice of the 
 canal in it is oval, and so situated that it divides the 
 convex surface of the neck into two portions, which 
 are called the Lips. The anterior or upper portion 
 is thicker than the other. 
 
 This extremity of the uterus protrudes into the va- 
 gina, and is commonly called Os Tincse . As the an- 
 terior portion or lip is larger and more tumid than 
 ‘the posterior, the vagina extends further beyond the 
 os tincse on the posterior part than on the anterior., 
 
Fallopian Tubes. —Round Ligaments 209 
 The Fallopian Tubes 
 
 Are two canals, from four to five inches in length? 
 which proceed between the lamina of the broad liga- 
 ments, from the upper angles of the uterus, in a 
 transverse direction, to some distance from the ute- 
 rus, when they form an angle, and take a direction 
 downwards towards the ovaries. 
 
 They are formed, for a considerable part of their 
 extent, by a substance which resembles that of which 
 the uterus consists, and are lined by a membrane 
 continued from the internal membrane of the uterus* 
 Their extremities appear to be composed of mem- 
 brane, which is rendered florid by the blood vessels 
 in its texture* At the commencement their diameters 
 are extremely small ; but they enlarge in their pro- 
 gress. This enlargement is gradual for the first half, 
 and afterwards sudden ; the enlarged part is more 
 membranous than the small part, and has a bright 
 red colour. The large extremity is loose in the ca- 
 vity of the pelvis, and is not invested by the lamina 
 of the broad ligaments. Near the termination the 
 diameter is often contracted ; after which the mem- 
 brane which forms the tube expands into an open 
 mouth, the margin of which consists of fringed pro- 
 cesses : this margin is also oblique, as respects the 
 axis of the tube ; and the different fringed processes 
 are not all of the same! length ; but the longest are 
 in the middle, and the others regularly diminish on 
 each side of them : these processes constitute the 
 Fimbriae of the fallopian tubes. 
 
 The internal surface of the large extremities of 
 these tubes is extremely vascular ; and there are 
 some longitudinal fibres of a red colour to be seen 
 on it. 
 
 The Round Ligaments , 
 
 Which have already been mentioned, are cords of 
 
 Vjpffc. n, 27 
 
21 U 
 
 * Structure of the Ovaries . 
 
 a fibrous structure, with many blood vessels in them. 
 They arise from the uterus below the origin of the 
 fallopian tubes, and proceed under the anterior la- 
 mina of the broad ligaments to the abdominal rings, 
 through which they pass; and then the fibres and 
 vessels are expanded upon the contiguous cellular I 
 substance. 
 
 The Ovaries 
 
 Are two bodies of a flattened oval form ; one of 
 which is situated on each side of the uterus on the 
 posterior surface of the broad ligament, and invested 
 completely by a process of the posterior fa men, 
 which forms a coat, and also a ligament for it. The 
 size of this organ varies in different subjects, but in 
 a majority of those who are about the age of matu- 
 rity it is between ten and twelve lines in length. It 
 is connected to the uterus by a small ligament, or 
 bundle of fibres of the same structure with the round 
 ligaments, which is not more than two lines in dia- 
 meter, and is included between the lamina of the 
 broad ligament. 
 
 The process of the broad - ligament forms an exter- 
 nal coat to the ovary ; within this is the proper coat 
 of the organ, which is a firm membrane. This mem- 
 brane is so firmly connected to the substance of the 
 ovary which it encloses, that it cannot be easily se- 
 parated from it. The ovary is of a whitish colour 
 and soft texture, and has many blood vessels. Ia 
 virgins of mature age it contains from fen to twenty 
 vesicles, formed of a delicate membrane, filled with 
 a transparent coagulable fluid. Some of these vesi- 
 cles are situated so near to the surface of the ovary 
 that they are prominent on its surface; others are 
 near the centre. They are very different in size ; 
 the largest being between two and three lines ir 
 
Arteries of the Uterus „ 21 1 
 
 diameter, and others not more than one-third of that 
 size. 
 
 In women who have had children, or in whom 
 conception has taken place, some of these vesicles 
 are removed ; and in their place a cicatrix is found. 
 
 It has been ascertained, that during the sexual 
 intercourse with males, one of these vesicles, which 
 was protuberant on the surface, is often ruptured, 
 and a cavity is found. A cicatrix -is soon formed, 
 where the membrane was ruptured ; and in the place 
 occupied by the vesicle there is a yellow substance 
 denominated Coi'pus Luteum. This corpus luteum 
 generally continues until the middle of pregnancy: 
 it often- remains during that state, and for some time 
 after delivery, but it gradually vanishes. The cica- 
 trization continues during life. 
 
 In many cases these cicatrices correspond with the 
 number of conceptions which have taken place ; but 
 they often, exceed the number of conceptions, and 
 they have been found in cases where conception has 
 not been known to have taken place. 
 
 In very old subjects, where conception has never 
 taken place, the vesicles are either entirely removed, 
 or small dense tubercles only remain in their place. 
 
 The Arteries 
 
 Of the uterus are derived from two very different 
 sources ; viz. from the spermatic and from the hy- 
 pogastric arteries. 
 
 The spermatic arteries, instead of passing directly 
 down to the abdominal ring, proceed between the 
 lamina of the broad ligament, and send branches to 
 the ovaries, which may sometimes be traced to the 
 vesicles. They also send branches to the fallopian 
 tubes and to the uterus. Those which are on the 
 opposite sides of the uterus anastomose with each 
 other, and also with the branches of the hypogastric 
 
3X2 .Veins of the Uterus . 
 
 arteries. There are also branches of these arteries 
 in the round ligaments which accompany them to 
 their termination outside of the abdominal ring. 
 
 The principal arteries of the uterus are those de- 
 rived from the hypogastric, which sends to each side 
 of it a considerable branch, called the Uterine. This 
 vessel leaves the hypogastric very near the origin of 
 the internal pudic, and proceeds to the cervix of the 
 uterus : it passes between the lamina of the broad li- 
 gaments, and sends branches to the edge of the ute- 
 rus, which penetrate its texture. The branches which 
 are in the texture of the uterus, are very small in- 
 deed. in young subjects. In women who have had 
 children they are considerably larger; but during 
 pregnancy they gradually enlarge with the growth of 
 the uterus, and become very considerable. These 
 arteries observe a serpentine and peculiarly tortu- 
 ous course. Those on the opposite sides anastomose 
 with each other. 
 
 The Veins 
 
 Of the uterus, like the arteries, form spermatic 
 and uterine trunks. The Spermatic Vein is much 
 larger than the artery. It ramifies as in males, and 
 forms a very large plexus, w hich constitutes the cor- 
 pus pampiniforme. Many of the veins which form 
 this body, originate near the ovary: a considerable 
 jjumber also come from the fallopian tubes and the 
 uterus. The spermatic vein and its branches are 
 greatly enlarged indeed during pregnancy ; and it is 
 said that they are enlarged the same way during the 
 menstrual discharge. 
 
 The most imporant veins of the uterus are the 
 branches of the Uterine Veins. They are extremely 
 numerous, and form a plexus on the side of the ute- 
 rus ; from which two or more uterine veins proceed 
 in the course of the artery, and join the hypogastric 
 
Lymphatics. —Bladder and Urethra. 213 
 
 These veins also are greatly enlarged during preg- 
 nancy. 
 
 The Lymphatic Vessels 
 
 Of the uterus, and its appendages, are very nu- 
 merous. In the unimpregnated state they are small ; 
 but, during pregnancy, they increase greatly. They 
 proceed from the uterus in very different directions. 
 Some that accompany the round ligaments go to the 
 lymphatic glands of the groin. Others which take 
 the course of the uterine blood vessels pass to glands 
 in the pelvis, and a third set follows the spermatic 
 arteries and veins to the glands on the loins. 
 
 The JYerves 
 
 Of the ovaries are derived from the renal plexus, 
 and those of the uterus and vagina from the hypo- 
 gastric plexus, or the lower portions of the sympa- 
 thetic, and the third and fourth sacral nerves, 
 
 SECTION IV. 
 
 Of the Bladder and Urethra. 
 
 The situation of the Bladder , as respects the sym 
 phisis pubis, is nearly alike in both sexes ; but that 
 part of it which is immediately behind the insertion 
 of the ureters is rather lower in males than in fe- 
 males. The bottom of the bladder rests upon the 
 upper part of the vagina, a thin stratum of cellular 
 substance only intervening: when that viscus is dis- 
 tended it forms a tumour, which compresses the va- 
 gina. 
 
 The ureters are inserted, and the urethra commen- 
 ces in the same part of the bladder, in both sexes. 
 
 The length of the Urethra is between one and 
 two inches. When the body is in a direct position, 
 it is nearly horizontal; but it is slightly curved? with 
 
314 General Change in (he Gravid Uterus. 
 
 its convexity downwards. It is immediately above 
 the vagina, and it passes below the body of the cli- 
 toris. The external orifice of it is rather more than 
 an inch within the gians or head of the clitoris. 
 This orifice is somewhat prominent in the vagina. 
 
 In the internal or lining membrane of the urethra 
 there are many orifices of mucous follicles, and also 
 longitudinal wrinkles, as in the urethra of males. 
 The diameter of the female urethra and its orifice in 
 the bladder are greater than they are in the male. 
 For this reason it has been supposed, that women are 
 less liable to calculus of the bladder than men.* • 
 
 The urethra is intimately connected with the ex- 
 ternal coat of the vagina, and between them there is 
 a spongy cellular substance which makes the fough 
 surface of the vagina prominent ; so that the urethra 
 has been supposed, although erroneously, to be in- 
 vested with the prostate. It is capable of great ar- 
 tificial dilatation. - 
 
 Of the Changes induced in the Uterus in the pro- 
 gress of Pregnancy . 
 
 The alteration which takes place in the size of the 
 uterus during pregnancy is truly great. About the 
 conclusion of that period, instead of the small body 
 above described, which is almost solid, the uterus 
 forms an immense sac, which extends from the ter- 
 mination of the vagina in the pelvis, into the epigas- 
 tric region ; and from one jside of the abdomen to the 
 other ; preserving, however an ovoid figure. 
 
 This change is so gradual at first, that the uterus 
 does not extend beyond the cavity of the pelvis be- 
 fore the third month, although at the end of the se- 
 venth month it is very near the epigastric region. 
 
 For the first six months the body of the uterus 
 
 * It has however been asserted that they are also less liable to calculi m 
 the kidneys. 
 
General Observations, 
 
 215 
 
 appears principally concerned in the enlargement : 
 after this the cervix begins to change, and is gradu- 
 ally altered so as to compose a portion of the sac, 
 rather of less thicknes than the rest of the uterus ; 
 the mouth being ultimately an aperture in a part 
 which is much thinner than the other portions of the 
 organ. 
 
 The change which takes place in the texture of 
 some of the appendages of the uterus is very import- 
 ant. 
 
 The Broad Ligaments , which seem particularly 
 calculated to favour the extension of the uterus, are 
 necessarily altered by the change in the ’size of that 
 organ, but not entirely done away. The portion of 
 peritoneum of which they are formed must be very 
 much enlarged with the growth of the uterus, as it 
 continues to cover it. The Round Ligaments are 
 much elongated ; and they observe a more straight 
 course to the abdominal ring. The Fallopian Tubes 
 are enlarged ; and instead of passing off laterally 
 from the uterus, they now proceed downwards by 
 the side of it. The Ovaries appear rather larger 
 and more spongy : their relative situation is necessa- 
 rily lower. 
 
 The change in the Uterus itself is particularly in- 
 teresting. The great increase of its size is not at- 
 tended with any considerable diminution of thick- 
 ness in its substance ; nor are the arteries much less 
 convoluted than before pregnancy , as might have 
 been expected. They are greatly enlarged in diam 
 eter, and the orifices of the exhalent vessels on the 
 internal surface of the uterus are much more percep- 
 tible. 
 
 The veins are much more enlarged than the arte- 
 ries, and in some places appear more than half an 
 inch in diameter. They are not regularly cylindri- 
 
216 Peculiarity of the Female Hottentots. 
 
 cal, but rather flat. They anastomose so as to form 
 an irregular net work. 
 
 The uterus appears much more fibrous and mus- 
 cular in the gravid than in the unimpregnated state. 
 The contractile power of the gravid uterus is not only 
 proved by the expulsion of its contents, but also by 
 very vigorous contractions, which are occasionally 
 observed by accoucheurs. 
 
 Although the general effects which result from the par- 
 ticular conditions of the uterus in pregnancy, men- 
 struation, &c. evince that the influence of this organ 
 upon the whole system is very great, yet it seems pro- 
 bable'that the sexual peculiarities of females are espe- 
 cially dependent upon the ovaria. 
 
 This sentiment is confirmed by an account of a wo- 
 man in whom the ovaria were deficient, which is pub- 
 lished in the London Philosophical Transactions for 
 1805, by Mr. C. Pears. The subject lived to the age 
 of twenty-nine years. She ceased to grow after the 
 age of ten years, and therefore was hot more than four 
 feet six inches in height : her breadth across the hips 
 was but nine inches, although the breadth of tne 
 shoulders was fourteen. Her breasts and nipples ne- 
 ver enlarged more than they are in the male subject. 
 There was no hair on the pubes, nor were there any 
 indications of puberty in mind or body. She never 
 menstruated. At the age of twenty -nine she died of a 
 complaint in the breast, attended with convulsions. — 
 The uterus and os tine® were found not increased 
 beyond their usual size during infancy. The cavity 
 of the uterus was of the common shape, but its coats 
 were membranous. The Fallopian Tubes were per- 
 vious. “ The Ovaria were, so indistinct that they ra- 
 ther showed the rudiments which ought to have form- 
 ed them , than any part of the natural structure .V 
 Another case, which confirms the aforesaid sentiment, 
 is related in one of the French periodical publications.. 
 
 It has been long known that a race of savages near 
 the Cape of Good Hope were distinguished trom the 
 generality of their Species by a* peculiarity about the 
 pudendum. An account of this structure has been 
 
Peculiarities in the Abdomen of the Fcetus 217" 
 
 given with some precision by Messrs. Peron and Le- 
 sueur, in a paper which was read to the National Insti- 
 tute of France. It is a flap or apron, four inches in 
 length, which is united to the external labia near their 
 upper angle, and hangs down before the clitoris and 
 the external orifice of the parts of generation. It is 
 divided below into two lobes, which covers the orifice. 
 It is formed by a soft distensible skin, free from hair, 
 which is occasionally corrugated like the scrotum, and 
 is rather more florid than the ordinary cutis. s 
 
 The Abdomen of the Fcetus. 
 
 The difference between the foetus and the adult, 
 in the cavity of the abdomen, is very conspicuous at 
 the first view. 
 
 The Liver in the foetus is so large that it occupies 
 a very considerable part of the abdomen. Its left 
 lobe, which is larger in proportion than the right, 
 extends far into the left hypochondriac region. 
 
 The Bladder of urine , when filled, extends from 
 the cavity of the pelvis a considerable distance to- 
 wards the umbilicus : so that the greatest part of it 
 is in the cavity of the abdomen. A ligament of a 
 conical figure extends from the centre of the upper 
 part of the bladder to the umbilicus ; with an artery 
 on each side of it, which is soon to be described. 
 This ligament, which is in the situation of the ura- 
 chus of the fcetus of quadrupeds, is hollow, and thus 
 frequently forms a canal, which has a very small 
 diameter, that communicates with the bladder by an 
 aperture still smaller, and continues a short distance 
 from the bladder towards the umbilicus. In a few 
 rare instances this canal has extended to the umbili- 
 cus, so that urine has been discharged through it, but 
 the ligament is commonly solid there. 
 
 * This paper has not yet been published by the Institute, but it is refer- 
 red to by M. Cuvier in his Lemons d’Anatomie Comparee, voL v. page 
 124.— Messrs. Peron and Lesueur were naturalists who accompanied captain 
 Baudin in his voyage of discover} - ; the latter has been for some years re- 
 sident in Philadelphia, 
 
 VOL-v IT, 
 
 18 
 
218 Descent of the Testicle in the Foetus . 
 
 The Stomach appears to be more curved in the 
 foetus than in the adult. 
 
 The Great Intestine does not extend sufficiently 
 far, beyond the insertion of the ileon, to form the 
 cfecum completely. 
 
 The Glandalse JRenales are much larger in pro- 
 portion in the foetus than in the adult. The colour 
 of the fluid they contain is more florid. 
 
 The Kidneys are lobulated. 
 
 The Testicles in the foetus are found above the 
 pelvis, in the lumbar region, behind the peritoneum, 
 until two months before birth. Thus situated, their 
 blood vessels and nerves proceed from sources which 
 are near them ; but the vas deferens, being connected 
 to the vesiculac seminales by one extremity, is neces- 
 sarily in a very different situation from what it is in 
 the adult: it proceeds from the testicle downwards to 
 the neck of the bladder. — While each testicle is in 
 this situation, it is connected with a substance or liga- 
 ment, called Gubernaculwn , of a conical or pyrami- 
 dical form, attached to its lower end, and extends 
 from it to the abdominal ring. This substance is 
 vascular, and of a fibrous texture: its large extremity 
 adheres to the testicle, its lower and small extremity 
 passes through the abdominal ring, and appears to 
 terminate in the cellular substance exterior to that 
 opening, like the round ligament in females. The 
 Gubernaculum, as well as the testicle, is behind the 
 peritoneum ; and the peritoneum adheres to each of 
 them more firmly than it does to any of the surround- 
 ing parts. It seems that, by the contraction of the 
 Gubernaculum , the testicle is moved down from its 
 original situation to the abdominal ring, and through 
 the abdominal ring into the scrotum. The perito- 
 neum, which adheres firmly to the gubernaculum and 
 testicle, and is loosely connected to the other parts, 
 yields to this operation ; and \yhen the testicle has 
 
Descent of the Testicle in the Fcetus . 219 
 
 arrived near the abdominal ring, a portion of the pe- 
 ritoneum is protruded a little way before it into the 
 scrotum ; forming a cavity like the finger of a glove. 
 The testicle passes down behind this process of the 
 peritoneum, and is covered by it as it was in the ab- 
 domen. Although it appears protruded into the ca- 
 vity, it is exterior to it, and behind it ; and the ves- 
 sels, &c. which belong to the testicle are also ex- 
 terior to it. 
 
 The cavity formed in the scrotum, by this process 
 of the peritoneum, necessarily communicates with the 
 cavity of the abdomen at its formation ; but very soon 
 after the testicle has descended into the scrotum, the 
 upper part of this cavity is closed up, while the low- 
 er part of the process continues unchanged, and con- 
 stitutes the Tunica Vaginalis Testis. In some in- 
 stances the upper part of this process does not close 
 up, and the communication with the cavity of the 
 abdomen continues. The descent of the intestine 
 into the cavity thus circumstanced, constitutes that 
 species of Hernia which is denominated Congenital.* 
 
 The most important peculiarities in the abdomen 
 of the foetus are those connected with the circulation 
 of the blood. 
 
 The internal iliac or hypogastric arteries are larger 
 than the external iliacs. Their main trunks are 
 
 * These interesting circumstances respecting the original situation of 
 the testicle, and its descent into the scrotum, were discovered and elu- 
 cidated by Haller, Hunter, Pott, Camper, and several other very respect- 
 able anatomists and surgeons. There is, however, a difference of opin- 
 ion, between some of them, as to the time when the testicle leaves the 
 abdomen. Haller thought the testicles were seldom in the scrotum at 
 birth. Hunter and Camper found them so generally. 
 
 It has been suggested that there are some national peculiarities in this re- 
 spect ; that amongst the Hungarians, for example, the testicles often re- 
 main above the abdominal ring until near the age of puberty. 
 
 The student will find an interesting description of the situation of the 
 testis, and its descent, in the foetus, in the “ Observations o.n certain parts 
 of the Animal Economy, 51 by John Hunter, 
 
Umbilical Vessels. 
 
 ;i2U 
 
 continued on each side of the bladder to its fundus t 
 and proceed from it, with the ligament, to the umbi- 
 licus ; when they pass out of the abdomen to go along 
 the umbilical cord to the placenta. These arteries 
 are now denominated the Umbilical, and are very 
 considerable in size. After birth, as there is no cir- 
 culation in them, they soon begin to change : the ca- 
 vity of them is gradually obliterated, and they are 
 converted into ligaments. They are exterior to the 
 peritoneum, and contained in a duplicature of it. 
 
 A vein also called the Umbilical, which is much 
 larger in diameter than both of the arteries, returns 
 from the placenta along the cord, and enters the ca- 
 vity of the abdomen at the umbilicus. It proceeds 
 thence, exterior to the peritoneum, but in a duplica- 
 ture of it called the Falciform Ligament , to the 
 liver, and enters that viscus at the great fissure ; 
 along which it passes to the left branch of the sinus 
 of the vena portarum, into which it opens and dis- 
 charges the blood which flows through it from the 
 placenta. It opens on the anterior side of the branch 
 of the vena portarum, and from the posterior side of 
 the branch, opposite to this opening, proceeds a duct 
 or canal, which opens into the left hepatic vein near 
 its junction with the vena cava. This communicating 
 vessel is called the Ductus, or Canalis Venosus ; to 
 distinguish it from the duct which passes from the 
 pulmonary artery to the aorta, and is called Ductus , 
 or Canalis Arteriosus. This venous duct carries 
 some of the blood of the umbilical vein directly to 
 the vena cava ; but it is much smaller than the um- 
 bilical vein, and of course a considerable quantity of 
 the blood which passes through the umbilical vein 
 must pass through the liver, by the vena portarum, 
 before it can enter the cava. 
 
 In some foetal subjects, if a probe of sufficient 
 
Object of the Circulation in the Placenta. 221 
 
 length be introduced within the umbilical vein and 
 pushed forwards, it will pass to the heart without 
 much difficulty or opposition, as if it proceeded along 
 one continued tube, although it really passes from 
 the umbilical vein across the branch of the vena por- 
 tarum, and then through the ductus venosus, and 
 through a portion of the left hepatic vein, into the 
 inferior vena cava. 
 
 If the umbilical vein be injected with a composi- 
 tion, which will be firm when cool, it appears to 
 terminate in a rounded end, which is situated in the 
 transverse fissure of the liver : the sinus of the vena 
 portarum, into which this vein enters, appears like 
 two branches going off, one from each side of it, and 
 the ductus venosus like a branch continuing in the 
 direction of the main trunk of the umbilical vein. 
 
 The umbilical vein, in its progress through the 
 fissure of the liver, before it arrives at the sinus of 
 the vena portarum, sends off a considerable number 
 of branches to each of the lobes of that organ, but 
 more to the left than to the right lobe. 
 
 After birth, when blood ceases to flow through the 
 umbilical vein, it is gradually converted into a liga- 
 ment ; and the venous duet is also converted into a 
 ligament in the same manner. The vena portarum, 
 which before appeared very small, when compared 
 with the umbilical vein, now brings all the blood 
 which fills its great sinus, and increases considerably 
 in size. 
 
 It has been ascertained by anatomical investiga- 
 tion, that the umbilical arteries above mentioned, 
 after ramifying minutely in the placenta, communi- 
 cate with the minute branches of the umbilical vein ; 
 and it is probable that the whole blood carried to the 
 placenta by these arteries, returns by the umbilical 
 vein to the foetus. 
 
 It is dearly proved by the effects of pressure on 
 
222 Object of the Circulation in the Placenta. 
 
 the umbilical cord, in cases of delivery by the feet, 
 as well as by other similar circumstances* that this 
 circulation cannot 'be suspended for any length of 
 time without destroying the life of the foetus.' From 
 these circumstances, and from the florid colour 
 which the blood acquires by circulating in the pla- 
 centa, it seems probable that the object of the circu- 
 lation through that organ is somewhat analogous to 
 the object of the pulmonary circulation through the 
 lungs of adults.* * 
 
 * During the first four months of pregnancy a very small vesicle, which 
 does not exceed the size of apea, is found between the chorion and the amnios, 
 near the insertion of the umbilical cord into the placenta. It is connected 
 to the fetus by an artery and a vein, which pass from the abdomen through 
 the umbilicus, and proceeding along the cord to the placenta, continue 
 from it to the vesicle. The artery arises from the mesenteric, and the 
 veii^ is united to the mesenteric branch of the vena portarum. It is proba- 
 ble that these vessels commonly exist no longer than the vesicle, viz. 
 about four months ; but they have been seen by Haller fujd-Chaussier at 
 the termination of pregnancy. They are called Omphat&iiHesenteric -ves- 
 sels. The vesicle is denominated the Umbilical Vesicle. 
 
 This inexplicable structure is delineated in Hunter’s Anatomy of the 
 Gravid Uterus, plate xxxiii. figures v. and vi. ; in the Academical Annota- 
 tions of Albums, first book, plate i. figure xii.; and also in the leones Em- 
 bryonum Humanortun of SoemmeriDg, figure & 
 
SYSTEM OF ANATOMY. 
 
 PART IX. 
 
 OF THE BLOOD VESSELS. 
 
 The blood vessels are flexible tubes, of a peculiar 
 texture, through which blood passes from the heart 
 to the different parts of the body, and returns again 
 from these parts to the heart. They are to be found, 
 in varying proportions, in almost every part of the 
 body, and seem to enter into its texture. 
 
 The tubes which carry blood from the heart, are 
 more substantial and more elastic than those through 
 which it returns to the heart. They are generally 
 found empty after death ; and, therefore, were called 
 Arteries by the ancient anatomists, who supposed 
 that they carried air, and not blood. 
 
 The tubes which return the blood to the heart are 
 denominated Veins . They are less substantial and 
 less elastic than arteries, and are generally fall of 
 blood in the dead subject. 
 
 There are two great arteries, from which all the 
 Other arterial vessels of the body are derived. They 
 are very justly compared to the trunks of trees, and 
 the smaller vessels to their branches. One of these 
 great arteries, called the Aorta, carries blood to eve- 
 ry part of the body. The other great vessel, called 
 the Pulmonary Artery , carries blood exclusively to 
 the lungs. 
 
S24 The Blood vessels in general . 
 
 The veins which correspond to the branches of the 
 Aorta, unite to each other, so as to form two great 
 trunks that proceed to the heart. One of these 
 trunks, coming from the superior parts of the body, 
 is called the Superior, or Descending Vena Cava. 
 The other, which comes from the lower parts of the 
 body, is called the Inferior, or Ascending Vena 
 Cava. 
 
 The veins which correspond with the branches of 
 the Pulmonary Artery, and return to the heart the 
 blood of the lungs, are four in number : two of them 
 proceeding from each lung. They are called Pul- 
 monary Veins. 
 
 In many of the veins there are valves, which pre- 
 vent the blood they contain from moving towards the 
 surface and extremities of the body, but allow it to 
 pass towards the heart without impediment. 
 
 From the construction of the cavities of the heart, 
 and the position of the valves which are in them ; as 
 well as the situation of the valves at the commence- 
 ment of the great arteries, and the above mentioned 
 valves of the veins, it is evident, that when the blood 
 circulates, it must move from the heart, through the 
 aorta and its branches, to the different parts of the 
 body, and return from these parts through the venae 
 cavae, to the heart ; that, when deposited in the heart 
 by the venae cavae, it must proceed through the pul- 
 monary artery to the lungs, and return from the 
 lungs through the pulmonary veins to the heart, in 
 order to pass again from that organ into the aorta. 
 
 It is also certain, that the blood is forced from the 
 heart into the arteries, by the contraction of the mus- 
 cular fibres of which the heart is composed ; and that 
 the blood vessels likewise perform a part in the cir- 
 culation, they propelling the blood which is thus 
 thrown into them : but their action appears to depend 
 upon causes of a complex nature. 
 
CHAPTER I. 
 
 OF THE GENERAL STRUCTURE AND ARRANGEMENT 
 OF THE BLOOD VESSELS, 
 
 SECTION r. 
 
 Of the Arteries. 
 
 The arteries are so much concerned in the im- 
 portant function of the circulation of the blood, that 
 every circumstance connected with them is very in- 
 teresting. 
 
 They are composed of coats or tunics, which are 
 very elastic and strong, and which are also very thick. 
 In consequence of the firmness of their coats, they 
 continue open, after their contents are discharged, 
 like hard tubes. They submit to great dilatation, 
 and elongation, when fluids are forced into them, and 
 return to their former dimensions when the distend- 
 ing cause is withdrawn. This elasticity is particu- 
 larly subservient to the circulation of the blood. ' It 
 admits the artery to distend readily, and receive the 
 biood which is thrown into it by the contraction of 
 the heart. It also produces the contraction of the 
 artery; which takes place as soon as the action of the 
 heart ceases ; and this contraction of the artery neces- 
 sarily forces the blood forward, as the valves at its 
 orifice prevent it from returning to the heart. 
 
 The motion of the artery, which is so easily per- 
 ceived by the touch, and in many instances also by 
 the eye, is completely explained by the discharge of 
 blood into the arterv from the heart, and by the 
 VOL.il. 29 ' 
 
226 
 
 Structure of the Arteries. 
 
 elasticity of the vessel, by which it re-acts upon the 
 blood. In some cases it is not simply the diameter 
 of the artery which is enlarged, but a portion of the 
 vessel is elongated; and this elongation, by pro- 
 ducing a curvature of it, renders its motion more 
 visible. 
 
 In the aorta, and probably in its large branches, 
 Elasticity seems to be the principal cause of the con- 
 tinuance of the motion which is originally given to 
 the blood by the heart. But there are many circum- 
 stances connected with the smaller vessels, which 
 evinee that they exert a power which is very differ- 
 ent indeed from elasticity. Thus the application of 
 local stimulants or rubefacients, and of heat, is fol- 
 lowed by an increase of motion in the arteries of the 
 parts to which they are applied. Neither of these 
 causes could produce their effect by the influence of 
 elasticity : but the effect of these and other similar 
 causes is uniformly produced ; and a power of inde- 
 pendent motion, or Irritability , is thus proved to 
 exist in these vessels, and seems essentially necessa- 
 ry to the circulation of the blood. 
 
 The Structure of the Arteries 
 
 Is, therefore, a subject of importance; and has re- 
 ceived a considerable degree of attention from anato- 
 mists. 
 
 They are composed of a dense elastic substance, 
 of a whitish colour. Their external surface is rough, 
 and intimately connected with the cellular membrane, 
 which every where surrounds it in varying quanti- 
 ties. Internally, they are lined with a thin mem- 
 brane, which is very smooth and flexible, and is also 
 very elastic. The substance which composes the 
 artery, and is situated between the cellular invest- 
 ment and the internal membrane, consists of fibres, 
 which are nearly, though not completely, circular, 
 
227 
 
 / Structure of the Arteries . 
 
 but so arranged as to constitute a cylinder. These 
 fibres may be separated from each other so. as to 
 form lamina, which have been considered as differ- 
 ent coats of the arteries ,• but there is no arrange- 
 ment of them which composes regular distinct strata. 
 The coats of arteries may, therefore, be separated 
 into a greater or smaller number of lamina, accord- 
 ing to the thickness of these lamina. 
 
 The fibres which compose these lamina appear to 
 be united to each other in a way which readily al- 
 lows of their separation, at the same time that they 
 form a firm texture. Although arteries thus appear 
 essentially different from muscles in their hardness 
 and their elasticity, as well as in their general tex- 
 ture, they are considered, by a great majority of 
 anatomists, as partaking more or less of a muscular 
 structure. 
 
 In the human subject their structure is very diffi- 
 cult of demonstration, and great differences exist in 
 the accouuts which are given of it, even by anato- 
 mists who agree in the general sentiment that the 
 arteries are muscular. 
 
 Thus Haller believed that muscular fibres were 
 most abundant in the large arteries, while J. Hunter 
 thought the reverse. 
 
 Hunter appears to have investigated this subject 
 with great attention, and supposed the muscular 
 substance, in the composition of arteries, to be inte- 
 rior, and the elastic matter exterior ; that in large 
 arteries this muscular substance is very small in 
 quantity, and gradually increases in proportion as 
 the artery diminishes in size. He however observes, 
 that he never could discover the direction of the 
 muscular fibres* 
 
 When the great talents of Mr. Hunter as an 
 
 ' Treatise on the Blond, &c, Voi I, p. ITS. Bradford’s edition 
 
228 Question? expecting the muscularity of Arteries . 
 
 anatomist, are considered, this circumstance cannot 
 fail to excite a belief that the existence of these ' 
 fibres is not certain : and if to this be added the fact, 
 that even the red coloured substance of the arteries 
 is elastic, and in that respect different from muscu- 
 lar substance, the reasons for doubting must be in- 
 creased. 
 
 Bichat appears to have entertained very strong 
 doubts on the subject ; but he stands almost alone ; 
 for a large number both of the preceding and cotem- 
 porary anatomists, seem to have adopted the senti- 
 ment, that the arteries have a muscular structure. 
 
 The student of anatomy can very easily examine 
 this subject himself, by separating the coats of arte- 
 ries into different lamina ; and by viewing the edges 
 of the transverse and longitudinal sections of those 
 vessels. While thus engaged with this question, he 
 will read with great advantage what has been writ- 
 ten upon it by Mr. Hunter, in his Treatise on the 
 Blood, &c. See chapter second, section 3. Bichat 
 ought also to be read upon this subject, which he 
 has discussed in his Anatomie Generate — -Systeme 
 Vasculaire a Sang Rogue , article Troisieme, &c. and 
 also in his Traite des Membranes , article Sixieine. 
 
 The belief of the irritability of arteries does not 
 however, rest upon the appearance of their fibres. 
 
 1. It is asserted by very respectable authors,* 
 that they have been made to contract by the appli- 
 cation of mechanical and of chemical irritation, and 
 also of the electric and galvanic power. 
 
 2. A partial or local action of arteries is often 
 produced by the local application of heat and rube- 
 facients, as has been already observed. 
 
 * See Soemmering on the structure of the Human Body, Vol. IV. Ger- 
 man edition. Dr. Jones, on the Process employed by nature for suppressing 
 Hemorrhage, &c. 
 
Proofs of the Irritability of the Jlrteries, 
 
 3. Arterial action is often suspended in a particu- 
 lar part by the application of cold. It has also been 
 observed that the arteries have for a short time ceas- 
 ed to pulsate in cases of extreme contusion and lace- 
 ration of the limbs.* 
 
 4. When arteries are divided transversely in living 
 animals, they often contract so as to close completely 
 the orifice made by the. division. 
 
 5. In a horse bled to death, it was ascertained by 
 Mr. Hunter, that the transverse diameter of the ar- 
 teries was diminished to a degree that could not be 
 explained by their elasticity. He also found that, 
 after death, the arteries, especially those of the 
 smaller size, are generally in a state of contraction, 
 which is greater than can be explained by their elas- 
 ticity: for if they are distended mechanically, they 
 do not contract again to their former size, but conti- 
 nue of a larger diameter than they were before the 
 distention; although their elasticity may act so as to 
 restore a very considerable degree of the contraction 
 observed at death. 
 
 The contraction, which is thus done away by dis- 
 tention, Mr. Hunter supposed to have been produced 
 by muscular fibres : for, if it had been dependent on 
 elasticity, it must have re-appeared when the distend- 
 ing power was withdrawn. 
 
 It therefore seems certain, that the arteries have a 
 power of contraction 'different from that which de- 
 pends upon elasticity ; but whether this depends 
 upon muscular fibres superadded to them, or upon 
 an irritable quality in the ordinary elastic fibres of 
 blood vessels, is a question which is not perhaps 
 completely decided. 
 
 * This local suspension of arterial motion by cold, &c. applied locally, 
 is very difficult to explain; as the' action of the heart and the elasticity of 
 the arteries appear sufficient to account for the pulsation of the large ar- 
 teries. 
 
230 General Observations on ■ the Arteries. 
 
 The motion of the blood in the arteries appears to 
 depend, 
 
 1st, Upon the impulse given to it by the action of 
 the heart. 
 
 2dly, Upon the elasticity of the arteries, in conse- 
 quence of which they first give way to the blood 
 impelled into them, and then re-act upon it; and 
 
 3dly, Upon the power of contraction in the arte- 
 ries, or their irritability. 
 
 In the larger arteries the blood seems to move as 
 it would through an inanimate elastic tube, in conse- 
 quence of the impulse given by the heart, and kept 
 up by the arteries themselves. In the smaller ves- 
 sels it seems probable that the motion of the blood 
 depends in a considerable degree upon the contrac- 
 tion which arises from their irritability. 
 
 The obvious effect of the elasticity of the arteries 
 is to resist distention and elongation, and to contract 
 the artery to its natural state, when the distending 
 or elongating cause ceases to act. But it must also 
 resist the contraction induced by the muscular fibres, 
 and restore the artery to its natural size when the 
 muscular fibres cease to act after contracting it, as 
 has been observed by Mr. Hunter. 
 
 It seems probable that all the fibres of which the 
 artery consists are nearly but not completely circular, 
 for it is not certain that there are any longitudinal 
 fibres in the structure of an artery. 
 
 The internal coat of these vessels is very smooth, 
 but extremely dense and firm; and seems to be ren- 
 dered moist and flexible by an exudation on its sur- 
 face. It adheres very closely to the contiguous fibres 
 of the coat exterior to it, but may be very readily 
 peeled off from them. It is of a whitish colour, 
 and, like the fibrous structure of the artery, is very 
 elastic. Like that substance also it is easily torn or 
 broken, and when ligatures have been applied to 
 
General Observations on the Arteries . 231 
 
 arteries, it has often been observed that the fibrous 
 structure and the internal coat have been separated 
 while this external cellular coat has remained en- 
 tire. 
 
 The arteries are supplied with their proper blood 
 vessels and lymphatics. It is to be observed, that 
 the blood vessels are not derived from the artery on 
 which they run, but from the contiguous vessels. 
 
 These vessels have nerves also, which are rather 
 small in size, when compared with those which go to 
 other parts. 
 
 Arteries appear to have a cylindrical form, for no 
 .diminution of diameter is observable in those portions 
 of them which send off* no ramifications. 
 
 When an artery ramifies the area of the differ- 
 ent branches exceeds considerably that of the main 
 trunk. Upon this principle the aorta and its branches 
 have been compared to a cone, the basis of which 
 is formed by the branches, and the apex by the 
 trunk.* 
 
 The transverse section of an artery is circular. 
 
 There are no valves in the arteries, except those 
 of the orifices of the aorta and the pulmonary artery, 
 at the heart. The valves of the pulmonary artery 
 have been described in the 51st page of this volume, 
 and those of the aorta have an exact resemblance to 
 them, but are rather larger. 
 
 The course of the arteries throughout the body is 
 obviously calculated to prevent their exposure to 
 pressure, or to great extension from the flexure of the 
 articulations by which they pass. With this view 
 they sometimes proceed in a winding direction ; and 
 when they pass over parts which are subject to great 
 distention or enlargement, as the cheeks, they often 
 
 * According to Brassiere the relation of the branches of the aorta to its 
 trunk is as 25 to 16; Helvetius reckons the orifice of the aorta in compa^ 
 visori ■with its branches as 64 to 71. Lassus.— Es. 
 
 I 
 
232 General Observations on the Arteries, 
 
 meander; and, therefore, their length may be in- 
 creased by straightening, without stretching them. 
 
 Their course appears sometimes to have been 
 calculated to lessen the force of the blood, as is the 
 case with the Internal Carotid and the Vertebral ar- 
 teries. 
 
 In the trunk of the body the branches of arteries 
 generally form obtuse angles with the trunks from 
 which they proceed. In the limbs these angles are 
 acute. 
 
 The communication of arteries with each other is 
 termed Anastomosis. In some instances, two branches 
 which proceed in a course nearly similar, unite, 
 with an acute angle, and form one common trunk. — 
 Sometimes, a transverse branch runs from one to the 
 other, so as to form a right angle with each. In 
 other cases, the two anastomosing branches form an 
 arch, or portion of a circle, from which many branches 
 go off. 
 
 By successive ramifications, arteries gradually di- 
 minish in size, until they are finally extremely small. 
 
 The smallest arteries do not carry red blood, their 
 diameters being smaller than those of the red parti- 
 cles of that fluid, the serous or aqueous part of the 
 blood can, therefore, only pass through them. 
 
 Many of the arteries which carry red blood, and 
 of the last mentioned serous arteries terminate in 
 veins, which are in some respects, a continuation of 
 the tube reflected backwards.# 
 
 * Malpighi and Leeuwenhoek declare, that by the aid of a microscope, 
 they have seen arteries terminating in the veins. Haller advances for- 
 mally his own experience in support of his assertion. Other anatomists 
 have seen, that in blowing into an artery, the air passed into the corres- 
 ponding veins. Nevertheless, Duverney and some others say, that a 
 particular substance is interposed between the extremities of these ves- 
 sels. Ruyseh in his Thesauras Anatomic'us, VI. No. 73, says, in repletione 
 arteriarum, replentur et plurimum quosque vense, et vice versa, ita ut im- 
 possible videatur precise dicere quomodo res .se habeat. Discours sur 
 i’Anat — E p. ~ ' • 
 
General Observations on the Ferns. 233 
 
 They likewise terminate in exhalent vessels, which 
 open upon the external surface, and upon the various 
 internal surfaces of the body. The secretory vessels 
 of glands are likewise the termination of many arte- 
 ries. 
 
 SECTION II. 
 
 Of the Feins. 
 
 These tubes, which return to the heart the blood 
 carried from it by the arteries, are more numerous 
 than the arteries, and often are larger in diameter. 
 
 They generally accompany the arteries, and very 
 often two veins are found with one artery. 
 
 In addition to these last mentioned veins, which 
 may be called deep-seated , there are many subcuta- 
 neous veins which appear on almost every part of 
 the surface of the body. 
 
 The capacity of all the veins is therefore much 
 greater than that of all the arteries. 
 
 Those subcutaneous veins, which are of consider- 
 able size, communicate very freely with each other, 
 and also with the deep-seated veins. 
 
 The trunks of the veins, in those places where no 
 branches go off, are generally cylindrical. There 
 are, however, some exceptions, in which these ves- 
 sels are irregularly dilated, as sometimes happens in 
 the case of the internal jugular vein. It is how- 
 ever, not easy to determine from the appearance of 
 veins injected after death, respecting their situation 
 during life, as their coats are very yielding ; and it 
 is very probable that they are, therefore, preterna- 
 turally dilated by the injection. 
 
 Veins , directly or indirectly, originate from the 
 termination of arteries : but they do not pulsate as 
 the arteries do, because the impulse given to the 
 
 Vgl. EE. 30 
 
234 
 
 Coats of Veins. 
 
 blood by the heart is very much diminished in con- 
 sequence of the great diminution of the size of the 
 vessels through which the blood has passed. 
 
 In some cases, however, when blood flows from 
 an opened vein ; the extent of its projection is alter- 
 nately increased and diminished, in quick succes- 
 sion, as if it were influenced by the pulsation of the 
 heart. 
 
 The Coats of Veins differ considerably from those 
 of Arteries, — for they are thinner , and so much less 
 firm, that veins, unlike arteries, collapse when they 
 are empty. 
 
 They Consist of a dense elastic substance, the 
 fibres of which are much less distinct than those of 
 arteries, but some of them are to be seen in a longi- 
 tudinal direction. These fibres can be made to con- 
 tract by local irritation ; for if a vein be laid bare 
 in a living animal, and then punctured, it will often 
 contract so as to diminish its diameter very consi- 
 derably, although no blood shall have escaped from 
 the puuctures. 
 
 Next to the elastic substance is the internal coat, 
 which is smooth and polished. It is separated from 
 the substance exterior to it with difficulty, although 
 it may be taken from it very easily in the vena cava. 
 
 This internal coat is more ostensible than the in- 
 ternal coat of arteries, and is not, like the latter, dis- 
 posed to ossification. It is frequently so arranged 
 as to form valves, which are plaits or folds, of a se- 
 milunar form, that project from the surfaces into the 
 cavities of these vessels.* 
 
 Two of these valves are generally placed opposite 
 
 The valves of the veins were first described by Charles Etienne of Pa- 
 ris in 1546. In 1547, Amatus, a Portuguese, saw at Ferrara those at the 
 mouth of the vena azygos. Sylvius of Paris announced them about the 
 same time in the jugular, brachial and crural veins. Fabricus ab Acjua- 
 osndente claims the discovery for himself in 1574 Lassus. — Ei?- 
 
Colour of the Blood in the / 'inns, 235 
 
 to each other ; and, when raised up, they form a sep- 
 tum in the cylindrical cavity of the vessel. The sep- 
 tum, thus composed, is concave towards the heart. 
 
 The valves have a great effect in preventing the 
 contents of the veins from moving in a retrograde 
 course : they, therefore necessarily modify the effects 
 of lateral pressure, in such a manner, that it propels 
 the blood forward, or to the heart. 
 
 These valves are generally found in the veins of 
 the muscular parts of the body, especially in those of 
 the extremities. They are not found in those veins 
 which are in the cavities of the body, nor in the in- 
 ternal jugulars. — They are placed at unequal dis- 
 tances from each other. 
 
 The coats of the veins are somewhat transparent ; 
 and, therefore, those veins which are subcutaneous 
 have a bluish aspect, which is derived from the co- 
 lour of the blood they contain. 
 
 The colour of the blood in the veins is different 
 from that in the arteries, being of a darker red. 
 
 The situation and arrangement of the large trunks 
 of veins is much alike in different subjects ; but the 
 branches, especially those which are subcutaneous, 
 are very variable in their situations. 
 
CHAPTER II. 
 
 A PARTICULAR ACCOUNT OF THE DISTRIBUTION OF THE 
 ARTERIES. 
 
 SECTION r. 
 
 Of the AORTA,* 
 
 Or the Great Trunk of the Arterial System „ 
 
 When the heart ia in its natural position, the right 
 ventricle is nearly anterior to the left, and, therefore, 
 the aorta, where it originates from the left ventri- 
 cle, is behind the pulmonary artery, and covered by 
 it. Its first direction is so oblique towards the right 
 side of the body, that it crosses the pulmonary artery 
 behind, and appears on the right side of it. It has 
 scarcely assumed this position before its course alters, 
 for it then proceeds obliquely backwards, and to the 
 left; so as to form a large curve or arch, which ex- 
 tends to the left of the spine. 
 
 The position of this curve or arch is so oblique, 
 with respect to the body, that the cord or diameter 
 of it, if it were extended anteriorly and posteriorly, 
 would strike the cartilage of the second or third right 
 rib about the middle of its length, and the left rib 
 near the head. In consequence of this position of 
 the curve, the aorta crosses over the right branch 
 of the pulmonary artery, and the left branch of the 
 windpipe : and assumes a situation, in front, and to 
 the left of the third dorsal vertebra: from this situa- 
 tion it proceeds downwards; in front, but rather on 
 
 * This name was given by A ristotle.— Et>. 
 
Situation ofthe Aorta in the Thorax fy Abdomen. 237 
 
 the left side of the spine, and in contact with that 
 column. 
 
 The aorta, as well as the Pulmonary Artery , 
 for a small distance from the heart, is invested by 
 the pericardium ; and, when that sac is opened, ap- 
 pears to be contained in it. 
 
 After crossing the right branch of the Pulmonary 
 Artery , a ligament is inserted into it, which proceeds 
 from the main trunk of the Pulmonary artery at its 
 division : this ligament was the Canalis Arteriosus 
 in the foetus. 
 
 As the aorta proceeds down the spine, it is si- 
 tuated between ,the two lamina of the mediastinum, 
 and in contact with the left lamen, through which it 
 mav be seen. It descends between the crura of the 
 diaphragm, in a vacuity which is sufficiently large 
 to admit of its passage without pressure from the 
 surrounding parts, and is still in contact with the 
 anterior surface of the spine, but rather te) the left of 
 • the middle of it. It continues this course along the 
 spine until it arrives at the cartilaginous substance 
 between the fourth and fifth lumbar vertebra, when 
 it divides into two great branches of equal size, 
 which form an acute angle with each other. These 
 are denominated the common, or primitive iliac 
 Arteries. 
 
 From the aorta in this course are sent off the ar- 
 teries which are distributed to all the parts of the 
 body for their nourishment and animation. ^ 
 
 From the curve proceed the great branches which 
 supply the heart, the head, the upper extremities, 
 and part of the thorax. Between the curve and the 
 great primitive iliac arteries, the aorta sends off 
 those branches which supply the viscera contained 
 in the cavities of the thorax and abdomen,* and part 
 
 * It ought to be observed here, that the viscera iu the lower part of the 
 pelvis receive some branches from the internal iliac arteries. 
 
238 Origin of the Subclavian and Carotid Arteries . 
 
 of the trunk of the body. The great ILIAC branches 
 of the AORTA are divided into smaller arteries, 
 which supply the whole of the lower extremities and 
 some of the viscera of the pelvis. 
 
 SECTION II. 
 
 Of the Branches which go off from the (well of the- 
 AORTA, 
 
 The proper arteries of the heart, denominated co- 
 ronary arteries, proceed from the aorta so 
 near to the heart that their orifices are covered by 
 the semilunar valves, vrhen those valves are pressed 
 against the sides of the artery. These arteries have 
 been described in the account of the heart.— -See 
 p. 50. 
 
 The arteries of the head and of the upper extremi- 
 ties proceed from the upper part of the curve in the 
 following manner. 
 
 A large trunk, called arteria innominata, goes 
 off first. This is more than sixteen lines in length, 
 when it divides into two branches : one of which 
 supplies the right side of the head, and is denomi- 
 nated the right carotid : the other proceeds to the 
 right arm, and from its course under the clavicle, is 
 called, at first, the right subclavian. Almost in 
 contact with the first trunk, another artery goes off, 
 which proceeds to the left side of the head, and is 
 called the left carotid. Very near to this, arises 
 the third artery, which proceeds to the left arm, and is 
 denominated the left subclavian. From these great 
 branches originate the blood vessels, which are spent 
 upon the head and neck and the upper extremities. 
 
 As these arteries arise from the curve of the 
 aorta, they are situated obliquely with respect to 
 each other. The arteria innominata is not only 
 
Situation of the Common Carotid Arteries. 239 
 
 to the right, bat it is also anterior to the two others : 
 and the left subclavian is posterior, as well as to 
 the left of the left carotid and the arteria in- 
 
 NOMINATA. 
 
 THE CAROTID ARTERIES. 
 
 The two carotid arteries above mentioned have 
 been denominated common carotids, to distinguish 
 them from their first ramifications which are called 
 internal and external carotids. 
 
 THE COMMON CAROTIDS 
 
 Proceed towards the head on each side of the trachea : 
 at first they diverge, but they soon become nearly 
 parallel to each other, and continue so until they have 
 ascended as high as the upper edge of the thyroid 
 cartilage, when they divide into the internal and 
 
 EXTERNAL CAROTIDS. 
 
 These arteries are at first very near each other, 
 and rather in front of the trachea ; they gradually 
 diverge and pass backwards and outwards on the 
 sides of it, and of the oesophagus, until they have ar» 
 rived at the larynx. In the lower part of the neck 
 they are covered by the sterno mastoidei, the sterno 
 hyoidei, and thyroidei, as well as by the platysma 
 myoidei muscles. Above, their situation is more su- 
 perficial ; and they are immediately under the pla- 
 tysma myoides. 
 
 On the inside, they are very near the trachea and 
 larynx, and the oesophagus ; on the outside, and ra- 
 ther anterior to them, are the internal jugular veins; 
 and behind, on each side, are two important nerves 
 called the intercostal and the par vagum . These 
 blood vessels and nerves are surrounded by absor- 
 bent vessels. 
 
£40 External Carotid Artery. 
 
 The common carotid artbries send off no 
 branches from their origin to their bifurcation ; and 
 they appear to preserve the same diameter through- 
 out their whole extent. In some few instances the 
 right carotid has been found larger than the left. 
 The external and internal branches into which they 
 divide, are nearly equal in the adult ; but it is sup- 
 posed that the internal is the largest during infancy. 
 The relative position of these branches is also differ- 
 ent at the commencement from what it is afterwards. 
 The internal carotid forms a curve which pro- 
 jects outwardly, so as to be exterior to the exter- 
 nal carotid, while this last proceeds upwards, and 
 rather backwards. 
 
 THE EXTERNAL CAROTID ARTERY 
 
 May be considered as extending from its commence- 
 ment, which is on a line with the superior margin of 
 the thyroid cartilage, to the neck of the condyle of 
 the lower jaw, or near it. 
 
 At first it is superficial ; but as it proceeds up- 
 wards it becomes deep-seated ; and passing under 
 the digastric and stylo-hyoidei muscles, and the ninth 
 pair of nerves, is covered by the Parotid Gland. 
 After this, it again becomes superficial ; for the tem- 
 poral artery, which may be regarded as the contin- 
 uation of the external carotid, passes over the zygo- 
 matic process of the temporal bone. 
 
 As the external carotid supplies with' blood the 
 upper part of the neck and throat, the exterior of 
 the head and face, and the inside of the mouth and 
 nose ; its branches must necessarily be numerous, 
 and must pass in very various directions. 
 
 Thus, soon after its commencement, it sends off, in 
 an anterior direction, three large branches; viz. to the 
 upper part of the neck, to the parts within the lower 
 jaw, and to the cheeks and lips. These are deno- 
 
External Carotid and its Branches. 241 
 
 minated, the superior thyroid, the sublingual, 
 and the facial. It then sends off to the back of the 
 head one which is called the occipital ; and, as it 
 proceeds upwards near the condyle of the lower jaw, 
 another which passes internallv, behind the jaw, to 
 the deep-seated parts in that direction. After this, 
 it forms the temporal artery, which supplies the fore- 
 head and central parts of the cranium. Besides these 
 larger branches, the external carotid sends of two 
 which are smaller ; one from near the origin of the 
 sublingual artery, which is spent principally upon the 
 pharynx and fauces, and is called the inferior pha- 
 ryngeal : and another, while it is involved with the 
 parotid gland, which goes to the ear; and is there- 
 fore called posterior auris. 
 
 These arteries are distributed in the following 
 manner : 
 
 1. The superior thyroid branch 
 
 Comes off very near the root of the external carotid, 
 and sometimes from the common trunk ; it runs ob- 
 liquely downwards and forwards, in a meandering’ 
 course, to the thyroid gland, where it is speut. Dur- 
 ing this course it sends off one branch to the parts 
 contiguous to the os hyoides ; another to the neigh- 
 bourhood of the larynx : and a third branch, which 
 may be termed laryngeal , that passes with a small 
 nerve derived from the laryngeal branch of the par 
 vagum, either between the os hyoides and thyroid 
 cartilage, or the thyroid and cricoid cartilages, to 
 the interior muscles of the larynx ; and finally re- 
 turns again to terminate externally. 
 
 While in the thyroid gland this artery anastomo- 
 ses with the inferior thyroid, and also with its fellow 
 •on the opposite side., 
 
 VoL, IX. 31 
 
242 Brandies of the External Carotid . 
 
 t. The LINGUAL, or sublingual branch, 
 
 Goes off above the last mentioned artery, and very 
 near it ; but in a very different direction, for it runs 
 upwards and forwards, to the tongue. In this course 
 it crosses obliquely the os hyoides, and is commonly 
 within the hyoglossus muscle. It gives off branches 
 to the middle constrictors of the pharynx, and to the 
 muscles contiguous to the tongue. It also sends off a 
 branch which penetrates to the back of ' the tongue, 
 which is called, from its situation, Dorsalis Linguse. 
 ^t the anterior margin of the hyoglossus muscle it 
 divides into two branches, one of which passes to the 
 sublingual gland and the adjacent parts, and is thence 
 called Sublingual ,* while the other branch, thei?am- 
 na , passes by the side of the genio glossus muscle to 
 the apex of the tongue. 
 
 3. The facial or external maxillary, 
 
 Runs obliquely upwards and forwards under the ninth 
 pair of nerves, the stylo hyoideus muscle and the ten- 
 don of the digastric, across the lower jaw and cheek, 
 towards the inner corner of the eye, in a serpentine 
 course. Before it crosses the jaw it sends off several 
 branches, viz. to the pharynx, the tonsils, the inferior 
 maxillary gland and the parts contiguous to it. It also 
 sends a branch towards the chin, which passes between 
 the mylo-hyoideus, the anterior belly of the digastric, 
 and the margin of the lower jaw : and some of its 
 branches continue to the muscles of the under lip. 
 This branch is called the Submental. 
 
 This artery then passes round the basis or inferior 
 edge of the lower jaw, very near the anterior margin 
 of the masseter muscle, and is so superficial that its 
 pulsations can be readily perceived. After this turn, 
 its course is obliquely upwards and forwards. Near 
 f he basis of the jaw it sends off a branch to the mas 
 
Branches of the External Carotid. 243 
 
 seter, which anastomoses with small branches from 
 the temporal ; and another which passes superficially 
 to the under lip and contiguous parts of the cheeks. 
 This last is called the Inferior Labial. 
 
 After the artery has passed as high as the teeth in 
 the lower jaw, it divides into two branches ; which 
 go, one to the under, and the other to the upper lip; 
 that to the upper lip is largest. These branches are 
 called Coronary. 
 
 The Coronary Artery of the lower lip passes under 
 the muscles called Depressor Angtili Oris, and Or- 
 bicularis Oris, into the substance of the lip, and 
 anastomoses with its fellow of the opposite side. 
 
 The Coronary Artery of the upper lip passes un- 
 der the zygoinaticus major and the orbicularis, and 
 very near the margin of the upper lip internally. It 
 also anastomoses freely with its fellow on the oppo- 
 site side. These anastomoses are frequently so con- 
 siderable that the arteries on one side can be well 
 filled by injecting those of the other. The coronary 
 branches, as well as the main trunk of the facial ar- 
 tery, observe a serpentine or tortuous course ; in con- 
 sequence of which they admit of the motions of the 
 cheeks and lips, which they would greatly impede 
 if they were straight. 
 
 from the upper coronary artery a branch conti- 
 nues in the direction of the main trunk of the fa- 
 cial artery, by the side of the nose, which extends 
 upwards, sending olf small branches in its course, 
 and finally terminates about the internal angle of the 
 eye and the forehead. 
 
 4. The INFERIOR PHARYNGEAL 
 
 Is a very small artery ; it rises posteriorly from the 
 external carotid, opposite to the origin of the sublin- 
 gual, and passes upwards to the basis of the era- 
 
244 Branches of the External Carotid. 
 
 nium. In this course it sends several branches to the 
 pharynx, and to the deep seated parts immediately 
 contiguous. 
 
 It also sends branches to the first ganglion of the 
 intercostal nerve, to the par vagum, and to the lym- 
 phatic glands of the neck ; and finally it enters the 
 cavity of the cranium by the posterior foramen ia- 
 
 cerum. 
 
 In some cases it also sends a small branch through 
 the anterior foramen lacerum. 
 
 5. The occipital artery 
 
 Arises from the posterior side of the external caro- 
 tid, nearly opposite to the facial, but sometimes 
 higher up ; it ascends obliquely, and passes to the 
 back part of the cranium, between the ; transverse 
 process of the atlas and the mastoid process of the 
 temporal bone. 
 
 In this course it passes over the internal jugular 
 vein and the eighth pair of nerves, and under the 
 posterior part of the digastric muscle ; it lies very 
 near to the base of the mastoid process, and under 
 the muscles which are inserted into it. After 
 emerging from these muscles, it runs superficially 
 upon the occiput, dividing into branches which ex- 
 tend to those of the temporal artery. 
 
 The occipital artery sends off branches to the 
 muscles which are contiguous to it, and to the glands 
 ef the neck. 
 
 It also gives off the following branches : one 
 called the Meningeal , which passes through the 
 posterior foramen lacerum to the under and back 
 part of the dura mater : one to the exterior parts of 
 the ear : another which passes downwards, and is 
 spent upon the complexus, trachelo mastoideus, and 
 other muscles of the neck : and' several smaller ar- 
 teries. 
 
Branches of the External Carotid. 245 
 
 The artery next to be described, is sometimes sent 
 off by the occipital artery. 
 
 6. The posterior auricular, or stylo mastoid 
 
 ARTERY, 
 
 When it arises from the external carotid, comes off 
 posteriorly from the artery, where it is involved with 
 the parotid gland, and passes backwards between the 
 meatus auditories externus and the mastoid process. 
 It then ascends, in a curved direction, and termin- 
 ates behind the ear. 
 
 In this course it sends off small branches to the 
 parotid gland, and to the digastric and sterno mas 
 toid muscles. Sometimes a distinct branch, which 
 is particularly visible in children, passes through an 
 aperture in the meatus auditorius externus, and is 
 spent on its internal surface. , 
 
 * It also sends off a branch which enters into the 
 Stylo Mastoid Foramen, and supplies small vessels 
 to the membrana tympani and the lining membrane 
 of the cavity of the tympanum; to the mastoid eeiis; 
 to the muscle of the stapes, and to the external semi- 
 circular canal. One of these vessels anastomoses, in 
 the upper and posterior part of the cavity of the tym- 
 panum, with a small twig derived from the artery of 
 the dura mater. When it has arrived behind the 
 ear, the Posterim' Auricular Artery terminates upon 
 the external ear and the parts contiguous to it. 
 
 7. The INTERNAL MAXILLARY ARTERY^' 
 
 Arises from the external carotid under the parotid 
 gland, at a little distance below the neck of the con- 
 
 * The general situation of this artery, and the distribution of several of 
 its most important branches, cannot be understood without a knowledge of 
 the bones through which they pass. The student of surgery will therefore 
 derive benefit from a re-examination of these bones, and of the zygomatic 
 fossa, &c. when he studies this artery. (See Y< 1. 1. page 73.) — He ought 
 
246 Th e Internal Maxillary Artery. 
 
 • 
 
 dyloid process of the lower jaw, and extends to the 
 bottom of the zygomatic fossa : varying its direction 
 in its course. It is rather larger than the temporal. 
 
 a. It first sends off one or two small branches to 
 the ear, and a twig which penetrates into the cavity 
 of the tympanum by the glenoid fissure. 
 
 b. It also sends off a small artery called the Les- 
 ser Meningeal, which passes upwards, and after 
 giving branches to the external pterygoid and the 
 muscles of the palate, passes through the foramen 
 ovale, and is spent upon the dura mater about the 
 sella turcica. 
 
 c. It then sends off one of its largest branches, the 
 Great or Middle Artery of the Dura Mater , which 
 passes in a straight direction to the foramen spinale, 
 by which it enters into the cavity of the cranium. 
 
 This artery ramifies largely on the dura mater, 
 and makes those aboreseent impressions which are 
 so visible in the parietal bone. It generally divides 
 into two great branches : the anterior, which is the 
 largest, passes over the anterior and inferior angle of 
 the parietal bone: the posterior branch soon divides 
 into many ramifications, which are extended lateral- 
 ly and posteriorly. 
 
 It furnishes the twig which passes to the ear by 
 the hiatus of Fallopius, and anastomoses with the 
 small branches of the stylo mastoid artery. 
 
 It also supplies some other small vessels which 
 pass to the cavity of the tympanum by small forami- 
 na near the junction of the squamous and petrous 
 portions of the temporal bone. 
 
 d. The next branch sent off by the internal max- 
 illary leaves it about an inch from its origin, and is 
 
 to be well acquainted with this subject, if he should undertake the man- 
 agement of necrosis of the jaw bones ; or of those fungous tumours, 
 which sometimes originate in the antrum iraxillare its well as of several 
 other complaints. 
 
The Internal Maxillary Artery, 247 
 
 called the Inferior Maxillary . It passes between 
 the internal pterygoid muscle and the bone, and after 
 giving small branches to the contiguous miiscles, en- 
 ters the canal in the lower jaw, in company with the 
 nerve. This canal has a very free communication 
 with the cellular structure of the jaw, and the artery 
 in its progress along it sends branches to the respective 
 teeth and the bone. At the anterior maxillary fora- 
 men, this artery sends off a considerable branch, which 
 passes out and anastomoses with the vessels on the 
 chin, while another branch passes forward and sup- 
 plies the canine and incisor teeth and the bone con- 
 tiguous to them. 
 
 Sometimes the inferior maxillary artery divides 
 into two branches before it has arrived at this fora- 
 men. In this ease, one of thp arteries passes out of 
 the foramen, while the other continues to the sym- 
 phisis. 
 
 e. Two branches pass off to the temporal muscle, 
 which originate at a small distance from each other : 
 one of them passes upwards on the tendon of the 
 temporal muscle ; the other arises near the tuberosity 
 of the upper maxillary bone: they are called the ex- 
 terior deep , and the interior deep temporal artery . 
 They are both spent upon the temporal muscle; . but 
 the interior branch sends a small twig into the orbit 
 of the eye. 
 
 F. There are some small branches which pass to 
 the Pterygoid Muscles and to the Masseter , which 
 arise either from the internal maxillary artery, or from 
 the anterior deep temporal. They are generally small, 
 and often irregular, 
 
 g.. An artery, particularly appropriated to the 
 cheek, perforates the buccinator muscle from within 
 outwards, and generally terminates on the buccinator, 
 the zygomatieus major and the muscles of the lips. 
 This Artery of the Cheek is very irregular in its 
 
248 The Internal Maxillary Artery. 
 
 origin, sometimes arising from the internal maxillary, 
 sometimes from the deep temporal, and sometimes 
 from the suborbitary, or from the alveolar artery, to 
 be immediately described. 
 
 h. The Alveolar Artery, or the Artery of the 
 Upper Jaiv, arises generally from the internal maxil- 
 lary, but sometimes from one of its branches. It winds 
 round the tuberosity of the upper jaw, and sends 
 branches to the buccinator muscle, to the bone and 
 the gums, to the antrum highraorianum, and some of 
 the molar teeth: and also to the teeth generally, by 
 means of a canal which is analogous to that of the 
 lower jaw. 
 
 i. The Infra orbitar Artery arises from the inter- 
 nal maxillary in the zygomatic fossa, and soon enters 
 the infra orbitary canal, through which it passes to 
 the face, and emerges below the orbit of the eye, 
 supplying the muscles in the vicinity, and anasto- 
 mosing with the small ramifications of the two last 
 described arteries, and also of the facial artery and 
 the ophthalmic. 
 
 This artery in its course sends off small twigs to 
 the periosteum, the adipose membrane, and the mus- 
 cles in the inferior part of the orbit, and also to the 
 great maxillary sinus or antrum highmorianum, and 
 to the canine and incisor teeth. 
 
 j. The Palato Maxillary , or Superior Palatine 
 Artery, arises also in the zygomatic fossa, and, de- 
 scending behind the upper maxillary bone, enters the 
 posterior palatine canal. It generally forms two 
 branches, the largest of which advances forward, 
 supplying the palate and gums, and finally sends a 
 twig through the foramen incisivum to the nose, while 
 the posterior branch, which is much smaller, supplies 
 the velum pendulum palati. 
 
 k. The Ptery go Palatine, or Superior Pharnygeal, 
 is a small vessel ; which sometimes arises from the 
 
249 
 
 Temporal Artery, 
 
 artery next to be mentioned. It is spent upon the 
 upper part of the pharynx, and a branch passes 
 through the pterygo palatine foramen, which is spent 
 upon the arch of the palate and the contiguous parts. 
 
 L. The internal maxillary at length termi- 
 nates in the Spheno- Palatine, or Large Nasal Ar- 
 tery, which passes through the spheno-palatine fora- 
 men to the back part of the nose. This artery 
 sometimes separates into two branches before it en- 
 ters the foramen; sometimes it enters singly, and 
 divides into two branches soon after; one of them is 
 spread upon the septum, and the other upon the ex- 
 ternal side of the nose ; each of these branches rami- 
 fies very minutely upon the Schneiderian membrane 
 and its processes in the different sinuses, and also in' 
 the ethmoidal cells. 
 
 8. The TEMPORAL ARTERY 
 
 Is considered as the continuation of the external ca- 
 rotid, because it preserves the direction of the main 
 trunk, although the internal maxillary is larger. 
 
 After parting with the internal maxillary it pro- 
 jects outwards ; and passing between the Meatus 
 Auditorius Externus and the condyle of the lower 
 jaw, continues upwards, behind the root of the zygo- 
 matic process of the temporal bone, to the aponeuro- 
 sis of the temporal muscle : on the outside of which, 
 immediately under the integuments, it divides into 
 two large branches denominated anterior and poste- 
 rior. 
 
 Before this division the temporal artery sends off 
 several branches of very different sizes. 
 
 One, which is considerable'in size, and called the 
 Transverse Facial Branch, advances forwards across 
 the neck of the condyle of the lower jaw, and giving 
 small branches to the masseter, runs parallel to the 
 parotid duct,, and below it. This branch is spent 
 Vol, it. • -32 
 
250 Temporal Artery.-— Internal Carotid . 
 
 upon the muscles of the face, and anastomoses With 
 the other vessels of that part. 
 
 The temporal gives off small branches to the pa- 
 rotid gland and to the articulation of the jaw. From 
 the last mentioned branch small twigs pass to the ear, 
 one of which enters the cavity of the tympanum by 
 tbe glenoid fissure. 
 
 ■While this artery is on a line with the zygoma, it 
 sends off a branch called the middle temporal artery , 
 which penetrates the aponeurosis of the temporal 
 muscle, and ramifies under it upon the muscle in an 
 anterior direction. 
 
 The two great branches of the temporal artery are 
 distributed in the following manner. The Anterior 
 passes up in a serpentine direction on the anterior 
 part of the temple, and supplies the front side of the 
 head, and the upper part of the forehead. 
 
 The Posterior extends upwards and backwards, 
 and supplies the scalp on the lateral and middle part 
 of the cranium, and also the bone. 
 
 Ramifications from each of these branches anasto- 
 mose on the upper part of the cranium with those of 
 its fellow of the opposite side. The anterior branch 
 also anastomoses on the forehead with the facial and 
 ophthalmic artery; and the posterior branch with the 
 occipital artery on the back part of the head. 
 
 THE INTERNAL CAROTID ARTERY 
 
 Is sometimes called the Artery of the Brain , as it is 
 almost entirely appropriated to that viseus. 
 
 From its origin to the commencement of its rami- 
 cations the course of this blood vessel is peculiarly 
 tortuous. In consequence of which the force of the 
 blood in it is greatly diminished before it arrives at 
 the brain. 
 
 An instance of this curvature occurs immediately 
 
Cnrmtnres cf the Internal Carotid . 251 
 
 after its separation from the external carotid, when it 
 protrudes outwards so much as to be exterior to that 
 vessel ; after this it ascends to the carotid canal, and. 
 in its course is in contact, or very near the par va- 
 gum and intercostal nerves. 
 
 The carotid canal in the os petrosum is by no 
 means straight; it forms a semicircular curve, for- 
 wards and inwards; and its upper portion, which is 
 nearly horizontal, opens obliquely against the body 
 - of the sphenoidal bone, at a small distance from it. 
 Therefore, after the artery lias passed through the 
 canal, it must turn upwards to get fairly into the 
 cavity of the cranium ; and of course, its direction 
 while in the canal, forms almost a right angle with 
 its direction before it enters, and after it emerges 
 from it. 
 
 In consequence of this curvature, much of the mo- 
 mentum of the blood must be impressed upon the 
 cranium. 
 
 After the artery has arrived at the end of the caro= 
 tid canal, and has turned upwards to get within the 
 cavity of the cranium, it bends forwards, and passes 
 nearly in a horizontal direction, through the caver- 
 nous sinus on the side of the sella turcica, to the an- 
 terior clinoid process ; here it again forms a conside- 
 rable curve, which is directly upwards, and then it 
 perforates the dura mater. 
 
 These curvatures must also deprive the blood of 
 the carotid of a portion of the momentum which it 
 has retained after leaving the bone. 
 
 The object of these various flexures of the internal 
 carotid appears to be analogous to that of the Rete 
 Mirabile in certain quadrupeds, which is formed by 
 the division of this artery into many small branches, 
 that reunite again, without producing any other ef- 
 fect than the diminution of the momentum of the 
 blood . 
 
252 
 
 Ophthalmic Artery. 
 
 During its course from the place of bifurcation to 
 its entrance into the carotid canal, the internal carotid 
 artery very rarely sends off any branches. In the 
 canal it gives off a small twig which enters the cavity 
 of the tympanum ; and sometimes a second which 
 unites with the Pterygoid branch of the internal 
 maxillary. 
 
 As it goes by the sella turcica, it passes through 
 the cavernous sinuses, and gives off two branches 
 which are called the Postet'ior and Anterior Arteries 
 of the Cavernous Sinus or Receptacle. 
 
 The posterior branch goes to that part of the dura 
 mater which is connected with the posterior clinoid 
 process, and the cuneiform process of the occipital 
 bone. It likewise gives branches to several of the 
 nerves which are contiguous, and to the pituitary 
 gland. 
 
 The anterior artery also gives branches to the con- 
 tiguous nerves, to the dura mater, and the pituitary 
 gland. 
 
 When the internal carotid turns upwards at the 
 anterior clinoid process, it sends off the 
 
 OPHTHALMIC ARTERY 
 
 Which passes under the optic nerve through the fo- 
 ramen opticum into the orbit of the eye, and is about 
 a line and a half in diameter. 
 
 Although this artery enters the orbit under the op- 
 tic nerve, it soon takes a position on the outside of it, 
 but afterwards gradually proceeds to the inner side 
 of the orbit, crossing over this nerve in an oblique di- 
 rection, and finally passes out of the orbit near the in- 
 ternal angle. In this spiral course it sends off nu- 
 merous branches, viz. 
 
 a. To those parts which are auxiliary to the eye. 
 
 b. To the bail of the eye. 
 
Branches of the Ophthalmic Artery. 253 
 
 c. To the cavity of the nose, through small fora- 
 mina in the ethmoid bone, and 
 
 d. To the forehead and external side of the nose. 
 
 These branches generally go off in the following 
 
 order. 
 
 1. The Lachrymal artery arises soon after the 
 ophthalmic arrives within the orbit, and passes 
 above the abductor muscle to the lachrymal gland, 
 where it terminates, sending off many small branches 
 in its course. 
 
 2. The Central artery of the retina also leaves 
 the ophthalmic soon after its arrival in the orbit: it 
 is a small vessel which penetrates into the centre of 
 the optic nerve, and passing with it into the eye is 
 spread upon the internal surface of the retina. Here 
 it appears to terminate in the adult ; but in the foetus 
 it is continued through the vitreous humour to the 
 capsule of the crystalline lens. 
 
 3. While the ophthalmic is passing over the optic 
 nerve the branches which enter the ball of the eye 
 leave it. Their number varies, but they form three 
 classes, viz. The Long Ciliary , the Short Ciliary. 
 and the Anterior Ciliary arteries. (See description 
 of the eye, vol. i. p. 352,) the supra orbitary and 
 muscular branches leave it also near the same places. 
 
 4. The Supra Orbitary Branch often gives off 
 several muscular twigs : but it passes out of the orbit 
 through the supra orbitar foramen, and generally 
 divides into two branches, one of which is spent 
 upon the periosteum, and the other upon the skin 
 and muscles of the forehead. 
 
 5. There are sometimes two muscular branches, a 
 Superior and an Inferior. The superior branch is 
 often deficient : when it exists it supplies the levator 
 palpebrae, the levator oculi, obliquus superior, &c. ; 
 but these parts are often supplied by the branches 
 above mentioned. The supra orbitar so frequently 
 
&o4 Branches of the Ophthalmic Artery* 
 
 gives off branches to the muscles that it has been 
 called the Superior Muscular Branch. The inferior 
 muscular branch is more constant. It commonly 
 supplies the rectus inferior, the adductor, and the 
 inferior oblique muscles, and also the lachrymal sac, 
 and the lower eyelid, &c. 
 
 When the artery is on the inside of the nerve it 
 sends off the two branches to the cavity of the nose, 
 viz, The Ethmoidal Arteries ; and also, branches to 
 the eyelids. 
 
 6. The Posterior Ethmoidal branch is first. It 
 passes between the levator and abductor muscles, 
 and above the obliquus superior ; and penetrates the 
 cavity of the cranium by the posterior orbitary fora- 
 men : after giving some twigs to the dura mater, it 
 passes to the posterior cells of the ethmoid by the 
 foramina of the cribriform plate of that bone, and 
 sends a small branch to the Schneiderian membrane 
 on the back part of the septum of the nose. 
 
 7. The Anterior Ethmoidal artery arises from the 
 ophthalmic nearly opposite to the anterior orbitary 
 foramen, through which it passes: and after enter- 
 ing the cranium is distributed like the other through 
 some of a foramina of the cribriform plate to the 
 anterior cells of the ethmoid bone, and to the ante- 
 rior part of the Schneiderian membrane on the sep- 
 tum of the nose, to which it sends a considerable 
 branch. 
 
 In its course it sends twigs to the frontal sinuses, 
 and to the dura mater and its falciform process. 
 
 8. The arteries of the Palpebrse are called Supe- 
 rior and Inferior ; they leave the ophthalmic near 
 the loop or pully of the superior oblique muscle. 
 The inferior comes off first ; it sends branches to the 
 ligaments of the tarsus, the caruncula lachrymalis, 
 and the parts connected with the cartilage of the un- 
 der eyelid, and unites with the lachrymal artery near 
 
Brandies of the Ophthalmic Artery. Carotid. 2 53 
 
 the external canthus, forming ail arch called the In* 
 ferior Tarsal Arch. 
 
 9. The Superior Artery supplies the superior part 
 of the orbicularis muscles, the ligament and carun- 
 cula also : and it likewise unites with a twig of the 
 lachrymal, and forms the superior tarsal arch. 
 
 Soon after sending off the palpebral branches, the 
 Ophthalmic Artery arrives at the internal canthus, 
 and then finally divides into two branches, the nasal 
 aiid the frontal. 
 
 10. The A r asal Branch passes above the superior 
 part of the lachrymal sac and the ligament of the 
 eye-lid to the nose ; after sending a twig to the fron- 
 tal muscle and the lachrymal sac, it passes down the 
 side of the nose and anastomoses with the facial ar- 
 tery. 
 
 11 . The Frontal Artery is not so large as the na- 
 sal ; it generally divides into three parts. . A super- 
 ciliary branch which is principally spent upon the 
 eyebrows ; a superficial branch which is spent upon 
 the forehead ; and a branch which is distributed to 
 the pericranium. 
 
 The mTEENAL carotid, soon after parting with 
 the ophthalmic, sends off, in a posterior direction, a 
 branch to join one from the vetebral artery. From 
 its distination this vessel is called the arteria com - 
 municans , 
 
 After this it sends off another branch, which is so 
 large that it may be considered as a continuation of 
 the main trunk : this is called the middle cadery of 
 the brain, or the Arteria Sylviana. It runs outwards 
 nearly in the direction of the fossa Sylvii, which se- 
 parates the anterior from the middle lobes of the ce- 
 rebrum. In its course it divides and subdivides into 
 numerous branches which are spread upon the Pici 
 Mater , and finally enter the surface of the brain, in a 
 very minute state. 
 
256 Right and Left Subclavian Arteries , 
 
 The internal carotid then terminates in a branch 
 which is smaller than the last mentioned, and from 
 its situation is called the Anterior Artery of the 
 Brain , or Arteria Callosa, This vessel first inclines 
 towards its fellow on the opposite side, and after ap- 
 proaching within half an inch of it, forms another 
 curve, and runs forward to the anterior part of the 
 brain, dividing itself gradually into branches which 
 pass in several directions. 
 
 When these anterior arteries are nearest to each 
 other, a small transverse branch, which passes at 
 right angles, connects them together. This branch 
 completes the anterior part of the Circle of Willis. 
 
 It crosses immediately before the sella turcica and 
 pituitary gland, and sends off branches. Which pass 
 to the third ventricle, to the fornix and septum luei- 
 dum, and also to the pia mater. 
 
 The Anterior Arteries of the brain also send off 
 branches to the optic and olfactory nerves ; to the 
 opposite surfaces of the two hemispheres on each 
 side of the falx ; to their inferior surfaces, and to the 
 corpus callosum. 
 
 They have likewise some branches which anasto- 
 mose with those of the middle artery of the brain, 
 and of the vertebral artery. 
 
 The SUBCLAV’IAN Arteries. 
 
 The right subclavian may be considered as the 
 continuation of the arteria innominata. This last 
 mentioned artery, after leaving the aorta, forms a 
 curve or arch, which extends obliquely backwards 
 and outwards, over the first rib to the axilla, crossing 
 the trachea in its course. At the distance of an inch 
 and a quarter, or an inch and a half from its origin, 
 it sends of the right carotid, and then, assuming the 
 name of Right Subclavian , continues in the above 
 stated direction- ' 
 
257 
 
 The Left Subclavian Jittery. 
 
 The chord of the carve of this artery, and the 
 chord of the curve of the aorta, are not in the same 
 direction, but form an angle with each other. 
 
 The position of the left subclavian is somewhat 
 different from that of the right. Its origin is posterior, 
 and, therefore, the direction of the chord of its curve 
 is more immediately lateral. The curve or arch is 
 also smaller. The situation of the two subelavians 
 as relative to the contiguous parts, is, therefore, 
 somewhat different ; but each of them proceeds be- 
 tween the anterior and the middle scaleni muscles, 
 and when they have arrived at these muscles, their 
 respective positions are very similar. 
 
 The anterior and middle scaleni muscles arise from 
 the transverse processes of several of the cervical 
 vertebrae, and are inserted into the first rib, one be- 
 fore the other, so as to leave a considerable space be- 
 tween them. The subclavian arteries § pass through 
 this 3pace, and before they arrive at it, but when they 
 are very near the above mentioned muscles, they 
 send off several very important branches in various 
 directions, viz. to the cavity of the cranium, to the 
 parietes of the thorax, to the thyroid gland, and to 
 the lower part of the neck. 
 
 They proceed near to the scaleni muscles before 
 they send off any branches ; and it is to be observed, 
 that the subclavian veins which correspond with these 
 arteries, are anterior to them, for they pass before 
 the scaleni muscles, and not between them. 
 
 The internal mammary Jlrtery 
 
 Goes downwards, from the lower and anterior part 
 of the subclavian, along the inner side of the anterior 
 scalenus muscle. It proceeds, exterior to the pleura, 
 across the cartilages of the true ribs, and and near their 
 middle ; and, continuing between the cartilages and 
 the diaphragm, exterior to the peritoneum, term!* 
 tTo h. Ho 3fS 
 
258 Course and Distribution of the Inferior 
 
 nates on the rectus .abdominis muscle, in branches 
 which anastomose with those of the epigastric artery. 
 In this course it gives branches to almost all the 
 parts to which it is contiguous, viz. to the muscles 
 and glands at the lower part of the neck ; to the 
 thymus gland ; to the parts in the intercostal spaces; 
 to the sternum ; to the mediastinum and pericar- 
 dium ; to the diaphragm and to the muscles of the 
 abdomen. 
 
 From some of its ramifications upon the parts be- 
 tween the ribs, small branches go off to the mamma, 
 and thereby give a name to the artery. There is also 
 a small vessel which is sent off by the mammary ar- 
 tery, or by one of its upper branches, which accom- 
 panies the phrenic nerve to the diaphragm. 
 
 The inferior thyroid Artery 
 
 Arises from the upper side of the subclavian nearly 
 opposite to tKe origin of the internal mammary. It 
 passes upwards and inwards, between the carotid 
 artery and the spine, to the thyroid gland : then it 
 anastomoses with the branches of the superior thyroid 
 on the same side, and with those of its fellow on the 
 opposite side. 
 
 This vessel sometimes sends off large branches to 
 the muscles at the lower part of the neck. 
 
 The vertebral Artery 
 
 Arises from the upper and posterior part of the sub- 
 clavian. It goes upwards and backwards between 
 the muscles which lie on the front of the spine, and 
 passing under the transverse process of the sixth or 
 seventh cervical vertebra, enters into the canal form- 
 ed in the transverse processes of the vertebrae. In 
 this course, as it proceeds from the «third to the se- 
 cond cervical vertebra, it inclines outwards laterally , 
 and, in its passage from the traosvere process of 
 
Thyroid and the Vertebral Arteries, 259 
 
 the second to that of the first vertebra, it forms a 
 considerable curve, the convexity of which has a 
 lateral and external aspect. After passing the trans- 
 verse process of the Atlas , it is turned suddenly 
 backwards, in a groove, and finally passes through 
 the great occipital foramen into the cavity of the cra- 
 nium. It then proceeds upon the cuneiform process, 
 of the occipital bone, under the Medulla Oblongata , 
 and joins its fellow so as to form an acute angle with 
 it near the union of the medulla oblongata with the 
 pons Varojii. From each of the vertebral arteries, 
 before their union, there generally goes off a small 
 branch called the Posterior Meningeal , which is 
 spent upon the posterior part of the dura mater. 
 
 The trunk formed by the union of the vertebral 
 arteries is called 
 
 The BASILAR Artery . 
 
 It extends forward near to the anterior part of the 
 pons Varolii, where it bifurcates ; but previously 
 sends off several branches on each side. The first 
 pair go off in a lateral direction, soon after its com- 
 mencement, near the back part of the pons Varolii, 
 and are spent upon the medulla oblongata, the pons 
 Varolii, and the other contiguous parts, and also 
 upon the fourth ventricle and the Plexus Choroides 
 of that cavity. They are called the Posterior or 
 Inferior Arteries of the Cerebellum. 
 
 Two other lateral branches, which are called the 
 Superior Arteries of the Cerebellum , go off from the 
 Basilar artery, near its anterior extremity. These 
 are principally spent upon the crura of the cerebel- 
 lum and cerebrum ; upon the cerebellum itself, and 
 the contiguous parts. 
 
 Soon after sending off the last mentioned arteries, 
 the Basilar artery divides into two branches, which 
 also take a lateral direction, and are of considerable 
 
260 Arteries of the lower part of the JYech. 
 
 size. In their course outward, these branches are 
 curved with their convexity forward. About ten of 
 twelve lines from its commencement, each of them 
 sends off a branch called the Arteria C omnium cans? - 
 which passes directly forward, and communicates 
 with the internal carotid, thus forming the arrange- 
 ment which is called the Circle of Willis .* After 
 sending off these arteries, they continue their lateral 
 direction, and are distributed principally to the pos- 
 terior parts of the cerebrum. These terminating 
 branches of the Basilar Artery , are called the Pos- 
 terior Arteries of the Cerebrum . 
 
 The superior intercostal Artery 
 
 Arises from the upper part of the Subclavian , after 
 the Vertebral and Thyroid arteries, and very near 
 them. It descends by the side of the spine across 
 the first and second ribs, near their heads, and exte- 
 rior to the great intercostal nerve. It generally forms 
 two branches, which are appropriated to the mus- 
 cles, &c. in the first and second intercostal spaces, 
 and sometimes a small branch is continued to the 
 third intercostal space. From each of these branches 
 a small vessel proceeds backwards, and is spent upon 
 the contiguous muscles, &c. on the back of the tho» 
 rax. The Intercostal Artery also sends a branch 
 upwards to the deep-seated parts of the neck. 
 
 In addition to the arteries above mentioned, there 
 are several others of considerable size which origi- 
 nate either directly or indirectly from the subcla- 
 
 * The arteria communicans is also considered as a branch of the Inter- 
 nal Carotid. The arrangement here alluded to is very remarkable. As 
 the branches which pass off laterally from the single trunk of the Basilar 
 Jittery unite to the Internal Carotids, and the Internal Carotids are united 
 to each other, there is an uninterrupted continuation of artery. Which en- 
 closes a portioh of space of a determined form ; but this form resembles 
 an oblong square more than a circle. By this connexion blood will pas? 
 from any one of the four arteries of t’ne brein <o all the others. 
 
Branches that go off in the Axilla, 261 
 
 Vi an, and are spent upon the lower portion of the 
 neck, and the contiguous parts. These arteries are 
 very different in different subjects, especially as to 
 their origin. Two of them, which have been called 
 the Anterior and Posterior Cervieals, are generally 
 distributed to the muscles and other parts which lie 
 on the lower portion of the neck anteriorly and pos- 
 teriorly. 
 
 A third, which passes transversely on the lower 
 part of the neck, is called the Superior Scapular. 
 
 In some cases the two Cervical Arteries arise from 
 the subclavian, after the mammary and the thyroid, 
 in a common trunk, which soon divides. Very fre- 
 quently they go off from the Inferior Thyroid . — 
 Sometimes one of them goes off from the Inferior 
 Thyroid , and the other from one of the branches of 
 tho Subclavian .* 
 
 The Superior Scapular most commonly arises with 
 some other artery, and very often from the Inferior 
 Thyroid. It runs transversely outwards, within and 
 above the clavicle, and passing through the notch in 
 the upper costa of the scapula, divides into branches 
 which are distributed to the parts on the dorsum of 
 that bone. 
 
 The subclavian artery, in Its progress from the 
 aorta to the axilla, forms an arch or curve, over the 
 first rib, as has been already observed. The ante- 
 rior scalenus muscle is before it, and the great nerves 
 of the upper extremity are above it. After passing 
 
 * Haller paid great attention to the arterial system, and made many dis- 
 sections, with a view to engravings of it, which he published with descrip- 
 tions, in folio fasciculi. 
 
 These fasciculi have been collected, and, with some other engravings, 
 form a large volume, entitled icones anatomic.se, which is truly valuable. 
 
 There are some very interesting observations on tills work of Haller’s, 
 and also on these arteries, in a description or the arteries, by Dr. Bar- 
 clay of Edinburgh, which I have read with advantage, as well as a work 
 on the muscles by the same author. 
 
£62 Branches that go off in the Axilla. 
 
 between the scaleni it descends upon the first and 
 second rib into the axilla. The nerves which were 
 above, descend with it : at first they are necessarily 
 exterior to it, but they form a plexus which the 
 artery enters into, so as to be partly surrounded, by 
 them. This course of the artery is obliquely under 
 the clavicle, and behind the pectoral muscle. In the 
 axilla, the vessel and nerves which surround it are 
 placed between the tendons of the pectoralis and the 
 latissimus dorsi muscles. Here the artery takes the 
 name of axillary, and sends off several important 
 branches. 
 
 The principal branches that go off from the axil- 
 lary artery are distributed, 
 
 1st. Anteriorly, to the pectoral muscle, and the 
 parts on the anterior surface of the thorax. 
 
 2d. Posteriorly, to the muscles which are on the 
 scapula and contiguous to it ; and 
 
 3 d. To the parts which are near the upper extre- 
 mity of the os humeri. 
 
 Anterior Branches . 
 
 The arteries which go to the pectoral muscle, &e. 
 are very various in different subjects, both as to their 
 number, origin, and size. 
 
 They have also been called by different names, as 
 Thoracicse, Mammarise Externse , fyc. 
 
 There are almost always three of them, and very 
 often more 5 one of them, which is called by several 
 authors the Acromialis, proceeds towards the end of 
 the clavicle, and generally passes out at the interval 
 between the deltoid and the pectoral muscle, sending 
 various branches to the contiguous parts ; the largest 
 of its branches often passing in the direction of the 
 interstice between those muscles. 
 
 Another of these arteries, which is called Superior 
 
Branches that go off in the Axilla. 263 
 
 Thoracic , is generally very small : it often is a branch 
 of the above mentioned Acromialis. 
 
 There is very often to be found here an artery 
 called the Inferior Thoracic , or the External Mam- 
 mary, which is of considerable length, although its 
 diameter is not very great. This artery originates 
 near the two last mentioned, and sometimes from the 
 Acromialis. It often extends downwards as low as 
 the sixth rib, and send branches to the anterior part 
 of the thorax, to the mamma, and the other contigu- 
 ous parts. Many of the small branches of this ar- 
 tery anastomose very freely with those of the inter- 
 nal mammary. 
 
 There are always small arterial branches in the 
 axilla, which ramify upon the glands and adipose 
 matter always existing there. They often arise by 
 one commom trunk, which is called the Axillary 
 Thoracie . 
 
 Posterior Branch . 
 
 One large artery is commonly sent to the muscles 
 on the scapula, which is called the Scapular , the 
 Common Scapular, or the Internal Scapular. It 
 commonly passes off from the axillary after the tho- 
 racic arteries, and supplies the muscles on both sur- 
 faces of the scapula. This large vessel passes down- 
 wards a short distance in the direction of the inferior 
 costa of the scapula, and soon sends off a branch 
 that winds round to the dorsum of the bone, to be 
 distributed to the infra spinatus and the contiguous 
 muscles, which is called the Dorsalis Scapulse. The 
 main trunk then inclines to the subscapularis muscle, 
 and generally divides into two branches, which are 
 distributed to the subscapularis, teres major, latissi- 
 mus dorsi, &c. 
 
 Sometimes the Scapular artery divides into two 
 branches before it sends off the dorsal. In this case 
 
264 Humeral Artery. 
 
 the last mentioned artery goes off from one of those 
 branches. 
 
 Branches near the Os Humeri . 
 
 The arteries which are near the body of the os 
 humeri at its upper end, are generally two in number, 
 and denominated the Anterior and Posterior Circum* 
 flex. Sometimes they arise separately, and some- 
 times in a common trunk from the axillary artery. 
 Frequently one of them arises from the scapular. 
 
 The Anterior Circumflex passes between the 
 united heads of the biceps and coraco-brachialis mus- 
 cles and the body of the os humeri, at a small distance 
 below its head. It sends branches to the capsular li- 
 gament, the periosteum of the os humeri, the mem- 
 branes of the groove for the long head of the biceps, 
 the upper portions of the biceps and coraco-brachia« 
 lis, and some contiguous muscles. 
 
 The Posterior Circumflex proceeds between the 
 subscapularis and teres major muscles, and continues 
 between the os humeri and the head of the triceps 
 and the deltoides. It is distributed to the muscles 
 and parts about the joint, especially the deltoides. 
 
 These arteries surround the os humeri, and the 
 small branches anastomose with each other. The 
 Posterior Circumflex is much larger than the Ante- 
 rior. 
 
 The great artery of the arm proeeeds from the 
 axilla to the elbow; and, during this course, is gene- 
 rally denominated 
 
 The HUMERAL Artery 
 
 Its direction is influenced by the position of the os 
 humeri. When the arm hangs down, with the palm 
 of the hand presenting forward, this direction is 
 
 It is called Brachial Artery by several Writers. 
 
Branches of the Humeral Artery. 265 
 
 somewhat spiral. The situation of the artery is on 
 the inside of the biceps muscles, and between that 
 muscle, and the triceps extensor. It also continues 
 very near and on the inside of the tendon of the bi- 
 ceps, and under the Aponeurosis which proceeds 
 from that tendon. In consequence of the spiral or 
 oblique course of the artery, its direction would be 
 from the inside of the tendon of the biceps to the ra- 
 dial side of the fore arm, but soon after it passes 
 across the joint of the elbow, it divides into two 
 branches : one which preserves, for some distance, 
 the direction of the Main Trunk, is called the Ra- 
 dial artery : the other, which inclines obliquely down- 
 wards and towards the ulna, is the Common Trunk 
 of the Ulnar and Interosseal arteries. 
 
 During this course, the humeral artery sends off 
 several branches to the muscles and other parts on the 
 os humeri. The largest of them is denominated the 
 Profunda Humeri or Spiralis. This artery very 
 often arises as high as the insertion of the latissimus 
 dorsi, and passing between the heads of the triceps 
 extensor muscle, proceeds downwards under that 
 muscle, in a spiral direction, towards the external 
 or radial condyle. It sends several branches to the 
 triceps and the contiguous muscles, and one consider, 
 able branch, which is generally called the Profunda 
 Minor , to the parts contiguous to the internal con- 
 dyle. The ramification of these branches near the 
 condyle frequently anastomose with small branches of 
 the radial and ulnar arteries.* 
 
 A small branch frequently arises from the Hume- 
 ral artery, at a short distance from the Profunda 
 Humeri , which sends a ramification to the medullary 
 
 * The Profunda sometimes originates from the scapular, or one of the 
 circumflex. The profunda minor sometimes has a distinct and separate 
 origin, lower down than the other. 
 
 Vol. n, 34 
 
266 
 
 Radial Artery. 
 
 foramen of the os humeri. This vessel is, therefore, 
 denominated Arteria JYutritia. 
 
 There are very often several anastomoses between 
 the branches of the humeral artery, which originate 
 above the elbow, and certain branches of the Radial 
 and Ulnar arteries, which are called from their di- 
 rection recurrents. Among these arteries there is 
 generally one of considerable size, which proceeds 
 across the elbow joint near the internal condyle.— 
 Sometimes this is the ulnar recurrent, which goes up 
 to anastomose with the branches of the profunda ; 
 but more frequently it is a separate branch of the 
 Humeral artery which goes off a little above the 
 elbow, and passes across the articulation, near the 
 internal condyle, to anastomose with tbe branches of 
 the ulnar artery. This artery is denominated the 
 Anastomotica. 
 
 There are often other branches sent off by the 
 humeral artery ; but they are commonly small, and 
 very irregular. 
 
 The two great ramifications of the humeral ar- 
 tery on the fore arm have very different directions. 
 The Radial artery preserving the course of the main 
 trunk, while the Common Trunk of the Ulnar and 
 Interosseal projects from it in a direction downwards 
 and towards the ulna, passing under the pronator 
 teres, &c. 
 
 The radial Artery 
 
 Passing over the pronator teres muscle proceeds be- 
 tween the supinator radii longus and the flexor carpi 
 radialis, very near to the lower end of the radius, 
 without changing its direction materially, being deep- 
 seated above and superficial below ; it then alters its 
 course, and, passing under the tendons of the exten- 
 sors of the thumb, to the back part of the radius, it 
 
Course and Ramifications of the Radial Artery . 267 
 
 continues between the metacarpal bones of the thumb 
 and of the index finger, when it divides into three 
 branches. 
 
 In this course it gives off but few branches. The 
 first is the Radial Recurrent, which passes upwards 
 and towards the external condyle, and frequently 
 anastomoses with the ramifications of the profunda 
 humeri. 
 
 The branches which it sends off between the origin 
 of the recurrent and the lower end of the radius arc 
 generally very small, and distributed to the parts im- 
 mediately contiguous to the artery.— Before it turns 
 under the tendons of the extensors of the thumb, it 
 sends a branch over the wrist towards the root of the 
 thumb, from which proceeds a branch to anastomose 
 with the volar branch of the ulnar ; and another, not 
 so large, which is frequently continued on the radial 
 or external side of the thumb, very near to its extre- 
 mity. While, the radial artery is under the aforesaid 
 tendons, it sends off small branches to the back of 
 the wrist and back of the hand, and often to the 
 back of the thumb. Those which are distributed to 
 the wrist and back of the hand, generally anastomose 
 with the small branches of the ulnar and interosseal 
 arteries. 
 
 The three branches into which the radial artery 
 divides between the metacarpal bones of the thumb 
 and index are, 1st, a branch to the external side of 
 the index ; 2dly, a branch to the thumb, that some- 
 times divides into two which pass up on the anterior 
 or volar surface, and sometimes continues, without 
 much diminution, on the internal side of the thumb, 
 near to the end of the last phalanx ; and, 3dly, a 
 branch, called Palmaris Profunda , which dips down 
 into the palm of the hand, and, proceeding in con- 
 tact with the metacarpal bones, under the flexor 
 tendons, forms an arch which extends across the 
 
268 Origin of the Ulnar and Interosseal Arteries. 
 
 hand, and often terminates by anastomoses with an- 
 other arch, soon to be described, which is formed by 
 the ulnar artery. 
 
 This flexure, which is denominated Arcus Pro- 
 fundus, sends off branches of a very small size, which 
 are distributed to the bones, ligaments, muscles, &c. 
 contiguous to it. 
 
 The common trunk of the ulnar and interos- 
 seal Arteries 
 
 Passes under several of the muscles which originate 
 from the internal condyle, and between the flexor 
 sublimis and the flexor profundus. Before the Ulnar 
 Recurrent goes off from this vessel, the interosseal 
 artery often leaves it. This recurrent artery passes 
 upwards between the muscles of the internal condyle, 
 and distributes branches among them. It then passes 
 up in the groove behind the internal condyle, and 
 anastomoses with the branches of the- Anastomotica 
 or Profunda Humeri. 
 
 The ulnar and interosseal arteries separate from 
 each other at the distance of fifteen or twenty lines 
 from the origin of the radial artery, very near the 
 commencement of the interosseal ligament. 
 
 The interosseal Artery 
 
 In a majority of cases, arises in a single branch from 
 the common trunk of the ulnar and interosseal. When 
 it does so, the single branch soon sends off the Pos- 
 terior Interosseal artery, which perforates the inte- 
 rosseous ligament, and passes down on its posterior 
 surface, while the main branch continues on the an- 
 terior surface of the ligament, and is denominated 
 the Anterior Interosseal Artery. In some cases the 
 main branch proceeds on the anterior surface as low 
 as the upper edge of the pronator quadratus muscle, 
 before it sends off tlie posterior branch, Sometimes 
 
269 
 
 Course of the Ulnar Artery. 
 
 the anterior and posterior interosseals arise separate- 
 ly. In this ease the posterior soon perforates the li- 
 gament. 
 
 The Anterior Interosseal passes down almost in 
 contact with the ligament, and gives branches to the 
 contiguous parts in its course. It generally perforates 
 the interosseous ligament near the wrist, and sends 
 off many small branches to the back of the wrist and 
 hand, which anastomose with the small branches of 
 the radial and the posterior interosseal arteries. 
 
 The Posterior Interosseal soon gives off a recur- 
 rent or anastomosing branch, and then proceeds down- 
 wards towards the wrist, sending branches in its 
 course to the extensor muscles and tendons. 
 
 This vessel sometimes divides into two branches. 
 
 The ulnae Artery. 
 
 The Ulnar artery proceeds among the muscles ob= 
 liquely downwards, and is not superficial until it has 
 arrived within three or four inches of the carpus : it 
 then continues towards the hand, sending off very 
 small branches in its progress. It passes over the 
 annular ligament at the wrist, and winds round the 
 pisiform bone : here it is supported by a delicate liga- 
 ment, which seems to lie upon it: from this it passes 
 upon the palm of the hand, under the aponeurosis 
 palmaris, and over the tendons of the flexors of the 
 fingers. When thus situated, it forms, in perhaps a 
 majority of subjects, an arch or bow, called Arcus 
 Sublimis, which extends across the palm of the hand, 
 from the ulnar towards the radial edge, and, after 
 sending branches to the fingers, &c. from its convex 
 side, terminates near the root of the thumb, by anas- 
 tomosis with that important branch of the radial ar- 
 tery, which passes up on the inside of the thumb. 
 
270 
 
 Digital Jirt fries. 
 
 The Jlrcus Sublimis almost always sends off small 
 branches to the integuments, &c. on the palm of the 
 hand. It often sends off, near the root of the meta- 
 carpal bone of the little finger, a branch which passes 
 between the flexor tendons and the metacarpal bones, 
 and anastomoses with the jlrcus Profundus. It then 
 generally sends off a branch to the inner or ulnar 
 side of the little finger ; and afterwards three 
 branches in succession, which pass from its convex 
 side towards the angles formed by the fingers. These 
 are called 
 
 The Digital Arteries. 
 
 When they have arrived near to the heads of the 
 first phalanges of the fingers, each of these arteries 
 divides into two branches, one of which passes along 
 the side of one of the fingers to its extremity, and the 
 other on the opposite side of the next finger : and in 
 this way they pass on the sides of all the fingers, ex- 
 cept the inside of the little finger and the outside of 
 the index. 
 
 These branches of the digital arteries are called 
 Digito Radial and Digito XJlnar arteries, according 
 to the sides of the fingers on which they are placed. 
 They are situated on the angle, if it may be so term- 
 ed, which is formed by the anterior and lateral sur- 
 faces of each finger. In their course from the basis 
 to the extremity of the finger, they send off very 
 small transverse branches, which anastomose with 
 each other, especially near the other. Some trans- 
 verse branches are observable on the posterior as 
 well as the anterior surfaces. Near the extremity 
 of each finger, beyond the insertion of the flexor 
 tendon, the extremities of these arteries ramify mi- 
 nutely. Some of these small branches go to the 
 skin, and others anastomose with their fellows of 
 
Bronchial Artery. 271 
 
 the opposite side. Some also go to the back of the 
 fingers.* 
 
 section nr. 
 
 Of the Branches which go off between the arch and 
 the great bifurcation of the AORTA. 
 
 PART I. 
 
 In the Cavity of the Thorax. 
 
 THE arorta sends branches to the Lungs, to the 
 oesophagus, and to the parietes of the thorax. 
 
 The bronchial Arteries 
 
 Are the vessels which go from the aorta to the ram- 
 ifications of the trachea, and the substance of the 
 lungs. They are not large, and are very irregular 
 as to number and origin. 
 
 In a majority of cases the right lung is supplied, in 
 part, by a branch from the first aortic intercostal of 
 that side ; while the left lung receives two or three 
 branches from the aorta directly. In some eases a 
 large vessel arises from the aorta, which divides into 
 two branches, one of which goes to each lung. 
 
 * The distribution of the radial and uinar arteries in the hand, is very 
 different in different subjects. 
 
 Upon examining a large number of injected preparations in Philadelphia, 
 it was found that, in a very small majority of them, the ulnar artery form- 
 ed an arcus sublimis, whose branches extended as far as the ulnar side of 
 the index, and sometimes beyond it. 
 
 That, in near a third of the preparations, the ulnar artery ramified with- 
 out forming an arcus, and supplied only two of the digital branches, viz, 
 the first two on the ulnar side. In such cases the radial artery generally 
 made up the deficiency of the ulnar, but in a few instances the interosseal 
 wa6 extended on the palm of the hand, and supplied the radial side of the 
 middle finger and the corresponding side of the index. 
 
 In a few instances also the ulnar artery was still more deficient, and the 
 radial was proportionally extended. 
 
272 (Esophageal and Intercostal Arteries, 
 
 The Bronchial arteries frequently send small 
 branches to the posterior mediastinum, the pericar- 
 dium, &c. 
 
 Injections have shown, that there is a direct com- 
 munication between these vessels and the branches 
 of the pulmonary artery. 
 
 The (Esophageal Arteries 
 
 Are very small vessels, which generally arise from 
 the aorta, but sometimes are branches of the bron- 
 chials or intercostals that are spent upon the oesopha- 
 gus. They occur in succession, and sometimes are 
 five or six in number. They also send twigs to the 
 contiguous parts, and the lowermost often descend to 
 the stomaeh. 
 
 The Inferior Intercostals 
 
 Are the arteries which proceed directly from the 
 aorta to the parietes of the thorax. Their name is 
 derived from their position between the ribs. They 
 are ramified on the intercostal muscles and ribs, and 
 on the pleura and some of the contiguous parts. They 
 are called Inferior or Aorta Intercostals, to distin- 
 guish them from the superior intercostals, which are 
 derived from the subclavian artery. Their number 
 varies from ten to eight, according as the superior 
 intercostals are more or less numerous. 
 
 They originate in pairs on the posterior surface of 
 the aorta. The uppermost of them pass obliquely 
 upwards, and the lowermost nearly in a horizontal 
 direction, to the lower edges of those ribs to which 
 they are appropriated. They meet the rib near its 
 tubercle, or place of junction with the transverse 
 process of the vertebra, and then proceed forward, 
 between the internal and external intercostal mus- 
 cles, in a superficial but large groove, which is ge- 
 
Intercostal Arteries. 
 
 273 
 
 tierally to be found on the interior margin of the 
 lower surface of the rib.* There is necessarily a 
 difference in the length of the right and left inter- 
 costals, owing to the position of the aorta, which is 
 s’ather on the left of the spine. In consequence of 
 this circumstance, the oesophagus is anterior to, and 
 also in contact with those of the right side. 
 
 They generally send off an important branch, call- 
 ed the Dm'sal, which arises near their origin, and, 
 passing backwards, sends ramifications to the mus- 
 cles of the back. From this dorsal branch also pro- 
 ceeds a ramification, which enters the spinal cavity, 
 and is spent upon its membrane and upon the medulla 
 spinalis. 
 
 After the Intercostals, in their progress forward, 
 have passed beyond the middle of the ribs, they send 
 off a branch, which generally proceeds very near to 
 the upper side of the lower rib. The main trunk 
 generally leaves the lower edge of the rib when it 
 has arrived within one-third of the length of the bone 
 from its anterior extremity. It then generally di- 
 vides into several branches, some of which are spent 
 upon the pleura, and others on the intercostal and 
 the contiguous muscles. 
 
 According to the situation of the different inter- 
 costals, some of their ramifications communicate with 
 those of the internal and external mammaries, of the 
 phrenic, the lumbar, or the epigastric arteries. 
 
 * See Vol. I. page 95. 
 
 35 
 
 Vol. n. 
 
274 
 
 Cavity of the Abdomen . 
 
 PART II. 
 
 In the Cavity of the Abdomen . 
 
 The aorta passes into the cavity of the abdomen 
 between the crura of the diaphragm, as has been al- 
 ready mentioned. In its course from the crura to its 
 great bifurcation, it sends off one pair of small arte- 
 ries, called Phrenie , to the diaphragm. Three sin- 
 gle arteries, the cceliac, the superior, and the in- 
 ferior mesenteric, to the viscera of the abdomen. 
 A pair of large arteries, the emulgents, to the kid- 
 neys, with several that are very small to their ap- 
 pendages ; as the Spennatices, Capsular , the Ure- 
 teric, and the Adipose . In addition to these, there 
 is one pair of small arteries that go to the testicles, 
 or to the ovaria and the uterus, and four or live pair, 
 called Lumbar Arteries, that go off laterally, like 
 the intercostals, to the parietes of the abdomen, and 
 to the muscles, &c. on the back, which are contiguous 
 to them. 
 
 The phrenic Arteries 
 
 Are ramified on the concave surface of the dia- 
 phragm, and are almost always two in number ; they 
 are denominated right and left from their position. 
 They commonly originate separately from the aorta, 
 but sometimes they arise in a common trunk which 
 soon divides. In some instances they are derived 
 from the cceliac. In a few cases, the aorta furnishes 
 one, and the cceliac the other. Each of the phrenic 
 arteries commonly crosses the crus of the diaphragm 
 on its respective side, and proceeding laterally, in a 
 circular direction, often ramifies so as to form an in- 
 
Distribution of the Cceliac Artery, 275 
 
 ternal and external branch. Each of them generally 
 sends branches to the cardia or oesophagus, to the 
 glandule renales, and other contiguous parts. 
 
 The CCELIAC Artery 
 
 Is the first great branch given off by the aorta in the 
 abdomen, and is distributed almost entirely' to the sto- 
 mac h, the liver, and the spleen. It projects from the 
 anterior part of the aorta so as to form a right angle 
 with it, and is of course nearly horizontal, when the 
 body is erect. 
 
 The main trunk of this great artery is so remarka- 
 bly short, that it has been compared to the stump of a 
 tree : for at the distance of half an inch from its origin, 
 it generally divides into three branches, which pass 
 to the stomach, the liver, and the spleen, and are, 
 therefore, denominated the Gastric or Coronary , the 
 hepatic and the splenic arteries. 
 
 The first mentioned branch may be called 
 
 THE SUPERIOR CORONARY OR GASTRIC ARTERY, 
 
 To distinguish it from other branches, soon to be de- 
 scribed. It is commonly in the centre of the three 
 great ramifications of the cceliac, and is also the 
 smallest of them. It proceeds from its origin to the 
 upper orifice of the stomach or cardia, and continues 
 thence along the lesser curvature of that viscus, until 
 it approaches near to the pylorus. In this course it 
 sends branches to the oesophagus, which frequently 
 inosculate with the oesophageal arteries. It also fur- 
 nishes branches to the cardia, which partially surround 
 it ; and on this account, the artery has been called 
 Coronary. Some of these last mentioned branches 
 are often continued on the great extremity of the sto- 
 mach, and anastomose with those ramifications of the 
 splenic artery, called Vasa Brevia . 
 
 It continues on the lesser curvature between the 
 
£76- Distribution of 
 
 lamina of the small omentum* and sends off sueces- 
 sively branches which pass between the peritoneal 
 and muscular coats, and are distributed to the ante- 
 rior and posterior surfaces of the stomach, communi- 
 cating with the branches of the inferior gastric arte- 
 ries, soon to be described.# 
 
 THE HEPATIC ARTERY 
 
 Proceeds from the great ramification of the coeliac to 
 the transverse fissure of the liver called the Portse , in 
 which it generally divides into two branches. In this 
 course it very frequently sends off an artery to the 
 pylorus, which ramifies about the small extremity of 
 the stomach, and often inosculates with some of the 
 branches of the superior coronary. This branch is 
 called the Pylorica, and sometimes it arises from the 
 artery next to be mentioned. 
 
 The GASTRICA INFERIOR DEXTRA, 
 
 Which also generally originates from the main trunk 
 of the hepatic, but sometimes from one of its branches. 
 It is an artery of considerable size, which proceeds 
 along the great curvature of the stomach, from the 
 pylorus towards the great extremity, between the 
 lamina of the anterior portion of the omentum, and 
 distributes its ramifications to both sides of the sto= 
 maeh, and also to the Omentum . In its progress 
 from the hepatic artery to the stomach, it sends off 
 branches to the Duodenum , and to the right end of 
 the Pancreas . 
 
 The two great branches into which the hepatic 
 artery divides, are denominated right and leftfivom 
 the lobes of the viscus, to which they are respective- 
 ly appropriated. The right branch is the largest.— 
 
 * This artery sometimes sends a branch to the liver, When this is the 
 ’ease, it Ss always very large 
 
277 
 
 the Splenic Artery. 
 
 Before it penetrates the substance of the liver, it 
 sends off a branch to the gall bladder, called the 
 Cystic Artery . 
 
 The branches of the hepatic artery ramify very 
 minutely in the liver, as has been stated in the ac- 
 count of that organ. 
 
 The last great branch of the coeliae is 
 
 The SPLENIC Artery , 
 
 Which is generally supposed to be larger than the 
 hepatic in adults, although it is less in children. It 
 proceeds in a transverse direction from its origin to 
 the spleen : its course is not straight, but meandering 
 or serpentine. It is situated behind and above the 
 pancreas, and passes along the groove in the upper 
 edge of that viseus. In its progress, it sends off 
 many small branches, and one that is of considerable 
 size, to the Pancreas. It also sends one branch to 
 the left extremity of the stomach, which arises com- 
 monly from the main trunk, but sometimes from the 
 ramifications, which are soon to be mentioned. This 
 branch, which is called 
 
 The GASTRICA INFERIOR SINISTRA, 
 
 Is sometimes, but not often very large : Its course is 
 from left to right. It is situated between the lami- 
 na of the anterior portion of the omentum. It sends 
 some small branches to the omentum, and others 
 which are larger and more numerous, to both sides 
 of the stomach. Some of these last mentioned anas- 
 tomose with the ramifications of the gastrica dextra, 
 which come from the hepatic. 
 
 When the splenic artery approaches near to the 
 spleen, it divides into four, five, or six branches 
 each of which penetrates into that viseus by a dis* 
 
278 Distribution of the Superior' Mesenteric 
 
 tinct foramen, and then ramifies in the manner de» 
 scribed in the account of the structure of the spleen.* 
 Either from the splenic artery, or from these rami- 
 fications, four or five branches pass to the large extre* 
 mity of the stomach, and ramify there, communicating 
 with the vessels already described. These arteries 
 have received great attention from physiologists, and 
 are denominated Vasa Brevia . 
 
 The SURERIOR MESENTERIC, 
 
 Which is the second great branch given off in the 
 abdomen by the aorta, is not very different in size, 
 from the coeliac, and originates about half an inch 
 below it. It is distributed to the small intestines j 
 to that portion of the great intestine, which is situated 
 on the right side of the abdomen ; and to the arch of 
 the colon. From its origin it proceeds downwards, 
 under the pancreas, and over the lower portion of the 
 duodenum, to the commencement of the mesentery. 
 When it has arrived between the lamina of that mem- 
 brane, it descends in a direction which corresponds 
 with that of the root of the mesentery, }- and forms a 
 gentle curve, with its convexity directed towards the 
 intestines. It necessarily diminishes as it descends, 
 and generally terminates by anastomosing with one 
 of its own branches. — This great artery sends off 
 some very small ramifications to the pancreas and 
 the duodenum, while it is in their vicinity. It also 
 sends two or three branches to the transverse part of 
 the colon, to the right portion of the colon, to the be- 
 ginning of the great intestine, and the contiguous 
 portion of the ileon. These branches are commonly 
 termed the Colica Media , Colica Dextra , and Ilco 
 
 * It frequently happens that the splenic artery divides only into two or 
 three branches, and they subdivide so as to form five or six, which pene- 
 trate the spleen. 
 
 f Vol. IT p. 115, 
 
and the Inferior Mesenteric Arteries. 279 
 
 Colica. From the convex side of the curve, the 
 superior mesenteric sends off the important 
 branches which pass between the lamina of the me- 
 sentery, and supply the Small Intestines. These 
 branches are numerous, and many of their ramifica- 
 tions anastomose with each other so as to form 
 arches. From these arches go off other branches, 
 which anastomose again with some of similar origin; 
 and this process is repeated successively several 
 times, so that a net-work of blood vessels seems to 
 be formed on the mesentery. From the mesentery 
 the small ramifications are continued in great num- 
 bers to the intestines. Some of them anastomose 
 with each other on the coats of the intestine ; but an 
 immense number of minute arteries are continued to 
 thfe villous coat, so that, when they are successfully 
 injected, the surface of that coat appears uniformly 
 coloured by the injection.* 
 
 The INFERIOR MESENTERIC Artery 
 
 Does not go off from the aorta next in order after the 
 superior mesenteric, but succeeds it immediately on 
 the intestines, and continues the arterial ramifications 
 to the left portion of the colon , to which the branches 
 of the superior mesenteric do not extend. 
 
 This artery arises between the origin of the emul- 
 gents and the great bifurcation of the aorta, and pro- 
 ceeds downwards, inclining to the left, but keeping 
 near to the aorta. There are generally three branches 
 distributed to the left portion of the colon, which arise 
 from this artery, either separately, or by a common 
 trunk which soon divides. It frequently happens, 
 that one of these arteries arises separately, and two 
 by a common trunk. These are called the Left 
 
 * See the account of the termination of these arteries, at page 110 of 
 this volypie. 
 
280 Emulgent and Capsular Arteries. 
 
 Colic arteries; and are also sometimes denominated, 
 from their position, Superior , Middle , and Inferior . 
 The Superior generally anastomoses with that 
 branch of the superior mesenteric, which is called 
 Colica Media , and forms a remarkable arch, called 
 the Great Mesocolic Arch . The ramifications of the 
 other branches frequently anastomose with each 
 other, and are finally spent upon the left portion of 
 the colon. 
 
 The main trunk, diminished by sending off these 
 branches, but still of considerable size, runs down- 
 wards on the posterior part of the intestine rectum, 
 between that intestine and the sacrum, where it often 
 divides into two branches, which continue near to 
 the termination of the rectum. From them proceed 
 many ramifications that are spent upon the rectum. 
 Some of these ramifications anastomose with each 
 other, and others with the ramifications of the he- 
 morrhoidal artery, soon to be mentioned. 
 
 The EMULGENT or RENAL Arteries 
 
 Are the large vessels which pass from the aorta to 
 the kidneys. They arise between the superior and 
 inferior mesenteries, one on each side; and proceed 
 in a direction which is nearly reetangler to the 
 aorta. The right emulgent artery is necessarily 
 longer than the left, and it generally passes behind 
 the vena cava. When they approach near the con- 
 cave edges of the kidneys, each emulgent commonly 
 divides into three or four branches, which pass into 
 the fissure of that organ, and ramify in the manner 
 described in the account of it. Sometimes two arte- 
 ries proceed from the aorta to the kidney : but this 
 is not a frequent occurrence. 
 
 The Capsular Arteries 
 
 Are the small vessels which pass to the glandule 
 
2S1 
 
 Adipose and Spermatic Arteries. 
 
 renales. There are almost always several of them 
 appropriated to each gland. They often arise on 
 each side from the coeliae artery, the aorta, and the 
 emulgent. 
 
 The Adipose Arteries 
 
 Supply the adipose substance surrounding the kid- 
 neys.— There are several of them on each side, and, 
 like the last mentioned arteries, they are very small, 
 and arise from several sources as well as the aorta. 
 The testicles and ovaria are supplied by the 
 
 Spermatic Arteries , 
 
 Which are very remarkable for their great length and 
 small diameter. In a majority of cases these vessels 
 arise from the anterior surface of the aorta, a little 
 below the emulgents : but it often happens that the 
 left spermatic arises from the emulgent on that side. 
 They also sometimes arise from other neighbouring- 
 arteries. It has been observed when they arise from 
 the aorta, that the origin of one of them is generally 
 higher than that of the other. 
 
 They pass downwards, so as to form an acute an- 
 gle with the aorta, and proceed behind the perito- 
 neum, and before the psoas muscle and ureter. While 
 this artery is in contact with the psoas muscle, it 
 meets with the ramifications of the spei'matic vein 9 
 and, in its progress to the abdominal ring, also joins 
 the spermatic cord. In this course it sends off some 
 very small twigs to the contiguous parts, and others 
 that anastomose with similar ramifications from the 
 mesenteric, epigastric, &c. Before it arrives at the 
 testicle, it divides into several branches, two of which 
 generally go to the epididymis, and the others pene- 
 trate the upper and back part of the tunica albuginea 
 Yol, ii, 36 
 
282 
 
 Spermatic Arteries. 
 
 The Spermatic Arteries in the Female , 
 
 Instead of passing to the abdominal ring, proceed be- 
 tween the lamina of the broad ligaments, and send 
 branches to the ovaria, which, in some cases, may be 
 traced to the vesicles. They also send branches to 
 the fallopian tubes and uterus, and to the round liga- 
 ments. Those which are on the opposite sides of the 
 uterus, anastomose with each other and with the 
 branches of the hypogastric arteries. 
 
 The lumbar regions are supplied with arteries 
 which originate, like the intercostals, from the poste- 
 rior part of the aorta between the thorax and pelvis. 
 There are four or five of these vessels on each side, 
 and they are denominated 
 
 The Lumbar Arteries . 
 
 They pass between the spine and the psoas muscles, 
 and send branches to the spinal cavity, to the muscles 
 of the lumbar regions, and the abdominal muscles. 
 They anastomose with the internal mammary, the 
 epigastric, the circumflex of the ilium, &c. 
 
 A small artery passes off singly from the posterior 
 part of the aorta at its bifurcation, which is called 
 
 The Middle Sacral Artery. 
 
 It proceeds down the middle of the sacrum to the os 
 coccygis, and sends off lateral branches, which are 
 spent upon the contiguous parts, and inosculate with 
 the arterice sacra} laterales.. 
 
General Account of the Internal Iliac. 283 
 
 SECTION IV. 
 
 Of the Arteries which originate at and below the 
 Great Bifurcation of the Aorta. 
 
 The PRIMITIVE ILIACS 
 
 Form an acute angle with each other. They proceed 
 downwards behind the peritoneum, very near the 
 margin of the pelvis, without sending off any branch 
 of importance. At the junction of the sacrum with 
 the ossa ilea, they divide into two great branches : 
 the internal iliac, or hypogastric, which de- 
 scends into the pelvis ; and the external iliac, 
 which passes under the crural arch to the lower ex- 
 tremity. 
 
 The INTERNAL ILIAC, or HYPOGASTRIC, 
 
 Is distributed, in part, to the viscera of the pelvis and 
 the organs of generation, and also to the large mus- 
 cles exterior to the pelvis : it is, therefore, very large, 
 although not quite equal to the external iliac. 
 
 It has already been mentioned, that in the foetal 
 state, this vessel appeared to continue in a curved 
 direction from its origin to the lower part of the side 
 of the bladder, and from thence to the Umbilicus, 
 under the denominations of the Umbilical Artery. 
 From the convex side of this curve the different 
 branches of the internal iliac go off. In the foetal 
 state they are very small, in proportion to the umbi- 
 lical artery ; but as the artery becomes ligamentous, 
 these branches increase in size. 
 
 In the adult, the arrangement of these vessels is 
 very different. The internal iliac generally di- 
 vides into two great branches: the Gluteal, which 
 passes through the sacro sciatic notch, and ramifies 
 
5384 Smaller Branches of the Internal Iliac. 
 
 on the exterior and upper part of the os ilium : and 
 the Ischiatic, which passes downwards on the outside 
 of the tuberosity of the ischium. 
 
 The first of these large ramifications passes out of 
 the pelvis above the pyriform muscle, and the last 
 of them below it. Several smaller arteries arise from 
 these branches near their origin, or from the main 
 trunk of the internal iliac, which are distributed to 
 the different parts of the pelvis; and one important 
 •branch of the ischiatic, called the Pudic, proceeds 
 downward on the inside of the tuberosity of the is- 
 chium. 
 
 The first of the smaller branches which the inter- 
 nal iliac commonly sends off, is called the 
 
 Ileo Lumbalis : 
 
 It sometimes arises from the gluteal artery, and 
 sometimes from the main trunk of the internal iliac. 
 It passes outwards under the psoas muscle, and sud- 
 denly divides into two branches. One of them pro- 
 ceeds upwards, and is distributed* in the lumbar re- 
 gion, while the other ramifies on the illacus internus 
 muscle, and is spent on the contiguous parts. 
 
 There are also two or three small arteries called 
 
 Jlrteria Sacrse Later ales* 
 
 v 
 
 Which \sometimes arise singly, and sometimes in 
 common, from the great trunk. They also occa- 
 sionally originate from the gluteal artery. These 
 vessels enter the anterior foramina of the os sacrum, 
 to be distributed on the cauda equina and the mem- 
 branes which invest it. Some of their ramifications 
 anastomose with branches of the sacra media and 
 other contiguous arteries. 
 
 On the anterior side of the internal iliac, near the 
 origin of the above mentioned vessels, a ligament 
 which was originally the umbilical artery, goes off 
 
Smaller Branches of the Internal Iliac: §8 5 
 
 to the side of the bladder, and continues from thence 
 to the umbilicus. Sometimes it continues pervious 
 for a short distance, and then small branches pass 
 from it to the bladder. 
 
 In the female it also sends small branches to the 
 uterus and vagina. 
 
 In addition to these Vesical Arteries derived from 
 the umbilicals, there are other branches distributed 
 to the bladder, which arise very differently, in dif- 
 ferent subjects, from branches which are soon to be 
 described, as the hsemorrhoidal, pudic, &e. 
 
 From the anterior side of the internal iliac, or from 
 one of its great branches, an artery often arises which 
 passes out of the pelvis through the aperture in the 
 margin of the ligamentous membrane which closes 
 the foramen thyroideum of the os innominatum : this 
 is called the 
 
 Obturator Artery . 
 
 This vessel, while it is in the pelvis, often sends 
 small branches to the bladder and its appendages, and 
 to the obturator internus muscle. After it passes out 
 of the pelvis, it frequently divides into branches ; 
 some of which are spent on the obturator externus, 
 and the contiguous muscles, and others go to the hip 
 joint. The origin of this artery is variable. Most 
 commonly it arises from the internal iliac, but often 
 from the ischiatic, and sometimes from the gluteal. 
 In some instances it originates in a way that is par- 
 ticularly interesting when the operation for crural 
 hernia is to be performed, viz. from the epigastric 
 artery, soon to be described : for in this case the ob- 
 turator artery sometimes nearly surrounds the neck 
 of the hernial sac.* 
 
 See Astley Cooper’s great work on Hernia, Vol. I. 
 
 There is reason to believe that this position of the artery occurs more 
 frequently than has been supposed. 
 
286 Larger Branches of the Internal Iliac. 
 
 A small artery passes from the internal iliac or 
 one of its branches, to the rectum, which is called 
 the 
 
 Middle Hsemorrhoidal, 
 
 From its situation between the branches which are 
 sent to that intestine from the inferior mesenteric, 
 and those which go to it from the pudic. This arte- 
 ry is spent upon that part of the rectum, which is 
 above and in contact with the sphincter. It sends 
 branches to the prostate and vesiculte seminales in 
 males, and the vagina and bladder in females. 
 
 In females there is a peculiar artery, ■ 
 
 The Uterine , 
 
 Which originates either from the internal iliac, near 
 the origin of the ischiatic, or from one of its branches. 
 It passes between the lamina of the broad ligaments 
 to the cervix uteri, and penetrates the texture of that 
 organ. The size of this vessel varies with the vary- 
 ing size of the uterus. 
 
 The gluteal or posterior iliac Artery , 
 
 One of the two great branches of the internal iliac, 
 proceeds exteriorly through the sciatic notch above 
 the pyriform muscle, very near the edge of the bone. 
 On the outside of the ilium it generally divides into 
 two branches, one of which ramifies between the 
 gluteus medius and minimus, and the other between 
 the medius and maximus. It is principally spent 
 upon these muscles, and sends branches to the conti- 
 guous parts. 
 
 The ischiatic Artery , 
 
 The other great branch of the internal iliac, passes 
 through the sciatic notch below the pyriform muscle, 
 and proceeds downwards, between the great tro- 
 chanter of the os femoris and the tuberosity of the 
 ischium, under the gluteus maximus muscle. Soon 
 
287 
 
 Pndic Artery* 
 
 after its orgin, it commonly sends off a considerable 
 branch, the Arteria Pudica , which also passes down- 
 wards : it then continues its course as above mention- 
 ed, and its principal branches are distributed to the 
 gluteus maximus and the muscles of the upper and 
 back part of the thigh, while its smaller branches go 
 to the os sacrum and coccyx, and the contiguous 
 small muscles. 
 
 The PUDICA INTERNA, 
 
 As has been just mentioned, is often a branch of the 
 ischiatic artery, but sometimes originates immediately 
 from the internal iliac. It proceeds downwards and 
 inwards, diverging from the ischiatic, and passing be= 
 tween the two sacro-sciatic ligaments to the interior 
 side of the tuberosity of the ischium, whence it con- 
 tinues on the inside of the crus of the os ischium and 
 pubis until it approaches the symphisis, when it gen- 
 erally divides into three branches, which are spent 
 upon the organs of generation, from which circum- 
 stance the name of this artery is derived. 
 
 One or more branches from it also pass to the low- 
 er part of the rectum and sphincter ani, and are call- 
 ed the Lower Hsemorrhoidal Arteries . 
 
 In its course it sends off many small branches to 
 the contiguous parts ; one of which, called the Pfli 
 neal, leaves it near the transversus perinei, and passes 
 between that muscle and the skin, and between the 
 bulb of the urethra and the crus of the penis, to the 
 scrotum. 
 
 When the Pudic has arrived near the bulb of the 
 urethra it sends a branch into it, which is continued 
 into the corpus spongiosum urethras, and ramifies 
 there minutely. 
 
 At the symphisis of the pubis, it sends off a second 
 branch, which passes to the back of each crus, and, 
 proceeding along it, parallel to its fellow, terminates 
 
288 External Iliac. — Branches of the External Iliac , 
 
 in the glans penis: in this course it sends branches to 
 the elastic coat, to the integuments, and to the pre- 
 puce. This vessel is called the Arteria Dorsalis. 
 
 The main trunk of the pudic artery then penetrates 
 the corpus cavernosum, and proceeds through it in a 
 straight direction. Its ramifications appear to be dis- 
 tributed through the internal structure of the corpus 
 cavernosum, and some of them extend through the 
 septum to the other side, while others pass to the 
 corpus spongiosum urethrze. 
 
 The EXTERNAL ILIAC, 
 
 The great artery of the lower extremity, appears 
 soon after birth, like a continuation of the primitive 
 iliac, and proceeds along the brim of the pelvis be- 
 hind the peritoneum, to Poupart’s ligament or the 
 crural arch, under which it passes. 
 
 The psoas muscle is at first in contact with it on 
 the outside, and the internal iliac vein on the inside. 
 As it passes under PouparPs ligament, it is immedi- 
 ately anterior to the psoas and iliacus internus mus- 
 cles where they are united, and the crural nerve is 
 exterior to it. Before it arrives at the lower edge 
 of PouparPs ligament, it sends off 
 
 The Epigastric Artery. 
 
 Which arises on its internal side, and proceeds down- 
 wards and inwards about half an inch, then it turns 
 upwards and inwards, and continues in that direction 
 for a small distance, after which its course is less ob- 
 lique. It passes between the peritoneum and the ab- 
 dominal muscles, behind the spermatic cord, and the 
 round ligaments in females. 
 
 It generally changes its oblique direction after 
 passing about two inches, and then proceeds in con-- 
 
General Account of the Femoral Artery . 289 
 
 £act with the rectus, and very near its external edge. 
 Its ramifications are expended upon the anterior pa- 
 rietes of the abdomen ; and, after it has arrived as 
 high as the umbilicus, it commonly divides into 
 branches, which often inosculate with the ramifica- 
 tions of the internal mammary.* 
 
 An artery, which is rather smaller than the epigas- 
 tric, arises nearly opposite to it, but rather lower, 
 from the external side of the external iliac. It is 
 called 
 
 The Circumflex Artery of the Os Ilium , 
 
 And proceeds upwards and outwards to the upper 
 margin of the os ilium, along which it continues very 
 near to the spine. It is distributed principally to 
 the abdominal muscles, to the iliacus internus and the 
 psoas, and the parts contiguous. 
 
 The artery of the lower extremity, after passing 
 under PouparPs ligament, takes the name of 
 
 FEMORAL Artery , 
 
 And proceeds downwards in a direction so spiral, 
 that although it is in front at the upper part of the 
 thigh, it is completely behind at the lower part. It 
 sends branches to the muscles of the thigh, as the 
 aorta does to the viscera of the abdomen, viz. by a 
 few large vessels which extend and ramify to a great 
 distance among them. 
 
 The situation of the abductor muscles, and their 
 attachment to the os femoris, is such, that the artery 
 in this course must necessarily perforate their com- 
 
 * Several respectable surgeons have been taught by experience, that 
 when the abdomen is distended by ascites, the position of the epigastric 
 artery is so much altered, that it will sometimes be found in the middle of 
 the oblique line, which extends from the umbilicus to the superior anterior 
 spine of the ilium, 
 
 VOL, II, 
 
 3 ? 
 
290 Branches of the Profunda and the Femoral . 
 
 mon tendon, which it does at the distance of one- 
 third of the length of the bone from its lower end. 
 The aperture in this tendon corresponds precisely 
 with the general course of the artery ; and before 
 the artery enters this perforation, it is on the inter- 
 nal side of the bone ; after it has passed the perfo- 
 ration, it is on the posterior side of it. After 
 passing through the tendon of the abductors, it is 
 denominated The Popliteal Artery, and it retains 
 this name until it divides. 
 
 It then proceeds downwards, being very near the 
 bone, and between the tendons of the flexors of the 
 leg, covered by the great nerve of the lower extre- 
 mity, and very often also by the vein. After cross- 
 ing the articulation of the knee, when it is between 
 the heads of the gastrocnemii muscles, at the lower 
 edge of the popliteus muscle, it divides into the an- 
 terior tibial and the common trunk of the peroneal 
 and posterior tibial arteries. 
 
 The femoral artery, soon after emerging from 
 Poupart’s ligament, sends off very small branches to 
 the inguinal glands, and other contiguous parts. It 
 also sends off the 
 
 External Pudics , 
 
 Which are two or three small arteries that are gene- 
 rally spent upon the Scrotum in males, and the Labia 
 Pudendi in females. 
 
 About two inches below Poupart’s ligament, the 
 great branch which has been called the muscular 
 artery of the thigh, leaves it. This vessel is com- 
 monly denominated 
 
 ARTERIA PROFUNDA. 
 
 It arises from the baek part of the trunk of the femo- 
 ral, and passes downwards and backwards, in a way 
 that has been compared to the separation of the in» 
 
Branches of the Prof unda and the Femaral. 291 
 
 ternal iliac from the external. Very soon after its 
 origin, it sends off two branches, which proceed, one 
 on the internal, and the other on the external side of 
 the thigh, and are called the circumflexa interna and 
 externa. It then passes downwards behind the trunk 
 of the femoral, and sometimes very near it, on the 
 adductor muscles, and finally divides into branches, 
 which are called the Perforating. 
 
 The External Circumflex 
 
 Sometimes arises from the femoral, but most common- 
 ly is a branch of the profunda, as above stated. It 
 passes under the rectus and tensor vaginse femoris 
 towards the great trochanter, and generally divides 
 into two branches, one of which continues in the 
 transverse direction, and sends branches to the upper 
 and back part of the thigh, and the parts contiguous 
 to the joint ; while the other descends in the course 
 of the rectus femoris muscle, and some of its ramifi- 
 cations extend near to the outside of the knee. 
 
 The Internal Circumflex 
 
 Is often smaller than the other. It generally passes 
 between the psoas, and the pectineus muscles, and 
 continues round the thigh towards the lesser trochan- 
 ter. Its ramifications are expended on the upper por- 
 tions of the adductor muscles and the muscular parts 
 contiguous to the lesser trochanter. It also sends 
 branches to the articulation. 
 
 The Perforating Arteries 
 
 Are two or three ramifications of the profunda, which 
 pass through the adductor muscles, and are expended 
 upon the flexor muscles on the back of the thigh. 
 Some of the terminating branches of the profunda 
 itself are also called perforating arteries. 
 
 The next branch of importance which is sent off 
 
292 
 
 Branches about the Ham . 
 
 by the femoral artery, leaves it before it enters the 
 aperture in the tendon of the adductors, and is called 
 The Anastomotic Artery. 
 
 This vessel soon inclines downwards. Its ramifica- 
 tions extends into the vastus internus muscle ; some 
 of them follow the tendon of the adductors, and ram- 
 ify about the internal condyle. 
 
 Several small branches go off from the great artery 
 soon after it passes though the tendon of the adduc- 
 tors, which are distributed to the contiguous mus- 
 cles. Some of them are also called 
 
 Perforating Arteries. 
 
 Among them is the principal Medullary artery of the 
 os femoris. 
 
 In the ham, the great vessel there called 
 POPLITEAL, 
 
 generally sends ofF several small branches. Two of 
 them go off orf the inside, one above and the other 
 below the knee ; and two on the outside in the same 
 manner. They are named, from their situation, The 
 Superior and Inferior Internal , and The Superior 
 and Inferior External Articulary Arteries. 
 
 The Superior Internal artery perforates the ten- 
 don of the adductors above the internal condyle, and 
 ramifies minutely on the inner side of the joint. 
 
 The Superior External artery passes through the 
 lower portion of the biceps above the external condyle, 
 and ramifies minutely on the outer side of the joint. 
 Its superior ramifications anastomose with those of 
 the descending branch of the external circumflex, 
 while its inferior ramifications communicate with 
 those of the corresponding artery below. 
 
 The two inferior arteries originate nearly opposite 
 to the middle of the joint, and pass downwards. 
 
 The Inferior Internal artery passes under the 
 
293 
 
 Artery of the Leg. 
 
 internal head of the gastrocnemius muscle, on the 
 posterior and internal side of the head of the tibia. 
 Its ramifications communicate with those of the cor- 
 responding artery above and of the tibialis antiea.-=- 
 Below they also extend to the interior of the joint. 
 
 The Inferior External artery passes under the 
 external head of the gastrocnemius and the plantaris 
 muscle, and continues under the external lateral and 
 the capsular ligament. It is distributed on the ex- 
 ternal and inferior part of the articulation, and sends 
 also some branches to the interior of the joint. 
 
 There is frequently an azygous vessel, called the 
 Middle Articular artery, which arises from the back 
 of the popliteal, and is distributed to the posterior 
 part of the articulation. 
 
 The popliteal artery, after this, sends off a few 
 small branches to the heads of the muscles of the leg, 
 and among them one of considerable length, to each 
 of the heads of the gastrocnemii. At the under 
 edge of the popliteus muscle, it sends off horizon- 
 tally a large branch which passes directly forward 
 between the tibia and fibula, above the commence- 
 ment of the interosseous ligament. After this it con- 
 tinues to descend, nearly in the same direction, un- 
 der the soieus muscle, behind the tibia ; but before 
 it has proceeded further than twelve or fifteen lines, 
 it sends off a branch which forms an acute angle with 
 it, and approaches near the fibula, along which it de- 
 scends. 
 
 The branch sent off anteriorly, is called the Ante- 
 rior Tibial artery. 
 
 The main trunk, which continues downwards, is 
 called the Posterior Tibial artery ; 
 
 And the branch which descends near the fibula is 
 called the Peroneal or Fibular artery. 
 
294 
 
 Anterior Artery of the Leg . 
 
 The anterior tibial Artery , 
 
 After its arrival on the anterior part of the leg, pass= 
 es down close to the interosseous ligament, with the 
 tibialis anticus muscle on the inside, and the extensor 
 communis on the outside, in the first part of its 
 course; and afterwards, with the extensor pollicis 
 pedis on the outside of it. It gradually inclines in* 
 ternally as it descends, so that a little above the ankle 
 it is upon the front part of the tibia. It proceeds 
 thence with the tendons of the extensor digitorum 
 pedis, under the annular ligament, to the upper sur- 
 face of the foot, on which it continues to the inter- 
 stice of the first and second metatarsal bones, where 
 it descends to anastomose in the way presently to be 
 mentioned. 
 
 In this course it sends off, soon after it has arrived 
 at its anterior situation, a recwrent branch, which 
 Is distributed to the heads of the muscles and the 
 ligaments of the articulation, and which anastomoses 
 with the branches of the inferior articular arteries. 
 It also sends off, on each side, many arterial twigs 
 to the contiguous muscles, and very frequently one 
 branch of considerable size, which passes down near 
 the fibula. 
 
 When it has arrived near the end of the tibia, it 
 sends a branch on each side, called the Internal and 
 External Malleolar. On the top of the foot, among 
 several smaller arteries, it sends off a branch under 
 the extensor brevis digitorum pedis, which passes out- 
 wards and forwards, and supplies the muscles, &c. 
 on the upper part of the foot. This vessel is called 
 Arteria Tarsea. There is also another branch, call- 
 ed Metatarsea, which generally arises about the mid- 
 dle of the foot, and passes obliquely outward and for- 
 ward, supplying the contiguous parts. 
 
Posterior Tibicil and Peroneal Arteries. 295 
 
 The Anterior Tibial artery, having arrived at the 
 space between the metatarsal bones of the first and 
 second toes, bends down to the sole of the foot, but 
 previously sends off a branch which passes near the 
 external edge of the metatarsal bone of the great toe, 
 and divides into two branches, one of which goes to 
 the outside of the great toe, and the other to the op- 
 posite side of the toe next to it. 
 
 The posterior tibial Artery , 
 
 After sending off the anterior tibial, parts with the 
 Peroneal or Fibzilar, as has been already stated, and 
 then continues on the back of the tibia, behind the 
 internal ankle, to the sole of the foot. 
 
 The Peroneal or Fibalar Artery 
 
 Is not commonly so large as either of the two other 
 arteries of the leg, nor is it so constant. It passes 
 down very near the internal edge of the fibula. It 
 is in contact, for some distance, with the tibialis pos- 
 ticus muscle, and is anterior to the soleus and the 
 flexor pollicis longus ; it sends branches to the 
 contiguous muscles. After it has passed along two- 
 thirds of the length of the fibula, it frequently, but 
 not always, divides into an anterior and a posterior 
 branch. 
 
 The anterior peroneal soon perforates the interos- 
 seous ligament, and passing down some distance on 
 its anterior surface, continues to the ankle and upper 
 surface of the foot. It gives ramifications to all the 
 contiguous parts in its progress, and anastomoses 
 with some of the small ramifications of the tibialis 
 antica. 
 
 The posterior peroneal branch is the continuation 
 of the main trunk. It passes behind the external 
 malleolus, and ramifies upon the external side of the 
 foot. 
 
296 
 
 Arteries of the Foot . 
 
 The posterior tibial artery passes down, inclining 
 rather obliquely inwards, between the gastrocne- 
 mius internus, which is posterior to it, and the tibia- 
 lis posticus and flexor digitorum, which are anterior 
 to it. Upon the leg it gives off many small branches, 
 one of which, termed the Arteria JVutriiia Tibise 9 
 comes off high up,* and, after ramifying as it de- 
 scends, sends a branch to the medullary foramen of 
 the tibia. 
 
 At the lower part of the leg the Posterior Tibial , 
 is situated rather superficially between the tendo 
 Achillis and the tibia. It proceeds thence behind 
 the internal ankle in a deep situation, covered by an 
 annular ligament, and passes between the abductor 
 muscle of the great toe and the bones of the tarsus. 
 It then divides into two branches— the internal and 
 the external plantar arteries. 
 
 The Internal Plantar Artery 
 
 Is commonly much smaller than the other ramifica- 
 tion. It passes in the direction of the internal edge 
 of the foot, but at some distance from it, and often 
 lies between the aponeurosis plantaris and the ab- 
 ductor pollicis. It frequently terminates by anasto- 
 mosing with one of the arteries of the great toe, and 
 in its course sends off several branches to the conti- 
 guous parts on each side of it. 
 
 The External Plantar Artery 
 
 Is the continuation of the main trunk. It proceeds 
 outwards and forwards between the short flexor of 
 the toes and the flexor accessorius; and continues 
 afterwards between the first of these muscles and the 
 abductor of the little toe. At the metatarsal bone of 
 
 * This artery sometimes comes off from the popliteal. 
 
297 
 
 Arteries of the Foot . 
 
 the little toe it begins to curve, and continues its cur- 
 vature across the other metatarsal bones to the inter- 
 stice between the great toe and the one next to it, 
 passing between the tendons of the long extensor and 
 the metatarsal bones. At the interstice above mention- 
 ed, it anastomoses with the tibialis antica. The cur- 
 vature, thus formed, is called the Arcus Plantar is. 
 
 In this course, the External Plantar sends off se- 
 veral branches, to the heel and the parts of the foot, 
 especially on the external side; the deep-seated parts 
 of the foot being supplied from the eurve. 
 
 Digital branches go off from the curve, as they do 
 in the hand, from the curve of the ulnar. There is 
 first a small branch to the outside of the little toe ; 
 and then three regular branches, which pass to the 
 junction of the roots of the four small toes, and divide, 
 like the digital arteries of the hand, so as to send a 
 branch to the side of each toe. These digital arteries 
 pass between the muscle called Transversalis Pedis 
 and the metatarsal bones. Near the heads of these 
 bones, each of them generally sends off two arteries 
 that pass upwards between the interossei muscles and 
 the bones, and anastomose with the ramifications from 
 the top of the foot. 
 
 The External Plantar , soon after sending off the 
 third digital artery, anastomoses with the anterior 
 tibial, and then continues to the junction of the root 
 of the great toe with the one next to it, when it di- 
 vides into two branches, which go to the opposite 
 sides of those toes. In its course it also sends a branch 
 to the internal side of the great toe. 
 
 38 
 
 VOL. II. 
 
CHAPTER III. 
 
 OF THE PARTICULAR DISTRIBUTION OF THE VEINS. 
 
 Anatomists of great respectability have very dif- 
 ferent sentiments respecting the best method of de- 
 scribing the veins. Some of them, in order to follow 
 the course of the circulation, commence with the small 
 veins, and proceed to the large trunks which are 
 formed by their union. Others begin with the great 
 veins that empty into the heart, and proceed from 
 them to the small ramifications of the venous system, 
 in a direction the reverse of the circulation. 
 
 As the last method is the easiest for the student of 
 anatomy, it will be adopted here ; but it must always 
 be kept in mind, that the blood flows from the small 
 veins into the larger, and not from the latter into the 
 former, as the mode of description seems to imply. 
 
 The great trunk of the venous system differs con- 
 siderably from that of the arterial with respect to 
 its connexion with the heart ; for it communicates 
 with that organ in such a manner that, when viewed 
 from before, it appears like two vessels ; one open- 
 ing into the upper, and the other into the lower part 
 of the right auricle. When viewed from behind, it 
 appears like a continued tube, three-fourths of which 
 are deficient anteriorly ; and to the margin of this 
 deficiency the right sinus or pouch of the heart is 
 connected. 
 
 In some preparations of the heart, where all the 
 great vessels connected with it are much distended 
 by the injection, and the pulmonary vessels are in- 
 
299 
 
 The Feins of the Heart. 
 
 jected first, the right auricle is so much pressed 
 upon from behind, by the vessels which go to the 
 right lung, that the direction of the superior and in- 
 ferior portions of the vena cava, which thus commu- 
 nicate with it, is altered. Each of them is turned 
 obliquely forwards, so that it forms an angle with 
 the other. This occasions them to appear more like 
 distinct vessels than they otherwise would do. 
 
 The above mentioned portions of the great veins 
 are denominated the Superior or Descending , and the 
 Inferior or Ascending Vena Cava ,* as if they were 
 perfectly distinct and unconnected with each other. 
 
 The coronary Veins. 
 
 Which are exclusively appropriated to the heart, 
 may be considered here, as they are not included in 
 the general arrangement of the veins. 
 
 The great vein of the heart begins at the lower 
 part of the right auricle, very near to the septum, 
 which divides the two auricles. It soon proceeds to 
 the left in a circular direction, surrounded with adi- 
 pose matter, in the deep groove which exists between 
 the left auricle and the left ventricle. It continues 
 between the auricle and ventricle, until it is imme- 
 diately over the septum, which divides the two ven- 
 tricles. Here its direction changes, and it proceeds 
 to the apex of the heart, where its small ramifications 
 anastomose with others soon to be described. In its 
 course round the basis of the left ventricle, it sends 
 off several branches, one of which is considerable, 
 that proceed from the basis towards the apex of the 
 heart, ramifying on the surface of the left ventricle. 
 
 A second vein, much less than the first, appears 
 to proceed from the great vessel at its commence- 
 ment,* and continues on the lower flat surface of 
 
 * It often opens into the amide by a separate orifice. 
 
GOO Superior Vena Cava and its Great Branches . 
 
 the heart, between the two ventricles, to the apex, 
 accompanied by a branch of the right coronary ar- 
 tery. This has been called the Middle Vein of the 
 heart. 
 
 In addition to these there are several veins which 
 begin at the right auricle, and extend on the surface 
 of the right ventricle towards the apex of the heart. 
 These have been called the Anterior Veins. 
 
 SECTION I. 
 
 Of the SUPERIOR or DESCENDING VENA CAVA, 
 and the Veins ivhich communicate with it. 
 
 This great vessel proceeds upwards from the 
 superior and posterior part of the right sinus or 
 pouch of the heart;* and a portion of it is so involv- 
 ed by the pericardium, that it seems to be included in 
 that sac, as the heart is in this situation. It is some- 
 what anterior as well as to the right of the aorta. It 
 continues above the pericardium, adhering to the 
 right lamen of the mediastinum, and rather inclining 
 forward. When it is as high as the lower margin 
 of the upper rib, it sends off a very large branch, 
 which conveys the venous blood of the left arm and 
 the left side of the head and neck. This large vein, 
 which is very important, both on account of its size 
 and its situation, proceeds in a transverse direction 
 within the sternum, almost in contact with and but 
 little below the upper and internal margin of that 
 bone. Immediately behind or within the origin of 
 the left sterno-mastoid muscle, it divides into the 
 left subclavian, which preserves a transverse course, 
 and the left internal jugular, which proceeds to the 
 cavity of the cranium by the foramen lacerum. 
 
 After sending off" this transverse branch to the left, 
 
 * See (he description of the. heart.- in page 51. of this volume. 
 
301 
 
 Vena Azygos . 
 
 the great vein continues upwards and behind the 
 right sterno-mastoid muscle, and there sends off, near- 
 ly at right angles, the right subclavian vein. After 
 it has parted with this vein, it takes the name of In- 
 ternal Jugular, and continues to the right foramen 
 lacerum, in the basis of the cranium. The superior 
 vena cava is, therefore, principally formed by the 
 union of the subciavians and internal jugulars from 
 each side of the body. 
 
 Immediately after the superior cava rises above 
 the pericardium, before it divides as above stated, it 
 sends off, from its posterior part, a large vein which 
 is single, and therefore called 
 
 VENA AZYGOS. 
 
 This vessel projects backward above the right 
 pulmonary artery and right branch of the trachea, 
 and then curves downwards behind them. It pro- 
 ceeds down the spine to the right of the aorta and at 
 a small distance from it, into the abdomen, between 
 the crura of the diaphragm, and sometimes between 
 some of the portions of that muscle, which are at- 
 tached to the dorsal vertebrae. In the abdomen it 
 often anastomoses either with the lumbar veins or 
 the vena cava. 
 
 The azygos frequently sends off several small 
 veins from its curvature to the contiguous parts, and 
 also the right Bronchial Vein , which passes along 
 the ramifications of the trachea into the substance of 
 the lungs.* In its course downwards it gives off 
 branches to the oesophagus, some of which are consi- 
 derable. 
 
 The Inferior Intercostal Veins originate directly 
 or indirectly from the azygos. In some cases there 
 is no Superior Intercostal on the right side ; and then 
 
 This bronchial vein sometimes arises from the superior cava. 
 
302 Inferior intercostal Veins , 
 
 the two or three uppermost of the right intercostals, 
 are also derived from the azygos ; and often origi- 
 nate from it by a common trunk, which soon divides. 
 Most commonly the ten inferior intercostals on the 
 right side proceed directly from the azygos, and ac- 
 company the intercostal arteries. Their posterior 
 branches pass into the vertebral cavity, and commu- 
 nicate with the veins which are there. 
 
 About the sixth or seventh rib, the vena azygos 
 frequently sends off a branch to the left which de- 
 scends on the left side of the vertebrae, and sends off 
 those Left intercostal veins which are below its ori- 
 gin. It passes through the diaphragm with the aorta, 
 or to the left of it, and anastomoses either with the 
 azygos itself, or in a way which is analogous to the 
 anastomosis of that vessel. 
 
 The Vena Azygos may be regarded as the great 
 trunk of the veins of the parietes of the thorax, 
 which are thus collected, because they could not 
 with convenience pass singly to the vena cava, as the 
 arteries do to the aorta. 
 
 Soon after sending off the vena azygos, the Supe- 
 rior Cava sends off the great transverse branch 
 above mentioned. From this it continues upwards 
 but a short distance, when it divides, behind the 
 right sterno-mastoid muscle, into the right subcla- 
 vian and right internal jugular. 
 
 The branches of the superior cava, which thus 
 intervene between the great trunk and the subdi- 
 visions behind the sterno-mastoid muscles, are often 
 called the Subclavian Veins ; but they do not appear 
 to be accurately named. For, 1st, they are not situ- 
 ated under the clavicle, and, 2dly, they are the com- 
 mon trunks of the subclavians and internal jugulars 
 united. 
 
 There is a difference in the places where some of 
 the smaller veins originate on each side. The inter- 
 
303 
 
 Superior Intercostal Veins , 
 
 iial mammary and the inferior thyroid, on the right 
 side, arise from the superior cava, or from the sub- 
 clavian at its origin. On the left side they arise from 
 the subclavian. 
 
 The superior intercostal Veins 
 
 Are somewhat different on the two sides. That on 
 the right is often the smallest and the least exten- 
 sive. It commonly originates from the posterior and 
 inferior part of the subclavian opposite to the origin 
 of the vertebral, and is generally distributed to the 
 first and second intercostal spaces, but rarely to the 
 third. 
 
 The Left Intercostal frequently originates near the 
 left internal mammary, and sometimes in common 
 with it. It descends behind the aorta, on the left of 
 the spine, and commonly sends off the six upper in- 
 tercostal veins, of which the two or three superior 
 pass upwards from a part of the vein which is oppo- 
 site to the third dorsal vertebra. Its extent is very 
 different in different subjects. In some instances it 
 passes so low as to supply the seventh or eighth in- 
 tercostal space. This vein also gives off the Left 
 Bronchial Vein, which sends branches to the oeso- 
 phagus and bronchial glands. 
 
 The vertebral Veins 
 
 Arise from the subclavians, but sometimes they pro=> 
 ceed differently in different subjects : the right pass- 
 ing behind, and the left before, the subclavian artery 
 of its respective side. Each of them, however, be- 
 comes contiguous to its corresponding artery. When 
 it has arrived at the place in the transverse processes, 
 where the artery enters the vertebral canal, it sends 
 off an external branch, which passes up, before and 
 nearly in contact with, those processes, and gives 
 ramifications to the contiguous muscles, and also to 
 
304 
 
 Vertebral Veins. 
 
 the cavity of the spine. These last mentioned, rami- 
 fications enter by the lateral apertures between the 
 transverse processes, and anastomose with the veins 
 and sinuses of the cavity. The branch often finally 
 terminates in the lateral sinus of the dura mater, by 
 passing through the foramen near the mastoid process 
 of the temporal bone. The Main Trunk of the ver- 
 tebral vein generally sends off another external branch 
 to the muscles near the basis of the neck, and after- 
 wards enters the canal with the vertebral artery. 
 While in this canal it generally sends off two branches 
 through each of the lateral apertures between the ver- 
 tebrae. One of these branches passes backwards to 
 the muscles of the neck, and the other proceeds into 
 the great spinal cavity, and communicates with the 
 venous sinuses. 
 
 When it has arrived at the atlas, the Vertebral 
 vein sends branches to the contiguous muscles of the 
 neck. It also frequently sends a branch through the 
 posterior condyloid foramen of the occipital bone to 
 the lateral sinus. 
 
 It is evident, from these circumstances that the 
 vertebral vein carries a portion of blood from the 
 sinuses of the brain and of the spinal marrow, as 
 well as from the muscles of the neck, into the sub- 
 clavian veins. 
 
 The veins of the head are frequently very differ- 
 ent in different subjects. 
 
 The INTERNAL JUGULAR , 
 
 Already mentioned, is often almost exclusively ap- 
 propriated to the cavity of the cranium ; and all the 
 exterior veins of the head are ramifications of one or 
 more smaller vessels, which pass up superficially on 
 the neck, and are denominated External Jugulars . 
 In some instances almost all the exterior veins of the 
 head are united to the internal jugular at the upper 
 
The internal Jugular , 305 
 
 part of the neck, and it of course conveys the blood 
 of the exterior as well as of the interior parts of the 
 head. Frequently these veins are divided between 
 the internal and external jugulars, but they are di- 
 vided very differently in different subjects. 
 
 The Internal Jugular, however, almost always 
 passes in the same direction from the inside of the 
 origin of the sterno-mastoid muscle to the posterior 
 foramen lacerum of the cranium. It is deeply seat- 
 ed on the external side of the common carotid artery, 
 and under the sterno-mastoid muscle. Between the 
 upper margin of the thyroid cartilage and the angle 
 of the lower jaw, it often sends off branches which 
 are very different in different subjects, but commonly 
 pass to the anterior parts of the neck and face : 
 above these it generally sends another to communi- 
 cate with the external jugular. One of the branches 
 which often go off from the internal jugular is that 
 which corresponds with the superior thyroid or la- 
 ryngeal artery. This vein, which has sometimes 
 been called the Guttural, sends many ramifications 
 to the thyroid gland. The Ranular veins, which 
 are so conspicuous under the tongue, are also derived 
 from it ; and it likewise sends branches to the larynx 
 and pharynx. 
 
 Before the internal jugular enters the foramen la- 
 cerum, it suffers a partial dilatation, which is gener- 
 rally larger on one side than the other. * This dila- 
 tation occupies the fossa at the foramen lacerum. 
 After passing through the aforesaid foramen, the in- 
 ternal jugular terminates in the lateral sinuses of the 
 
 * When the veins of the neck are injected, it very often appears that a 
 considerable portion of the internal jugular is much larger on one side than 
 the other, as if it were affected with varicose distention. 
 
 It also often appears that the general arrangement of the exterior vein is 
 different on the two sides of the head and neck, 
 
 VOL, II. 39 
 
306 
 
 The External Jugular . 
 
 dura mater.* These and the other sinuses within 
 the cavity of the cranium are important portions of 
 the venous system, which are interposed between the 
 smaller branches spread upon the pia mater and the 
 great trunks of the neck. They are described in 
 the account of the brain, (Yol. I. page 316.) Into 
 these sinuses the very numerous veins of the pia 
 mater open, proceeding to the sinuses in a direction 
 the reverse of that in which the blood flows in those 
 channels. 
 
 These veins are divided very minutely on the pia 
 mater before they enter the substance of the brain. 
 
 Into one of these sinuses, denominated the Ca- 
 vernous, the ophthalmic vein discharges its contents. 
 This vein proceeds from the anterior part of the 
 sinus into the orbit of the eye through the sphenoid 
 fissure. t Its ramifications correspond generally with 
 those of the ophthalmic artery^ and some of them 
 pass out of the orbit to anastomose with the branches 
 of the facial vein. 
 
 The superficial veins of the neck are variously 
 arranged in different persons. There is often one 
 considerable vein, 
 
 The EXTERNAL JUGULAR, 
 
 Which is sent off by the subclavian, very near its 
 union with the internal jugular ; but sometimes it 
 goes off from that vein much nearer the shoulder. 
 There are sometimes two external jugulars, an ante- 
 
 * It is asserted that the internal coat, or lining membrane of the inter, 
 nal jugulars, is continued into the lateral sinuses, and extends throughout 
 all the sinuses of the dura mater ; so that the blood, during its passage 
 through the sinuses, does not come in contact with any membrane different 
 from that of the veins. 
 
 f See the account of this fissure in vol. i. p. 63. 
 
 t The Vasa Vorticasa of the choioides aie one of the exceptions to this. 
 See vol. i. p- 356. 
 
General Account of the Great Fein of the Arm. 307 
 
 rior and a posterior, nearly of equal size. More fre- 
 quently one of them is much smaller than the other. 
 In a majority of cases, the principal external jugular 
 goes off near the junction of the internal jugular and 
 subclavian, as above stated, and proceeds upwards 
 towards the angle of the lower jaw, passing between 
 the platysma myoides and the stern o- mastoid muscle. 
 It often sends off, at the basis of the neck, one or more 
 branches to the contiguous muscles, and then proceeds 
 upwards. Near the angle of the jaw, it often com- 
 municate&with the internal jugular : itthen continues 
 upwards, covered with the parotid gland, near the 
 temporal artery, and finally divides into superficial 
 and deep-seated temporal branches. 
 
 The External Jugular, near the angle of the jaw, 
 often sends off the facial vein, which crosses the basis 
 of the lower jaw, near the facial artery, and distri- 
 butes branches to the side of the face and to the fore- 
 head. It also very often sends off, near this place, 
 the internal maxillary vein, which generally ramifies 
 in such a manner that its branches correspond with 
 those of the internal maxillary artery. Veins which 
 correspond to some of the other branches of the exter- 
 nal carotid artery, the lingual, occipital, &c. are of- 
 ten sent off near this place by the external jugular. 
 They take the names of the arteries to which they 
 correspond, and commonly accompany them. 
 
 The SUBCLAVIAN Vein, 
 
 Although it originates differently on the two sides of 
 the neck, is situated alike on each of them. After 
 parting with the internal jugular, it proceeds over 
 the first rib, under the clavicle, and does not pass 
 between the scaleni muscles, as is the case with the 
 arteries, but before the anterior muscle. It soon 
 joins the great artery of the arm, and proceeds be- 
 fore or below it to the axilla. In this situation it gives 
 
308 General Account of the Great Vein of the Arm. 
 
 off branches to the contiguous parts, which correspond 
 with those given off by the artery. In this course 
 it also often gives off a large branch, called the 
 
 CEPHALIC, 
 
 Which soon becomes superficial, and proceeds down- 
 wards between the margins of the deltoid and pecto- 
 ral muscles : it continues superficial on the external 
 side of the biceps muscle, sending off many subcuta- 
 neous branches. Near the external condyle of the os 
 humeri, it generally sends off a branch towards the 
 middle of the anterior part of the fore-arm, which is 
 called the Median Cephalic, and also some other su- 
 perficial branches. It then continues over the radius, 
 and inclining to the back of the fore-arm, until it ar- 
 rives at the back of the hand, where it divides into 
 branches, some of which go to the thumb. 
 
 In the axilla, the great vein, there called 
 
 The AXILLARY Vein, 
 
 Generally divides into two or three branches. One, 
 which is commonly the largest, and appears like the 
 continuation of the main trunk, is called 
 
 The basilic Vein . 
 
 This vessel passes down, deeply seated, to the bend 
 of the elbow. It becomes superficial near the inter- 
 nal condyle, and divides into several branches. — One 
 of these generally proceeds to join the median branch 
 of the cephalic, and from the union of the two 
 branches is formed the median vein, which passes 
 down near the middle of the anterior part of the fore- 
 arm. This vein generally sends off a branch which 
 proceeds internally, and anastomoses with the deep- 
 seated veins of the fore- arm. 
 
 There are frequently two other branches of the 
 basilic vein. One, which is small, passes down on 
 
Situation of the Inferior Vena Cava. 309 
 
 the ulnar side of the anterior part of the fore-arm, 
 but does not extend to the wrist. The other passes 
 down on the ulna, and gradually proceeds to the 
 back of the hand, when it divides into several 
 branches, one of which is generally appropriated to 
 the little finger. 
 
 The axillary vein, after the Basilic leaves it, 
 sometimes divides into two branches, and sometimes 
 continues undivided. In either case it accompanies 
 the humeral artery, and takes the name of humeral 
 Vein or Veins. It sends off branches which corres- 
 pond to those of the artery, and continues to the bend 
 of the elbow ; here it is so divided, that two of its 
 ramifications accompany each of the three arteries of 
 the fore-arm. These ramifications sometimes com- 
 municate with each other by anastomosing branches 
 near the elbow, and they communicate also with the 
 superficial veins. 
 
 The superficial veins of the arm are so different in dif- 
 ferent subjects, that a general description will rarely 
 apply accurately to an individual case. It may, how- 
 ever, be observed, that a Cephalic vein will generally 
 be found, which very frequently arises from the sub- 
 clavian instead of the axillary, and commonly conti- 
 nues to the hand on the radial side of the arm. The 
 superficial veins, on the ulnar side of the fore-arm, 
 * very frequently are branches of a large vein which ac- 
 companies the humeral artery to the elbow, viz. the 
 basilic ; but the median vein, formed by branches of 
 the cephalic and basilic veins, is very often not to be 
 found. 
 
 SECTION II. 
 
 Of the INFERIOR VENA CAVA, and the Veins 
 which are connected with it. 
 
 This great vessel exceeds the Superior Cava in 
 diameter. It proceeds from the lower part of the 
 
310 Situation of the hiferior Vena Cava. 
 
 right auricle, and very soon perforates the dia- 
 phragm, at a small distance in front of the spine, 
 and rather to the right of the centre. As the peri- 
 cardium adheres to the diaphragm at this place, the 
 vessel appears to leave it abruptly. Immediately 
 after leaving the diaphragm, it proceeds along a 
 groove in the posterior edge of the liver, formed by 
 the great lobe and the lobulus Spigelii.* After 
 leaving the liver, it continues downwards, inclining 
 backward and to the left, and is soon in contact with 
 the aorta, which is on the left of it. It accompanies 
 the aorta to its great bifurcation, and divides in the 
 same manner. It sends off, during this course, 
 branches to the Diaphragm, Liver, Right Renal 
 Gland, the Kidneys, and the testicles ; and also 
 the Lumbar and Middle Sacral veins. 
 
 The Inferior Phrenic Veins 
 
 Are thus denominated to distinguish them from other 
 veins, which are derived from the internal mammary, 
 &c. They generally accompany the phrenic arteries, 
 and are distributed in the same manner. 
 
 The hepatic Veins 
 
 Pass off from the vena cava, nearly at right angles, 
 into the substance of the liver, while it is in the 
 groove of that viscus, and before it has proceeded 
 more than eight or ten lines from the heart. 
 
 They arise from the anterior part of the vena 
 cava, and are generally three in number. Some- 
 times there are two only, but then one of them di- 
 vides immediately after it enters the substance of the 
 gland. 
 
 The distribution of these vessels in the liver has 
 
 4 Sometimes it is completely surrounded by the live/. 
 
The Vena Portarum.**— Splenic Vein. 311 
 
 been detailed in the account of that organ, and there- 
 fore need not be stated here ; but the veins which 
 unite to form the vena portarum, and the trunk of 
 that great vein also, before it is connected with the 
 liver, may be regarded as a portion of the regular 
 venous system, and ought now to be considered. 
 
 The VENA PORTARUM 
 
 Passes downwards from the great sinus of the liver 
 behind the pancreas, and inclining to the left. In this 
 course it sends branches to the gall bladder, the sto- 
 mach and pylorus, and the duodenum. At the up- 
 per and posterior edge of the pancreas, it sends off 
 a very large branch to the spleen, which often pass- 
 es, with slight meanders, along a groove in the pan- 
 creas. 
 
 The SPLENIC Vein 
 
 Often sends off the inferior mesenteric vein, 
 which proceeds downwards between the aorta and 
 the left portion of the colon. It also sends off some 
 of the coronary veins and the left gastro epiploic 
 vein to the stomach ; many small branches to the pan- 
 creas; and, finally, either from the main trunk or 
 its branches before they enter the spleen, the venae 
 breves, which pass to the great extremity of the sto- 
 mach. Before it enters the spleen, it forms several 
 ramifications, which accompany the branches of the 
 splenic artery. 
 
 After sending off the splenic, the Vena Portarum 
 takes the name of 
 
 The SUPERIOR MESENTERIC Vein; 
 
 Which is larger than the splenic, and passes from 
 behind the pancreas > before the transverse portion of 
 
312 Superior Mesenteric Vein. —Emulgen t Veins, 
 
 the duodenum , into the mesentery ; where it accom- 
 panies the superior mesenteric artery. 
 
 It is evident that the above, described portion of 
 the vena portarum simply performs the functions of 
 a great vein ; but when it takes on the arrangements 
 for entering the liver, it no longer acts like a vein, 
 but an artery. 
 
 The lower portion of the trunk of this vein and its 
 ramifications is denominated Vena Portse Ventralis. 
 The part which ramifies in the liver, Vena Portx 
 Hepatica. 
 
 The Capsular Veins 
 
 Are small vessels, one on each side. That on the 
 right passes from the vena cava to the right glandula 
 renalis. That on the left arises from the left emul- 
 gent vein. 
 
 The EMULGENT, or RENAL Veins, 
 
 Are very large vessels; and, like the arteries, go off 
 nearly at right angles, one to each kidney. 
 
 The right emulgent vein is not so long as the left, 
 and it is rather anterior to its corresponding artery. 
 The left emulgent, in its course to the kidney, cross- 
 es the aorta, and is anterior to it. 
 
 These veins pass to the sinus of each kidney, and 
 ramify before they enter it. The ramifications fol- 
 lows those of the arteries. 
 
 The Spermatic Veins 
 
 Arise one on each side : the right from the vena cava 
 and the left from the emulgent vein. They proceed 
 downwards behind the peritoneum, and on the psoas 
 muscle generally divide into many branches which 
 communicate with each other as they progress down- 
 wards, and form a plexus denominated Corpus 
 Pampiniforme, These branches proceed in the 
 
Internal Iliac and its Ramifications. 313 
 
 spermatic cord to the back of the testis. The prin- 
 cipal part enters the body of that gland; but some of 
 the branches go to the epididymis. In females the 
 spermatic vein, like the artery, passes to the ovary, 
 the uterus and its appendages, &c. 
 
 The Lumbar Veins 
 
 Correspond to the arteries of the same name. They 
 arise from the posterior and lateral parts of the in- 
 ferior cava, and those on the left side pass under the 
 aorta. 
 
 The Middle Sacral Vein 
 
 Resembles the artery of the same name in its origin 
 and distribution. 
 
 The INFERIOR VENA CAVA accompanies 
 the aorta to the space between the fourth and fifth 
 lumbar vertebrae, and there it also divides into the 
 two 
 
 PRIMITIVE ILIAC VEINS. 
 
 • 
 
 The left vein crosses behind the artery of the right 
 side, and rather behind the left primitive iliac artery, 
 which it accompanies until they are opposite to the 
 junction of the sacrum and ilium, when it divides 
 again, like the artery, into the internal and exter- 
 nal iliac veins. 
 
 The INTERNAL ILIAC , or HYPOGASTRIC 
 
 Vein ' 
 
 Descends into the pelvis behind the artery, which i£ 
 accompanies. Its ramifications correspond in gene- 
 ral with those of the artery, and, therefore, need not 
 be particularly described. 
 
 The VENiE VESICALES 
 
 Have such peculiarities that their ramifications re- 
 quire particular attention. They arise from the hy- 
 Vol. ii« 40 
 
314 JRamiJications of the External Iliac . 
 
 pogastric, very near the origin of the obturator, and 
 are large as well as numerous. 
 
 They are somewhat different in the two sexes. In 
 men they form a remarkable plexus on the lateral 
 and inferior portions of the bladder, and on the ve- 
 siculse seminales. This plexus extends more or less 
 to the prostate : from it a number of veins proceed to 
 the symphisis of the os pubis, which communicate in 
 their course with the pudic vein. From thence 
 arises the great vein of the penis, which proceeds in 
 the groove between the corpora cavernosa, and ter- 
 minates in the glans penis. This vein often divides, 
 near the root of the penis, into two : one of which is 
 in the groove, and the other more superficial.* 
 
 In females, the venae vesicales form a considerable 
 plexus on each side of the bladder and vagina. — • 
 Many veins pass from these to the upper portions 
 of the bladder and the contiguous parts, and form 
 plexuses. The clitoris has a dorsal vein like the 
 penis, and it originates in a manner analogous to the 
 dorsal vein of the male. 
 
 The EXTERNAL ILIAC Vein . 
 
 The great trunk of the veins of the lower extremity 
 proceeds on the inside of the artery, under the crural 
 arch or Poupart’s ligament. Before it passes from 
 under the arch, it sends off two branches which an- 
 swer to the circumflex artery of the ilium and to the 
 epigastric artery. 
 
 The Circumflex Vein 
 
 Arises from the external side of the iliac vein, and 
 passes towards the anterior end of the spine of the 
 
 * The pudic veins accompany the arteries of that name. They com- 
 wmnicate with the plexus, as above mentioned, and continue into the 
 penis 
 
315 
 
 Veins of the Leg . 
 
 ilium. It divides into branches which accompany 
 those of the artery of the same name. 
 
 The Epigastric Vein 
 
 Arises from the external iliac, and accompanies the 
 epigastric artery.— After passing a small distance in=? 
 ward and downward, it turns up on the inside of the 
 abdominal muscles. In the first part of its course 
 it sends off some small branches to the spermatic 
 cord. 
 
 After passing beyond Poupart’s ligament the 
 name of the great vessel is changed from external 
 iliac to 
 
 FEMORAL VEIN. 
 
 It proceeds downwards at first on the inside of the 
 femoral artery, but gradually changes its relative 
 situation, so that in the thigh and in the ham it is 
 behind or on the outside of that vessel. 
 
 At a short distance below Poupart’s ligament, af- 
 ter giving off some small branches to the external or- 
 gans of generation, and to the glands of the groin, it 
 sends off on the internal side of the thigh a very 
 large vein which is called the 
 
 SAPHENA MAJOR. 
 
 This vein immediately becomes superficial, and 
 passes down on the internal side of the thigh, some- 
 what anteriorly; giving off some small branches to 
 the contiguous parts, soon after it originates; and 
 many superficial veins afterwards. It continues along 
 the inside of the knee and leg to the internal ankle, 
 the anterior part of which it passes over. It then 
 proceeds along the internal part of the upper surface 
 of the foot to the middle, when it curves towards the 
 external edge, and joins the lesser saphena. On the 
 
GIG Instances of peculiar arrangement of the Veins . 
 
 leg and foot it also sends off many branches, which 
 anastomose with each other, and with those of the 
 aforesaid vein. 
 
 The femoral vein, after parting with the saphena, 
 soon sends off the vena profunda, and the circum- 
 flex® also, when they do not arise from the profun- 
 da. These veins are generally larger than the arte- 
 ries to which they correspond, and their branches 
 are more numerous ; but they observe the same 
 course. 
 
 The great vein accompanies the artery down the 
 thigh and through the perforation in the biceps ; 
 but it changes its relative position, so that it is 
 placed behind or on the exterior side of the artery 
 at the lower part of the thigh. It is very often be- 
 hind it in the ham, where, like the artery, it takes 
 the name of popliteal. In the ham it sends off an- 
 other superficial vein, which seems very analogous 
 to the basilar vein of the arm. This is called 
 
 The Lesser or External Saphena. 
 
 It proceeds from the ham over the external head of 
 the gastrocnemius, and down the outside of the leg, 
 sending off many branches in its course. It passes 
 behind the external ankle and near the exterior edge 
 of the upper surface of the foot, about the middle of 
 which it inclines towards the great saphena, and 
 forms with it the anastomosis already mentioned. 
 
 The popliteal vein, after passing across the arti- 
 culation, ramifies like the artery, but sends two 
 veins, which accompany each of the three arteries of 
 the leg. 
 
 In a few instances some of the larger veins have 
 been found to be arranged in a manner very differ- 
 ent from that which is commonly observed. 
 
Pulmonary Vessels, 317 
 
 One case of this kind has already been mentioned 
 in the account of the liver,* where the Vena Porta- 
 rum terminated in the Vena Cava , below the liver, 
 without entering into it. 
 
 Another very remarkable instance of peculiar ar- 
 rangement is to be seen in a preparation now in the 
 University of Pennsylvania, in which the Inferior 
 Cava, instead of opening into the lower part of the 
 right auricle, passes behind it, in the tract of the 
 Vena Azygos, and opens into the Superior Cava, in 
 the place where the Vena Azygos usually communi- 
 cates with that vessel, receiving the Intercostal 
 Veins in its course. 
 
 In this preparation, the HepaticVeins communicate 
 directly with the right auricle, at its lower part; the 
 middle and left hepatic veins forming one trunk before 
 they enter, and the right vein passing in singly.f 
 
 Of the PULMONARY Arteries and Veins, 
 
 Those portions of the Pulmonary artery and veins 
 which are distinct from the lungs may be described 
 very briefly. 
 
 It has been already observed , % that the pulmonary 
 artery arises from the left and most anterior part of 
 the basis of the right ventricle, and proceeds thence 
 
 * See note to p. 132, of this volume, 
 
 f The foregoing preparation was made by the present editor in 1814, 
 since which two other anomalous cases have occurred to him. 
 
 1819, Case 1st. The ascending cava passed into the thorax on the left 
 side of the spine, and getting as far as its upper part, was joined there by 
 the trunk of the internal jugular and subclavian of the left side. It there 
 passed across the vessels of the arch of the aorta and joined with the de» 
 scending cava. The vessels of th'e liver entered the heart at the usual 
 place, in the lower part of the right auricle. 
 
 1820, Case 2d. The trunk formed by the junction of the internal jugu- 
 lar and subclavian of the left side instead of taking its usual course, passed 
 down vertically, before the left branch of the pulmonary artery and be 
 fore the left auricle, then making a slight curve between this auricle and 
 the diaphragm joined with the ascending cava.-— E d. 
 
 t See page 59 oi this volume 
 
3i 8 Pulmonary Vessels. 
 
 obliquely backwards, inclining gradually to the left 
 side for about eighteen or twenty lines when it divides 
 into two branches, which pass to the two lungs. This 
 course places it under the curve of the aorta : for that 
 great vessel passes over the right branch of the pul- 
 monary artery, and the right side of the main trunk 
 of it, in such a manner that it proceeds downwards 
 between the two branches and behind the angle form- 
 ed by their bifurcation. From this place of bifurcation 
 a short ligament proceeds to the lower part of the curve 
 of the aorta, which is almost in contact with it. This 
 ligament was originally the canal that formed the 
 communication between the pulmonary artery and 
 the aorta of the foetus. Each of the great branches 
 of the pulmonary artery takes a direction backwards, 
 and to its respective side. It soon joins the corres- 
 ponding branch of the trachea and the two pulmona- 
 ry veins, being anterior to the branch of the trachea, 
 and above the pulmonary veins. It is also invested, 
 in common with them, by that portion of the pleura 
 which forms the mediastinum, and thus enters into 
 the composition of the root of the lungs. 
 
 The Pulmonary Veins are four in number — two 
 on each side. In conformity to the mode of descrip- 
 tion which we have adopted, it may be said that they 
 arise from the sides of the Left Auricle , and proceed 
 nearly in a transverse direction, two of them to each 
 lung ; where they accompany the branches of the 
 artery and of the trachea, being invested by the 
 mediastinum in common with these branches. It 
 has been observed, that they differ from veins in 
 general, by preserving a diameter nearly similar to 
 that of the arteries which they accompany. 
 
SYSTEM OF ANATOMY. 
 
 PART X. 
 
 OF THE NERVES. 
 
 The nerves are those whitish cords which pass 
 from the brain and spinal marrow to the various parts 
 of the body. 
 
 A general account of their origin is contained in 
 the description of the basis of the brain and of the 
 spinal marrow,* which may be considered as intro- 
 ductory to the present subject. 
 
 The nerves, in general, appear to be bundles or 
 fasciculi of small cords, each of which is composed 
 of a series of fibres that are still smaller. These 
 fibres consist of medullary matter, which is derived 
 from the brain and spinal marrow, and is enclosed in 
 a membranous sheath that appears to arise from the 
 pia mater. The smaller the fibre the more delicate 
 is the membrane which invests it. 
 
 As the nerves proceed from the brain and spinal 
 marrow, through the foramina of the cranium and the 
 spine, they are enclosed in a sheath formed by the 
 dura mater; but when they arrive at the exterior 
 extremities of the foramina in those bones, this coat, 
 derived from the dura mater, appears to separate 
 into two lamina. The exterior lamen combines 
 with the periosteum, and the interior continues to in- 
 
 * See volume I. p^ge 33? 
 
320 General Structure of the Nerve. 
 
 vest the nerve, but seems to change immediately into 
 cellular substance ; so that the exterior coat of the 
 nerves may be regarded as composed of cellular 
 membrane, which is continued from the sheath de- 
 rived from the dura mater. 
 
 It has been supposed that the membrane which 
 forms the sheaths for the medullary fibrils, of which 
 the nerves are composed, is of a peculiar nature ; 
 but it appears to be derived from the pia mater, in- 
 vesting the brain and the spinal marrow. It is very 
 vascular.* 
 
 The ramification of a nerve is simply the separa- 
 tion of some fibres from the general fasciculus. The 
 branch commonly forms an acute angle with the main 
 trunk. 
 
 The course of these branches from their origin to 
 their termination, is generally as straight as possible. 
 
 When the nervous cords are examined in an ani- 
 mal recently dead, there is an appearance of white 
 lines arranged in a transverse or spiral direction. 
 The cause of this appearance is not well understood. 
 
 In various parts of the body net works are formed 
 by the combination of different nerves, or the branches 
 of nerves. In those instances the branches of one 
 nerve, unite with those of another, and form new 
 branches. These new branches again divide, and 
 their ramifications unite with other new ramifications 
 to form other new trunks. These new trunks divide 
 again, and form new combinations in the same way. 
 
 The trunks last formed proceed to the different 
 
 * Several authors have written professedly on the structure of the 
 nerves, viz. Monro, in his “ Observations on the Structure and Functions 
 of the nervous System.” — Bichat, “ Anatomie Generale.” — Fontana, 
 “ Treatise on the Poison of the Viper.” — Reil, “ Exercitationes Anato- 
 mies.” — Scarpa, “ Annotations Academicse.” — Prochaska, “ De Struc- 
 tura Nervorum.” 
 
 I regret, that it has not been in my power to procure Reil, Prcchask:!, 
 or Scarpa. 
 
321 
 
 Plexuses . — - Ganglions. 
 
 parts of the body, as other nerves do which arise im- 
 mediately from the brain. 
 
 These combinations are denominated Plexuses. 
 There are several of them in the cavities of the abdo- 
 men and thorax, formed by the ramifications of the 
 par vagum and the sympathetic nerves. The four 
 lower cervical and the first dorsal nerve form a very 
 remarkable plexus of this kind, which extends from 
 the side of the neck to the axilla, and forms the 
 nerves of the arm. The lumbar nerves form a similar 
 plexus, although not so complex, from which the cru- 
 ral nerve arises. The anterior nerves of the sacrum 
 also unite for the formation of the great sciatic nerve. 
 
 It appears to be clearly ascertained, that the great 
 object of this peculiar arrangement is the combina- 
 tion of nervous fibres from many different sources, 
 in each of the nerves, which are distributed to any 
 organ. Thus, the smaller nerves of the arm that are 
 distributed to the different parts, are not to be re- 
 garded simply as branches of any one of the five 
 nerves which are appropriated to the upper extre- 
 mity, but as composed of fibres which are derived 
 from each of them. 
 
 Many of the nerves are enlarged in particular 
 places so as to form small circumscribed tumours, 
 which are denominated Ganglions. 
 
 These Ganglions are generally of a reddish co- 
 lour. By very dextrous management, they can be 
 shown to consist of a texture of fibres. The larger 
 cords, which compose the nerve, seem suddenly to 
 be resolved into the small fibres, of which they con- 
 sist. These small fibres, after proceeding separate- 
 ly a greater or lesser distance, according to the size 
 of the ganglion, and changing their relative situa- 
 tion, are again combined in cords whieh recompose 
 the nerve. 
 
 These fibres appear to be surrounded by a fine 
 
 Vol, ii. 41 
 
322 Structure of Ganglions. 
 
 cellular substance, which is vascular, moist and soft. 
 It is asserted that, in fat subjects, an oily substance, 
 resembling fat ; and in hydropic subjects, a serous 
 fluid has been found in this texture. 
 
 Ganglions are often connected with but one nerve, 
 which seems to enter at one extremity and go out at 
 the other. But they frequently receive additional 
 branches from other nerves, and send off additional 
 branches to parts different from those to which their 
 principal nerves are directed. When connected with 
 but one nerve, they have been called simple gang- 
 lions: when they receive and give off additional 
 branches, they are denominated compound gang- 
 lions.— It does not appear that there is any impor- 
 tant difference in their structure in these cases. 
 
 The simple ganglions occur in the nerves of the 
 spinal marrow— the posterior fasciculus of the nerves 
 having always formed a ganglion before it is joined 
 by the anterior fasciculus. The sympathetic nerve, 
 throughout its whole extent, forms compound gang- 
 lions. 
 
 The use of this particular structure does not ap- 
 pear to be perfectly known. It seems, however, 
 certain, that the different fibres— (of which the 
 nerves forming ganglions are composed)— are blend- 
 ed together and arranged in a manner different from 
 that in which they were arranged before the nerve 
 entered the ganglion. 
 
 It ought to be observed, that the combination of 
 nervous fibrillse, so as to bring together those fibrils 
 which originally belonged to different cords, seems 
 to have been kept in view throughout the whole ar- 
 rangement of the nervous system. It is not only in 
 the plexus and the ganglion that this appears, but 
 also in some of the larger nerves ; for in them, the 
 fibres which form the cords that compose the nerve, 
 instead of running parallel to each other, along the 
 
Reproduction of Nerves. 323 
 
 whole extent of the nerve, form a species of plexus in 
 their course ; separating from the fibres with which 
 they were originally combined, and uniting with the 
 fibres of other cords ; as in other cases of plexus.* 
 
 There have been doubts respecting the possibility 
 of a reproduction of the substance of the nerves when 
 it has been destroyed ; but it appears to have been 
 clearly proved by the experiments of Mr. Haighton, 
 that a reproduction does really take place.f 
 
 Nine pair of nerves proceed from the brain through 
 the foramina of the cranium. They are called Nerves 
 of the Brain , or Cerebral Nerves. One pair passes 
 off between the cranium and the spine, which is call- 
 ed Sub-Occipital. Twenty-nine or thirty pair pass 
 through the foramina of the spine : they are deno- 
 minated Cervical, Dorsal, Lumbar , and Sacral , 
 from the bones with which they are respectively 
 connected. There are seven pair of Cervical nerves, 
 twelve Dorsal, five Lumbar, and five or six Sacral — - 
 amounting, with the nerves of the brain, to thirty- 
 nine or forty pair. 
 
 NERVES OF THE BRAIN 
 
 The nerves which go off from the brain and me- 
 dulla oblongata are named numerically, according 
 to the order in which they occur ; beginning with 
 the anterior. They also have other names, which 
 generally are expressive of the functions of the dif- 
 ferent parts to which they are distributed. 
 
 Those which go to the nose are anterior to all the 
 others, and are therefore denominated 
 
 THE FIRST FAIR, OR THE OLFACTORY NERVES. 
 
 They arise by three delicate white fibres from the 
 
 * See Monro’s Observations on the Structure and Functions of the Ner- 
 vous System. Plate xviii. 
 
 t See London Philosophical Transactions, for 1795, Part I. 
 
324 Olfactory Nerves . 
 
 under and posterior part of the anterior lobes of the 
 brain, being derived from the Corpora Striata. They 
 proceed forward to the depression on the cribriform 
 plate of the ethmoid bone, on each side of the crista 
 galli. The upper surface occupies a small sulcus 
 formed by the convolutions of the lower surface of 
 the brain, and, therefore, has a longitudinal ridge on 
 it. The lower surface is flat. Their texture is like 
 that of the medullary part of the brain. 
 
 On each side of the crista galli each of them forms 
 a pulpy enlargement of a brownish colour, which is 
 called the bulb , and has been considered as a gang- 
 lion. 
 
 From this bulb many fine and delicate cords go off, 
 which proceed through the dura mater and the fora= 
 mina of the cribriform plate to the Schneiderian 
 membrane. — These ramifications of the olfactory 
 nerve seem to receive a coat from the dura mater, 
 as they are much more firm after they have passed 
 through it. They appear to be arranged in two rows 
 as they proceed from the ethmoid bone — one running 
 near to the septum, and the other to the opposite 
 surface of the ethmoid bone."*' 
 
 THE SECOND PAIR, OR THE OPTIC NERNES, 
 
 Originate from the Thalami Nervorum Opticorum , 
 and appear on the external and lower surface of the 
 brain, on each side of the sella turcica. 
 
 Each of them seems like a cord of medullary mat- 
 ter, enclosed in a coat derived from the pia mater, and 
 has not the fasciculated appearance of the other nerves. 
 The medullary matter, however, appears to be divided 
 by processes that pass through it, which are derived 
 from the coat of the nerve. 
 
 See VoJ- n. p a. 
 
325 
 
 Second and Third Pair of JYerves, 
 
 They proceed obliquely forward, and inward, on 
 each side of the sella turcica, in contact with the 
 brownish cineritious substance, in which the infundi- 
 bulum and the corpora albican tia of Willis are situa- 
 ted.* Anterior to this substance they come in con- 
 tact with each other, and again separate, in such a 
 way, that it is an undecided question whether they 
 decussate each other, or whether each forms an an- 
 gle, and is in contact with the other at the angle. 
 
 From this place of contact, each nerve proceeds 
 to its respective foramen opticum, where it receives 
 a coat from the dura mater, which extends with it to 
 the eye, as has been described in the account of that 
 organ. 
 
 THE THIRD PAIR OF NERVES 
 
 Are sometimes called Motor es Oculorum , in conse- 
 quence of their distribution to several muscles of the 
 eye. They arise at the inside of the crura cerebri, 
 and make their appearance on the basis of the brain^ 
 at the anterior part of the pons Varolii. 
 
 They originate by numerous threads, which soon 
 unite so as to form a cord, which passes through the 
 dura mater, on each side of the posterior clinoid pro- 
 cess, and continues through the cavernous sinus, and 
 the foramen lacerum, to the orbit of the eye. 
 
 Before this nerve enters the orbit it generally di- 
 vides into two branches, which are situated one above 
 the other. The Uppermost Branch is spent princi- 
 pally upon the rectus superior muscle of the eye, but 
 sends a twig to the levator palpebrae. The Inferior 
 Branch is distributed to two of the recti muscles, 
 viz. the internus and the inferior, and also to the 
 inferior oblique. It likewise sends a twig to a small 
 ganglion in the orbit, called the Lenticular or Oph - 
 
 * See VoL I. page 323 
 
^526 Fourth and Fifth Fair of Nerves. 
 
 thalmic Ganglion,* from which proceed the fine 
 nervous fibres that perforate the sclerotica coat.f 
 
 THE FOURTH FAIR OF NERVES 
 
 Are called the Pathetic, in consequence of the ex- 
 pression of the countenance produced by the action 
 of the muscle on which they are spent. They arise 
 from the side of the valve of the brain, below and be- 
 hind the Tubercula Quadrigeminal and are so small 
 that they appear like sewing thread. They proceed 
 round the crura of the cerebrum, and appear on the 
 surface between the pons Varolii arid the middle 
 lobes of the brain. They proceed along the edge of 
 the tentorium which they perforate, and passing 
 through the upper part of the cavernous sinus, enter 
 the orbit by the foramina lacera. They are exclu- 
 sively appropriated to the Superior Oblique or Troch- 
 learis muscle. 
 
 THE FIFTH PAIR OF NERVES 
 
 Are called Trigemina, because each nerve divides 
 into three great branches. 
 
 These nerves arise from the crura of the cerebel- 
 lum where they unite to the pons Varolii, by distinct 
 fibres, which are connected so as to form a cord or 
 nerve, that is larger than any other nerve of the 
 brain. In many subjects this cord seems partially 
 divided into two portions, the anterior of which is 
 much smaller than the posterior, and appears softer 
 at its origin. 
 
 It passes into a short canal formed by the dura 
 mater, near the anterior extremity of the petrous por- 
 
 * This ganglion, which is considered as the smallest in the body lies on 
 the outside of the optic nerve, near its entrance into the orbit, and is ge- 
 nerally surrounded by soft adipose matter, 
 t See Vol I. page 356. 
 
S2 7 
 
 First Branch of the Fifth Fair . 
 
 Sion of the temporal bone, at a small distance below 
 the edge of the tentorium. It is perfectly loose and 
 free from adhesion to the surface of this canal ; but 
 it soon passes out of it under the dura mater, and then 
 adheres to that membrane. After leaving the canal 
 it expands like a fan, but still consists of fine fibres 
 which have some firmness. It is said that there are 
 seventy or eighty of these fibres in the expansion, but 
 they appear to be more numerous. Round the cir- 
 cumference of the expansion is a substance of a brown- 
 ish colour, into which the fibres enter. This is the 
 Semilunar Ganglion, or the Ganglion of Gasser , 
 and from it the three nerves go off. 
 
 These nerves pass off from the convex side of the 
 Ganglion, and are denominated the Ophthalmic, the 
 Superior Maxillary, and the Inferior Maxillary. 
 
 The Ophthalmic Nerve 
 
 Passes into the orbit of the eye through the foramen 
 lacerum : it there divides into several branches, which 
 are called, from their distribution, the Frontal or Su- 
 pra Orbitar, the Nasal, and the Lachrymal. 
 
 The Frontal or Supra Orbitar branch proceeds 
 forward in the upper part of the orbit, exterior to 
 the membrane which lines it, and divides into two 
 ramifications. One of these is small, and passes out 
 of the orbit near the pulley of the superior oblique, 
 to be spent upon the orbicularis muscle and the con- 
 tiguous parts. 
 
 The other ramification passes through the Supra 
 Orbitary Foramen, or through the notch, which is in 
 the place of that foramen, and divides into a number 
 of twigs, some of which pass transversely towards 
 the side of the head, and communicate with twigs 
 from the portio dura. Most of the others extend up- 
 wards on the head. Some are distributed to the an- 
 
328 Second Branch of the Fifth Pair. 
 
 terior part of the oceipito-frontalis muscle, and the 
 integuments of the forehead ; others are spent upon 
 the upper portion of the scalp. Some of the extreme 
 parts of these ramifications also communicate with the 
 portio dura. 
 
 The Nasal Branch proceeds obliquely forward 
 towards the inner side of the orbit, and sends a twig 
 in its course to the lenticular ganglion. It also sends 
 off some small twigs, to join the ciliary nerves which 
 go from the ganglion. On the inside of the orbit a 
 branch leaves it, which proceeds through the Fora- 
 men Orhitare Internum Anterius to the cavity of 
 the cranium, and passes a small distance upon the 
 cribriform plate of the ethmoid bone, under the dura 
 mater, to a fissure in the said plate near the crista 
 galli, through which it proceeds into the cavity of 
 the nose. Here it divides into twigs, some of which 
 pass on the septum near its anterior edge, and ter- 
 minate on the integuments at the end of the nose, 
 while others pass down on the inferior turbinated 
 bone. 
 
 After parting with the ramification to the nose, the 
 remainder of the nasal branch continues to the in- 
 ternal canthus of the eye, and sends twigs to the 
 lachrymal sac, the caruncula lachrymalis, the eye- 
 lids, and the exterior surface of the upper part of the 
 nose. 
 
 The Lachrymal Branch proceeds obliquely for- 
 ward and outwards, towards the lachrymal gland. 
 In its course it sends off a twig which passes through 
 the spheno maxillary fissure, and communicates with 
 a twig of the upper maxillary nerve, and one or 
 more twigs that pass to foramina in the malar bone. 
 The main branch passes to the lachrymal gland, and 
 some twigs continue beyond it to the contiguous 
 parts. 
 
829 
 
 Second Branch of the Fifth Pair. 
 
 The Superior Maxillary Nerve. 
 
 The second branch of the fifth pair is examined 
 with great difficulty on account of its peculiar situa- 
 tion. It proceeds from the semilunar ganglion, and 
 passes through the foramen rotundum of the sphe- 
 noid bone into the upper part of the zygomatic fossa. 
 In this situation it sends a twig to the orbit by the 
 spheno maxillary fissure, and a branch, called the 
 Infra Orbitar, which appears like the main nerve, 
 as it preserves a similar direction, to the infra orbitar 
 eanal. At the same place it sends downwards two 
 branches which* unite together almost immediately af- 
 ter their origin, and, as soon as they have united, en- 
 large into a ganglion.* This ganglion is called the 
 Spheno- Palatine. It is rather of a triangular figure, 
 and lies very near the spheno-palatine foramen. It 
 gives off a posterior braneh, which passes through the 
 pterygoid foramen to the cavity of the cranium : some 
 branches which proceed through the spheno-palatine 
 foramen to the nose, and are called the Spheno- Pala- 
 tine or Lateral JYasal Nerves: and an inferior branch 
 that proceeds through the posterior palatine canal, 
 and is called the Palatine Nerve. 
 
 The small braneh, which was first mentioned, as 
 going to the orbit by the spheno maxillary fissure, 
 divides into two ramifications. One of them unites 
 with a twig of the lachrymal branch above mention- 
 ed, and passes out of the orbit, through a foramen in 
 the malar bone, to the face ; where it is distributed. 
 The other passes also through a foramen of the ma- 
 lar bone, into the temporal fossa, and, after uniting 
 with twigs from the Inferior Maxillary Nerve , pro- 
 ceeds backwards and perforates the aponeurosis of 
 
 * Sometimes a single branch passes downwards instead of two ; but it 
 forms a ganglion in the same place. 
 
 Vol. n. 42 
 
330 
 
 Superior Maxillary Nerve. 
 
 the temporal muscle, to terminate on the integuments 
 of the temporal region. 
 
 Before the Infra Orbitar branch enters the canal 
 of that name, it sends off two twigs, called Posteriw 
 Dental Nerves , which pass downwards on the tube- 
 rosity of the upper maxillary bone, and enter into 
 small canals in that bone, that are situated behind 
 the Antrum Maxillare. They subdivide into fine 
 twigs that proceed forward to the alveoli of three or 
 four of the last molar teeth ; and penetrate each of 
 the roots by a cavity at its extremity. Twigs also 
 proceed from thege nerves to the posterior part of the 
 gums and buccinator muscle. 
 
 After the posterior dental nerves have left it, the 
 Infra Orbitar nerve proceeds forwards in the canal of 
 that name ; and near the extremity of it, gives off the 
 anterior dental nerve, which accompanies it for some 
 distance, and then proceeds downwards in a canal in 
 the bone anterior to the antrum maxillare. In its 
 course this nerve divides into many fibres, which pass 
 to the roots of the incisor, canine, and small molar 
 teeth, each in its proper eanal. These dental branches 
 sometimes pass in the antrum maxillare between the 
 lining membrane and the bones. The Infra Orbitar 
 nerve passes out of the foramen upon the cheek, and 
 divides into several branches of considerable size, 
 which are distributed on the face from the side of the 
 nose to the back of the cheek, and also upon the un- 
 der eye-lid and the upper lip. 
 
 The Pterygoid Nerve , or posterior branch, passes 
 backwards, from the ganglion to a eanal in the base 
 of the pterygoid process of the Os Sphenoides, and 
 proceeds through it. After leaving this canal, it 
 passes through a substance almost as firm as carti- 
 lage, which closes the anterior foramen lacerum, at 
 the basis of the cranium; and divides into two 
 branchy The smallest of them, called the Vidian 
 
Superior Moccdlldry Nerve , 331 
 
 Nerve , proceeds with a small artery to the small fo- 
 ramen, or Hiatus Fallopii, on the anterior side of the 
 petrous portion of the temporal bone, and continues, 
 through a small canal, to join the Portio Dura of the 
 seventh pair in the larger canal, called the Aqueduct 
 of Fallopius , at the first tarn in that canal.* The 
 other branch of the pterygoid nerve proceeds to the 
 Foramen Carotieum, and passes through it, with a 
 twig of the sixth pair, to join the first cervical gan- 
 glion of the Intercostal Nerve. 
 
 The Spheno- Palatine, or Lateral Nasal Nerves, 
 consist of several branches which pass from the 
 spheno-palatine ganglion through the Spheno-pala- 
 tine foramen into the nose. Some of them are dis- 
 tributed to that part of the pituitary membrane, which 
 is above the upper meatus, and others to the part which 
 is immediately below it. Some of the branches which 
 thus enter th£ nose are spread upon the septum ; one 
 among them extends upon it, downwards and for- 
 wards to the anterior part of the palatine process of 
 the upper maxillary bone, where it enters into the 
 foramen incisivum, and terminates in a papilla in the 
 roof of the month. f 
 
 The Palatine Branch proceeds through the canal 
 formed by the upper maxillary and palate bones, to 
 the roof of the mouth and the soft palate. Soon af- 
 ter its origin, it sends off a twig which proceeds 
 down a small canal that is behind it. It also sends 
 off, as it proceeds downwards, several twigs to that 
 part of the membrane of the nose which covers the 
 
 * The late Mr. John Hunter believed that this nerve parts from the 
 portio dura at the lower end of the aqueduct, and is the chorda tym= 
 pani. 
 
 f The curious distribution of this nerve appears to have been known to 
 the late John Hunter, and also to Cotunnius; but it is minutely described by 
 Scarpa, and is delineated by Soemmering in his plate of the nose — See 
 “ Observations on certain parts of the Animal Economy,” by J. Hunter, 
 page 219, and also Scarpa “ De Organo Olfactus.” In this last are some 
 interesting observations relative to the ducts of Steno. 
 
332 
 
 Third Branch of the Fifth Pair . 
 
 inferior turbinated bone. When it arrives at the 
 roof of the mouth, it divides into several branches 
 which run forwards, and are distributed to the mem- 
 brane which lines the roof of the mouth. Some of 
 its branches pass to the soft palate, the uvula, and 
 the tonsils; small filaments pass into the back part of 
 the upper jaw. 
 
 The inferior Maxillary Nerve , or the Third Branch 
 of the Fifth Pair , 
 
 Passes through the foramen ovale into the zygomatic 
 fossa, and divides into two branches , one cf which 
 sends ramifications to many of the contiguous mus- 
 cles, as the Temporal, the Masseter, the Buccina- 
 tor, the Pterygoid ; and also to the anterior part of 
 the ear and the side of the head. The other branch 
 passes between the pterygoid muscles, and divides 
 into two ramifications, one of which proceeds to the 
 tongue, and is called the Lingual or Gustatory , 
 while the other passes into the canal of the lower 
 jaw. 
 
 The Lingual Nerve proceeds between the ptery- 
 goid muscles, and in its course is joined by the 
 chorda tympani. It continues forward between the 
 maxillary gland and the lining membrane of the 
 mouth ; and passes near the excretory duct of that 
 gland, above the mylo-hyoideus and the sublingual 
 gland, to the under side of the tongue, near the 
 point : it then divides into a number of branches 
 which enter into that body between the genio-hyoi- 
 deus and lingualis muscles. This nerve has been 
 supposed to be particularly concerned in the function 
 of taste, because many of its branches continue to 
 the upper surface of the tongue, especially near the 
 point. In its course it has a communication with 
 the ninth pair of nerves, and it, sends twigs to the 
 
The Sixth Pair of Nerves. 333 
 
 membrane of the mouth and gums, and the contiguous 
 parts. 
 
 After parting with the lingual nerve, the inferior 
 maxillary continues to the upper and posterior orifice 
 of the canal in the lower jaw. Before it enters this 
 canal it sends a branch to the sub-maxillary gland, 
 and to the muscles under the jaw. It then enters the 
 canal, attended by blood vessels, and proceeds along 
 it to the anterior maxillary foramen, on the side of the 
 .chin, through which it passes out. In this course it 
 sends twigs to the sockets of the teeth, and generally 
 supplies all the large and one of the small grinders. 
 Before it leaves the jaw it sends a branch forwards, 
 which supplies the remaining teeth on the side to 
 which it belongs. After passing out, through the an- 
 terior foramen, it is spent upon the muscles and inte- 
 guments of the front of the cheek, the chin, and the 
 under lip. 
 
 THE SIXTH PAIR OF NERVES 
 
 Are called Motores Externi. They arise from the 
 commencement of the medulla oblongata, and pro- 
 ceed forward under the pons Yarolii. They proceed 
 through the dura mater on the inside of the fifth pair, 
 and appear to pass through the cavernous sinuses, 
 but are enclosed in sheaths of cellular membrane 
 while they are in those sinuses. When in this situa- 
 tion they are near the carotid arteries, and each nerve 
 sends off one or more very fine twigs, which being 
 joined by a twig from the pterygoid branch of the 
 fifth pair, accompany the carotid artery through the 
 carotid canal, and then unite themselves to the upper 
 extremity of the upper cervical ganglion of the in- 
 tercostal nerve. 
 
 The sixth pair afterwards pass into the orbit of the 
 eye, each through the foramen lacerum of its respective 
 
334 Composition of the Seventh Pair. 
 
 side, and is spent upon the Rectus Externus or Ab- 
 ductor muscle of the eye. 
 
 THE SEVENTH PAIR OF NERVES 
 
 Comprises two distinct cords which have very differ- 
 ent destinations; and have, therefore, been considered 
 as different nerves, by several anatomists. One of 
 these cords is appropriated to the interior of the ear, 
 and is the proper Auditory Nerve. The other is 
 principally spent upon the face, and, therefore, has 
 been called the Facial. They have, however, more 
 frequently been denominated the Seventh Pair , and 
 distinguished from each other, in consequence of a 
 great difference in their texture, by the appellations 
 of Portio Dura and Portio Mollis. 
 
 These two cords pass off nearly in contact with 
 each other, from the side of the upper part of the 
 Medulla Oblongata , where it is in contact with the 
 pons Varolii ; but the Portio Mollis can be traced to 
 the fourth ventricle, while the Portio Dura is seen to 
 rise from the union of the pons Varolii with the me- 
 dulla oblongata and the crura Cerebelli. The Portio 
 Dura , at its*origin, is on the inside of the Portio 
 Mollis. Between these cords are one or more small 
 fibres, called Portio Media , which seem to originate 
 very near them, and finally unite with the Portio 
 Dura. 
 
 Each of the seventh pair of nerves, thus compo- 
 sed, proceeds from its origin, to the Meatus Audito- 
 rius Internus of the temporal bone ; and the Portio 
 Mollis divides into fasciculi, which proceed to the 
 different parts of the organ of hearing, in the man- 
 ner described in the account of the ear.* 
 
 The Portio Dura enters an orifice at the upper 
 and anterior part of the end or bottom of the Meatus 
 
 See Vol. I. p. SS6-. 
 
Chorda Tymptmi^Pes Ansennus. 33 5 
 
 Audiiorius Interims. This orifice is the commence- 
 ment of a canal, which has been called the Aqueduct 
 of Fallopius, and proceeds from the Meatus Audit o- 
 rius Intemus to the external foramen, between the 
 mastoid and styloid processes at the basis of the era- 
 nium. This canal first carves backwards and out- 
 wards, near to the upper surface of the petrous bone,, 
 then forms an acute angle, and proceeds, (back- 
 wards and downwards,) to the stylo-mastoid foramen, 
 passing very near the cavity of the tympanum in its 
 course. 
 
 The Portio Dura, as it passes into the canal from 
 the meatus internus, seems to receive an investment 
 from the dura mater. It fills up the canal, but does not 
 appear to be compressed.* Near the angle it is joined 
 by the twig of the vidian nerve, whieh proceeds from 
 the pterygoid branch of the fifth pair, and enters the 
 petrous bone by the small foramen innommatum on 
 its anterior surface. In its course through the canal 
 it sends off some very small twigs to the muscles 
 and appurtenances of the small bones of the ear, and 
 to the mastoid cells ; and, when it has arrived almost 
 at the end of the canal, it sends off, in a retrograde 
 direction, a small branch which proceeds into the ca- 
 vity of the tympanum, (entering it by a foramen near 
 the base of the pyramid,) and crosses the upper part 
 of it, near the membrana tympani, between the long 
 processes of the Malleus and Incus. This twig is 
 th eCorda Tympani ; it proceeds from the cavity, by 
 a fissure on the outside of the Eustachian tube, to 
 join the lingual branch of the fifth pair, as has been 
 already mentioned.* 
 
 The Portio Dura , after passing out of the Fora- 
 
 * The late John Hunter believed that the chorda tympani is merely a 
 continuation of the twig of the pterygoid branch which joins the portio 
 dura above— See Observations on certain par's of the Animal Econcmv, 
 220 
 
336 Composition of the Eighth Pair of Nerves* 
 
 men Stylo -Mastoideum , is situated behind and with- 
 in the parotid gland. Here it gives small twigs to 
 the back of the ear and head, and to the digastric 
 and stylo-hyoideus muscles. It perforates the gland 
 after sending filaments to it, and then divides into 
 branches which are arranged in such a manner that 
 they constitute what has been called the Pes Jlnse- 
 rinus. 
 
 To describe the various branches in this expan- 
 sion would be more laborious than useful. Some of 
 them are spread upon the temple and the upper part 
 of the side of the head, and unite with the supra-or= 
 bitar branches of the ophthalmic nerve. Some pass 
 above and below the eye, and are distributed to the 
 orbicularis muscle, and communicate with nervous 
 twigs that pass through foramina in the malar bone, 
 &c. Some large branches pass transversely. They 
 cross the masseter muscle, and divide into ramifica- 
 tions which are spent upon the cheek and the side of 
 the nose and lips, and communicate with the small 
 branches of the superior maxillary nerve. 
 
 A large number of branches pass downwards. 
 Many of them incline forwards, and are spent on 
 the soft parts about the under jaw ; while others pro- 
 ceed below the jaw to the superficial muscles and 
 integuments of the upper part of the neck, communi- 
 cating with the branches of the contiguous nerves.*' 
 
 THE EIGHTH PAIR OF NERVES 
 
 Are very frequently denominated the Par Vagum 9 
 on account of their very extensive distribution. 
 
 * A most minute and laboured description of the nerves of the face was 
 published by the celebrated Meckel, in the seventh volume of Memoirs 
 of the Royal Academy of Sciences of Berlin, for the year 1751, accompa- 
 nied with a plate, exhibiting the'side of the head, of three times the natu- 
 ral size. This is republished in the Collection Academiaue : Partie 
 Etrang6re.—' Tom. viii. 
 
Composition of the Eighth Pair of Nerves. 337 
 
 They arise from those portions of the medulla ob- 
 longata which are denominated the Corpora Olivaria . 
 Each nerve consists of a cord, which is anterior, and 
 called the Glosso Pharyngeal ; and of a considerable 
 number of small filaments, which arise separately, 
 but unite and form another cord, the proper Par Fa- 
 gum. Associated with these is a third cord, called 
 the Spinal , or Accessory Nerve of Willis, which ori- 
 ginates in the great canal of the spine, and, passing 
 up into the cavity of the cranium, goes out of it with 
 these nerves through the foramen lacerum. 
 
 The two first mentioned nerves proceed from their 
 origin to the posterior foramen lacerum, and pass 
 through it with the Internal Jugular vein, — being 
 separated from the vein by a small process of bone. 
 They are also separated from each other by a small 
 process of the dura mater. In the foramen they are 
 very close to each . other ; but soon after they have 
 passed through it, they separate and proceed towards 
 their different destinations. 
 
 The Glosso -Pharyngeal proceeds towards the 
 tongue, between the stylo-pharyngeus and the stylo- 
 glossus muscles, following the course of the last men- 
 tioned muscle to the posterior part of the tongue. At 
 the commencement of its course it receives a twig from 
 the Portio Dura and one also from the Par Vagum. 
 It soon gives off a branch which passes down on the 
 inside of the common carotid to the lower part of the 
 neck, where it joins some twigs of the intercostal to 
 form the cardiac nerves. Afterwards it sends off 
 several twigs to the muscles of the pharynx and its 
 internal membrane, and also some twigs which unite 
 with others from the upper cervical ganglion of the 
 Sympathetic , and form a network that lies over the 
 anterior branches of the external carotid. The Glosso- 
 pharyngeal finally enters the tongue, at the termina- 
 
 Vol. ii.' 43 
 
338 Giosso- Pharyngeal Nerve,*— Par Vagum . 
 
 tion of the hyo-glossns muscle ; and after sending 
 t ranches to the lingualis, and the various muscles in- 
 serted into the tongue, terminates in small ramifica- 
 tions that are spent upon the sides and middle of the 
 root of the tongue, and upon the large papillae. 
 
 THE PAR VAGUM 
 
 Are slightly enlarged after passing through the fora- 
 men lacerum. As they descend, they adhere to the 
 superior ganglion of the intercostal, and also to the 
 ninth pair. They proceed behind and on the outside 
 of the carotid, and are contained in the same sheath of 
 cellular membrane which encloses that artery and the 
 internal jugular vein. Each of these nerves, soon 
 after it leaves the cranium, gives a twig to the glosso- 
 pharyngeal ; that soon after it sends off a branch called 
 the Pharyngeal, which unites to one from the acces- 
 sory nerve, and to one or more from the glosso-pha- 
 ryngeal, and proceeds to the middle constrictor of 
 the pharynx, when it expands into ramifications that 
 form a plexus from which proceed a number of small 
 twigs that go to the larynx, and some that pass down 
 on the common carotid artery. 
 
 It then sends off, downward and forward, the Su- 
 perior Laryngeal nerve, which continues in that di- 
 rection behind the carotid artery, and divides into 
 an external and internal branch. 
 
 The Internal Branch , which is the largest, pro- 
 ceeds between the os hyoides and the thyroid carti- 
 lage ; and divides into numerous ramifications which 
 are distributed to the arytenoid muscles and to the 
 membrane which lines the larynx and covers the epi- 
 glottis. It is said, that fine twigs can be traced into 
 the foramina, which are to be seen in the cartilage 
 of the epiglottis ; — some ramifications can be traced 
 to the pharynx ; — others communicate with the 
 branches of the recurrent nerve. 
 
Superior Laryngeal Branch of the Par Vagum . 339 
 
 The External Branch sends twigs to the pharynx, 
 to the lower and inner part of the larynx, and to the 
 
 thyroid gland. 
 
 In its course downwards, the great nerve some- 
 times sends off a twig, which unites with one from 
 the ninth pair that passes to the sterno-hyoidei and 
 sterno-thyroidei muscles. 
 
 It uniformly sends off one or more twigs, which 
 pass into the thorax and combine with small 
 branches from the sympathetic or intercostal nerve, 
 to form the Cardiac plexus , which sends nerves to 
 the heart. 
 
 After entering the thorax, the right trunk of the 
 Par Vagum passes before the subclavian artery ; and 
 the left trunk before the arch of the aorta ; and im- 
 mediately after passing these arteries, each of the 
 nerves divides into an interior and posterior branch. 
 The anterior is the continuation of the Par Vagum ; 
 the posterior is a nerve of the Larynx; which, from 
 its retrograde course, is called the Recurrent Nerve. 
 
 On the left side the Recurrent Nerve winds back- 
 wards round the aorta, and on the right side round 
 the subclavian artery, and proceeds upwards, deeply 
 seated, on the side of the trachea, to the Latnjnx. 
 Soon after its origin it sends filaments to a ganglion 
 of the sympathetic, to the cardiac plexus, and to a 
 pulmonary plexus soon to be mentioned. In its 
 course upwards it sends twigs to the trachea and the 
 oesophagus. It proceeds behind the thyroid gland, 
 and sends twigs to that organ. At the lower part of 
 the larynx it sends off a branch which communicates 
 with branches of the superior laryngeal nerve. It 
 also divides into branches which are spread upon the 
 posterior crico-arytenoid, and the arytenoid muscles : 
 and also upon the lateral crico-arytenoid and the 
 thvro-arytenoid muscles, as well as upon the mem- 
 
340 Recurrent Branch of the Par Vagum. 
 
 brane which lines the hack part of the larynx and the 
 contiguous surface of the pharynx. 
 
 There is a difference in the arrangement of the re- 
 currents on the different sides in consequence of one 
 winding round the aorta, while the other winds round 
 the subclavian artery. 
 
 After sending off the recurrents, each trunk of the 
 par vagum proceeds behind the ramifications of the 
 trachea ; but previously detaches some small branches, 
 which are joined by twigs from the intercostal and 
 from the recurrent, and form a plexus upon the an- 
 terior part of the vessels going to the lungs. This 
 Anterior plexus, after sending off some minute 
 branches to the cardiac nerves and the pericardium, 
 transmits its branches with the bronchia and the 
 blood vessels, into the substance of the lungs. 
 
 Some of the branches which proceed from the par 
 vagum, pass down on the posterior part of the tra- 
 chea, and enter into the membrane which forms it, 
 and the mucous glands which are upon it ; and some 
 pass to the oesophagus. 
 
 When the par vagum is behind the great vessels 
 of the lungs, a number of branches go off transverse- 
 ly, and are also joined by some fibres from the sym- 
 pathetic. These form the Posterior pulmonary 
 plexus ; the ramifications from which proceed into 
 the substance of the lungs, and are principally spent 
 upon the ramifications of the bronchia. It has been 
 said,* that the small twigs into which they divide, 
 very generally penetrate into the small ramifications 
 of the bronchia, and are spent upon their internal 
 membrane. 
 
 Soon after sending off the nerves of the pulmona- 
 ry plexus, the Par Vagum proceed dow’nwards 
 
 * See Buisson, in the continuation of the Descriptive Anatomy of 
 Bichat. 
 
Different Functions of the Laryngeal , fye. 341 
 
 upon the oesophagus; the left nerve being situated 
 anteriorly, and the right posteriorly. Each of these 
 nerves forms a plexus so as nearly to surround the 
 oesophagus, as they descend on it; but the net- work 
 is thickest on the posterior side. They pass through 
 the diaphragm with the (esophagus, and unite again 
 so as to form considerable trunks. 
 
 The Anterior , which is the smallest, proceeds along 
 the lesser curvature of the stomach to the pylorus. 
 Some of its fibres are spread upon the anterior side 
 of the stomach and the lesser omentum. Others of 
 them extend to the left hepatic, and also to the solar 
 plexus. 
 
 The Posterior trunk sends branches to surround 
 the cardiac orifice of the stomach. Many branches 
 are spread upon the under side of the great curvature 
 of the stomach. Some of them pass in the course of 
 the coronary artery to the cceliac, and unite to the 
 hepatic and splenic plexuses; and one trunk, which 
 is thick, although short, proceeds to the solar plexus. 
 
 The Accessory Nerve of Willis , 
 
 Which has been mentioned as associated with the 
 eighth pair of nerves, within the cranium, has a very 
 peculiar origin. 
 
 It arises by small filaments, which come off from 
 the spinal marrow, between the anterior and posteri- 
 or fasciculi of the cervical nerves, and proceeds up- 
 wards to the great occipital foramen, between these 
 fasciculi. It commences sometimes at the sixth or 
 seventh cervical vertebra, and sometimes about the 
 fourth. It enters the cavity of the cranium through 
 the foramen magnum, and proceeds upwards and out- 
 wards, so as to join the eighth pair of nerves at some 
 distance from its origin, and in this course it receives 
 filaments from the medula oblongata. 
 
 After approaching very near to the eighth pair of 
 
342 
 
 JYinth Pair of jYerves. 
 
 nerves, it accompanies it to the foramen lacerum, and 
 passes out in its own separate sheath. It then leaves 
 the eighth pair and descends towards the shoulder, 
 proceeding through the sterno-mastoid muscle. Soon 
 after it emerges from the cranium, it sends a ramifi- 
 cation to the pharyngeal branch of the Par Vagurn 
 and another to the par vagum itself. After passing- 
 through the upper and back part of the sterno-mastoid 
 muscle, it terminates in the trapezius. It adheres 
 to the ninth pair of nerves as it passes by it, and 
 sends a twig to the sub-occipital and some of the 
 cervical nerves. It also gives ramifications to the 
 sterno-mastoid muscle as it passes through it. 
 
 It has already been stated that the Laryngeal and Re- 
 current Nerves appear to answer different purposes in 
 their distribution to the Larynx. — When both of the 
 recurrent nerves are divided in a living animal, the 
 voice seems to be lost. When the laryngeal nerves 
 only are divided, the strength of the voice remains, 
 but it is flatter. The recurrent nerves, therefore, seem 
 essential to the formation of the voice. The laryngeal 
 nerves are necessary to its modulation. 
 
 The history of the investigation of this subject is 
 contained in Mr. Haighton’s paper in the third 
 volume of Memoirs of the Medical Society of 
 London. 
 
 THE NINTH PAIR OF NERVES. 
 
 Each of these nerves arises from the groove in the 
 medulla oblongata, between the corpora pyramidalia 
 and the corpora olivaria. Three or four fasciculi, of 
 distinct filaments, unite to form it. Thus composed, 
 it proceeds to the anterior condyloid foramen of the 
 occipital bpne, and passes through the dura mater. 
 It seems firmly united, by the cellular membrane, to 
 the eighth pair, and to the first ganglion of the sym- 
 pathetic, soon after it passes from the occipital bone. 
 It is either connected to the sub-occipital nerve by a 
 small ramification, or it joins a branch which pro 
 
343 
 
 Ninth and Tenth Pair of Nerves . 
 
 eeeds from the sub-occipital to the cervical, and 
 bends round the transverse process of the atlas. It 
 passes between the internal carotid artery and the 
 internal jugular vein, and crosses the external caro- 
 tid at the origin of the occipital artery. At this 
 place it generally sends downwards a large branch 
 which is called the Descendens Noni. Passing for- 
 wards, it is on the outside of the posterior portion 
 of the digastric muscle, and inclines downwards ; but 
 near the tendon of the muscle it turns upwards, and 
 proceeds on the inside of the mylo-hyoideus, where 
 it divides into ramifications, which, at the anterior 
 edge of the hyo glossus muscle, begin to enter into 
 the substance of the tongue, between the genio-glos- 
 sus and the lingualis muscles. 
 
 Some of the branches of this nerve unite with 
 those of the lingual branch of the fifth pair. Others 
 are distributed to almost all the muscles connected 
 with the tongue. 
 
 The branch called descendens noni passes, down 
 in the course of the common carotid artery, and 
 sends branches in its progress to the upper portions 
 of the eoraco-hyoidei and sterno- thy roidei muscles; 
 it unites with ramifications of various sizes from the 
 first, second and third cervical nerves, which form a 
 bow under the sterno- mastoid muscle, from which 
 ramifications go to the lower portions of the sterno- 
 byoidei and thyroidei muscles and of the coraco- 
 hyoidei. 
 
 OF THE CERVICAL NERVES. 
 
 The tenth or last pair of the head, commonly call- 
 ed the Sub occipital , may be arranged with these 
 nerves, because they arise* like them, from the me- 
 dulla spinalis, and are distributed to the muscles on 
 
 the neck. 
 
344 Siib-Oceipitul or , Tenth pair of Serves, 
 
 The sub-occipital JYet'vcs 
 
 Arise on each side of the spinal marrow, nearly op- 
 posite to the interval between the great foramen of 
 the os occipitis and the atlas. 
 
 Each of these nerves consists of an anterior and 
 posterior fasciculus, or bundle of fibres, which pass 
 outwards immediately under the vertebral arteries, 
 and form a ganglion, from which proceeds an ante- 
 rior and a posterior branch. 
 
 The anterior branch is united to the second cervi- 
 cal nerve below, and to the ninth nerve, or the hy- 
 po-glossal,. above. It also sends filaments to the up- 
 per ganglion of the great sympathetic nerve. 
 
 The posterior branch is spent upon the Recti> the 
 Obiiqui, and some other muscles of the head. 
 
 The proper Cervical Nerves consist of seven pair; 
 of which the first six go off between the vertebrae of 
 the neck, and the seventh between the last of the 
 neck and the first of the back. 
 
 The first cervical JYerve 
 
 Passes out between the atlas and the Vertebra Den - 
 tata. It originates from two fasciculi, which are 
 connected to each other at a ganglion, and then sepa- 
 rate into an anterior and a posterior branch.* 
 
 The anterior branch is connected by filaments with 
 the accessory nerve, with the ninth pair of the head, 
 and with the upper ganglion of the sympathetic. It 
 is also connected with the second cervical nerve ; and 
 sends some branches to the muscles on the anterior 
 part of the spine. 
 
 The posterior branch, after communicating with 
 the posterior branches of the sub-occipital and the 
 
 * This arrangement is common to the nerves of (he spine. The ganglion 
 is formed by the posterior fasciculus. 
 
Cervical and Phrenic JVerves, 345 
 
 second nerves of the neck, perforates the complexus 
 muscle, and ascending upon the back of the head, is 
 distributed with the occipital artery. 
 
 THE SECOND CERVICAL NERVE 
 
 Sends off, from its Anterior Branch , a twig which 
 descends to the low r er cervical ganglion of the sympa- 
 thetic, and a considerable ramification to the third cer- 
 vical nerve. It also sends off some twigs to the sterno- 
 mastoid muscle, and others to join the accessory nerve. 
 Some of its small ramifications pass down upon the 
 external jugular vein, and others unite with the de- 
 scending branch of the ninth pair of the head. A 
 small branch is also concerned in the formation of the 
 phrenic nerve. Two larger branches of this nerve 
 wind round the posterior edge of the sterno-mastoid, 
 and are spread under the integuments of the anterior, 
 lateral and posterior parts of the neck and lower parts 
 of the head; they have a communication with the 
 portio dura of the seventh pair.*— The posterior 
 branch of this nerve is spent upon the extensor mus- 
 cles of the head and neck. 
 
 The THIRD CERVICAL NERVE 
 
 Sends down, from its Anterior Branch , the princi- 
 pal trunk of the phrenic nerve. It also sends twigs 
 to the fourth cervical, to the lower cervical ganglion 
 of the intercostal, and to the descending branch of 
 the ninth of the head. Some of its branches, unite 
 with twigs of the accessory nerve, and others are 
 spent upon the muscles and integuments of the shoul- 
 der and lower part of the neck. A small Posterior 
 Branch is spent upon the muscles of the back of the 
 neck. 
 
 * These superficial branches have sometimes been described as coming 
 from a plexus ; but they often arise directly from the Second Cervical 
 nerve. 
 
 VOL, If, 
 
 44 
 
346 Cervical JVerve$, 
 
 THE NERVES OF THE DIAPHRAGM 
 
 Are generally denominated the Phrenic. The prin- 
 cipal root of each of them is commonly derived from 
 the third cervical nerve, but frequently the second and 
 the fourth cervical nerves contribute to the forma- 
 tion ; and they are sometimes joined by a twig which 
 is derived from the ninth pair. 
 
 Each nerve proceeds down the neck, between the 
 rectus capitis major and the scalenus anticus, and 
 continues along the fore part of the scalenus anticaS; 
 it descends into the thorax within the anterior end of 
 the first rib, between the subclavian vein and the ar- 
 tery. It sometimes receives a twig from the fifth cer- 
 vical nerve, and a twig passes between it and the great 
 sympathetic. After entering the thorax, they descend, 
 attached to the mediastinum, before the root of the 
 lungs. In consequence of the projection of the point 
 of the heart to the left, the course of the left is a little 
 different from that of the right; that of the right pro- 
 ceeding in a more perpendicular direction. When 
 they arrive at the diaphragm, they divide into many 
 ramifications, which have a radiated arrangement, and 
 terminate on the fibres of that muscle, both on the 
 upper and lower surface. Some fibres from each 
 nerve are continued downward, and communicate in 
 ^ the abdomen with fibres from the intercostal, 
 
 THE FOURTH, FIFTH, SIXTH, AND SEVENTH CERVI- 
 CAL NERVES, 
 
 May be comprised in one description. They pass 
 off successively from the Medulla Spinalis* between 
 the vertebrae, like the other nerves. Their Posterior 
 Branches are generally distributed to the back of the 
 neck, and are very small. Their Anterior Branches 
 are principally appropriated to the upper extremi- 
 ties, and are large. They generally send each a 
 
Remaining Cervical Nerves.- —^Brachial Plexus . 347 
 
 small twig to the lower cervical ganglion of the inter- 
 costal nerve, and a few small branches to some of the 
 contiguous muscles. They are arranged and com- 
 bined so as to form the net-work, now to be described, 
 which is called the Brachial or Axillary plexus ; 
 and, in the formation of this plexus, they are joined 
 by the first dorsal nerve. 
 
 The BRACHIAL PLEXUS 
 
 Extends from the lower part of the side of the neck, 
 into the arm-pit. It commences in the following 
 manner. The fourth and fifth cervical nerves pro- 
 ceed downwards, and after uniting to each other 
 about an inch and a half below their egress from the 
 spine, they separate again, almost immediately, into 
 two branches. 
 
 The sixth cervical nerve, after passing downwards, 
 divides also into two branches, one of which unites 
 with the uppermost branch that proceeds from the 
 union of the fourth and fifth, and the other with the 
 lowermost, and they all proceed downwards. 
 
 The seventh cervical is joined by the first dorsal, 
 which proceeds upwards, and unites with it at a 
 short distance from the spine. The cord produced by 
 their junction soon unites with one of the cords above 
 described. As these different cords proceed down- 
 wards, they divide, and their branches again unite. 
 The axillary artery, which passes in the same direc- 
 tion, is surrounded by them. In this manner the 
 axillary plexus is often formed. 
 
 The muscles about the shoulder, both before and 
 behind, are supplied by the axillary plexus. Thus, 
 it sends branches to the Sub -scapular is, Teres Major , 
 and Latissimus Dorsi, behind; and to the Pect ora- 
 lis Major and Minor , and the Mamma, before. It 
 also sends off a branch called the Scapularis , which 
 
348 
 
 Nerves of the Arm . 
 
 commonly arises from the upper part of the plexus, 
 and proceeds through the notch in the upper costa 
 of the scapula, to the supra and infra spinatus, teres 
 minor, &c. 
 
 Nerves of the Arm. 
 
 All the great nerves of the arm are derived from 
 the axillary plexus. There are six of them, which 
 are denominated The Musculo Cutaneous ; the Me- 
 dian The Cubital , or Ulnar ; The Internal Cu- 
 taneous ; The Radial or Muscular Spiral ; and the 
 Circumflex or Articular. 
 
 The Musculo Cutaneous, or Perforating Nerve , 
 passes obliquely through the upper part of the coraco 
 brachialis muscle. Before it enters the muscle, it 
 sends a branch to it. After leaving the muscle, it 
 passes down the arm between the biceps and the 
 brachialis internus, to which it also gives branches. 
 It proceeds to the outside of the biceps, and conti- 
 nues under the median cephalic vein to the anterior 
 and external part of the fore -arm ; along which it 
 passes, under the integuments. On the lower part 
 of the fore-arm it divides into many branches, which 
 extend to the root of the thumb and the back of the 
 hand, and terminate in the integuments. 
 
 The Median Nerve, which is one of the largest of 
 the arm, often proceeds from the axillary plexus next 
 to the musculo cutaneous ; it passes dow n the arm, 
 very near the humeral artery, within the edge of the 
 biceps flexor muscle, and, during this course, gives 
 off no branches of any importance. After passing 
 the bend of the elbow, it proceeds, under the apo- 
 neurosis of the biceps, between the brachialis inter- 
 ims and the pronator teres, and continues down near 
 
 Sometimes called Radial. 
 
Median and Cubital or Ulnar Nerves. 349 
 
 the middle of the fore-arm, between the flexor subli- 
 mis and the flexor profundus. At the elbow it sends 
 branches to several muscles on the anterior side of 
 the fore-arm, and to the integuments. Among these 
 branches is one, called the Interosseal Nerve, which 
 passes down on the anterior surface of the interos- 
 seal ligament, with the artery of that name. This 
 nerve sends branches, in its course, to the long flexor 
 of the thumb and the deep flexor of the fingers. 
 When it arrives at the pronator quadratus, it sends 
 branches to that muscle, and, passing between it and 
 the interosseous ligament, perforates the liganient, 
 and soon terminates on the posterior side of the wrist 
 and hand. 
 
 As the Median Nerve proceeds downwards, it be- 
 comes more superficial ; and continuing among the 
 tendons of the flexors of the fingers, it gives off a 
 branch which is principally spent upon the integuments 
 of the palm of the hand. This great nerve passes with 
 the tendons under the annular ligament ; and imme- 
 diately after, while it is covered by the Aponeurosis 
 Palmaris, and by that portion of the artery which is 
 called Arcus Sublimis, it divides into branches, which 
 separate from each other at acute angles, and subdi- 
 vide so as to send a ramification to each side of the 
 thumb, of the index, and of the middle finger ; and 
 to the radial side of the ring finger. 
 
 The Cubital or Ulnar Nerve is also of considera- 
 ble size. It passes down on the inside of the triceps 
 extensor muscle, to the great groove formed by the 
 olecranon process and the internal condyle of the os 
 humeri ; and in this course it often sends a branch to 
 the triceps, and some smaller twigs to the upper part 
 of the fore -arm. From the groove it proceeds on the 
 anterior part of the fore-arm, between the flexor carpi 
 ulnaris and the flexor sublimis, to the wrist. At a 
 small distance above the wrist it sends off a branch, 
 
350 Radial, or Muscular Spiral Nerve. 
 
 called the Dorsalis, which passes between the flexor 
 ulnaris and the ulna, to the back of the fore-arm and 
 wrist, where, after sending ramifications to the inte- 
 guments and contiguous parts, it divides into branches 
 which pass to the little finger and the finger next to 
 it. Those branches send off, in their course, many 
 twigs which pass to the skin and cellular sub- 
 stance. 
 
 The ulnar nerve then proceeds with the artery, 
 over the annular ligament, on the radial side of the 
 os pisiforme, and divides into two branches ; one of 
 which is superficial, and the other deep-seated. 
 
 The Superficial divides into two principal branches, 
 an external and an internal. The external passes 
 under the aponeurosis palmaris ; and, after sending 
 a branch to combine with one from the median, and 
 some twigs to the contiguous muscles, it subdivides 
 into two branches, one of which goes to the ulnar 
 side of the ring finger and the opposite side of the 
 little finger. The other branch sends off some twigs 
 to the muscles, and proceeds along the ulnar side of 
 the little finger. 
 
 The Deep-seated palmar branch of the ulnar nerve, 
 passes between the muscles of the little finger, under 
 the tendons of the flexors, and accompanies the deep- 
 seated arterial arch in the palm of the hand, giving 
 branches to the interossei, and other contiguous mus- 
 cles. 
 
 The Radial or Muscular Spiral nerve is one of 
 the largest nerves of the arm. It passes from the 
 axillary plexus downward, backward and outward, 
 under the triceps muscle, to the external side of the 
 os humeri. In this course it gives off several branches 
 to the different portions of the triceps. It also fre- 
 quently gives off a large branch, which passes down- 
 wards on the outside of the olecranon, to the back 
 of the fore-arm. and continues to the back of the 
 
Radial , ar Muscular Spiral Nerve. 351 
 
 hand, furnishing many branches which terminate in 
 the integuments. It then proceeds downwards be- 
 tween the supinator radii longus and the brachialis 
 interims. Immediately after passing the articulation 
 of the elbow, it divides into two branches, denomi- 
 nated the Superficial and the , Profound. The Su- 
 perficial soon joins the radial artery, and proceeds 
 downwards, sending branches to the contiguous mus- 
 cles. In its course about the middle of the arm, it 
 crosses the tendon of the supinator longus, and pro- 
 ceeds between it and the tendon of the extensor carpi 
 radialislongior ; itsoon after divides the two branches, 
 which are principally distributed to the thumb and 
 fore finger, and also to the integuments. 
 
 The Profound branch proceeds to the back of the 
 fore-arm under the radial extensor, and continues to 
 the back of the wrist and hand. Into this course it 
 divides into two branches, which are distributed to 
 the contiguous muscles and tendons, and the inte- 
 guments. 
 
 The Internal Cutaneous nerve is the smallest of 
 the nerves which proceed from the axillary plexus. 
 It descends in the course of the basilic vein, and 
 very near it. Above the elbow it divides into an 
 Internal branch, which proceeds over the Basilic 
 Vein, and separates into branches that pass down 
 on the side of the fore-arm ; and an External Branch 
 that passes under the Median Basilic Vein, and con- 
 tinues down on the anterior part of the fore-arm. 
 
 The Articular or Circumflex nerve proceeds 
 backwards from the plexus, between the teres major 
 and minor, and passes nearly around the body of the 
 os humeri, at a small distance below its head. It is 
 distributed to the contiguous muscles and to the arti- 
 culation ; but its principal branches terminate in the 
 deltoid muscle. 
 
352 
 
 The Dorsal JYerves. 
 
 THE DORSAL JYERVES 
 
 Proceed from the cavity of the spine between the 
 dorsal vertebrae. They are sometimes called Inter - 
 costals, because they pass between the ribs, like the 
 blood vessels of that name. There are twelve pair 
 of them, and they are named numerically, beginning 
 from above. 
 
 These nerves proceed from the medula spinalis 
 by two fasciculi of fibres — one from each of its late- 
 ral portions — the posterior fasciculus is the largest. 
 After passing through the lateral foramen and the 
 dura mater, a ganglion is formed by the posterior 
 fasciculus : the anterior fasciculus unites to this gang- 
 lion at its external extremity: and one nerve is 
 formed, which almost immediately divides into an 
 anterior and a posterior branch, of which the ante- 
 rior is the largest. 
 
 The posterior branch proceeds backwards, and is 
 distributed to the muscles of the back. The anterior 
 branch passes towards the angle of the rib, in con- 
 tact with the pleura. Soon after its origin, this an- 
 terior branch sends off two ramifications which unite 
 to the intercostal nerve, at the ganglion ; it then pro- 
 ceeds forwards with the blood vessels, between the 
 internal and external intercostal muscles, in the 
 groove near the lower margin of the ribs ; and ter- 
 minates on the anterior part of the thorax. In its 
 course it sends branches, not only to the intercostal 
 muscles and pleura, but to the other muscles and the 
 integuments of the thorax. 
 
 Some of the dorsal nerves differ from the others, 
 as to the ramifications which they send off. 
 
 The first nerve , of this order, joins the lower cer- 
 vical nerves in the axillary plexus ; but it sends off 
 the ramifications to the sympathetic ; and also a 
 
General Account of the Lumbar Nerves. 353 
 
 branch, which passes under the first rib, like the 
 other dorsal nerves. 
 
 The second nerve, sends off a branch, which passes 
 through the external intercostal muscle into the ax- 
 illa, and combines there with a branch of the cuta- 
 neous nerve, being distributed to the internal and 
 posterior part of the arm. 
 
 The third dorsal nerve also sends off a branch, 
 which is distributed to the axilla and the back part 
 of the arm. 
 
 These branches of the second and third dorsad 
 nerves, are called intercosto-humeral nerves. 
 
 The lower dorsal nerves supply the muscles and 
 integuments of the abdomen. 
 
 Of the L UMBAR Nerves . 
 
 There are five pair of these nerves. The first of 
 them passes off between the first and second of the 
 lumbar vertebras, and the others succeed regularly ; 
 so that the last pair is situated between the last lum- 
 bar vertebra and the sacrum. 
 
 The first lumbar nerves arise from the medulla 
 spinalis, before it forms the cauda equina ; the other 
 four pair are formed by the cauda equina. 
 
 They commence by anterior and posterior fascicu- 
 li, which are united at a ganglion. From these gang- 
 lion, anterior and posterior branches go off, which 
 are very different in size, the anterior being the 
 largest. 
 
 The posterior branches are distributed to the mus- 
 cles of the back. The anterior sends branches to the 
 ganglions of the sympathetic nerve, and also commu- 
 nicate with each other to form the Lumbar Plexus , 
 which is situated on the lateral parts of the bodies of 
 the Lumbar Vertebrae, before their transverse pro- 
 cesses, and supplies nerves to the muscles of the 
 thigh. 
 
 Vol. II, 
 
 45 
 
354 Lumbar JYerves. —Lumbar Plexus . 
 
 THE FIRST LUMBAR NERVE 
 
 Is connected, by its anterior branch, to the last dor- 
 sal and the second lumbar. From the same branch, 
 ramifications go off to the Quadratus Lumborum, and 
 obliquely across that muscle, to the lower part of the 
 abdominal muscles near the spine of the ilium. 
 
 THE SECOND LUMBAR NERVE 
 
 Sends off a muscular branch downwards and out- 
 wards : it also sends off the small branch, called the 
 External Spermatic, which passes down in such a 
 direction, that it perforates the transversalis and the 
 obliquus internus muscles, near their lower margin, 
 at a small distance from the superior anterior spine 
 of the ilium, and then proceeds within the lower edge 
 of the tendon of the external oblique to the abdomi- 
 nal ring, through which it passes. In the male it is 
 distributed to the spermatic cord and scrotum, and in 
 the female, to the labia pudendi. In the female it 
 also sends a branch to the uterus.* The Second 
 Lumbar, after sending off these branches, passes 
 downwards, and joins the Third lumbar nerve. From 
 this union of the second and third nerves, a branch 
 called the Cutaneus Medius, which will be soon de- 
 scribed proceeds downwards. 
 
 After sending off this branch, the united trunk of 
 the second and third joins the Fourth ; and from this 
 union is sent off the Obturator Nerve, which passes 
 through the aperture in the membrane that closes 
 the foramen thyroideum ; the Crural Nerve, which 
 passes under Poupart’s ligament ; and a third branch 
 that proceeds downwards, and joins the Fifth lumbar 
 nerve. The Fifth lumbar nerve, with this acces- 
 sion from above, descends into the pelvis, and unites 
 with the sacral nerves. 
 
 The external spermatic often comes off from the first lumbar nerve 
 
355 
 
 Obturator Nerve.— Crural Nerve . 
 
 This arrangement of the lumbar nerves constitutes 
 the Lumbar Plexus , which, as has been already sta- 
 ted, furnishes three nerves to the lower extremity, 
 viz. the Cutaneus Medius , the Obturator , and the 
 Crural Nerve . 
 
 The Cutaneus Medius , which arises from the 
 union of the second and third nerves, as has been 
 already observed, proceeds downwards, and fre- 
 quently adheres to the crural nerve, for a short dis- 
 tance, near Poupart’s ligament, but soon leaves it, 
 and descends on the inside of the thigh, supplying 
 the integuments as low as the knee. 
 
 THE OBTURATOR NERVE 
 
 Descends into the pelvis, and passes out of it at the 
 upper part of the foramen thyroideum ; proceeding 
 downwards in an internal direction, to be distributed 
 on the inside of the thigh. 
 
 This nerve is generally accompanied by the obtu- 
 rator artery and vein ; the artery being above, and 
 the vein below it. When it has arrived at the fora- 
 men ovale or thyroideum, it sends off a branch to 
 the internal and external obturator muscles, and, 
 after passing these muscles, divides into two branches 
 which are distributed to the muscles on the inside of 
 the thighs, the adductors, the pectineus, the graci- 
 lis, &c. 
 
 THE CRURAL NERVE 
 
 Is situated at first behind, and then on the outside of 
 the psoas muscle. It passes under Poupart’s liga- 
 ment with the great femoral vessels, being on the 
 outside of the artery. 
 
 It is distributed to the integuments, and also to 
 the muscles, which are situated on the anterior and 
 internal parts of the thigh. Some of its ramifications 
 go off before it passes under Poupart’s ligament* 
 
336 Crural Nerve. — Sacral Nerves. 
 
 Several of them are spent upon the integuments, and 
 are therefore denominated Cutaneas. — They are 
 distinguished by the terms Cutaneus Anterior , Cu- 
 taneous Interims, &c. according to their situations. 
 
 The deep-seated branches are the largest. They 
 are principally spent upon the muscles on the ante- 
 rior and the internal side of the thigh, viz. the four 
 extensors, the adductors, the pectineus, the sar tori us, 
 and the gracilis. Among these nerves there is one, 
 called the Saphenus, which has a different destina- 
 tion. It accompanies the great artery of the thigh to 
 the place where it perforates the Adductors : it there 
 separates from the artery, and passes over the tendon 
 of the Adductors, under the sartorius muscle ; thence 
 it continues, with the great saphena vein, on the in- 
 side of the leg, to the internal ankle ; sending branches 
 to the integument, in its course. It terminates in skin 
 and cellular substance on the upper and internal sur- 
 face of the foot. 
 
 The SACRAL Nerves 
 
 Are composed of those cords of the cauda equina, 
 which remain after the formation of the lumbar 
 nerves. They are frequently stated to consist of 
 five or six pair, four of which pass through the fo- 
 ramina of the sacrum, and the fifth between the sa- 
 crum and the os coccygis.* The cords of which 
 they are respectively composed arise by anterior and 
 posterior fasciculi. When they have arrived oppo- 
 site to the foramina of the sacrum, through which they 
 are to pass, a ganglion is formed, at which they 
 unite, and then divide into anterior and posterior 
 branches.! The uppermost of the anterior branches 
 
 * The sixth pair, when they exist, ’proceed in a groove in the os 
 coccygis. 
 
 t The ganglions of the fourth and fifth nerves are extremely small and 
 not so near the foramina as those of the others. 
 
Sciatic Plexus.— Pudic Nerve. 337 
 
 are large and pass through the anterior foramina of 
 the sacrum. The posterior are small, and go through 
 the posterior foramina. 
 
 The Posterior branches are generally spent upon 
 the muscles which lie on the sacrum, and posterior 
 parts of the pelvis, externally. 
 
 The anterior branches of the. three first nerves 
 send ramifications to the sympathetic. They unite to 
 each other, and are joined by the last lumbar nerve, 
 and by a branch of the fourth sacral, in the forma- 
 tion of the great sciatic nerve. This union constitutes 
 the Sciatic plexus. 
 
 The anterior branch of the fourth nerve transmits 
 branches to the sympathetic: it also sometimes sends 
 a branch to the united nerves above, or the sciatic 
 plexus. It sends branches to the hypogastric plexus, 
 and to the contiguous muscles. 
 
 The fifth and sixth pairs, which are very small, 
 terminate also in the contiguous muscles and in the 
 integuments. 
 
 From the Sciatic plexus , or the nerves which com- 
 pose it, several smaller branches go off. There are 
 generally two which pass off backwards through the 
 ischiatic notch, and are denominated Gluteal, as they 
 are distributed to the glutei muscles. From the low- 
 ermost of these a branch descends on the thigh. 
 
 The Pudic nerve, which is appropriated to the or- 
 gans of generation, also passes off from this plexus, 
 and appears to consist of fibres which are derived 
 from each of the nerves that compose it. It proceeds 
 between the sacrosciatic ligaments, and divides into 
 two branches — an inferior and a superior. The in- 
 ferior passes between the erector penis and the ac- 
 celerator urinse muscles, and is distributed to those 
 muscles, to the bulb of the urethra and the interior 
 of that canal, to the scrotum and dartos. 
 
 The superior proceeds along the os pubis to the 
 
U5& Course of the Great Sciatic Nerve. 
 
 symphisis, and passes between the bone and the body 
 of the penis to the dorsum. A considerable branch 
 accompanies the artery on the dorsum, and terminates, 
 by many ramifications, on the glans penis; after send- 
 ing branches in its course to the integuments gene- 
 rally, and to the prepuce. 
 
 In females, the Inferior pudic nerve proceeds along 
 the external labia pudendi to the mons veneris, send- 
 ing off many ramifications in its course. 
 
 The Superior pudic nerve proceeds, as in males, 
 along the branch of the pubis to the superior surface 
 of the clitoris, and terminates principally upon the 
 extremity of that organ. 
 
 The sacral nerves unite in the sciatic plexus to 
 form the great nerve of the lower extremity, which 
 is next to be described. 
 
 The GREAT SCIATIC JYerve 
 
 Proceeds from the pelvis through the ischiatic notch, 
 between the pyramidalis and the superior gemellus 
 muscle : it then passes down to the back part of the 
 thigh, between the tuberosity of the ischium and the 
 great trochanter of the os femoris ; and continues 
 downwards, inclining from within outwards, to the 
 ham, where it is situated between the tendons of the 
 semi-tendinosus and semi-membranosus on the inter- 
 nal side, and the tendon of the biceps on the external. 
 In this course it sends off branches to the muscles on 
 the posterior part of the thigh. 
 
 As the great nerve passes down the thigh, it sends 
 off obliquely downwards and outwards, a large 
 branch which is called the Fihular , that passes 
 across the head of the fibula to the external and 
 anterior part of the leg. The place where this 
 branch separates from the main nerve is different in 
 different subjects. It continues in contact with it 
 
Distribution of the Fibular Nerve » 359 
 
 for some distance, connected only by cellular mem- 
 brane. 
 
 THE FIBULAE Oil PERONEAL NERVE 
 
 Proceeds downwards on the inside of the tendon of 
 the biceps, and crosses obliquely to the outside of the 
 external head of the gastrocnemius: it then passes 
 inwards between the long peroneus muscle and the 
 fibula; and descending between the muscles on the 
 front of the leg, divides into two branches, one of 
 which inclines to the exterior side of the leg, and 
 the other preserves an internal situation. In its course 
 from the great sciatic nerve to the fibula, it sends off 
 some superficial ramifications. The two branches 
 into which it divides, after passing over the fibula, 
 continue downwards. The Internal , after supply- 
 ing the muscles on the anterior part of the leg, 
 passes under the annular ligament like the anterior 
 tibial artery; and on the upper part of the foot, di- 
 vides into two ramifications, one of which proceeds 
 forwards near the internal edge of the foot, and the 
 other near the external ; they divide again, and are 
 distributed to the parts on the upper surface of the 
 foot, one of their ramuli descending with the conti- 
 nuation of the anterior tibial artery to the sole of the 
 foot. 
 
 The External Branch of the fibular nerve, as it 
 proceeds downwards, supplies ramifications to the 
 contiguous muscles, and passing through the fascia 
 on the outside of the leg, continues between it and 
 the skin towards the foot. In this course it gene- 
 rally divides into two branches which are spent upon 
 the upper surface of the foot. 
 
 The GREAT SCIATIC Nerve , after the fibular 
 nerve leaves it, continues down the thigh, between 
 the tendons of the flexors, behind the great blood 
 vessels, and of course exterior to them. 
 
360 Distribution of the Tibial Nerve. 
 
 In the ham, this great nerve takes the name of 
 POPLITEAL, and proceeds across the articulation 
 of the knee, between the heads of the gastrocnemii, 
 to the posterior side of the tibia : here it passes 
 through the upper portion of the soleus or gastroc- 
 nemius internus, and continues between it and the 
 long flexor of the toes, near the Posterior Tibial Ar- 
 tery ; descending with that artery to the hollow of the 
 os calcis. In this situation it has the name of 
 
 POSTERIOR TIBIAL NERVE. 
 
 At the commencement of this course, a small dis- 
 tance below the internal condyle of the os femoris, 
 it sends off a branch of considerable size called the 
 Communieans Tibas, or Saphena Externa, which 
 passes down behind the gastrocnemii, and gradually 
 inclines externally, so that it is situated on the ex- 
 ternal edge of the tendo Achillis, soon after the com- 
 mencement of that tendon, and proceeds behind the 
 external ankle, near the outer side of the foot, to the 
 smaller toes: distributing branches to the contiguous 
 parts. In its course on the back of the leg, it sends 
 off a branch which unites with one of the superficial 
 ramifications of the fibular nerve, and descends to the 
 outer part of the foot. 
 
 The Tibial Nerve, in its course downwards, sends 
 branches to the contiguous muscles ; and a few twigs 
 which form a species of net-work on the artery. In 
 the hollow of the os calcis it sends off a superficial 
 branch to the integuments of the sole of the foot, 
 which proceeds on the outside of the aponeurosis 
 plantaris: it there also divides into branches, which 
 are denominated the Internal and External Plantar 
 Nerves. 
 
 The Internal Plantar Nerve proceeds forwards, 
 along side of the tendon of the long flexor muscle of 
 the great toe, givin'g off small branches in its course. 
 
Commencement of the Sympathetic Nerve, 361 
 
 About the middle of the foot it divides into four 
 branches, one of which proceeds to the inside of the 
 great toe ; and a second to the angle formed by thb 
 great toe and the toe next to it, where it divides and 
 sends a branch to the opposite sides of those toes : 
 the other two branches are distributed in a similar 
 manner, to the succeeding toes. These digital branches 
 are connected with each other by small ramifications. 
 
 The External Plantar Nerve proceeds with the 
 external plantar artery towards the externel side of 
 the foot, between the short flexor of the toes and the 
 flexor accessorius. Near the external edge of the 
 foot, about the posterior end of the metacarpal bones, 
 it divides into three branches. One proceeds to thd 
 outside of the little toe; another passes to the angle 
 between the fourth toe and the little toe, and divides 
 into branches which are distributed to the correspond- 
 ing sides of these toes. The third branch proceeds 
 more deeply in the foot, from the external towards 
 the internal edge of it, and is spent upon the deep- 
 seated contiguous muscles. 
 
 THE GREAT SYMPATHETIC OR INTERCOSTAL NERVE 
 
 Commences in the cranium with those small ramifica- 
 tions of the pterygoid branch of the upper maxillary 
 nerve, and of the sixth pair, which accompany the 
 carotid artery through the canal in the petrous portion 
 of the temporal bone. These small nerves from a 
 net-work which surrounds the artery in the canal, and 
 gives rise to the incipient sympathetic, a small cord 
 which passes down close- to the nerves of the eighth 
 and ninth pair of the neck. Opposite to the second 
 cervical vertebra, this nerve is swelled or dilated, so 
 as to form a body of a light red colour,, which is more 
 than an inch in length, and has the form of two cones 
 united to each other at their bases. This is the Su- 
 perior Cervical Ganglion of the Sympathetic Nerve* 
 Vol. ii, ^46 " 
 
362 First Ganglion, and other Cervical 
 
 and from it tlie nerve descends ? behind the Par Va- 
 guin, on the front part of the neck. 
 
 This ganglion receives twigs from the first, second, 
 third and fourth pairs of cervical nerves, and also from 
 the eighth and ninth nerves of the head. It sends off 
 several twigs, which pass behind the carotid artery, 
 at its bifurcation, and are joined by twigs of the Por- 
 tio Dura and the Glosso- Pharyngeal nerves. From 
 these united twigs proceed very small ramifications, 
 which accompany several branches of the external 
 carotid artery, and some of them pass down with the 
 Common Carotid. 
 
 This superior ganglion also furnishes small twigs 
 which accompany theGlosso-Pharnygeaho the tongue 
 and pharynx. Sometimes a twig from it passes on 
 the back part of the thyroid gland to communicate 
 with the recurrent nerve. From this ganglion go 
 off some small branches, which, uniting with others 
 from the superior laryngeal nerves, form the supe- 
 rior or superficial cardiac nerve, which will be soon 
 described. 
 
 The trunk of the Sympathetic Nerve descends, on 
 the front of the neck, front this ganglion, as has been 
 already stated. In its course it receives very small 
 twigs from the fourth and fifth cervical nerves, and 
 sends some very small twigs which appear to go 
 to the oesophagus, and some which unite to the la- 
 ryngeal nerve and go to the thyroid gland. Some 
 twigs, which are larger, proceed from it into the 
 thorax, and go to the cardiac plexus hereafter to be 
 described. 
 
 Opposite to the interval between the fifth and 
 sixth cervical vertebrae it forms another ganglion, of 
 an irregular shape, much smaller than the first. This 
 ganglion, in different subjects, differs in size as well 
 as in several other respects. Sometimes it is en- 
 tirely wanting, and sometimes it is doubled. It is 
 
Ganglions and Branches of the Sympathetic. 363 
 
 denominated the Middle Cervical , or Thyroid Gan- 
 glion. When the fourth, fifth, and sixth cervical 
 nerves do not send ramifications to the sympathetic 
 nerve, this ganglion receives twigs from them. 
 
 The Middle Cervical , or Thyroid Ganglion sends 
 many ramifications downwards. Some of them enter 
 the thorax and contribute to the formation of the 
 Cardiac Plexus ,* others accompany the inferior 
 thyroid artery, and, with twigs from the recurrent 
 nerve, form a plexus which extends towards the 
 thyroid gland. Some proceed downwards before, 
 and others behind, the subclavian artery, to the next 
 ganglion ; and among them is generally one which 
 may be regarded as the trunk of the Sympathetic. 
 
 This third Ganglion is denominated the Inferior. 
 Cervical , or the First Thoracic. It is almost con- 
 stantly found in the same situation, viz. between the 
 transverse process of the last cervical vertebra and 
 the head of the first rib, and is partly covered by the 
 origin of the vertebral artery. It is generally larger* 
 than the middle ganglion. It receives branches from 
 the sixth and seventh cervical, and the two first dor- 
 sal nerves. Ramifications pass from it to the par va- 
 gum and recurrent nerve, and also to the cardiac and 
 pulmonary plexus. 
 
 From this ganglion the Sympathetic Nerve pro- 
 ceeds downwards on the side of the spine, as will be 
 described hereafter. 
 
 The Nerves of the Heart , 
 
 Being derived from branches which have already been 
 mentioned, are now to be described. 
 
 They arise principally from an arrangement of 
 nerves denominated the Cardiac Plexus , or Plex- 
 uses, which is situated above the curve of the aorta, 
 and extends, on the posterior side of it, from the 
 root of the arteria imiominata to the bifurcation of 
 
 i 
 
>64 Branches of the Sympathetic . 
 
 the pulmonary artery. This plexus is composed of 
 nerves which are principally formed by the union 
 of small ramifications that are derived from the three 
 above mentioned ganglions of the Sympathetic Nerve , 
 and the nerve itself ; and also from the Par Vagum 
 and some of its branches* 
 
 These nerves are denominated the Cardiac . — - 
 They descend on their respective sides of the neck, 
 but are somewhat different on the different sides. — 
 On the right side three nerves have been described 
 as particularly entitled to this name, and on the left 
 side but two. 
 
 The first on the right side is denominated Supe- 
 rior , or Superficial Cardiac NeiPve . It generally 
 arises by several fine threads, which unite into one 
 delicate cord that passes down by the side of the 
 common carotid. When it has arrived on a line 
 with the middle ganglion, it sends a twig to the thy- 
 roid plexus, and another that communicates with a 
 twig from the par vagum, which continues downwards 
 on the carotid artery. After passing beyond the gan- 
 glion, it divides into several branches, which unite 
 themselves to branches of the recurrent nerve that 
 are going to the middle ganglion. 
 
 The second, which is denominated the Middle 
 Cardiac , the Great Cardiac, or the Deep Cardiac , 
 is the largest of the three. It arises from the Mid- 
 dle Cervical, or Thyroid Ganglion, by five or six 
 fine fibrils, which finally form one, that passes before 
 and across the subclavian; and at that place as well 
 as lower down, it receives twigs from the par vagum : 
 below this, it is joined by a considerable twig from 
 the recurrent, and terminates in the Cardiac Plexus , 
 to which it contributes largely. 
 
 The third cardiac nerve of the right side is called 
 the Inferior, or the Small Cardiac Nerve. It ori- 
 ginates from the third, or lower cervical ganglion, by 
 
365 
 
 Branches of the Sympathetic . 
 
 many fibrils which unite into a smaller number that 
 form a plexus. It crosses behind the subclavian, 
 and proceeds on the outside of the Arteria Irmomi- 
 nata to the curve of the aorta ; continuing between 
 it and the pulmonary artery, to the anterior corona- 
 ry plexus. In this course it receives several fibres 
 from the recurrent and the par vagum. 
 
 On the left side the first cardiac nerve arises from 
 the upper ganglion. The second derives its origin 
 from the two lower ganglions. 
 
 The left superior or superficial cardiac nerve arises 
 like the right, by many distinct fibres, and proceeds 
 downwards in the same way. It descends betweed 
 the carotid and the subclavian, and when it has ar- 
 rived at the place where they originate from the aorta, 
 it divides into a great number of small ramifications. 
 Some pass before the aorta, either to join the branches 
 of the inferior cardiac, or to unite with the cardiac 
 branches of the left nerve of the par vagum. The 
 others proceed behind the aorta, and enter into the 
 common cardiac plexus. 
 
 The second cardiac nerve of the left side may be 
 called the Great Left Cardiac, and has a double 
 origin as above mentioned. The principal branch 
 in its composition arises from the lowest cervical 
 ganglion, and passes behind the transverse portion 
 of the subclavian artery. , Where the inferior thyroid 
 arises from the subclavian, this branch receives a 
 considerable number of ramifications, which arise 
 from the upper ganglion, and are interwoven with 
 each other before they unite to it. It passes behind 
 the curve of the aorta, and terminates in the great 
 cardiac plexus, which it particularly contributes to 
 form. Here it is joined by many fibres from the 
 par vagum. • 
 
366 Plexus formed by the Nerves of the Heart . 
 
 The Cardiac Plexus 
 
 Is situated principally behind the curve of the aorta, 
 at a small distance above the heart. It commences 
 as high as the origin of the Arteria Innominata, and 
 extends downwards to the bifurcation of the pulmo- 
 nary artery. 
 
 As has been already mentioned, it is principally 
 composed of branches from the middle cardiac nerve 
 of the right side,, and the inferior cardiac nerve of 
 the left ; but it receives branches from the superior 
 cardiac of the left, and sometimes of the right side. 
 Some fibres of the inferior cardiac of the right are 
 also united to it. 
 
 Many branches proceed from this plexus. 
 
 A small number pass upon the aorta, and seem to 
 enter into its texture.* 
 
 Some of them also combine with the ramifications 
 of the Par Vagum in the anterior pulmonary plexus. 
 
 The majority proceed to the basis of the heart, 
 near the origin of the pulmonary artery and the aorta, 
 and constitute the proper nerves of that organ . They 
 accompany the coronary arteries, and are so arranged 
 around them that, by some anatomists, they have 
 been said to form plexuses, which have been deno- 
 minated Coronary. 
 
 The Sympathetic Nerve, as has been stated above, 
 proceeds from the ganglion, called the Lower Cer- 
 vical, or the First Thoracic, before the neck of the 
 first rib. It continues to descend, in the same direc- 
 tion, along the spine, exterior to the pleura, to the infe- 
 rior part of the thorax. Near the head of each rib it 
 forms a ganglion, which unites with the intercostal 
 nerve behind it, by two branches, and thus forms an 
 indirect communication with the medula spinalis. 
 
 * It has been asserted, that some of the anatomists of Paris have traced 
 tbese.nerves on the aorta, to a great distance from the heart. 
 
Sympathetic Nerve, fyits Splanchnic Branches. 367 
 
 From several of the uppermost of these ganglions, 
 small twigs proceed to the pulmonary plexus, and 
 also to the great trunk of the aorta, below the curve, 
 forming a species of net-work, or plexus, upon it. 
 
 From the ganglions near the heads of the fifth and 
 sixth ribs, and from four or five of the ganglions 
 tfhich succeed them, small nerves arise, which pro- 
 ceed downwards on the sides of the bodies of the 
 vertebrae, and unite into one trunk that is denomi- 
 nated the Splanchnic Nerve, because it is distributed 
 to the viscera of the abdomen. — This nerve proceeds 
 behind the crus of the diaphragm, on its respective 
 side, into the abdomen. A second and smaller nerve, 
 of the same destination, called the Lesser Splanchnic 
 Nerve, arises lower down, from two or three of the 
 lowermost dorsal ganglions, and penetrates separate- 
 ly into the cavity of the abdomen : it then generally 
 divides into two branches, one of which unites to the 
 great splanchnic nerve, and the other proceeds to the 
 renal plexus soon to be described. 
 
 As soon as the great splanchnic nerve has entered 
 the abdomen, it divides into many branches, which 
 commonly form small ganglions on each side of the 
 c celiac artery, but above it. • These ganglions are 
 generally contiguous ; but sometimes they are at a 
 small distance from each other, and united by nerves. 
 They are, however, commonly spoken of as one, and 
 called the Semilunar Ganglion. They are of ir- 
 regular forms, and very different from each other in 
 size, as well as form. Those formed by the splanch- 
 nic nerve on one side are sometimes different from 
 those on the other. 
 
 From this assemblage of ganglions proceed many 
 small nerves, which are woven together so as to form 
 a net-work denominated the Solar Plexus. 
 
 This plexus is situated anterior to the spine and 
 the crura of the diaphragm ; behind the stomach and 
 
368 Arrangement of the Nerves of the 
 
 above the pancreas ; and is extended upon the coeliae 
 arid superior mesenteric arteries. Some ramifications 
 from the par vagum and the phrenic also join it. 
 
 The lower part of the solar plexus, which sur- 
 rounds more immediately the coeliae artery, is termed 
 the Coeliae Plexus. From it net-works of nerves ex- 
 tend upon the great branches of the artery to the 
 organs which they go to. 
 
 They extend to the stomach, (although it is sup- 
 plied by the par vagum,) along the superior coronary 
 or gastric branch of the coeiiac ; and the fibres in their 
 composition being spread upon the coats of the sto- 
 mach, unite with the branches of the par vagum, 
 which are also spread upon them. 
 
 A similar net- work, denominated the Hepatic 
 Plexus , extends upon the Hepatic Artery , and from 
 it to the Vena Portarum ,* and accompanies those 
 vessels into the substance of the liver. It also sends 
 branches to the biliary duct and gall bladder ; to the 
 stomach by the arteria gastrica dextra ; and to the 
 omentum. 
 
 The Sple?iic Artery is invested by a similar but 
 smaller arrangement of nerves, denominated the 
 Splenic Plexus. In its course .to the spleen, this 
 plexus sends some nerves to the pancreas ; and also 
 to the stomach and omentum, with the left gastric 
 artery. 
 
 The superior mesenteric artery is surrounded by a 
 net-work, which extends to it directly from the solar 
 plexus, and is the largest of all which proceed from 
 that plexus. The Mesenteric Plexus at first nearly 
 surrounds the artery, and proceeds with it between 
 the lamina of the mesentery. In this course it sends 
 branches, with the arteria dolica dextra, to the trans- 
 verse portion of the colon. Between the lamina of 
 the mesentery, it sends ramifications with all the 
 branches of the artery, to the small intestines gene- 
 
Abdominal Viscera „ 
 
 369 
 
 rally; to the ececum, and the right portion of the 
 colon ; as well as to the mesenteric glands. 
 
 From the lower part of the solar plexus a net-work 
 proceeds, on the front of the aorta, to the inferior 
 mesenteric artery, and surrounds it. Nerves from 
 this plexus accompany the artery to the left portion 
 of the colon and the rectum. Some of their ramifi- 
 cations combine with those of the hypogastric plexus. 
 
 The Emulgent Artery is attended by nerves, which 
 are arranged like a net-work on its anterior and poste- 
 rior surfaces, and are denominated the Renal Plexus . 
 They are derived from the solar plexus, and fre- 
 quently contain small ganglions. They proceed 
 with the artery to the fissure of the kidney, and are 
 distributed with its different ramifications, in the 
 substance of the organ. 
 
 Some branches pass from them to the renal gland 
 with the capsular artery. 
 
 Before the renal plexus arrives at the kidney, it 
 sends off, from its inferior part, some new fibres, 
 which, after joining some others from one of the 
 lumbar nerves, accompany the spermatic arteries, and 
 are, therefore, called the Spermatic Plexus. In the 
 male these fibres proceed through the abdominal 
 ring, and many of them go to the testis, but they 
 are followed with great difficulty, on account of their 
 small size. 
 
 In the female, they go to the ovary and the fallo- 
 pian tube. 
 
 From the great plexuses above, a small net-w T ork 
 continues downwards on the aorta, receiving fibres 
 from the intercostals on each side ; at the great bifur- 
 cation of the aorta it divides, and is joined on each 
 side by many ramifications from the third lumbar 
 nerves, which thus form a plexus of considerable 
 extent, that sends nerves to the bladder, rectum, and 
 vesiculse seminales in males; and to the uterus and 
 
 Yol, ii. 47 
 
370 Termination of the Sympathetic Nerve, 
 
 vagina, as well as the bladder and rectum, in fe- 
 males.* This is called the Hypogastric Plexus . 
 
 The plexuses above mentioned are derived from 
 the splanchnic nerve, which came off from the Sym- 
 pathetic in the thorax. 
 
 The Sympathetic Nerve, after giving off the lesser 
 splanchnic^ is diminished in size, and approaches 
 nearer to the bodies of the vertebra. It passes 
 through the crura of the diaphragm, and then pro- 
 ceeds forwards and downwards upon the spine, be- 
 tween the tendinous crura of the diaphragm and 
 psoas muscle ; near the vena cava on the right side, 
 and the aorta on the left. In this course, it gene- 
 rally receives one or two small cords from the ante- 
 rior branch of each of the lumbar nerves: these cords 
 proceed downwards and forwards, between the bo- 
 dies of the vertebrae and the psoas muscle, and a 
 ganglion is generally formed at the plaee where they 
 join the nerve. 
 
 In its descent on the lumbar vertebrae, the Sym- 
 pathetic sends off several nerves that unite to the 
 net-work nvhich descends on the aorta from the plexus 
 above. After passing over the lumbar vertebrae, it 
 descends into the pelvis, close to the sacrum, on the 
 inner side of the great foramina: here it also forms 
 ganglions, and communicates with the sacral nerves, 
 and likewise with the hypogastric plexus. It termi- 
 nates on the os coccygis, where its minute fibres join 
 those of the opposite side. 
 
 * Although the testicle receives nerves which are derived from the Sym* 
 pathetic, the penis and other external parts of the organs of generation do 
 not: the nerves which accompany the pudic artery being derived from those 
 which unite to form the great Sciatic, 
 
SYSTEM of anatomy. 
 
 PART XI. 
 
 OF THE ABSORBENT VESSELS.* 
 
 The absorbent vessels are small transparent tubes, 
 of a delicate structure, which exist in considerable 
 numbers in almost every part of the body. 
 
 These tubes originate upon the surfaces of all the 
 cavities of the body; and of the cellular membrane, 
 in all the various parts into which it penetrates ; upon 
 the internal surface of the stomach and the intes- 
 tines ; and probably upon the skin. 
 
 Those which originate in the Lower Extremities 
 and the Cavity of the Abdomen, unite and form a large 
 trunk called the Thoracic Duct , which proceeds 
 through the thorax, and terminates in the left Sub- 
 clavian Vein, at its junction with the Internal Jugu- 
 lar. Those of the Left Upper Extremity, the Left 
 Side of the Head, and the contiguous parts, form a 
 trunk which terminates in the same place. While 
 the remaining absorbents, or those of the Right Up- 
 per Extremity, and the Right side of the Head , 
 8,'C. also form a trunk, which terminates in the cor- 
 responding part of the Right Subclavian Vein. 
 
 The absorbent vessels of the middle size, which 
 
 * Discovered at Leyden in 1650.. by Olaus Rndbeck. and at Copenhagen 
 in 1651. by Bartholine. — E d ' 
 
372 Structure of the JibsQrbent Vessels. 
 
 arise from the union of the small vessels, and unite 
 to form the larger, in their progress to these large 
 vessels, pass through certain bodies which have been 
 denominated Conglobate Glands, and may be consi- 
 dered as appendages of the absorbent system. 
 
 The absorbent vessels are composed of two coats, 
 v hich are thin, but dense and firm, and also elastic. 
 The coats of the thoracic duct may be separated 
 from each other. The internal surface of the exte- 
 rior coat is fibrous. The internal coat is a delicate 
 but strong membrane. — There is great reason to be- 
 lieve that the above mentioned fibres are muscular, 
 or at least irritable : for the absorbent vessels have 
 been observed, by Haller, to contract upon the ap- 
 plication of strong sulphuric acid. They have also 
 been observed to propel their contents with consider- 
 able rapidity, by their own contraction, independent 
 of pressure, or of motion communicated by any other 
 body. 
 
 Blood vessels are sometimes observable in the 
 coats of the larger absorbents, in injected subjects. 
 The vascularity of these tubes may also be inferred 
 from the inflammation which frequently takes place 
 in them. 
 
 Nerves have not been traced into their texture ; 
 but the absorbents seem to be painful when they are 
 inflamed, and, therefore, it is probable that they are 
 supplied with nerves. 
 
 The absorbent vessels are very generally supplied 
 with valves, which are much more numerous in some 
 of them than in others ; and are different in their 
 number, in the same vessels, in different subjects. 
 
 Very frequently there are several valves in the 
 course of an inch : sometimes a valve will not appear 
 in the course of several inches. In the Thoracic Duct , 
 the number of valves is very different in different 
 subjects. These valves are folds or plaits of the in- 
 
Commencement of the Absorbents. 373 
 
 ternal membrane, and are of a semi-circular form. 
 There are commonly two of them together origina- 
 ting from opposite sides of the vessel. 
 
 The absorbents are generally somewhat dilated 
 on the side of the valve which is next to their termi- 
 nation, and this occasions their knotted appearance 
 when they are injected. The object of this valvular 
 structure seems to be the prevention of retrograde 
 motion of the contained fluid, in consequence of la- 
 teral pressure. • 
 
 • Where the different trunks of the absorbents open 
 into the veins, there are one or two valves to prevent 
 the regurgitation of the blood into them. 
 
 The valves of course prevent the injection of the 
 branches of these vessels from their trunks. —In some 
 animals the valves have sometimes been ruptured, or 
 forced back; and the absorbents have been injected 
 in a retrograde direction. There are but two or 
 three instances upon record where this has been 
 practicable in the Human Subject. 
 
 In consequence of the impracticability of injecting 
 the small branches from the larger, the absorbent 
 vessels cannot, generally, be demonstrated at their 
 commencement, or origin. It is, however, to be ob- 
 served, that the Lacteals , or Absorbents of the Intes- 
 tines, appear no way different from other absorbents; 
 and they have been seen distended with chyle, from 
 their commencement, in certain subjects w’ho had 
 died suddenly. Their origins have been described 
 very differently by different observers. 
 
 Mr. Cruikshank describes them as originating on 
 the surfaces of the villi, by a number of very small 
 radiated branches with open orifices; which branches 
 soon unite to form a trunk. 
 
 Lieberkuhn believed them to commence in the form 
 of an ampullula . — See page 105 of this volume. 
 
 The second Monro also believes that the absorb- 
 
574 Conglobate Glands . 
 
 ents begin by very small tubes, with open orifices, in 
 several species of fish.* 
 
 It is stated by Dr. Soemmering upon the authority 
 of Haase, a German anatomist, that when mercury is 
 forced backwards in the absorbent vessels of tbe foot 
 and the heart, it has sometimes escaped on the sur- 
 faces of those parts. The probable inference from 
 these facts is, that those vessels originate by open 
 orifices on the surfaces of the heart and foot. 
 
 The bodies connected with the absorbent vessels, 
 which are called Conglobate Glands, are generally 
 of a roundish, or irregular oval form, and somewhat 
 flattened. They are of various sizes, from two lines 
 in diameter to more than twelve. Their colour is 
 frequently whitish, but sometimes it is slightly in- 
 clined to red. They are invested with a covering of 
 cellular membrane, which appears like a membranous 
 coat ; and they are connected to the contiguous parts 
 by a loose cellular substance. When the absorbent 
 vessels connected with these bodies approach near to 
 them, they divide into a number of ramifications, 
 most of which enter into the substance of the gland, 
 while some of them run over it. On the opposite 
 side of the gland a number of branches go out, which 
 unite and form trunks similar to those which entered 
 the gland. The vessels which enter the gland are 
 called Vasa infer entia , and those which go out of it 
 Vasa effer entia. 
 
 These vessels are generally much convoluted in 
 the substance of the glands, so that those bodies 
 sometimes appear like a mere convolution of absorb- 
 ent vessels. There has been much diversity of sen- 
 timent respecting the structure of these organs.! 
 
 * See his work on the Structure and Physiology of Fishes, p. 34. 
 
 f Mr. Abernethy states, that the mesenteric gland of the Whale con- 
 sists of large spherical bags into which a number of the lacteals open. — 
 Numerous blood vessels are ramified on the surfaces of these cysts ; 
 
/ 
 
 Fluid contained in the Absorbents, 375 
 
 The absorbent vessels, in the different parts of the 
 body, generally contain fluids resembling those which 
 are found in those parts. Mr. Hewson opened the 
 large absorbents in many living animals of different 
 kinds, and found that they contained a transparent 
 fluid, which coagulated when exposed to the air. 
 
 The arrangement of these vessels resembles that 
 of the veins in several respects. Many of them are 
 superficial ; but there are also deep-seated absorbents 
 which accompany the blood vessels. 
 
 and injection passes from them into the cyst. He also found cells in the 
 glands of the absorbent vessels, in the groin and the axilla of the horse— 
 See Philosophical Transactions, for 1796, Part I. 
 
CHAPTER I. 
 
 OF THE ABSORBENTS OF THE LOWER EXTREMITIES, 
 THE ABDOMEN, AND THE THORAX, 
 
 Under this head are arranged the ramifications of 
 all the vessels which unite to form the Thoracic Duct . 
 
 SECTION I. 
 
 Of the Absorbents of the Lower Extremities . 
 
 These absorbents, like the veins, are superficial 
 and deep-seated. The Superficial lie in the cellu- 
 lar membrane, very near the skin ; and form an irre- 
 gular net-work which extends over the whole limb. 
 They are, however, most numerous on the internal 
 side. 
 
 The Deep-seated accompany the arteries like the 
 veins, and there are two at least to each artery. 
 
 The Superficial Absorbents 
 
 Have been injected from the toes so as to form a 
 net-work, which occupies the upper surface of the 
 foot. They have also been injected in a similar 
 manner on the sole. Those on the upper surface of 
 the foot generally proceed upward on the anterior 
 and inner side of the leg; but some of them pass on 
 the external side of it. Those on the sole are con- 
 tinued on the back of the leg; but communicate very 
 frequently with the anterior vessels. Some of the 
 absorbents from the outside of the foot and leg enter 
 into some of the popliteal glands, soon to be de- 
 scribed; but they are not numerous; and the princi- 
 pal number continues up to the glands of the groin. 
 
Absorbents of the Lower Extremity. 377 
 
 The absorbents which originate on the surface of 
 the thigh, as we!! as those which pass over it from 
 below, incline gradually a!ong the auterior and pos- 
 terior surface, to the internal side of it; on which 
 they proceed, in great numbers, and very near to each 
 other, to the inguinal glands. Superficial absorbents 
 proceed also from the buttock, and lower part of the 
 back, from the lower part of the abdomen, the peri- 
 neum and the exterior of the genital organs, to these 
 glands. 
 
 The Deep-seated Absorbents 
 Are named from the arteries they accompany. 
 
 The Anterior Tibial Absorbents. 
 
 The anterior tibial artery is generally attended by 
 one which comes with it from the sole, and by another 
 which commences on the upper surface of the foot. 
 The first mentioned absorbent continues with the ar- 
 tery. The last often passes through an aperture in 
 the interosseal ligament, about one-third of the dis- 
 tance from the ankle to the knee, and accompanies the 
 fibular artery, while the anterior tibial artery is join- 
 ed by other absorbents about the same place. In 
 some instances a small absorbent gland occurs in this 
 course, at a short distance below the knee. 
 
 The Posterior Tibial Absorbents 
 
 Have been injected from the under side of the toes. 
 They accompany the ramifications on the sole of the 
 foot ; and after unitiug, continue with the main trunk 
 up the leg, where they enter the popliteal glands. 
 
 The Peroneal Absorbents arise also from the sole 
 of the foot, and its external side. They accompany 
 the peroneal artery, and terminate in the popliteal 
 glands, which receive also the absorbents from the 
 knee and ham. 
 
 Yol. ii. 
 
 •I 1 : 
 
 -I 
 
378 * absorbents of the Lower Extremity . 
 
 From these glands four or five absorbent vessels 
 proceed, which accompany the great blood vessels of 
 the lower extremity; and, proceeding with them 
 through the aperture in the tendon of the adductors, 
 continue upwards until they enter some of the glands 
 of the groin. 
 
 The glands of the ham and groin, which are so in- 
 timately connected with the absorbents of the lower 
 extremity, are very different from each other. 
 
 The Popliteal Glands , or those of the Ham , are 
 but three or four in number, and very small in size. 
 They are generally deep-seated, and very near the 
 artery. 
 
 The Inguinal Glands vary in number, from eight 
 to twelve or more. They are superficial and deep- 
 seated. The superficial communicate principally 
 with the superficial absorbents. The lowermost of 
 them are at some distance below Poupart’s ligament, 
 and the uppermost are rather above it. They are 
 exterior to the fascia of the thigh. Their number is 
 generally six or eight, while that of the deep-seated 
 is but three or four. 
 
 The superficial absorbents from below, approach 
 very near to each other, and enter these glands. — 
 They are commonly distributed among three or four 
 of the lowermost ; but some of them pass by these, 
 and proceed to one that is higher up; and some- 
 times there are absorbent vessels which pass to the 
 abdomen without entering into any of the glands of 
 the groin. 
 
 The deep-seated absorbents pass into the deep- 
 seated glands, which, as has been already observed, 
 are but few, and lie very near the artery under the 
 fascia of the thigh. The two sets of glands are 
 connected to each other by many absorbent vessels 
 that pass between them. The vessels which finally 
 go out of these glands are considerably less in num- 
 
Inguinal and External Iliac Glands. 379 
 
 ber than those which enter into them. They pro- 
 eeed under Pou part’s ligament, and, in some in- 
 stances, a large proportion of them passes through 
 three glands which lie below this ligament* and are 
 often so arranged, that they lie on each side of the 
 great femoral vessels, and above them. One very 
 frequently is found on the inside of the femoral vein, 
 in the vacuity between it and the internal part of the 
 ligament. All the absorbents of the lower extre- 
 mity, however, do not enter these glands. Some 
 pass along the great vessels and enter other glands 
 near the margin of the pelvis. Some also descend a 
 short distance into the pelvis, and unite with vessels 
 that are passing from the pelvis to the plexus and the 
 glands that surround the external iliac. 
 
 The absorbents which proceed from the glands 
 last mentioned, joined to those which pass under 
 Poupart’s ligament, without entering these glands, 
 and some which come from the pelvis, form a large 
 plexus, which almost surrounds the external iliac ves- 
 sels, aud contains many glands. 
 
 These External Iliac Glands vary in their number 
 from six to ten or twelve. They lie on the side of 
 the pelvis, in the course of the external iliac vessels, 
 and some of them are of considerable size. These 
 glands and the plexus of absorbents, extend in the 
 track of the iliac vessels, to the first lumbar vertebra. 
 In this course they are joined by the plexus which 
 comes from the pelvis ; and soon after they arrive at 
 the Lumbar Glands , which form a very large assem- 
 blage, that extends from the bifurcation of the aorta 
 to the crura of the diaphragm. 
 
 These glands lie irregularly, on the aorta, the 
 vena cava, and the lumbar vertebrae. Most if not all 
 the absorbents above mentioned pass through some of 
 them ; and from the union of these absorbents, some 
 
380 Absorbents of the Testicles, fyc. 
 
 of the great brandies, which unite to form the tho- 
 racic duct, are derived. 
 
 In this course from the thigh to the lumbar glands, 
 these absorbent vessels are joined by several others. 
 The Superficial Absorbents of the scrotum commonly 
 enter into the upper inguinal glands, and thus unite 
 to the great body of absorbents. 
 
 The Absorbents of the Testicles, originate in the 
 body, and the coats of the testicle, and in the epi- 
 didymis, and are remarkably large and numerous. — 
 They proceed along the spermatic cord, through the 
 abdominal ring, to the lumbar glands. These ves- 
 sels are remarkable for the little communication they 
 have with each other. 
 
 The Deep-seated Absorbents of the Scrotum ac- 
 company the absorbents of the testicle to the lumbar 
 glands; but those which are superficial enter the up- 
 per inguinal glands. 
 
 The Absorbents of the Penis are also deep-seated 
 and superficial. The deep-seated arise from the 
 body of the penis, and accompany the internal pudic 
 artery into the pelvis. The superficial absorbents 
 arise from the prepuce, and pass along the dorsum 
 of the penis. There are frequently several trunks 
 which receive branches from the lower surface of 
 the penis in their course. At the root of the penis 
 they generally separate to the right and left, and pass 
 to the glands on the respective sides. 
 
 In females, the absorbents of the interior of the 
 clitoris accompany the internal pudic artery. Some, 
 which arise about the vagina, pass through the abdo- 
 minal ring with the round ! 1 and ’ rs pro- 
 
 ceed to the inguinal- glands. 
 
Absorbents of the Pelvis and the Kidneys. 381 
 
 SECTION ir. 
 
 Of the Absorbents of the Abdomen and Thorax. 
 
 The Absorbents of the lower portions of the pa- 
 rietes of the Abdomen and the Pelvis unite into 
 trunks that follow the epigastric, the circumflex and 
 the iliac, as well as the lumbar and sacral arteries, 
 &c. They proceed to some of the glands which are 
 in the groin ; or in the external iliac, the hypogas- 
 tric, or some of the contiguous plexuses. 
 
 The Absorbents of the Womb are extremely nu- 
 merous; and, in the gravid state, are very large. 
 Those which are on the neck and anterior part of the 
 uterus, join the hypogastric plexus. Those which 
 are on the posterior part of the body, accompany 
 the spermatic vessels. 
 
 The Absorbents of the Bladder pass to small 
 glands on its lateral and inferior parts, and finally 
 join the hypogastric plexus. 
 
 The Absorbents of the Rectum are of considerable 
 size. They pass though glands that lie upon that 
 intestine, and unite with the lumbar plexus. 
 
 The Absorbents of the Kidney are superficial and 
 deep-seated. '1 hey are very numerous, but, in a 
 healthy state of the parts, are discovered with dilli- 
 culty. Cruikshank describes them as they appeared, 
 filled with blood, iri consequence of pressing upon 
 the kidney when its veins were full of blood. Mas- 
 cagni did not inject the superficial vessels with mer- 
 cury ; but describes them as they appeared when 
 filled with colourless size, after he had injected the 
 blood vessels of the organ with the coloured fluid. — 
 The deep-seated absorbents pass out of the fissure 
 of the* kidney with the blood vessels, and unite with 
 the superficial ; they proceed to the lumbar plexus, 
 and pass into different glands. 
 
382 Lacteals, or absorbents of the Intestines. 
 
 Absorbent vessels can be proved to proceed from 
 the pelvis of the kidney, and the ureters, by artifices 
 analogous to those above mentioned. 
 
 The Gian dulse Renales are also supplied with ab- 
 sorbents, which are numerous in proportion to the 
 size of the organs. They commonly join those of 
 the kidney. 
 
 The Absorbents of the Intestines 
 
 Have generally been called LACTEALS, from the 
 white colour of the chyle which they contain : but 
 there seems no reason for believing that they are dif- 
 ferent in their structure and nature from the absorb- 
 ents in other parts of the body. A small number of 
 them appear as if they formed a part of the struc- 
 ture of the intestines, and originated from their ex- 
 ternal surface, as they do in other parts of the abdo- 
 men ; while the principal part of them are appro- 
 priated to the absorption of the contents of the cavity 
 of the intestines. 
 
 The first mentioned absorbents run between the 
 muscular and peritoneal coats, and proceed for some 
 distance lengthways on the intestine, while the others 
 proceed for some distance within the muscular coat, 
 with the arteries ; and after passing through it, con- 
 tinue between the lamina of the mesentery. 
 
 Branches of these different absorbents are frequent- 
 ly united in one trunk so as to prove that there is no 
 essential difference between them. 
 
 The absorbents which come from the internal sur- 
 face of the intestines commence in the villi. The 
 manner in which they originate has been the subject 
 of considerable inquiry, as has been stated in the ac- 
 count of the intestines.* 
 
 The lacteals or absorbents of the intestines are 
 
 rr See page 105. 
 
Lac teals, or Absorbents of the Intestines. 383 
 
 very numerous. They pass between the lamina of 
 the mesentery to glands which are also seated be- 
 tween those lamina. The number of these glands is 
 very considerable,* and they are various in size — - 
 some being very minute, and others eight or ten lines 
 in diameter. They are generally placed at a small 
 distance from each other, and are most numerous in 
 that part of the mesentery which is nearest to the 
 spine. They are almost always at some distance from 
 the intestines. They appear to be precisely like the 
 absorbent glands in other places. 
 
 These absorbent vessels, in their course frequently 
 divide into branches; which sometimes go to the same 
 gland, sometimes to different glands, and sometimes 
 unite with other absorbent vessels. As they proceed, 
 they frequently enlarge in size. When they have ar- 
 rived near the spine, they frequently form three or 
 four trunks, and sometimes one or two ; which pro- 
 ceed in the course of the superior mesenteric artery, 
 until they have arrived near to the aorta. Here they 
 either pass into the thoracic duct, or descend and join 
 the trunks from the inferior extremities, to form the 
 thoracic duct. The absorbents of the great intestines 
 are not equal in size to those of the small; but they 
 are numerous. They enter into glands, which are 
 very near, and in some places, in contact with the 
 intestine; and are commonly very small in size. 
 The vessels which arise from the caecum, and the 
 right portion, as well as the arch of the colon, unite 
 with those of the small intestines ; while the vessels 
 from the left side of the colon, and the rectum, pro- 
 ceed to the lumbar glands. 
 
 The absorbents of the intestines are frequently 
 injected with mercury ; but the injection does not 
 proceed to their termination with so much facility as 
 
 They have been estimated between 130 and 150. 
 
384 
 
 Absorbents of the Stomach. 
 
 it does in others vessels cf the same kind. They 
 have, however, very oftt n been seen in animals, who 
 were killed for the purpose after eating miik ; and 
 in several human subjects who died suddenly during 
 digestion. — The description of the origin of the 
 lactoals, quoted in page 108, from Mr. Cruikshank, 
 was taken from a subject of this kind, of which an 
 account is given in his work on the absorbing ves- 
 sels, p. 59. 
 
 It is worthy of note, that in several instances, in 
 which the lac teals were thus found distended with 
 chyle, the glands in the mesentery were also uniform- 
 ly white. 
 
 The Absorbents of the. Stomach 
 
 Are of considerable size, and form three divisions. 
 The vessels of the first set appear upon both sides 
 of the stomach, and pass through a few glands on 
 the small curvature near the omentum minus. — 
 From these glands they proceed to others, which 
 are larger, and which also receive some of the deep- 
 seated absorbents of the liver. The vessels from 
 these glands pass to the thoracic duct, near the ori- 
 gin of the eoeliac artery. The second arise also on 
 both sides of the stomach, and pass to the left extre- 
 mity of the great curvature to unite with the absor- 
 bents of that side of the great omentum. They then 
 proceed with the lymphatics of the spleen and pan- 
 creas, to the thoracic duct. The last set, pass off 
 from the right extremity of the great curvature, and 
 unite also with absorbents from the right portion of 
 the omentum. They proceed near the pylorus, and 
 go to the thoracic duct, with some of the deep- 
 seated absorbents of the liver. 
 
 Although the absorbents of the stomach are deep- 
 seated, as well as superficial, it is a general senti- 
 ment, that they do not contain chyle in the' human 
 
Absorbents of the Liver . ,jsj 
 
 subject ; notwithstanding chyle has been found in the 
 absorbents on the stomach of dogs, and some other 
 animals. It ought, however to be remembered, that 
 Sabatier has, in some instances, seen white lines on 
 the stomach, which he supposed to be lacteals. 
 
 The Absorbents of the Liver 
 
 Are especially interesting, because they have been 
 more completely injected than those of any other 
 viscus. They are deep-seated and superficial . The 
 superficial it has been already observed admit of in- 
 jection in a retrograde direction, and, therefore, can 
 be exhibited most minutely ramified. They commu- 
 nicate freely with each other, and also with the deep- 
 seated vessels, by their small ramifications ; so that 
 the whole gland has been injected from one large 
 vessel. 
 
 The gland is so large, that the absorbents of the 
 superior and inferior surfaces proceed from it in dif- 
 ferent directions. 
 
 A large absorbent is generally found on the sus- 
 pensory ligament. This is formed by the union of 
 a great many branches that arise both on the right 
 and left lobes, but principally on the right. It often 
 passes through the diaphragm at an interstice which 
 is anterior to the xiphoid cartilage, and then proceeds 
 through glands on the anterior part of the pericar- 
 dium. 
 
 Several absorbents proceed to the lateral ligaments 
 on each side, and then pass through the diaphragm. 
 Some of these branches return again into the abdo- 
 men, and the others generally run forwards in the 
 course of the ribs, and join those which passed up 
 from the suspensory ligament. The trunk, or trunks, 
 formed by these vessels, either pass up between the 
 lamina of the mediastinum, and terminate in the up- 
 
 Vol. il 49 
 
386 Absorbents of the Liver and Spleen . 
 
 per part of the thoracic duct ; or they accompany 
 the internal mammary arteries, and terminate on the 
 left side in the thoracic duct, and on the right in the 
 trunk of the absorbents of that side. 
 
 The Absorbents on the concave side of the Liver 
 are as numerous as those on the convex side ; they 
 are also very abundant on the surface of the gall 
 bladder. The greatest part of them join the deep- 
 seated vessels. 
 
 The Deep-seated Absorbents proceed in consider- 
 able numbers front the interior of the liver through 
 the portae. They accompany the billiary ducts and 
 the great blood vessels of the organ ; and, after 
 passing through several glands, near the vena porta- 
 rum, terminate in the thoracic duct, near the com- 
 mencement of the superior mesenteric artery. 
 
 Mascagni states, that the absorbents of the liver 
 will be distended, by injecting warm water into the 
 biliary ducts, or the vena portarum. 
 
 He also observes, that in those preparations in which 
 the superficial vessels are completely injected, in the 
 retrograde direction, the peritoneal coat of the liver 
 appears to be composed entirely of absorbent vessels ; 
 and to be connected to the membrane within, by 
 many filaments which are also absorbent vessels. 
 
 The Absorbents of the Spleen 
 
 Are composed of superficial and deep-seated vessels; 
 but they differ greatly from those of the liver, in 
 this respect, that the superficial vessels are remark- 
 ably small in the human subject. 
 
 Mascagni however asserts, that when the blood 
 vessels of the spleen are injected with size, colour- 
 ed with vermilion, these absorbents will be filled 
 with colourless size. 
 
 In the spleen of the calf the superficial absorbents 
 are remarkably large. 
 
887 
 
 Absorbents- of the Pancreas. 
 
 In the human subject the superficial absorbents of 
 the spleen proceed from the convex to the concave 
 surface, and there communicate with the deep-seated 
 absorbents., which proceed from the interior of the 
 organ with the blood vessels. 
 
 These Beep-seated Absorbents are very numer- 
 ous, and also large. They accompany the splenic 
 artery; and in their course pass through many glands, 
 some of which are said to be of a dark colour. The 
 glands lie on the splenic artery, at a short distance 
 from each other. The absorbents of the spleen re- 
 ceive the absorbents of the pancreas in their course; 
 they unite with the absorbents of the stomach and 
 the lower surface of the liver, and pass with them to 
 the thoracic duct. 
 
 Little has been latterly said by practical anato- 
 mists respecting 
 
 The Absorbents of the Pancreas, 
 
 Mr. Cruikshank once injected them in the retrograde 
 direction ; he found that they came out of the lobes 
 of the pancreas in short branches like the blood ves- 
 sels, and passed at right angles into the absorbents 
 of the spleen, as they accompanied the artery in the 
 groove of the pancreas. 
 
 THE THORACIC DUCTf 
 
 Or common trunk of the absorbent system, is formed 
 by the union of those absorbent vessels which are 
 collected on the lumbar vertebrae. 
 
 These vessels, as it has been already observed, 
 are derived from various sources, viz. 
 
 The Lower Extremities ; the lower part of the 
 Trunk of the Body; the Organs of Generation; the 
 
 * First discovered by Eustachius in the horse, 15G4, but he considers it 
 a vein for the nourishment of the thoracic viscera. — Ed. 
 
3SS Commencement of the Thoracic Duct. 
 
 Intestines, with the other Viscera of the abdomen 
 and Pelvis, except a part of the liver. Their num- 
 ber is proportioned to the extent of their origin : for, 
 with the numerous glands appropriated to them, they 
 form the largest absorbent plexus in the body, and 
 are spread over a considerable portion of the aorta 
 and the vena cava. 
 
 The manner in which these vessels unite to form 
 the thoracic duct, is very different in different sub- 
 jects; but in a majority of cases it originates imme- 
 diately from three vessels, two of which are the 
 trunks of the absorbents of the lower extremities, 
 and the other is the common trunk of the lacteals and 
 the other absorbents of the intestines. 
 
 These vessels generally unite on the second or 
 third lumbar vertebrae ; and, in some instances, the 
 trunk which they form dilates considerably, soon af- 
 ter its commencement ; in consequence of which it 
 was formerly called the RECEPTACLE of the 
 CHYLE. At first it lies behind the aorta, but it 
 soon inclines to the right of it, so as to be behind the 
 right crus of the diaphragm. In the thorax, it ap- 
 pears on the front of the spine, between the aorta 
 and the vena azygos, and continues between these 
 vessels until it has arrived at the fourth or third dor- 
 sal vertebra. It then inclines to the left, and pro- 
 ceeds in that direction until it emerges from the 
 thorax, and has arisen above the left pleura, when 
 it continues to ascend behind the internal jugular, 
 nearly as high as the sixth cervical vertebrae : it then 
 turns downward and forward, and, after descend- 
 ing from six to ten lines, terminates in the back part 
 of the angle formed by the union of the left internal 
 jugular with the left subclavian vein. Sometimes, 
 after rising out of the thorax, it divides into two 
 branches, which unite before they terminate. Some- 
 times it divides, and one of the branches terminates 
 
Absorbents of the Lungs. 389 
 
 at the above mentioned angle, and the other in the 
 subclavian vein, to the left of it. 
 
 The orifice of the thoracic duct has two valves, 
 which effectually prevent the passage of blood into 
 it from the vena cava. 
 
 There are sometimes slight flexures in the course 
 of the duct; but it generally inclines to the left, in 
 the upper part of the thorax, as above mentioned: 
 and is then so near the left larnen of the mediastinum 
 that if it be filled with coloured injection, it can be 
 seen through that membrane, when the left lung is 
 raised up and pressed to the right. 
 
 The duct sometimes varies considerably in its dia- 
 meter in different parts of its course. About the mid- 
 dle of the thorax it has often been found very small. 
 In these cases it generally enlarges in its progress 
 upwards, and is often three lines in diameter, in its 
 upper part. Many anatomists have observed it to 
 divide and to unite again, about the middle of the 
 thorax. 
 
 Absorbents of the Lungs. 
 
 The absorbents of the lungs are very numerous, 
 and, like those of other viscera, are superficial and 
 deep-seated. 
 
 The large superficial vessels run in the interstices 
 between the lobuli, and therefore form angular figures 
 of considerable size. In successful injections, the 
 vacancies within these figures are filled up with small 
 vessels, and the whole surface appears minutely in- 
 jected. 
 
 Mascagni observes, that the superficial vessels are 
 very visible when any fluid has been effused into 
 the cavity of the thorax ; or when warm water is in- 
 jected, either into the blood vessels of the lungs, or 
 the ramifications of the trachea. Cruikshank de- 
 monstrated them by inflating the lungs of a still born 
 
390 Absorbents of the Lungs. 
 
 child ; in which case the air passes rapidly into 
 them. 
 
 The deep-seated absorbents accompany the blood 
 vessels and the ramifications of the bronchi®. They 
 pass to the dark coloured glands, which are situa- 
 ted on the trachea at its bifurcation; and on those 
 portions of the bronchi® which are exterior to the 
 lungs. The injection of the absorbents, which pass 
 to and from these glands, seems to prove that they 
 are of the same nature with the absorbent glands in 
 general notwithstanding their colour. They are nu- 
 merous, and they vary in size; from a diameter of 
 two lines, to that of eight or ten. 
 
 From these glands, some of the absorbents of the 
 left lung pass into the thoracic duct, while it is in 
 the thorax, behind the bifurcation of the trachea; 
 others proceed upwards and enter into it near its ter- 
 mination; while those of the right lung terminate in 
 the common trunk of the absorbents of the right side 0 
 
CHAPTER II. 
 
 OF THE ABSORBENTS OF THE HEAD AND NECK ; OF 
 
 THE UPPER EXTREMITIES, AND THE UPPER PART 
 
 OF THE TRUNK OF THE BODY. 
 
 The absorbents from the various parts of the head 
 pass through glands, which are situated on the neck, 
 or the lower part of the head. Those on the head 
 are the least numerous, and also the least in size. — 
 Some of them, which are generally small, lie about 
 the parotid gland. Several of them, which are also 
 small, are on the occiput, below and behind the 
 mastoid process. Sometimes there are two or three 
 on the cheek, near the basis of the lower jaw, about 
 the anterior edge of the masseter muscle. Below the 
 lower jaw, in contact with the sub-maxillary gland 
 and anterior to it, there are always a number of these 
 glands, which are generally small, but often swelled 
 during infancy. 
 
 The Glands on the JYech are the most numerous. 
 Many of them are within the sterno- mastoid muscle, 
 and accompany the internal jugular vein and the 
 carotid artery down to the first rib. Many also lie 
 in the triangular space between the sterno- mastoid 
 muscle, the trapezius, and the clavicle ; therefore it 
 has been truly said thpt the glands of the neck are 
 more numerous than those of any other part, except 
 the mesentery. They are frequently called Glan- 
 dulse Concatenatae. It has already been mentioned 
 that the various absorbents, which are connected with 
 these glands, unite on each side into a trunk, which 
 on the left passes into the thoracic duct, and on the 
 right into the common trunk of the absorbents of 
 that side. 
 
392 Absorbents of the Head and JYeck . 
 
 SECTION i. 
 
 Of the Absorbents of the Head and Neck. 
 
 There is the greatest reason to believe that the 
 brain and its appendages are supplied with absorb- 
 ents like the other parts. Some of these vessels have 
 been discovered in the cavity of the cranium ; but 
 very little precise information has as yet been obtain- 
 ed, respecting the extent, or arrangement of the ab- 
 sorbent system, in this part of the body. 
 
 The absorbents on the exterior of the head are as 
 numerous as in other parts of the body. On the oc- 
 ciput they pass down, inclining towards the ear, and 
 continue behind it to the side of the neck ; behind 
 the ear they pass through several glands. — From the 
 middle or temporal region of the cranium, they pass 
 with the carotid artery before the ear, and enter some 
 small glands that lie on the parotid ; from which they 
 continue to the neck. 
 
 They are on every part of the face, and unite, so 
 that their principal trunks, which are very numerous, 
 pass over the basis of the lower jaw, near the facial 
 artery. They enter into glands, which are also very 
 numerous, immediately under the jaw, or which are 
 sometimes to be found on the cheek, at the anterior 
 edge of the masseter muscle. All the absorbents of 
 the exterior part of the head pass to the glands on 
 the side of the neck, already described. 
 
 Those from the interior of the nose accompany the 
 ramifications of the internal maxillary artery, and 
 proceed to glands behind the angle of the lower jaw; 
 into which glands also enter the absorbents of the 
 tongue and inner parts of the mouth. 
 
 The absorbents of the thyroid gland, on the left 
 side, pass down to the thoracic duct; those on the 
 right, unite to the trunk of the absorbents on that 
 
393 
 
 Absorbents of the Hand and Ann , 
 
 side, near its termination. It has been remarked that 
 they can be readily injected, by thrusting the pipe 
 into the substance of the gland. 
 
 SECTION II. 
 
 Of the Absorbents of the Arm and Upper Part of 
 the Trunk . 
 
 The absorbents of the arm are superficial and deep- 
 seated, like those of the lower extremity. 
 
 The superficial absorbents have been injected on 
 the anterior and posterior surfaces of the fingers and 
 the thumb, near their sides. On the back of the 
 hand they are very numerous, and increase consi- 
 derably in their progress up the fore-arm. As they 
 proceed upwards, they incline towards the anterior 
 surface of the fore-arm ; so that by the time they have 
 arrived at the elbow, almost all of them are on the 
 anterior surface. The absorbents on the anterior part 
 of the hand are not so numerous as those on the back. 
 Sometimes there are digital branches from the fin- 
 gers, and an arcus in the palm ; but this bow is not 
 formed by one large absorbent, analogous to the ulnar 
 artery. On the contrary, its two extremities are con- 
 tinued over the wrist, and pass on the fore-arm like 
 the absorbents. 
 
 At the elbow, some of them often pass into one or 
 two small glands, which are very superficial; but 
 the whole of the absorbents, somewhat reduced in 
 number, as some of them unite together, pass along 
 with the bloodvessels into the hollow of the arm-pit; 
 where they enter the axillary glands. There are 
 generally one or more vessels which pass in the 
 course of the cephalic vein, between the pectoral and 
 the deltoid muscle, and enter into some of the glands 
 under the clavicle. 
 
 VOL, II, 
 
 50 
 
394 Absorbents of the Upper Part of the Trunk. 
 
 There are almost always several glands in and 
 near the axilla. Some of them are very near the 
 great blood vessels ; sometimes one or more of them 
 are much lower; sometimes they are to be found 
 under the pectoral muscle. They are commonly not 
 so large as those of the groin, and are surrounded 
 with fat. 
 
 The deep-seated absorbents originate also at the 
 fingers, and soon accompany the branches of the ar- 
 teries. Those which attend the radial artery, origi- 
 nate on the back of the hand, and also in the palm, 
 where they are associated with the arcus profundus. 
 They go up with the radial artery to the elbow, and 
 sometimes pass through a small gland about the mid- 
 dle of the fore-arm. 
 
 Those which attend the ulnar artery, commence 
 under the aponeurosis palmaris, and go with the ar- 
 tery to the elbow; at the bend of the elbow they are 
 generally joined by one or more, which accompany 
 the interosseal artery ; there they unite, so as to form 
 several trunks which pass up to the axillary with the 
 humeral artery. They sometimes pass through one 
 or two glands, which are near the elbow ; and they 
 receive in their course, deep-seated branches from 
 the muscles on the humerus. 
 
 The absorbents from the anterior and external 
 part of the thorax, and the upper part of the abdo- 
 men, also proceed to the axilla, and enter into the 
 glands there ; those which are deep seated, joining the 
 deep-seated vessels. The absorbents of the mammae 
 pass to the same glands; and when they are affected 
 with the virus of cancer, can often be perceived, in 
 their course, in the living subject. 
 
 The absorbents of the uppermost half of the back, 
 and those of the back of the neck, go likewise to the 
 axilla. 
 
 The absorbent vessels, collected from these van- 
 
Facts relating to Cutaneous Absorption. 395 
 
 ous sources, proceed from the exterior to the inner- 
 most glands, but with a considerable diminution of 
 their number; they accompany the subclavian vein, 
 and are reduced to one or two trunks, that gene- 
 rally unite before their termination. On the left 
 side , the absorbents of the head and neck generally 
 open into the thoracic duct, as has been already ob- 
 served; and those of the left arm also open into the 
 thoracic duct, or into the subclavian vein very near 
 it. On the right side the absorbents from each of 
 these parts empty into the common trunk; which 
 often is formed by the union of large vessels, from 
 four sources; viz. the Head, the Thyroid gland, the 
 right arm, and the right cavity of the Thorax, &c. 
 The diameter of the trunk is very considerable ; but 
 it is often not more than half an inch in length. It 
 generally opens into the right subclavian vein, at 
 the place where it unites to the right internal ju- 
 gular. 
 
 Two respectable physiologists of Europe, (M. Seguin, of 
 Paris, and the late Dr. Currie, of Liverpool,) have 
 doubted whether absorption takes place on the exter- 
 nal surface of the skin.* This question has been ex- 
 amined in a very interesting manner by several gra- 
 duates of the University of Pennsylvania, who chose 
 it for the subject of their inaugural theses ; viz. Drs. 
 Rousseau, Klapp, Daingerfield, Mussey, and J. Brad- 
 ner Stewart. 
 
 The three first of these gentlemen state, that when spirit 
 of turpentine, and several other substances which are 
 commonly supposed to be absorbed by the skin, were 
 applied to it in a way which prevented their volatile 
 
 * I believe that M. Seguin’s Memoir on this subject was read to the 
 Academy of Sciences a short time before the meetings of that body were 
 suspended. It was published by M. Fourcroy, in La Medicine Eclairee 
 par les Sciences Physiques, vol. iii. An extract from M. Fourcroy’s pub- 
 lication may be se*n in the 19th chapter of the first volume of Dr. Currie’s 
 <! Medical Reports on the Effects of Water,” &c. in which is also con- 
 tained a statement of the Doctor’s own. experiments and reflections. 
 
396 Experiments of K. Boerhaewe and J. Hunter . 
 
 parts from entering the lungs by respiration, no ab- 
 sorption took place. But when they inspired air im- 
 pregnated with exhalations from these substances, they 
 perceived satisfactory proofs that the exhalations en- 
 tered the system. From these facts they inferred that 
 when those articles entered the body by absorption, 
 they were taken in by the lungs, and not by the exter- 
 nal surface. 
 
 On the other hand, the two gentlemen last mentioned, 
 state that alter immersing themselves in a bath con- 
 sisting ol a decoction of rhubarb, of madder, or of tur- 
 meric, their urine became tinged with these sub- 
 stances. They also assert that the colouring matter 
 of these different articles is not volatile ; and, there- 
 fore, could not have entered the lungs during the ex- 
 periments.* 
 
 The statement in page 374, from Dr. Soemmering, that 
 when mercury is injected backwards in the absorbent 
 vessels which originate on the foot, it will sometimes 
 appear in small globules on the skin of the foot, has 
 an important connexion with this subjeett 
 
 About the middle of the last century, it was generally 
 believed by anatomists, that absorption was performed 
 by the veins. This doctrine seemed to be established 
 by the experiments of Kaaw Boerhaave, which are re- 
 lated, with many other interesting statements, in his 
 work, entitled “ Perspiratio Dicta Hippocrati,” &c. 
 published at Leyden, in 1738. In these experiments 
 it appeared to the author, that when the stomach of a 
 dog was emptied of its contents, and filled with w arm 
 water, immediately alter death, the water passed into 
 the minute ramifications of the veins of the stomach, 
 
 * The Thesis of Dr. Rousseau was published in 1800. Those of Drs. 
 Klapp and Daingerfield in 1805. Dr. Mussey published in the Third 
 Supplement to the Medical and Physical Journal of Dr. Barton, in 1809. 
 Dr. Stewart published in 1810. Additional observations by Drs. Klapp, 
 Rousseau and Smith, are published in the Philadelphia Medical Museum, 
 Vol. i. new series. 
 
 f Since the publication of the first volume, the author has enjoyed the 
 advantage of consulting a translation, in manuscript, of some parts of the 
 German edition of Dr. Soemmering’s valuable work op the Structure of 
 rhe Human Body 
 
'Experiments of Magendie and Delile . 397 
 
 and from them to the vena portarum, and ultimately 
 to the heart, in large quantities. 
 
 This account appears to be disproved by some experi- 
 ments of the late John Hunter, made about twenty 
 years after, and published in the Medical Commenta- 
 ries of Dr. William Hunter, Part I. Mr. Hunter’s 
 
 experiments have been considered as establishing the 
 fact, that absorption, (in the intestines at least,) is per- 
 formed exclusively by the lacteals, or proper absorbent 
 vessels, and not at all by the veins. Kaaw Boer- 
 haave is of course supposed to have been mistaken | 
 and Mascagni, who has repeated his experiment, re- 
 fers the appearance of water in the veins to transuda- 
 tion through the coats of the intestines ; which he has 
 observed to take place to a great degree. 
 
 In the year 1809, a memoir was presented to the nation- 
 al institute of France by Messrs. Magendie and De- 
 lile, which contains an account of some experiments 
 that have an important relation to the above mentioned 
 subject.* — The authors being greatly surprised at the 
 rapidity with which the poison of Java, &c. appeared 
 to enter the sanguiferous system, instituted a series 
 of experiments to determine whether these substances 
 proceeded to that system by the circuitous route of the 
 absorbent vessels, or by the shorter course of the veins. 
 Two of their experiments are especially interesting. 
 They made an incision through the parietes of the ab- 
 domen of a living dog, who had eaten a large quantity 
 of meat some hours before, (that his lacteals might be 
 visible from their distension with chyle,) and, draw- 
 ing out a portion of the small intestine, they applied 
 two ligatures to it, at the distance of five inches from 
 each other. The portion of intestine between these 
 ligatures was then separated by incision from the rest 
 ot the intestinal tube, and all the lacteals, blood ves- 
 sels, &c. which passed to and from it, were divided, 
 except one artery and a vein. A considerable length 
 of this artery and vein were detached from all the sur- 
 rounding parts, so that the authors supposed these 
 
 ' The title of the paper is a “ Memoir on the Organs of Absorption 
 in Mammiferous Animals.” A translation of it was published in the Me- 
 dical and Philosophical Register of New York, and in several other perio- 
 dical works. 
 
398 Experiments of Magendie and Delile . 
 
 vessels to form the only connexion between the por- 
 tion of the intestine and the rest of the body. Into 
 the cavity of the intestine, which was thus circum- 
 stanced, they introduced a small quantity of the poison, 
 and, to their astonishment, it produced its fatal effects 
 in the same manner it would have done if it had been 
 introduced into the intestine while all its connexions 
 with the body were entire. This experiment, they 
 assert, was repeated several times, without any dif- 
 ference in the result. 
 
 After several other experiments, they finally separated 
 the thigh from the body of a living dog in such a man- 
 ner that the crural artery and vein were left undivi- 
 ded. A quill was then introduced into the artery, 
 and two ligatures were applied to fix it round the 
 quill. The artery was then divided between the two 
 ligatures. The vein was managed in the same man- 
 ner. There was, therefore, no communication be- 
 tween the limb and the body, except by the blood 
 which passed through the divided vessels and the 
 quills. The poison was then introduced under the 
 skin of the foot, and soon occasioned the death of the 
 animal : its deleterious effects commencing about four 
 minutes after its application to the foot. This expe- 
 riment appears to prove decidedly that the blood is the 
 vehicle by which poison, when applied to the extremi- 
 ties, is carried to the body ; although it may not de- 
 termine the question whether this poison was taken 
 up by the absorbents or by the veins.* 
 
 Some other experiments made by the authors gave re- 
 sults, which are very difficult indeed to explain. They 
 wished to know if the blood of an animal thus con- 
 taminated, would produce similar effects upon another 
 animal; and, with a view to ascertain this point, they 
 insinuated a small piece of wood, covered with the 
 poison, into the thick part of the left side of the nose 
 of a dog. Three minutes after the introduction of the 
 poison, they transfused blood from the jugular vein of 
 the same side, into one of the veins or another dog. 
 About one minute after the commencement of the 
 
 * This experiment has been repeated in Philadelphia. See Professor 
 
 Chapman’s Medical and Physical Journal for February, 1823, No. 10. 
 
 FiJD- 
 
Report of the Committee of the Institutes . 399 
 
 • transfusion, the effects of the poison began in the dog 
 to which it was applied, and continued until his death. 
 Transfusion into the vehis of the other dog went on 
 during the whole time, and he received a large quan- 
 tity of blood from the dying dog, without producing 
 any effect. — They varied this experiment in the fol- 
 lowing manner. The thigh of a dog was separated 
 from the body; the artery and the vein were arranged 
 as in the former experiment; and poison was intro- 
 duced into the foot. Three minutes after the intro- 
 duction of the poison, the blood of the crural vein was 
 passed into the jugular vein of another animal, and 
 transfusion was continued five minutes without pro- 
 ducing any effect upon the animal receiving the blood; 
 it was then stopped, and the crural vein was so ar- 
 ranged that the blood flowed from it into the animal 
 to which it belonged. This animal very soon exhibit- 
 ed symptoms of the operation of the poison.* 
 
 From these very interesting experiments the authors in- 
 fer that “ foreign matters do not always proceed 
 through the lymphatic or Absorbent Vessels, when 
 they enter into the Sanguiferous system. ” 
 
 This memoir was referred by the Institute to four of its 
 members, who are particularly distinguished by their 
 profound knowledge of anatomy and physiology. 
 These gentlemen, after stating their belief that the 
 functions of the lymphatic or absorbent system have 
 been completely ascertained by the experiments and 
 observations of Hunter, Cruikshank, Mascagni, &c, 
 say further, that, in their opinion, the above mention- 
 ed inference ought to be a little modified, and that 
 facts are not sufficiently numerous, or applicable to 
 the point in question, to justify the inference that 
 foreign matters do not always proceed through the 
 Lymphatic or Absorbent Vessels, when they enter the 
 Sanguiferous system. But they also add, that, as the 
 author is still engaged in a series of experiments on 
 the subject, they will suspend their judgment respect- 
 ing the inferences to be deduced from the present 
 statement. 
 
 * An account of these experiments was published by M. Magendie in a 
 pamphlet. A statement of them is also contained in the report made to 
 the Institute by the committee to whom the memoir was referred, which is 
 published in the Journal de Physique, for March 1813. In that statement 
 this last mentioned experiment is omitted. 
 
400 
 
 Of the Absorbent System. 
 
 The most extensive account of the absorbent system is 
 contained in the “ Historia et Ichnographia Yasorum 
 Lymphaticorum Corporis Humani” of Mascagni. — 
 “ The Anatomy of the Absorbing Vessels of the Human 
 Body, by W. Cruikshank — and “ The Description 
 of the Lymphatic System, by Wm. Ilewson,” (the 
 second volume of his Experimental Inquiries,) — are 
 also very interesting publications. 
 
 A most interesting series of inquiries and experiments in regard to the 
 laws of absorption will be found in Professor Chapman’s Journal of the 
 Medical and Physical Sciences, No. 6, in a report of a Committee of the 
 Academy of Medicine, signed by Doctors Lawrance and Coates, of this 
 city. — And a continuation of the same will be found in No. 10, of the same 
 Journal, signed by Doctors Lawrance and Coates. Since the publication 
 of the latter, to the regret of all who knew him, and to the great loss of 
 Anatomy and of Physiology, the indefatigable and excellent Lawrance 
 Is no more. — Eb. 
 
APPENDIX. 
 
 OF THE BLOOD. 
 
 THE blood of a healthy person indicates a ten= 
 dency to coagulate very soon after it is discharged 
 from the vessels which naturally contain it, although 
 it is perfectly fluid in those vessels. 
 
 If it remain at rest, after it is drawn from the 
 vessels, it soon coagulates, into a solid mass, of a soft 
 texture. From this solid mass a fluid is soon ob- 
 served to issue, which first appears in very small 
 drops on almost every part of the surface. These 
 drops quickly increase and run together, and in a 
 short time the fluid surrounds the solid mass, and ex- 
 ceeds it in quantity. 
 
 The solid part which thus appears upon the 
 spontaneous separation of the blood, is denominated 
 Crassamentum or Cruror: the fluid part is called 
 Serum. 
 
 The substance which contains the red colour of the 
 blood remains with the Crassamentum. The Serum , 
 when it separates without agitation, is free from the 
 red colour. 
 
 The colouring matter may be separated completely 
 from the Crassamentum by washing it with water. 
 
 The blood, therefore, consists of three parts, viz. 
 the Serum ; the Substance which coagulates spon- 
 taneously ; and the Colouring Matter . 
 
 VOL. ii. 51 
 
402 
 
 Appendix.— Of the Blood. 
 
 THE SERUM 
 
 Has a considerable degree of consistence, although 
 it is much thinner than blood. In its perfectly na- 
 tural state, it is almost transparent, and appears to 
 be very lightly tinged with a greenish yellow colour; 
 but it is very often impregnated with a portion of 
 bile, which is probably carried to the blood vessels 
 by the absorbents. It contains a large quantity of 
 albumen, or matter like the white of an egg. If 
 heated to 140° of Fahrenheit, it becomes opaque ; 
 and when the heat is increased to 156 or 160, it is 
 firmly coagulated. It is also coagulated by alcohol, 
 by mineral acids, and by rennet.* It is proved by 
 chemists, that it contains a small quantity of pure 
 soda. It therefore changes several of the blue co- 
 lours of vegetables green. It is also found to con- 
 tain a similar quantity of the muriate and the phos- 
 phate of soda, and the phosphate of lime. These 
 saline substances were discovered by diluting serum 
 with water, and exposing the mixture to heat, by 
 which the albumen was coagulated into flocculi : 
 these flocculi were separated by filtration : the li- 
 quor was then diminished by evaporation, and the 
 salts obtained from it by crystallization. 
 
 Serum likewise contains a portion of sulphur com- 
 bined with ammonia. 
 
 When it is exposed to a coagulating heat, a small 
 portion of it remains fluid. 
 
 This fluid portion has been supposed to contain a 
 considerable quantity of gelatine ; but it is contend- 
 ed by Mr. Brande,f that Gelatine does not exist in 
 
 * See Hewson, Vol I. p. 139. — I suspect that some particular manage- 
 ment is necessary in the use of rennet. 
 
 f In his Researches on the Blood communicated to the Royal Society 
 of London, in 1812, and republished in the Eclectic Repertory, for April, 
 1S1? 
 
403 
 
 Appendix.— Of the Blood. 
 
 the serum of the blood, and that this portion consists 
 of albumen combined with a proportion of alkali. 
 
 It is also asserted by Dr. Bostoek,* one of the 
 latest writers on the subject, that the serosity of the 
 blood, (the term applied to the last mentioned fluid,) 
 contains no gelatine ; but that, with a minute quan- 
 tity of albumen, it consists of a large portion of an 
 animal matter, which is different either from gela- 
 tine or albumen, being unlike either of them in its 
 chemical qualities. 
 
 THE CRASSAMENTUM 
 
 Is rendered very different in its appearance, by the 
 different circumstances in which it may coagulate. 
 
 When the blood remains at rest immediately after 
 it is drawn, the crassamentum which forms in it is a 
 concrete substance, without the smallest appearance 
 of fibre in its composition. If the blood is stirred 
 with a rough stick, while it is flowing from an ani- 
 mal, a large portion of it will concrete upon the 
 stick in a fibrous form, so as to resemble a mass of 
 entangled thread, some of the red colouring matter 
 still adhering to it. 
 
 The crassamentum, in either of these forms, may 
 be washed perfectly white ; the red colouring matter 
 passing completely away with the water. In this 
 state it appears - )- to have all the chemical properties 
 of the fibrous matter of muscular flesh. It also resem- 
 bles the gluten of vegetables, being soft and elastic. 
 The name fibrin is now generally applied to it. 
 
 If fibrin is washed and dried, its weight is very 
 small indeed when compared with that of the blood 
 
 * See his observations on the Serum of the Blood, in the Medico-Chi- 
 rurgical Transactions, Vol. II. republished in the Eclectic Repertory, for 
 October 1812. 
 
 t By the experiments of Mr. Charles Hatchett, published, in the London 
 Philosophical Transactions for 1800- 
 
404 Appendix.— Of the Blood. 
 
 from which it has been obtained. It is, therefore? 
 probable that a considerable proportion of the bulk 
 of the crassamentum, as it forms spontaneously, de- 
 pends upon the serum which exists in it, and can be 
 washed away. 
 
 The spontaneous coagulation of the blood, which 
 appears to depend principally upon the Fibrin , may 
 be prevented by the addition of several foreign sub- 
 stances to the blood, when it is drawn. It is subject 
 to great variations that depend upon the state of the 
 body at the time of bleeding ; and in some condi- 
 tions, it does not take place at all.* 
 
 In a majority of dead subjects the blood is found 
 more or less coagulated in the veins ; but in some 
 subjects it is found without coagulation. It is assert- 
 ed that it does not coagulate in subjects who have 
 died suddenly, in consequence of anger, lightning, 
 or a blow on the stomach. 
 
 THE COLOURING MATTER. 
 
 When the blood vessels in the transparent parts of 
 certain living animals are examined with magnifying 
 glasses, it appears that the red colour of the blood 
 is owing to bodies of a globular form, which are dif- 
 fused through a transparent fluid. The appearance 
 of these bodies has been examined, with great atten- 
 tion, by many physiologists, since the publication of 
 Leuwenhoeck, in the London Philosophical Trans- 
 actions, t 
 
 * See an Inquiry into the Properties of the Blood, by the late Win. 
 Hewson: and Experiments by his son, T. T. Hewson, in the Eclectic 
 Repertory, Jan. 1811 — See also a Treatise on the Blood, &c. by the late 
 J. Hunter. 
 
 t Among the most distinguished of these observers were Father de la 
 Torre, Haller, Hewson, Fontana, Spalanzani, J. Hunter, Cavallo. 
 
 Some short accounts of Leuwenhoeck’s original observations on the 
 blood are to be found in the Philosophical Transactions of l^ondon ; for 
 
405 
 
 Appendix .—Of the Blood. 
 
 Several of these gentlemen have described the ap- 
 pearance of the blood very differently ; but Haller, 
 Spalanzani and J. Hunter agree that the figure of 
 the red particles is globular.* Hunter observes 
 further, that the red globules do not run into each 
 other as two globules of oil would do when divided 
 by water ; and he believes that they cannot unite.— 
 At the same time they seem not to have the proper- 
 ties of a solid : for when circulating in the vessels, 
 they assume elliptical forms, adapting themselves to 
 the size of the vessels. They also excite no sensa- 
 tion of solidity when touched. 
 
 They appear to be more heavy than the other 
 parts of the crassamentum : for in healthy blood the 
 lower part of the mass contains more of the colour- 
 ing matter then the upper part; and in the blood of 
 persons who labour under acute local inflammation, 
 they often subside completely from the upper part ; 
 and thus occasion what is called by Mr. Hewson, the 
 inflammatory crust, or size. 
 
 It has been observed by Mr. Hewson, and also 
 by Mr. Hunter, that the globules do not retain their 
 form in every fluid. They are said to be dissolved 
 
 1664, in the fasciculi which are numbered 102 and 106. A more full de- 
 scription is contained in Boerhaave’s Academical Lectures on the Theory 
 of Physic. See the section on the nature of the blood. 
 
 The glasses of Father de la Torre were transmitted from Naples to the 
 Royal Society of London in 1765. They were accompanied by a letter 
 from Sir F. H. E. Stiles, to which are subjoined some observations by the 
 Rev. Father himself. The letter and the observations are published in the 
 55th volume of the Transactions of that society. 
 
 In the year 1798, Tiberius Cavallo published an Essay on the Medicinal 
 Properties of Factitious Air, with an Appendix on the Nature of the 
 Blood, in which is contained a further account of the glasses of de la 
 Torre. 
 
 * I believe that this is also the opinion of Fontana. — In J. Hunter’s 
 work en the Blood there are some interesting observations on micro- 
 scopical deceptions. See the note, commencing in page 39, Bradford’s 
 edition. 
 
406 Appendix .—Of the Blood. 
 
 very quickly in water, and then they form a fine 
 clear red. Several of the neutral salts, when dis- 
 solved in water, prevent the solution of the globules. 
 Mr. Hunter informs us, that the vitriolic acid, when 
 greatly diluted, does not dissolve them, &c. The 
 muriatic acid, when three times as strong as vinegar, 
 destroys their colour without dissolving them, al- 
 though when more diluted, it dissolves them. 
 
 The colour of the blood has, for a long time, been 
 supposed to depend upon Iron. About the middle 
 of the last century, Vicentius Menghini published 
 in the Transactions of the Academy of Sciences of 
 Bologna, an account of experiments which contri- 
 buted to establish this sentiment. In this account 
 he stated, that, after washing the colouring matter 
 from the crassamentum, he had separated it from the 
 water by boiling; in which case it either rose to the 
 surface of the water, or subsided, and left the water 
 clear. After drying, with a gentle heat, some of 
 the colouring matter thus separated, and then re- 
 peatedly washing it, he found that it contained a 
 considerable quantity of iron, which was attracted by 
 the magnet. 
 
 After exposing a large quantity of the colouring 
 matter to an intense heat, he found in it a small 
 piece of iron, of a spherical form, but hollow; and 
 a powder which was attracted by the magnet, but ap- 
 peared more like rust of iron than iron filings. 
 
 He believes the seat of this iron to be in the co- 
 louring matter of the blood, as neither the serum nor 
 fibrine appeared to contain it. According to his cal- 
 culation, the blood of a healthy man contains more 
 than two ounces of iron. 
 
 This doctrine of Menghini has been very gene- 
 rally admitted ; and several ehemists of the first 
 character, viz. Bucquet, Foureroy, Vauquelin, &c. 
 
407 
 
 Appendix .* — Of the Blood. 
 
 have made experiments to ascertain the substances 
 with which the iron in the blood is combined. 
 
 But within a few years, doubts have been express- 
 ed on this subject by several physiologists, and espe- 
 cially by Dr. Wells, and Mr. Brande. 
 
 The first of these gentlemen, in his “ Observations 
 and Experiments on the Colour of the Blood” pub- 
 lished in the London Philosophical Transactions for 
 1797, states three reasons for rejecting the opinion 
 that the colour of the blood is derived from iron. 
 
 1. The colour of blood is destroyed by a heat less 
 than that of boiling water; whereas no colour arising 
 from a metal is destroyed by exposing its subject, in 
 a close vessel, to such a heat. 
 
 2. If the colour from a metal, in any substance, be 
 destroyed by any alkali, it may be restored by the 
 immediate addition of an acid; and the like will 
 happen by the addition of a proper quantity of an al- 
 kali, if the colour has been destroyed by an acid.— 
 The colour of blood, on the contrary, when once de- 
 stroyed, can never be brought back, either by an 
 acid or an alkali. 
 
 3. If iron be the cause of the red colour of blood, 
 it must exist there in a saline state ; since the red 
 matter is soluble in water. The substances, there- 
 fore, which detect the smallest quantity of iron in 
 such a state, ought likewise to demonstrate its pre- 
 sence in blood; but upon adding Prussian alkali, 
 and an infusion of galls, to a very saturated solution 
 of the red matter, he could not observe “in the form- 
 er case the slightest blue precipitate; or in the latter 
 that the mixture had acquired the least blue or pur- 
 ple tint.” 
 
 Mr. Brande, in a paper entitled “ Chemical Re- 
 searches on the Blood” &e. communicated to the 
 Royal Society of London in 1812, relates many ex- 
 periments which were made on the colouring matter 
 
408 Appendix. —Structure of the Glands . 
 
 of that fluid, with acids, alkalies, astringents, &c. &e. 
 From these experiments, he also infers, that the co- 
 louring matter of the blood is perfectly independent 
 of iron . 
 
 In support of this inference, he adds, that the Ar- 
 menian dyers, in the preparation of their finest and 
 most durable red colours, use blood in addition to 
 madder, in order to ensure the permanency of these 
 colours. As the compounds of iron convert the co- 
 lour of madder to gray and black, the production of 
 a bright colour by the addition of blood to madder, 
 he regards as a proof, that iron is not the colouring 
 matter of blood. 
 
 Many estimates have been made of the quantity 
 of blood in the human body; but some of the best in- 
 formed physiologists have regarded them as falla- 
 cious. 
 
 STRUCTURE OF GLANDS. 
 
 Any original structure that discharges from the 
 blood vessels a fluid different from those which they 
 naturally contain, may be considered as glandular. 
 The function or process by which such fluids are de- 
 rived from the blood vessels is called secretion. 
 
 A structure of this kind seems to exist in very dif- 
 ferent situations: for it is distinctly circumscribed in 
 many of those bodies commonly denominated glands, 
 which are of a very precise form ; and it is also dif- 
 fused on some very extensive surfaces. The gastric 
 liquor, a most important secretion, is probably dis- 
 charged from vessels which open, like exhalents, on 
 the internal surface of the stomach; and not from any 
 circumscribed bodies, which are generally denomi- 
 nated glands. 
 
 The name of gland is theoretically applied to 
 
409 
 
 Appendix.— -Structure of Glands . 
 
 several bodies which cannot be proved to secrete 
 any fluid whatever ; and also to those bodies con- 
 nected with the absorbent vessels, which are called 
 the Lymphatic Glands ; but it is most commonly ap- 
 propriated to those organs which discharge a fluid 
 different from the blood. 
 
 The structure by which mucus is secreted in some 
 places, appears to be very simple. Thus in the 
 Schneiderian membrane and the urethra, there are 
 small ducts from four to six lines in length, and 
 equal in diameter to a bristle, which appear to be 
 formed of the membrane on which they open. From 
 these ducts mucus issues to cover the surfaces of 
 these membranes. In many instances there is no 
 substance resembling that of the circumscribed glan- 
 dular bodies, connected with these ducts; but the 
 secreted fluid seems to be discharged into the ducts 
 from the small vessels on their surfaces. The ducts 
 of this nature in the urethra are denominated La - 
 cunse. 
 
 In some other parts of the body, the cavities into 
 which mucus is discharged are somewhat different, 
 both in form and size, from those above mentioned, 
 and are called Follicles. These cavities are sur- 
 rounded with more or less of a pulpy vascular sub- 
 stance, which has been considered as glandular, and 
 essential to the mucous secretion. 
 
 The circumscribed bodies, which are commonly 
 called glands, differ in their internal appearance and 
 texture, from the other parts of animals. The sub- 
 stance of which they consist differs very much in the 
 different glands; and thus renders the liver, kid- 
 neys, salivary glands, mammae, &c. very different 
 from each other. Some glands, as the salivary, &c„ 
 are composed of several series of lobuli that succes- 
 sively diminish. The smallest of these are denomi- 
 nated Acini. Each of them is connected by a 
 
 Vol. ii. 52 
 
410 Appendix. — Structure of Glands. 
 
 small artery and vein, to the large blood vessels of 
 the glands ; and also sends a hranch to join the ex- 
 cretory duct. These Acini are therefore connected 
 to each other, by the blood vessels and excretory 
 duct of the gland, and also by the cellular membrane, 
 which cuvers them externally, and occasions them to 
 adhere to each other where they are in contact. In 
 consequence of this structure, these glands have a 
 granulated appearance. 
 
 The liver, when incised with a sharp instrument, 
 appears differently ; but when broken into pieces, it 
 seems to consist of small acini. Some other glands, 
 as the Prostate , appear to be uniform in their tex- 
 ture, and have none of this granulated appearance. 
 
 The structure of glands has long been an interest- 
 ing object of anatomical inquiry, and was investiga- 
 ted with great assiduity by those eminent anatomists, 
 Malpighi and Ruysch. 
 
 Malpighi, as was formerly observed, used ink and 
 other coloured fluids in his injections. He was also 
 very skilful in the use of microscopes, and took great 
 pains in macerating and preparing the subjects of his 
 inquiries. Ruysch, on the other hand, used a ce- 
 raceous injection, and was most eminently successful 
 in filling very small vessels with it. Malpighi be- 
 lieved that there were follicles or cavities in glandu- 
 lar bodies, which existed between the extremities of 
 the arteries and the commencement of the excretory 
 ducts of those bodies, and that in these cavities the 
 secreted fluids underwent a change. — Ruysch con- 
 tended, that the arteries of glands were continued 
 into excretory ducts, without the intervention of 
 any cavity or follicle ; that the small bodies, which 
 had been supposed to contain follicles or cripae, were 
 formed by convulsions of vessels, and that the change 
 of the fluid, or the process of secretion, is produced 
 by the minute ramifications of the artery. 
 
Appendix. — Structure of Glands. 411 
 
 A very interesting account of this subject is con- 
 tained in two celebrated letters, which passed be- 
 tween Boerhaave and Ruysch in the year 1721, and 
 are published at the end of the fourth volume of the 
 works of Ruysch. 
 
 The opinion of Ruysch has been most generally 
 adopted by anatomists, and has derived support and 
 confirmation from several anatomists since his time. 
 The late Mr. Hewson declared his conviction that 
 the small globular bodies which are scattered through 
 the kidneys, and were supposed to be follicles or 
 criptse, are merely convoluted arteries. He also as- 
 serted, that the acini which appeared in the mammae 
 as large as the heads of pins, when the excretory 
 ducts of that gland were injected with vermilion and 
 painters’ size, proved to be the minute ramifications 
 of the excretory duct, which divided very suddenly 
 into branches so small, that they could not readily be 
 seen by the naked eye.* 
 
 Notwithstanding these reasons for supposing that 
 the excretory ducts of glands were derived simply 
 from the arteries of those bodies, it is said that the 
 late Dr. W. Hunter used to declare his belief, that 
 there was a part in glands which was not injected, in 
 his preparations ; and to say further, that he believed 
 his preparations were injected as minutely as those 
 of Ruysch. 
 
 All of these opinions have been strenuously con- 
 troverted by the Italian anatomist, Mascagni, who 
 believes that the arteries terminate only in veins : 
 and. of course that they neither form exhalent ves- 
 sels, nor communicate with the excretory ducts of 
 glands. His idea of the structure of glands is dif- 
 ferent from those either of Malpighi or of Ruysch, 
 
 * See Experimental Inquiries, vol. ii. p. 178. 
 
412 Appendix . — Structure of Glands. 
 
 He supposes that glands contain a great number of 
 minute cells ; that the arteries, veins, and absorbent 
 vessels are spread upon the surfaces of these cells, 
 in great numbers, and very irregularly. From these 
 cells very small canals originate, which unite to 
 form the small branches of the excretory ducts. — 
 According to his idea the secreted fluid is dis- 
 charged through pores or orifices of the blood ves- 
 sels, into the cells, and proceeds from them through 
 the canals, into the branches of the excretory ducts. 
 Absorbent vessels, in great numbers, originate from 
 these cells. 
 
 In his great work on the absorbent system, when 
 treating on the termination of arteries and the com- 
 mencement of veins, (Part I. Section 2.) he asserts, 
 that if the kidneys are successfully injected with 
 size, coloured with vermilion, and then laid open by 
 a section with a razor, it will be found that the size 
 without the colour has passed into cells, which are 
 very numerous ; that the arteries and veins are ra- 
 ramified most minutely on the surfaces of these cells, 
 and that the tubuli uriniferi, as well as the absorbent 
 vessels, originate from them. 
 
 He supposes that a considerable portion of the fluid 
 thus passing off from the blood vessels, is commonly 
 taken up by the absorbent vessels of the kidneys; for 
 in two cases in which he found the absorbent vessels 
 obstructed, a diabetes existed, which he considered 
 as the effect of the inactivity of the absorbents. He 
 asserts, that in the liver, pancreas, mammas, and also 
 in the salivary and lachrymal glands, the minute ar- 
 teries and veins are also distributed upon the surfaces 
 of cells ; and that very small canals arise from these 
 cells, and unite to form the small branches of the ex- 
 cretory ducts. 
 
 This great anatomist appears to have been much 
 
Appendix.— Structure of Glands. 413 
 
 occupied with microscopical observations, and has 
 gone largely into the discussion of this subject.* 
 
 It must, however, be acknowledged, that no information 
 which has as yet been obtained respecting the struc- 
 ture of glands, enables us to explain their wonder- 
 ful effect upon the fluids which pass through them. 
 It remains yet to be ascertained why one structure 
 forms saliva and another bile ; or why so much ap- 
 paratus should be necessary for the s.ecretion of 
 milk, when adiopose matter appears to be produced 
 by the mere membi-ane in which it is contained. 
 
 Dr. Berzelius, professor of Chemistry at Stockholm, 
 in a late work on animal chemistry, asserts, that 
 if all the nerves going to a secretory organ are di- 
 vided, secretion will cease, notwithstanding the 
 continued circulation of the blood. From this, he 
 thinks, that secretions depend upon the influence of 
 nerves, although he cannot explain their effects. 
 
 Mr. Home, after relating some experiments upon 
 blood and serum, made with the Voltaic Battery, 
 proposes the following questions, among others : — - 
 Whether a weaker power of electricity than any 
 which can be kept up by art, may be capable of se- 
 parating from the blood the different parts of which 
 it is composed ; and forming new combinations of 
 the parts so separated ? — Whether the structure of 
 the nerves may enable them to possess a low elec- 
 trical power, which can be employed for that pur- 
 pose ? &c. 
 
 See the London Philosophical Transactions, for 
 1809, Part ll.t 
 
 * The late Dr. W. Hunter, in his Medical Commentaries, (p. 40,) avowed 
 his belief, that the fluids, which appear occasionally in the various cavi- 
 ties of the body, transude through the coats of the blood vessels. Mr. 
 Hewson, (Experimental Inquiries, Vol. II. Chap. 7.) suggested several 
 reasons for dissenting from this opinion; but Mascagni has endeavoured to 
 support it. — See a long note to the above mentioned section of his work, 
 page 74. 
 
 t Mr. Wollasion has also published a small paper on this subject in the 
 Philosophical Magazine, Vol. 33. 
 
GLOSSARY, 
 
 EXHIBITING THE DERIVATION OF CERTAIN ANATOMICAL 
 TERMS. 
 
 A. 
 
 ACETABULUM. The cavity which receives the head of 
 the thigh-bone ; from acetum vinegar : so called, because 
 it represents the acetabulum or saucer of the ancients, in 
 which vinegar was held for the use of the table. 
 
 Acini. From acinus a grape. 
 
 Acromion. A process of the scapula ; from ay,po 5 extremity, 
 and 1 vpes the shoulder. 
 
 Anastomosis. The communication of vessels with one ano- 
 ther; from ctva through, and rajtt* mouth. 
 
 Anatomy. The dissection of the human body ; from kvk, and 
 rs/itvo to dissect. 
 
 Anconeus . A muscle ; so called from ctynav the elbow. 
 
 Aorta. Aoprsj from ; a?,o air, and r-^eoj to keep. 
 
 Aponeurosis. A tendinous expansion ; from Karo, and vsvpev a 
 nerve ; from an erroneous supposition of the ancients, that 
 it was formed by an expansion of nerve. 
 
 Apophysis. A process of a bone ; from ct 7 n><pva to proceed 
 from. A synonyme of process. 
 
 Arachnoides. A net-like membrane ; from apayjn a spider, 
 and s 1^05 likeness. 
 
 Artery. From *-0? air, and r to keep ; because the ancients 
 supposed that air only was contained in them. 
 
 Arthrodia. A species of connexion of bones ; from ctpSpoa to 
 articulate. 
 
 Arytsenoides. The name of two cartilages of the larynx ; also 
 applied to some muscles of the larynx ; from ctpvTxi'nt a 
 funnel, and sifas a shape. 
 
 By Dr. Hooper. 
 
416 Glossary . 
 
 Astragalus. A bone of the tarsus ; so called from its resem- 
 blance to a die used in ancient games, from a 
 
 cockal or dje. 
 
 Atlas. The first vertebra of the neck ; so called, because it 
 sustains the head : from the fable of Atlas being supposed 
 to have supported the world; or from to sustain, be- 
 
 cause it sustains the head. 
 
 Azygos. A term applied to parts without a fellow, from « 
 priv. and ^yo? a joke, because it has no fellow. 
 
 B. 
 
 Bursa. A bag ; from /3 vpnx, : generally applied to the bursae 
 mucosae. 
 
 C. 
 
 Cancelli. Lattice work ; generally applied to the reticular 
 substance in bones. 
 
 Cardia. The superior opening of the stomach ; from x»p, het 
 the heart. 
 
 Carotid. The name of some arteries of the neck and head 
 from xetpoo) to cause to sleep ; for, if tied with a ligature, 
 the animal was said to be affected with coma. 
 
 Carpus. Kctpnos ; the wrist. 
 
 Clavicula. The clavicle or collar-bone, a diminutive of clavis 
 a key; so called from its resemblance to an ancient key. 
 
 Clinoid. Four processes of the sella turcica of the ethmoid 
 bone are so called, from a bed, and e«5as likeness ; 
 from their supposed resemblance to a couch. 
 
 Clitoris. A part of the female pudenda ; enclosed by the la- 
 bia majora ; from xXeicu to enclose or hide. 
 
 Colon. The first of the large intestines ; from xoiMv, quasi 
 jco/Aov, from xoiM 5 hollow. 
 
 Coracoid. From a crow, and eiS'op resemblance ; shaped 
 like the beak of a crow. 
 
 Coronary. From corona a crown. The vessels of the heart, 
 stomach, &c. are so called because they surround the parts 
 in the manner of a crown. 
 
 Cotyloid. From MtvXv, the name of an old measure, and a fop 
 resemblance : resembling the kotule. 
 
 Cranium. The skull ; xpeeviav, quasi, Kecpcauev, from xuptx. the head. 
 
 Cremaster. A muscle so called ; from to suspend, be- 
 
 cause it suspends the testicle. 
 
 Cribriform. From cribmm a sieve, it being perforated like a 
 sieve. 
 
Glossary. 417 
 
 Cricoid. Annular, round like a ring; from y^Uo 5 a ring and 
 £<&>$ likeness. 
 
 Cuboides. A bone of the foot ; from a cube, and enJ'uj 
 likeness ; because it resembles a cube. 
 
 Cuneiform. Some bones are so called ; from cuneus a wedge, 
 and forma likeness ; being shaped like a wedge. 
 
 D. 
 
 Deltoid. A muscle resembling the Greek letter A : from A, 
 and eih 5 resemblance. 
 
 Diaphragm. The muscle which separates the thorax from the 
 abdomen ; from to divide. 
 
 Diarthrosis. A moveable connexion of bones; from f$icto6goa 
 to articulate. 
 
 Digastric. From <5Vs twice, and ng a bell y ; having two 
 bellies. 
 
 Diploe. The spongy substance between the two tables of the 
 skull ; from fttrXttt to double. 
 
 Duodenum. The first portion of the small intestines ; so call- 
 ed because the ancients supposed that it did not exceed 
 the breadth of twelve fingers ; from. duodenUs, consisting 
 of twelve. 
 
 Dura Mater. The outermost membrane of the brain ; called 
 dura , because it is much harder than the other membranes, 
 and mater , from the idea of the ancient^ that it was the 
 source of all the other membranes. 
 
 E. 
 
 Embryo. The child in the womb is so called before the fifth 
 month, after which it is termed foetus ; from e^v&> to bud 
 forth. 
 
 Enarthrosis. An articulation of bones ; from -a in, and 
 a joint or articulation. 
 
 Enteric. Belonging to the intestines ; from evregov an entrail 
 or intestine. 
 
 Epidermis. The scarf or outermost skin ; from tm upon, and 
 thg/tii the skin. . .. 
 
 Epididymis. The small oblong body which lies above the tes- 
 ticles ; from upon, and JiS'v /. a testicle. 
 
 Epigastric. The superior part of the abdomen ; from svt 
 upon, and the stomach. 
 
 Epiglottis , A cartilage of the larynx so called; from em upon, 
 and yxarhi the aperture of the larynx, being situated upon 
 the glottis. 
 
 VOL, II. 53 
 
418 Glossary. 
 
 Epiphysis , A portion of bone growing upon another bone, but 
 separated from it by a cartilage : from em upon, and pva 
 to grow. 
 
 Epiploor i. The membranous viscusof the abdomen, which co- 
 vers the intestines, and hangs to the bottom of the stomach; 
 from eKin-Xsa to swim upon. 
 
 Ethmoid. From a sieve, and e/^05 resemblance; being 
 perforated like a sieve. 
 
 F. 
 
 Fascia. An expansion, enclosing other parts, like a band ; 
 from fascis a bundle. 
 
 Falciform. Shaped like a si the ; from falx, a si the. 
 
 Fasciculus. A little bundle, dim. of fascis a bundle. 
 
 Fauces. The plural of faux , the top of the throat. 
 
 G. 
 
 Ganglion. Tv/y^iot, a knot in the course of a nerve. 
 
 Gastrocnemius. The muscle which forms the thick of the leg; 
 from a belly, and the leg. 
 
 Genio. Names compounded with this word belong to mus- 
 cles which are attached to the chin, as geno-glossus — geno- 
 hyoideus, &c. ; from yeve;ov the chin. 
 
 Ginglymus. An articulation ; from yifyXv^ot; a hinge. 
 
 Glenoid cavity. From y*m a cavity, and a Sat resemblance. 
 
 Glosso. Names compounded with this word belong to muscles 
 which are attached to the tongue ; as glosso-pharyngeus — 
 glosso-staphilinus, &c. ; from yXawu, the tongue. 
 
 Glottis. The superior opening of the larynx at the bottom of 
 the tongue ; from yXcaria the tongue. 
 
 Glutseus. The name of a muscle ; from yA&rog the buttocks. 
 
 Gomphosis. To^paicng, a species of immoveable connexion of 
 bones ; from yo/tnpet a nail, because one bone is fixed in an- 
 other bone like a nail in a board. 
 
 II. , 
 
 Helix. The outward circle of the ear; from uXta to turn about. 
 
 Hepar. The liver. an abdominal viscus. 
 
 Hyaloid. From glass, and uS 'as likeness ; the capsule of 
 the vitreous humour of the eye is so called, from its trans- 
 parent and glassy appearance. 
 
 Hymen. The membrane situated at the entrance of the vir- 
 gin vagina ; from Hymen, the god of marriage. 
 
 Hyoides. A bone of the, tongue, so called from its resem- 
 blance to the Greek v ; from v, and resemblance. 
 
419 
 
 Glossary. 
 
 Hypochondrium. That part of the body which lies under the 
 cartilages of the spurious ribs ; from uxa under, and 
 a cartilage. ! 
 
 Hypogastric. The lower region of the fore part of the abdo- 
 men ; from v7ro under, and y« the stomach. 
 
 I. 
 
 lleon. A portion of the small intestines ; from uXea to turn ; 
 being always convoluted. 
 
 Ischium. The part of the os innominatum upon which we sit; 
 from nr%va to sustain. 
 
 L. 
 
 Lacuna. The excretory duct of the glands of the urethra and 
 vagina ; from lacus a channel. 
 
 Lambdoidal suture. So called because it is shaped like the 
 letter A ; from A, and etfos resemblance. 
 
 Larynx. The superior part of the windpipe; the larynx. 
 
 , M. 
 
 Masseter. A muscle of the face, which assists in the action 
 of chewing; paro-cupai to chew. 
 
 Mastoid. From yM?o<i a teat, and ei^og likeness ; shaped like a 
 nipple or teat. 
 
 Mediastinum. The production of the pleura, which divides 
 the thorax into two cavities ; from medium the middle, 
 quasi in medio stare. 
 
 Mesentery. The membranes to which the intestines are at- 
 tached ; from pto-o 5 the middle, and enr^ov an intestine, be- 
 cause it is in the middle of the intestines. 
 
 Mesocolon. That part of the mesentery in the middle of the 
 colon ; from the middle, and koA«v the colon. 
 
 Metacarpus. 1 hat part of the hand between the carpus and 
 lingers ; from yera. after, and nagnoi the wrist. 
 
 Metatarsus. I hat part ot the foot between the tarsus and 
 toes ; from y.sra after, and the tarsus. 
 
 Mylo. Names compounded with this word belong to muscles 
 which are attached near the grinders, as mylo-hyoideus, 
 &c. ; from a grinder tooth. 
 
 0 . 
 
 Odontoid. Tooth-like; from oS'm a tooth, and ufos resemblance. 
 
 (Esophagus. The canal leading from the pharynx to the sto- 
 mach ; from ota to carry, and tyaya to eat ; because it car- 
 ries the food into the stomach. 
 
420 
 
 Glossary . 
 
 Olecranon. The elbow, or bead of the ulna; from &)Xm the 
 cubit* and *£«vov the head. 
 
 Omentum. An abdominal viscus; so called from omen a guess, 
 because the soothsayers prophesied from the inspection of 
 this part. 
 
 Omo. Names compounded with this word belong to muscles 
 which are attached to the scapula, as omo-hyoideus , &c. 
 from aw the shoulder. 
 
 Omojjlata. The scapula or shoulder blade ; from apos the 
 shoulder, and vxwrvs broad. 
 
 Osteology. The doctrine of the bones; from «!■£« a bone, and 
 Aioy®s a discourse. 
 
 P. 
 
 Pancreas. A viscus of the abdomen ; so called from its fleshy 
 consistence; from nav all, and flesh. 
 
 Parenchyma. The substance of some of the viscera was so 
 called, from Trageytcva to pour through. 
 
 Parotid Gland. From near, and <ws the ear; because it 
 is situated near the ear. 
 
 Pelvis. A bony cavity shaped like a basin; from veXv<; a basin. 
 
 Pericardium. The membrane which surrounds the heart; 
 from Trefi around, and x.xgS'tx the heart. 
 
 Pericranium. The membrane which covers the bones of the 
 skull ; from 7rigt around, and xf«v£«v the cranium or head. 
 
 Periosteum. The membrane which surrounds the bones; from 
 around, and es-eov a bone. 
 
 Peristaltic motion of the intestines; from Tegus-xx a to contract. 
 
 Peritoneum. The membrane lining- the abdomen, and cover- 
 ing its viscera; from to extend around. 
 
 Phalanx. The bones of the fingers and toes are called pha- 
 lanxes, from their regular situation, like a <px,Xouy^, or ar- 
 rangement of soldiers. 
 
 Pharynx. A membranous bag at the end of the mouth ; 
 t« because it conveys the food into the stomach. 
 
 Phrenic or diaphragmatic nerve. <%eves the diaphragm ; from 
 sjv the mind ; because the ancients supposed it to be the 
 seat of the mind. 
 
 Pia Mater. The innermost membrane of the brain, so called 
 because it embraces the brain as a careful mother folds her 
 child. 
 
 Pleura. The membrane lining the thorax ; nx evga the side. 
 
 Plexus. A kind of net-work of vessels or nerves; from plecto 
 to weave together. 
 
Glossary. 421 
 
 Psoas. A muscle so called ; from fyoa, the loin, being situa- 
 ted in the loins. 
 
 Pterygoid process. From v% a pen or wing, and erfo s like- 
 ness, so called from its likeness to a pen or wing. 
 
 Pylorus. The lower orifice of the stomach, which opens into 
 the intestines; from •TrvXow to guard an entrance, because 
 it guards as it were the entrance of the bowels. 
 
 R. 
 
 Raphe. A suture ; from pair] a to sew. 
 
 Rcnes. The kidneys, a no m petv, because through tliem the 
 urine flows. 
 
 Retina. The net-like expansion of the optic nerve, on the 
 inner surface of the eye; from rete a net. 
 
 Rkomboides. A muscle so called from its shape; from pou.Sog 7 
 a geometrical figure, whose sides are equal but not right- 
 angled, and e«Jo; a likeness. 
 
 Rotula. The knee-pan; a dim. of rota a wheel, from its shape. 
 
 S. 
 
 Sacrum. A bone so called ; from sacer sacred, because it was 
 once offered in sacrifices. 
 
 Salvatella. A vein of the foot, so called because it was thought 
 that opening it preserved health, and cured melancholy; 
 from salvo to preserve. 
 
 Sanguis. The biood ; avo tx -onn yyi*. because it preserves 
 the body. 
 
 Sartorius. A muscle so called, because tailors cross their legs 
 with it ; from sartor a tailor. 
 
 Scupha. The depression of the outer ear before the anti-he- 
 lix; from o-kx^i a little boat or skill’. 
 
 Scaphoides. A bone of the carpus, so called from its resem- 
 blance to a skiff'; from a skiff, and eth 5 likeness. 
 
 Sclerotic. A term applied to the outermost or hardest mem- 
 brane of the eye ; from m^goca to make hard. 
 
 Sesamoid bones. From o-yrxf. ty a grain, and Jo? likeness ; 
 from their resemblance to the semen sesami. 
 
 Sigmoid. Parts are so called from their resemblance to the 
 letter £; from 2, the letter Sigma, and likeness. 
 
 Sphenoid. From jv a wedge, and etfo 5 likeness ; shaped like 
 a wedge. 
 
 Sphincter. The name of several muscles, whose office is to 
 shut up the aperture around which they are placed from ; 
 tnpryyoi to shut up. 
 
 Splanchnic. From e-^Aseyj^va;, an entrail. 
 
422 Glossary. 
 
 Symphysis. A connexion of bones ; from rv^cpva to grow to- 
 gether. 
 
 Synarthrosis. A connexion of bones; from rm with, and xpipov 
 a joint. 
 
 Synchondrosis. A species of union of bones by means of car- 
 tilage ; from c-t/v with, and ■ ^ov^og a cartilage. 
 
 Synneurosis. A species of connexion of bones by means of 
 membrane ; from < ruv with, and vfi^ag a nerve; because mem- 
 branes, ligaments, and tendons, were by the ancients con- 
 sidered as nerves. 
 
 Syssarcosis. A species of connexion of bones by means of 
 muscle ; from o-w with, and flesh. 
 
 Systole. The contractile motion of the heart and arteries; from 
 crys-rfMa to contract. 
 
 ,T. 
 
 Tendon , From ■mv&> to, extend. 
 
 Thorax. The breast or chest. 
 
 Thyroid. From Stress a shield, and uctog likeness; shaped like 
 a shield. 
 
 Trachea. The windpipe ; so called from its roughness ; from 
 TQv.yju', rough. 
 
 Trochanter. A process of the thigh-bone, so called from r^oyag 
 a wheel. 
 
 U. 
 
 Ulna. A name for the cubit ; from aXew the cubit. 
 
 Ureter. The canal which conveys the urine from the kidney 
 to the bladder; from xgov urine. 
 
 Urethra. The passage through which the urine passes from 
 the bladder ; from the urine. 
 
 Uvea. The posterior lamen of the iris, so called because in 
 many animals it is of the colour of unripe grapes ; from 
 uva an unripe grape. 
 
 Uvula. The conical substance which hangs down from the 
 middle of the soft palate : so called from its resemblance 
 to a grape. A dim. of uva a grape. 
 
 y. 
 
 Valves. From valvse folding doors. 
 
 Vertebrae. The bones of the spine are so called ; from verto 
 to turn. 
 
 X. 
 
 Xiphoid. So called from the resemblance to a sword ; from 
 | i<pt S a sword, and si^og likeness. 
 
 Z. 
 
 Zygoma. The cavity under the zygomatic process of the 
 temporal bones ; from <V/«s a yoke. 
 
ALPHABETICAL INDEX TO VOLUME II. 
 
 Aorta 
 
 Page. 
 50 and 236 
 
 Adhesion of lungs 
 
 73 
 
 Abdomen 
 
 82 
 
 
 regions of 
 
 86 
 
 
 contents of 
 
 85 
 
 
 situation of vis- 
 
 
 
 cera 
 
 87 
 
 Acini of liver 
 
 132 
 
 Arteries, 
 
 structure of 
 
 226 
 
 Artery, axillary 
 
 262 
 
 
 aorta thoracic 
 
 270 
 
 
 abdominal 
 
 274 
 
 
 adipose 
 
 281 
 
 
 anastomotic 
 
 292 
 
 
 anterior tibial 
 
 294 
 
 
 basilic 
 
 259 
 
 
 bronchial 
 
 270 
 
 
 carotid 
 
 239 
 
 
 external 
 
 240 
 
 
 internal 
 
 250 
 
 
 callous 
 
 256 
 
 
 cervical 
 
 261 
 
 
 circumflex 
 
 564 
 
 
 cceliac 
 
 275 
 
 
 capsular 
 
 280 
 
 
 circumflex of 
 
 
 
 ilium 
 
 289 
 
 
 of thigh 291 
 
 
 emulgent 
 
 280 
 
 
 epigastric 
 
 288 
 
 
 facial 
 
 242 
 
 
 femorial 
 
 289 
 
 
 gastric 
 
 2 75 
 
 
 right 
 
 276 
 
 
 left 
 
 277 
 
 
 gluteal 
 
 286 
 
 
 humeral 
 
 264 
 
 
 hepatic 
 
 276 
 
 
 haemorrhoidal 
 
 285 
 
 
 innominata 
 
 238 
 
 Page, 
 
 Artery, internal maxillary 245 
 mammary 257 
 intercostals supe- 
 
 rior 
 
 260 
 
 interosseal 
 
 267 
 
 intercostals infe- 
 
 
 rior 
 
 272 
 
 illiac primitive 
 
 282 
 
 internal 
 
 283 
 
 ilio lumbar 
 
 284 
 
 iliac external 
 
 288 
 
 internal plantar 
 
 296 
 
 ischiatic 
 
 286 
 
 lingual 
 
 242 
 
 lumbar 
 
 282 
 
 middle of brain 
 
 255 
 
 mammary exter- 
 
 
 nal 
 
 262 
 
 mesenteric supe- 
 
 
 rior 
 
 278 
 
 infe- 
 
 
 rior 
 
 279 
 
 occi- 
 
 
 pital 
 
 244 
 
 ophthalmic 
 
 252 
 
 oesophageal 
 
 271 
 
 obturator 
 
 285 
 
 pharyngeal infe- 
 
 
 rior 
 
 '243 
 
 phrenic 
 
 274 
 
 pudic internal 
 
 287 
 
 external 
 
 290 
 
 profunda femoris 290 
 perforating 291 
 popliteal 292 
 
 posterior tibial 295 
 peroneal 295 
 
 plantar external 296 
 radial 266 
 
 stylo-mastoid 245 
 
INDEX. 
 
 424 
 
 Artery, subclavian 256 
 
 scapular superior 260 
 
 internal 263 
 
 spiral 265 
 
 splenic 27 7 
 
 spermatic 28 1 
 
 sacral middle 282 
 
 lateral 284 
 
 thyroid superior 241 
 
 inferior 258 
 
 temporal 249 
 
 ulnar 268 
 
 uterine 286 
 
 vertebral 258 
 
 Arterial system, plan of 297 
 
 Abdominal viscera, nerves 
 of 368 
 
 Absorbents, structure of 371 
 
 of lower ex- 
 tremity 37fi 
 
 of abdomen 381 
 
 of thorax 389 
 
 of head and 
 neck 391 
 
 of upper ex- 
 
 tremity 393 
 
 Absorption, cutaneous 395 
 
 Black glands 64 
 
 Bile 141 
 
 Bladder of female 213 
 
 Blood vessels in general 223 
 
 Blood 401 
 
 colouring matter of 404 
 
 Cavities of nose 4 
 
 Caecum 118 
 
 Colon 119 
 
 Corpus pampiniforme 174 
 
 Corpora cavernosa 186 
 
 Corpus spongiosum .188 
 
 Canal of urethra 190 
 
 Clitoris 201 
 
 Canalis arteriosus 220 
 
 Cavae 299 
 
 Coronary veins 299 
 
 Chorda tympani 335 
 
 Crassamentum 403 
 
 Duodenum 1 1 1 
 
 Ductus communis 141 
 
 Dartos 173 
 
 Ductus venosus 220 
 
 Descending cava 300 
 
 External hose 2 
 
 Eustachion tube 11 
 
 Epididymis 177 
 
 Fauces 28 
 
 Foetus, thorax of 69 
 
 heart of 69 
 
 lungs of 69 
 
 abdomen of 217 
 
 Female organs of genera- 
 tion 200 
 
 Fallopian tubes 209 
 
 Gums 16 
 
 Glandulae molares 26 
 
 Glottis 34 
 
 Gastric liquor 101 
 
 Great intestines 117 
 
 Gall bladder and duct 139 
 
 Glandulae renales 154 
 
 Ganglions 321 
 
 of Gasser 327 
 
 sphino palatine 329 
 cervical 361 
 
 semilunar 367 
 
 Glands, structure of 408 
 
 Glossary 415 
 
 Heart 50 
 
 malformations of 72 
 
 nerves of 363 
 
 Hepatic duct 139 
 
 Hymen 202 
 
 Hottentots, peculiarity of 216 
 
 Intestines' 104 
 
 villous coat of 105 
 divison of 109 
 
INDEX 
 
 425 
 
 Intestines, small 110 
 
 Integuments of penis 195 
 
 Ilium 1 13 
 
 Jejunum 113 
 
 Kidneys 155 
 
 Larynx 31 
 
 arteries and nerves 
 of 35 
 
 Left auricle 55 
 
 ventricle 56 
 
 Lungs 65 
 
 Legallois on the heart 79 
 
 Liver 128 
 
 ligaments of 130 
 
 Labia externa 201 
 
 Lacteals 389 
 
 Mouth 14 
 
 Mamma; 41 
 
 Mediastinum 46 
 
 Muscular fibres of heart 57 
 
 Mesentery 115 
 
 Male organs of generation 171 
 
 Nose 1 
 
 nerves of 8 
 
 Nerves of liver 136 
 
 Neck of the bladder 167 
 
 Nerves, structure of 319 
 
 accessory 347 
 
 of arm 348 
 
 of brain 323 
 
 cervical 343 
 
 circumflex 351 
 
 crural 355 
 
 cardiac 363 
 
 of diaphragm 246 
 
 dorsal 352 
 
 eighth pair 336 
 
 fourth pair 325 
 
 fifth pair 326 
 
 fibular 359 
 
 glosso-pharyngeal 337 
 
 internal cutaneous 351 
 Yol. n. 
 
 Nerves, lumbar 353 
 
 laryngeal superior 339 
 maxillary inferior 332 
 superior 329 
 
 musculo cutane 
 
 
 ous 
 
 348 
 
 median 
 
 348 
 
 ninth pair 
 
 342 
 
 olfactory 6. 
 
 323 
 
 optic 
 
 324 
 
 ophthalmic 
 
 327 
 
 obturator 
 
 355 
 
 parvagum 
 
 338 
 
 recurrent 
 
 339 
 
 radial 
 
 350 
 
 sixth pair 
 
 333 
 
 seventh pair 
 
 334 
 
 sacral 
 
 356 
 
 sciatic 
 
 358 
 
 sympathetic 
 
 361 
 
 splanchnic 
 
 367 
 
 third pair 
 
 325 
 
 tibial posterior 
 
 360 
 
 ulnar 
 
 349 
 
 (Esophagus 
 
 94 
 
 Omentum 
 
 125 
 
 Orifice of urethra 
 
 167 
 
 Ovaries 
 
 210 
 
 Parotid gland 
 
 25 
 
 Pharynx 
 
 37 
 
 Pleurae 
 
 45 
 
 Pericardium 
 
 49 
 
 Pulmonary arteries and 
 
 
 veins 
 
 61 
 
 Peritoneum 
 
 90 
 
 Pylorus 
 
 102 
 
 Pancreas 
 
 141 
 
 Prostate gland 
 
 113 
 
 Penis 
 
 184 
 
 Prepuce 
 
 196 
 
 Placenta 
 
 221 
 
 Plexuses 
 
 321 
 
 pulmonary 
 
 340 
 
 brachial 
 
 347 
 
 54 
 
INDEX. 
 
 426 
 
 Plexuses lumbar 354 
 
 cardiac 366 
 
 solar 367 
 
 Rim a glottidis 34 
 
 Right auricle 52 
 
 ventricle 53 
 
 Rectum 122 
 
 Round ligaments 209 
 
 Schneiderian membrane 5 
 Sinuses of nose 12 
 
 Soft palate 17 
 
 Salivary glands 25 
 
 Submaxillary gland 26 
 
 Sublingual gland 26 
 
 Saliva 26 
 
 Sabatier on foetal circula- 
 tion 75 
 
 Stomach 96 
 
 lymphatics and 
 nerves of 103 
 
 Spleen 145 
 
 Scrotum 171 
 
 Serum 402 
 
 Spermatic cord 173 
 
 Tongue 18 
 
 papillae of 20 
 
 blood vessels of 23 
 nerves of 24 
 
 Throat 28 
 
 Tonsils 29 
 
 Thyroid gland 37 
 
 Thorax 41 
 
 Trachea 62 
 
 Thymus gland 69 
 
 Tunica vaginalis 175 
 
 albuginea 176 
 
 Testicle 177 
 
 descent of 218 
 
 Thoracic duct 387 
 
 Uvula 17 
 
 Urinary organs 154 
 
 Ureters 160 
 
 Urinary bladder 162 
 
 Urethra of male 188 
 
 Urethra of female 202 
 
 Uterus 205 
 
 changes of, in 
 pregnancy 214 ' 
 
 Umbilical arteries 219 
 
 Venae cavae 61 
 
 Valve of colon 120 
 
 Vena Portarum 134 
 
 Vessels of liver 133 
 
 Vas deferens 180 
 
 V efeiculas seminales 181 
 
 V agina 203 
 
 Veins, structure of 233 
 
 distribution of 298 
 
 Vena azygos 301 
 
 Veins, axillary 308 
 
 anomalies ot 317 
 
 basilic 308 
 
 cephalic 308 
 
 Cava inferior 309 
 
 capsular 312 
 
 circumflex 314 
 
 external jugular 306 
 
 emulgent 312 
 
 external iliac 314 
 
 epigastric 315 
 
 external saphena 316 
 
 femoral 315 
 
 hepatic 311 
 
 hypogastric 313 
 
 intercostal superior 303 
 primitive iliac 313 
 
 jugular internal 304 
 
 lumbar 313 
 
 middle sacral 313 
 
 mesenteric superior31 1 
 phrenic inferior 310 
 
 Vena portarum 311 
 
 Veins, pulmonary 317 
 
 subclavian 307 
 
 splenic 311 
 
 spermatic 312 
 
 saphena major 315 
 
 vertebral 304 
 
 vesical 313 
 
ANATOMICAL PLATES, 
 
 EXPLANATION OF THE PLATES OF OSTEOLOGY. 
 
 Plate II. 
 
 Fig. 1. A Front-view of the Male Skeleton. 
 
 A, The os frontis. B, The os parietale. C, The Coronal 
 suture. D, The squamous part of the temporal bones. E, The 
 squamous suture. F, The zygoma. G, The mastoid process. 
 
 H, The temporal process of the sphenoid bone. I, The orbit. 
 K, The os malm. L, The os maxiilare superius. M, Its nasal 
 process. N, The ossa nasi. O, The os unguis. P, The maxilla 
 inferior. Q, The teeth, which are sixteen in number in each 
 jaw. R, The seven cervical vertebrae, with their intermediate 
 cartilages. S, Their Transverse processes. T, The twelve 
 dorsal vertebrae, with their intermediate cartilages. U, The 
 five lumbar vertebrae. V, Their transverse process. W, The 
 upper part of the os sacrum. X, Its lateral parts. The holes 
 seen on its fore part are the passages of the undermost spinal 
 nerves and small vessels. Opposite to the holes, the marks of 
 the original divisions of the bones are seen. Y, The os ilium. 
 Z, Its crest or spine, a, The anterior spinous processes, b, The 
 brim of the pelvis, c, The ischiatic notch, d, The os ischium, 
 e, Its tuberosity, f, Its spinous process, g, Its crus, h, The 
 foramen thyroideum. i, The os pubis, k, The symphysis pubis. 
 
 I, The crus pubis, m, The acetabulum, n, The seventh or last 
 true rib. o, The twelfth or last false rib. p, The upper end of 
 the sternum, q, The middle piece, r, The under end, or car- 
 tilago ensiformis. s, The clavicle, t, The internal surface of 
 the scapula, u, Its acromion, v, Its coracoid process, w. Its 
 cervix, x, The glenoid cavity, y, The os humeri, z, Its head 
 which is connected to the glenoid cavity. 1, its internal tu- 
 bercle. 2, Its interna! tubercle. 3, The groove for lodging the 
 long head of the biceps muscle of the arm. 4, The internal 
 
428 Explanation of the Plates of Osteology. 
 
 condyle. Between 4 and 5, the trochlea. 6, The radius. 7, 
 Its head. 8, Its tubercle. 9, The ulna. 10, Its coronoid 
 process. 11, 12, 13, 14, 15, 16, 17, 18, The carpus ; compo- 
 sed of os naviculare, os lunare, os cuneiform, os pisiforme, 
 os trapezium, os trapezoides, os magnum, os unciforme. 19, 
 The five bones of the metacarpus. 20, The two bones of the 
 thumb. 21, The three bones of each of the fingers. 22, The 
 os femoris. 23, Its head. 24, Its cervix. 25, The trochan- 
 ter major. 26, trochanter minor. 2 7, The internal condyle. 
 28, The external condyle, 29, The rotula. 30, The tibia. 
 31, Its head. 32, Its tubercle. 33, Its spine. 34, The mal- 
 leolus interims. 35, The fibula. 36, Its head. 37, The mal- 
 leolus externus. The tarsus is composed of. 38, The astra- 
 galus; 39, fhe os calcis; 40, The os naviculare; 41, Three 
 ossa, cuneiformia, and the os cuboides, which is not seen in 
 this figure. 42, The five bones of the metatarsus. 43, The 
 two bones of the great toe. 44, The three bones of each of 
 the small toes. 
 
 Fig. 2. A Front-view of the Skull. 
 
 A, The os frontis. B, The lateral part of the os frontis, 
 which gives origin to part of the temporal muscle. C, the su- 
 perciliary ridge. D, The superciliary hole through which the 
 frontal vessels and nerves pass. EE, The orbitar processes. 
 F, ( he middle of the transverse suture. G, The upper part 
 of the orbit. H, The foramen opticum. I, The foramen la- 
 cerum. K, The inferior orbitar fissure. L, The os unguis. 
 M, The ossa nasi. N, The os maxillare superius. O, Its na- 
 sal process. P, The external orbitar hole through which the 
 superior maxillary vessels and nerves pass. Q, The os malse. 
 It, A passage for small vessels into or out of, the orbit. S, 
 The under part of the left nostril. T, The septum narium. 
 U, The os spongiosum superius. V, The os spongiosum in- 
 ferius. W, The edge of the alveoli, or spongy sockets for the 
 teeth. X, j he maxilla inferior. Y, The passage for the in- 
 ferior maxillary vessels and nerves. 
 
 Fig. 3. A Side-view of the Skull. 
 
 A, The os frontis. B, ; he coronal suture. C, The os pa- 
 rietale. D, An arched ridge which gives origin to the temporal 
 muscle. E, The squamous suture. F, The squamous part of 
 the temporal bone: and lurther forwards, the temporal process 
 of the sphenoid bone. G, The zygomatic process of the tempo- 
 ral bone. H, i he zygomatic suture. 1, The mastoid process of 
 the temporal bone. K, . he meatus auditorius externus. L, The 
 orbitar piate of the frontal bone, under which is seen the trans- 
 
V. I\ o , 
 
 * A J . • At-/ » A /tZ/i. • Z l /,//tto 
 
Explanation of the Plates of Osteology. 429 
 
 verse suture. M, The pars plana of the ethmoid bone. N, The 
 os unguis. 0, The right os nasi. P, The superior maxillary 
 bone. Q, its nasal process. II, The two ilentes incisores. S, 
 The dens caniuus. T, The two small molares. U, The three 
 large molares. V, The os malae. W, The lower jaw. X, Its 
 angle. Y, The coronoid process. Z, The condyloid process 
 by which the jaw is articulated with the temporal bone. 
 
 Fig. 4. The posterior and right side of the Skull. 
 
 A, The os frontis. BB, The ossa parietalia. C, The sagit- 
 tal suture. D, The parietal hole, through which a small vein 
 runs to the superior longitudinal sinus. E, The lambdoid su- 
 ture. FF, Ossa triquetra. G, The os occipitis. li, The squa- 
 mous part of the temporal bone. I, The mastoid process. K, 
 The zygoma. L, The os malm. M, The temporal part of the 
 sphenoid bone, N, The superior maxillary bone and teeth. 
 
 Fig. 5. The external surface of the Os Frontis. 
 
 A, The convex part. B, Part of the temporal fossa. C, 
 The external auguiar process. D, The internal angular pro- 
 cess. E, The nasal process. F, The superciliary arch. G, 
 The superciliary hole. H, The orbitar plate. 
 
 Fig. 6. The internal surface of the Os Frontis. 
 
 AA, The serrated edge which assists to form the coronal 
 suture. B. The external angular process. C, The internal 
 angular process. D, The nasal process. E, The orbitar 
 plate. F, The cells w liich correspond with those of the eth- 
 moid bone. G, The passage from the frontal sinus. H, The 
 opening which receives the cribriform plate of the ethmoid 
 bone. I, The cavity which lodges the tore part of the brain. 
 K, The spine to which the falx is fixed. L, The groove which 
 lodges the superior longitudinal sinus. 
 
 Plate 111. 
 
 Fig, 1 . A Back-view of the Skeleton. 
 
 AA, The ossa parietalia. B, The sagittal suture. C, The 
 lambdoid suture. D, The occipital bone. E, The squamous 
 suture. F, The mastoid process of the temporal bone. G, The 
 os malae. H, The palate piates of the superior maxillary bones. 
 I, The maxilla inferior. K, The teeth of both jaws. L , The 
 seven cervical vertebrae. M, Their spinous processes. N, 
 Their transverse and oblique processes. 0, The last of the 
 twelve dorsal vertebrae. P, Tiie filth or last lumbar vertebra. 
 Q. The transverse processes. R, The oblique processes. S, The 
 spinous process. T, The upper part of the os sacrum. U, The 
 posterior holes which transmit small blood vessels and nerves. 
 
430 Explanation of the Plates of Osteology. 
 
 V, The under part of the os sacrum which is covered by a 
 membrane. W, The os coccygis. X, The os ilium. Y, Its 
 spine or crest. Z, The ischiatic notch, a. The os ischium, b, 
 Its tuberosity, c, Its spine, d, The os pubis, e, The foramen 
 thyroideum. f, The seventh or last true rib. g, The twelfth or 
 last false rib. h, The clavicle, i, The scapula, k, Its spine. 1, 
 Its acromion, m, Its cervix, n, Its superior costa, o, Its pos- 
 terior costa. p, Its inferior costa. q, The os humeri, r, The ra- 
 dius. s, The ulna, t, Its olecranon, u, All the bones of the 
 carpus, excepting the os pisiforme, which is seen in plate II. 
 fig. 1. v, The five bones of the metacarpus, w, The two bones 
 ot the thumb, x, The three bones of each of the fingers, y. The 
 two sesamoid bones at the root of the left thumb, z, The os 
 femoris. 1, The trochanter major. 2, The trochanter minor. 
 3, The linea aspera. 4, The internal condyle. 5, The exter- 
 nal condyle. 6 6, The semilunar cartilages. 7, The tibia. 8, 
 The malleolus internus. 9, The fibul. 10, The malleolus ex- 
 ternus. 1 1, The tarsus. 12, The metatarsus. 13, The toes. 
 
 Fig. 2. The external Surface of the Left Os Parietale. 
 
 A, The convex smooth surface. B, The parietal hole. C, 
 An arch made by the beginning of the temporal muscle. 
 
 Fig. 3. The Internal Surface of the same bone. 
 
 A, Its superior edge, which, joined with the other, forms 
 the sagittal suture. B, The anterior edge which assists in the 
 formation of the coronal suture. C, The inferior edge for 
 the squamous suture. D, The posterior edge for the lamb- 
 doid suture. E, A depression made by the lateral sinus. F, 
 The prints of the arteries of the dura mater. 
 
 Fig. 4. The external Surface of the Left Os Temporis. 
 
 A, The squamous part. B, The mastoid process. C, The 
 zygomatic process. D, The styloid process. E, The petro- 
 sal process. F, The meatus auditorius externus. G, The 
 glenoid cavity for the articulation of the lower jaw. H, The 
 foramen stylo-mastoideum for the portio dura of the seventh 
 pair of nerves. 1, Passages for blood vessels into the bone. 
 K, The foramen mastoideum through which a vein goes to 
 the lateral sinus. 
 
 Fig. 5. The Internal Surface of the Left Os Temporis. 
 
 A, The squamous part; the upper edge of which assists in 
 forming the squamous suture. B, The mastoid process. C, 
 The styloid process. D, The pars petrosa. E, The entry of 
 the seventh pair, or auditory nerve. F, The fossa, which lodges 
 a part of the lateral sinus. G, The foramen mastoideum. 
 
Explanation of the Plates of Osteology* 431 
 
 Fig. 6. The External Surface of the Osseous Circle, which 
 terminates the meatus auditorious externus. 
 
 A, The anterior part. B, A small part of the groove in 
 which the membrana tympani is fixed. 
 
 N. B. This, with the subsequent bones of the ear, are here 
 delineated as large as the life. 
 
 Fig. 7. The Internal Surface of the Osseous Circle. 
 
 A, The anterior part. B, The groove in which the mem- 
 brana tympani is fixed. 
 
 Fig. 8. The Situation and Connexion of the Small Bones of 
 the Ear. 
 
 A, The malleus. B, The incus. C, The os orbiculare. 
 
 D, The stapes. 
 
 Fig. 9. The Malleus, with its Head, Handle, and Small 
 Processes. 
 
 Fig. 10. The Incus, with its Body, Superior and Inferior 
 Branches. 
 
 Fig. 11. The Os Orbiculare. 
 
 Fig. 12. The Stapes, with its Head, Base, and two Crura. 
 Fig. 13. An Internal View of the Labyrinth of the Ear. 
 A, The hollow part of the cochlea, which forms a share of 
 the meatus auditorious internus. B, The vestibulum. CCC, 
 The semicircular canals. 
 
 Fig. 14. An External View of the Labyrinth. 
 
 A, The semicircular canals. B, The fenestra ovalis which 
 leads into the vestibulum. C, The fenestra rotunda which 
 opens into the cochlea. D, The different turns of the cochlea. 
 Fig. 15. The Internal Surface of the Os Sphenoides. 
 AA, The temporal processes. BB, The pterygoid proces- 
 ses. CC, The spinous processes. DD, The anterior clinoid 
 processes. E, The posterior clinoid process. F, The ante- 
 rior process which joins the ethmoid bone. G, The sella tur- 
 cica for lodging the glandula pituitaria. H, The foramen op- 
 ticum. K, The foramen lacerum. L, The foramen rotun- 
 dum. M, The foramen ovale. N, The foramen spinale. 
 Fig. 16 . The External Surface of the Os Sphenoides. 
 AA, The temporal processes. BB, The pterygoid proces- 
 ses. CC, The spinous processes. D, The processus azygos. 
 
 E, The small triangular processes which grow from the body 
 of the bone. FF, The orifices of the sphenoid sinuses. G, 
 The foramen lacerum. H, The foramen rotundum. I, The 
 foramen ovale. K, The foramen pterygoideum. 
 
432 Explanation of the Plates of Osteology. 
 
 Fig. 17 . The External View of the Os Etiimoides. 
 
 A, The nasal lamella. BB, The grooves between the nasal 
 lamella and ossa spongiosa superiora. CC, The ossa spongi- 
 osa superiora. DD, The sphenoidal cornua. See Fig. 16. E. 
 
 Fig. 18. The Internal view of the Os Ethmoides. 
 
 A, The crista galli. B, The cribriform plate, with the dif- 
 ferent passages of the olfactory nerves. CC, Some of the 
 ethmoidal cells. D, The right os planum. EE, The Sphe- 
 noidal cornua. 
 
 Fig. 19. The right SA^noidal Cornu. 
 
 Fig. 20. The left Sphenoidal Cornu. 
 
 Fig. 21. The External Surface of the Os Occipitis. 
 
 A, The upper part of the bone. B, The superior arched 
 ridge. C, The inferior arched ridge. Under the arches are 
 prints made by the muscles of the neck. DD, The two con- 
 dyloid processes which articulate the head with the spine. E, 
 The cuneiform process. F, The foramen magnum through 
 which the spinal marrow passes. GG, The posterior condy- 
 loid foramina which transmit veins into the lateral sinuses. 
 HII, The foramina lingualia for the passage of the ninth pair 
 of nerves. 
 
 Fig. 22. The Internal Surface of the Os Occipitis. 
 
 AA, The two sides which assist to form the lambdoid suture. 
 B, The point of the cuneiform process, where it joins the 
 sphenoid bone. CC, The prints made by the posterior lobes of 
 the brain. DD, Prints made by the lobes of the cerebellum. 
 E, The cruciform ridge for the attachment of the process of the 
 dura mater. F, The course of the superior longitudinal si- 
 nuses. GG, The course of the two lateral sinuses. H, The 
 foramen magnum. II, The posterior condyloid foramina. 
 
 Plate IV. 
 
 Fig. 1 . A Side-view of the Skeleton. 
 
 A A, The ossa parietalia. B, The sagittal suture. C, The os 
 occipitis. DD, The lambdoid suture. E, The squamous part 
 of the temporal bone. F, The mastoid process. G, The meatus 
 auditorius externus. H, The os frontis. I, The os malae. K, 
 The os maxillare superius. L, The maxilla inferior. M, The 
 teeth of both jaws. N, The seventh, or last cervical vertebra. 
 0, The spinous processes. P, Their transverse and oblique 
 processes. Q, The twelfth or last dorsal vertebra. R, The 
 fifth, or last lumbar vertebra. S, The spinous processes. T, 
 Openings between the vertebrae for the passage of the spinal 
 nerves. U, The under end of the os sacrum. V, The oscoc- 
 
ffl o 
 
Explanation of the Elates of Osieotogf, 433 
 
 eygi;. W, The os ilium. X, The anterior spinous processes, 
 Y, The posterior spinous processes. Z, Ischiatic notch, a, The 
 right os ilium, b, The ossa pubis, c, The tuberosity of the 
 left os ischium, d, The Scapula, e, Its spine, f, The os hu- 
 meri. g, The radius. h, The ulna. i, The carpus, k, The me- 
 tacarpal bone of the thumb. 1, The metacarpal bones of the 
 fingers, m, The two bones of the thumb, n, The three bones 
 of each of the fingers, o, The os femoris. p, Its head, q, The 
 trochanter major, r, The external condyle, s, The rotula. t. 
 The tibia, u, The fibula, v, The malleolus externus. w. The 
 astragalus, x,- The os calcis. y, The-os naviculare. z, The 
 three ossa cuneiforma. l,The os cuboides. 2, The five m - 
 tatarsal bones. 3, The two bones of the great toe. 4, The 
 three bones of each of the small toes. 
 
 Fig. 2. A view of the Internal Surface of the Base of the 
 
 Skull. 
 
 AAA, The two tables of the skull with the diploe. BE, 
 The orbitar plates of the frontal bone. C, The crista gal .. 
 with cribriform plate of the ethmoidal bones on each side ol 
 it, through which the first pair of nerves pass. D, The cunei- 
 form process of the occipital bone. E, The cruciform ridge. 
 F, The foramen magnum for the passage of the spinal mar- 
 row. G, The zygoma, made by the joining of the zygomatic 
 processes of the os temporum and os malse. H, The pars squa- 
 mosa of the os temporis. I, The pars mammillaris. K, The 
 pars petrosa. L, The temporal process of the sphenoid bone. 
 MM, The anterior clinoid processes. N, The posterior cli- 
 noid process. O, The sella turcica. P, The foramen opticum 
 for the passage of the optic nerve and ocular artery of the 
 leftside. Q, The foramen lacerum, for the third, fourth 
 sixth, and first of the fifth pair of nerves and ocular vein. B, 
 The foramen rotundum, for the second of the fifth pair. S, 
 The foramen ovale, for the third of the fifth pair. T, The 
 foramen spinaie, for the principal artery of the dura mater. 
 U, The entry of the auditory nerve. V, The passage for the 
 lateral sinus. W, The passage of the eighth pair of nerves. 
 X, The passage of the ninth pair. 
 
 Fig. 3. A View of the External Surface of the Base of the 
 Skull. 
 
 A, The two dentes incisores of the right side. B, The dens 
 caninus. C, The two small molares. D, The three large mo 
 lares. E, The foramen incisivum, which gives passage to smalt 
 blood vessels and nerves. F, The palate plates of the ossa 
 maxillaria and palati, joined by the longitudinal and trails- 
 •’ erse palate sutures. G, The foramen palatinum posterius, fe: 
 
 Vol.ii, 55 
 
434 Explanation of the Plates of Osteology . 
 
 . he palatine vessels and nerves. H, The os maxillare superior* 
 of the right side. I, The os malm. K, The zygomatic process 
 of the temporal bone. L, The posterior extremity of the ossa 
 spongiosa. M, The posterior extremity of the vomer which, 
 forms the back part of the septum nasi. N, The pterygoid pro- 
 cess of the right side of the sphenoid bone. 00, The foramina 
 ovalia. PP, The foramina spinalia. QQ, The passages of the 
 internal carotid arteries. R, A hole between the point of each 
 pars petrosa and cuneiform process, of the occipital bone, which 
 is filled up with a ligamentous substance in the recent subject. 
 S3, The passage of the left lateral sinus. T, The posterior con- 
 dyloid foramen of the left side. U, The foramen mastoideum. 
 V, The foramen magnum. W, The inferior orbitar fissure. X, 
 The glenoid cavity, for the articulation of the lower jaw. Y, 
 The squamous part of the temporal bone. Z, The mastoid 
 process, at the inner side of which is a fossa for the posterior 
 belly of the digastric muscle, a, The styloid process, b, The 
 meatus auditorius externus. c, The left condyle of the occi- 
 pital bone, d, The perpendicular occipital spine, ee, The 
 inferior horizontal ridge of the occipital bone, ff, The supe- 
 rior horizontal ridge, which is oppposite to the crucial ridge 
 where the longitudinal sinus divides to form the lateral sinu- 
 ses. ggg, The lambdoid suture, h, The left squamous su- 
 ture. i, The parietal bone. 
 
 Fig. 4. The anterior surface of the Ossa Nasi. 
 
 A, The upper part which joins the os frontis. B, The un- 
 der end, which joins the cartilage of the nose. C, The in- 
 ner edge, where they join each other. 
 
 Fig. 5. The posterior surface of the Ossa Nasi. 
 
 AA, Their cavity, which forms part of the arch of the nose. 
 BB, Their ridge or spine, which projects a little to be fixed 
 to the fore part of the septum narium. 
 
 Fig. 6. The external surface of the Os Maxillare Superius 
 of the left side. 
 
 A, The nasal process. B, The orbitar plate. C, The un- 
 equal surface which joins the os malse. D, The external orbitar 
 hole. E, The opening into the nostril. F, The palate-plate. 
 G, The maxillary tuberosity. H, Part of the os palati. I, 
 The two dentes incisores. K, The dens caninus. L, The two 
 small dentes niolares. M, The three large dentes molares. 
 Fig. 7. The internal surface of the Os Maxillare Superius 
 and Os Palati. 
 
 A, The nasal process. BB, Eminences for the connexion 
 of the os spongiosum inferius. D, The under end of the la- 
 chrymal groove. E, The antrum maxillare. F, The nasal spine. 
 
Explanation of the Plates of Osteology . 435 
 
 "between which and B is the cavity of the nostril. G, The 
 palate-plate. H, The orbitar part of the os palati. I, The 
 nasal plate. K, The suture which unites the maxillary and 
 palate bones. The pterygoid process of the palate bone. 
 
 Fig. 8. The external surface of the right Os Unguis. 
 
 A, The orbitar part. B, The lachrymal part. C, The 
 ridge between them. 
 
 Fig. 9. The internal surface of the right Os Unguis. 
 
 This side of the bone has a furrow opposite to the external 
 ridge; all behind this is irregular, where it covers part of the 
 ethmoidal cells. 
 
 Fig. 10. The external surface of the left Os Mala:. 
 
 A, The superior orbitar process. B, The inferior orbitar 
 process. C, The malar process. D, The zygomatic process. 
 E, The orbitar plate. F, A passage for small vessels into or 
 out of the orbit. 
 
 Fig. 11. The internal surface of the left Os Mala:. 
 
 A, The superior orbitar process. B, The inferior orbitar 
 process. C, The malar process. D, The zygomatic process. 
 E, The interna) orbitar plate or process. 
 
 Fig. 12. The externa! surface of the right Os Spongiosum 
 Inferius. 
 
 A, The anterior part. B, The hook-like process for cover- 
 ing part of the antrum maxillare. C, A small process which 
 covers part of the under end of the lachrymal groove. D, 
 The inferior edge turned a little outwards. 
 
 Fig. 13. The internal surface of the Os Spongiosum Inferius. 
 
 A, The anterior extremity. B, The upper edge which joins 
 the superior maxillary and palate bones. 
 
 Fig. 14. The posterior and external surface of the right Os 
 Palati. 
 
 A, The orbitar process. B, The nasal lamella. C, The 
 pterygoid process. D, The palate process. 
 
 Fig. 15. The interior and external surface of the right Os 
 Palati. 
 
 A, The orbitar process. B, An opening through which the 
 lateral nasal vessels and nerves pass. C, The nasal lamella. 
 D, The pterygoid process. E, The posterior edge of the pa- 
 late process for the connexion of the velum palati. F, The 
 inner edge by which the two ossa palati are connected. 
 
 Fig. 16. The right side of the Vomer. 
 
 A, The upper edge which joins the nasal lamella of th 
 
1 36 Explanation of the Plates of Osteology. 
 
 ethmoid bone and the middle cartilage of the nose. B, The 
 inferior edge, which is connected to the superior maxillary 
 anti palate bones. C, The superior and posterior part which 
 receives the processes azygos of the sphenoid bone. 
 
 Fig, 17. The Maxilla Inferior. 
 
 A, The chin. B, The base and left side. C, The angle. 
 1), The coronoid process. E, The condyloid process. F, The 
 beginning of the inferior maxillary canal of the right side, 
 for the entry of the nerves and blood vessels. G, The ter- 
 n .'.nation of the left canal. H, The two dentes incisores. I, 
 The dens caninus. K, The two small molares. L, The three 
 large molares. 
 
 Fig. 18. The different classes of the Teeth. 
 
 1 , 2, A fore and back view of the two anterior dentes in- 
 cisores of the lower jaw. 3, 4, Similar teeth of the upper 
 jaw. 5, 6, A fore and back view of the dentes canini. 7, 8, 
 The anterior dentes molar, es. 9, 10, 11, The posterior den- 
 tes molares. 12, 13, 14, 15, 16, Unusual appearances in the 
 shape and size of the teeth. 
 
 Fig. 19. The external surface of the Os Hyoides. 
 
 A, The body. BB, The cornua. CC, The appendices. 
 Plate V. 
 
 Fig. 1. A Posterior View* of the Sternum and Clavicles, 
 with the ligament connecting the clavicles to each other, 
 a. The posterior surface of the sternum, bb, The broken 
 end of the clavicle, cccc, The tubercles near the extremity 
 of each clavicle, d, The ligament connecting the clavicles. 
 Fig. 2. A Fore-view of the Left Scapula, and a half of the 
 Clavicle, with their Ligaments, 
 a, The spine of the scapula, b, The acromion, c, The infe- 
 rior angle, d, Inferior costa, e, Cervix, f, Glenoid cavity 
 covered with cartilage for the arm-bone, gg, The capsular liga- 
 ment of the joint, h, Coracoid process, i, The broken end of 
 the clavicle, k, Its extremity joined to the acrimon. 1, A 
 ligament coming out single from the acromion to the coracoid 
 process, m, A ligament coming out single from the acromion, 
 and dividing into two, which are fixed to the coracoid process. 
 Fig. 3. The Joint of the elbow of the left arm, with the Li- 
 gaments. 
 
 a, The os humeri, b, Its internal condyle, cc, The two 
 prominent parts of its trochlea appearing through the capsu- 
 lar ligament, d, The ulna, e, The radius, f, The part of 
 the ligament including the head of the radius. 
 
Ava l < > my y Pla t 
 
Explanation of the Plates of Osteology. 43? 
 
 Fig. 4. The Bones of the Right Hand, with the Palm in view. 
 
 a The radius, b, The ulna, c, The scaphoid bone of the 
 carpus, d, The os lunare- e, The os cuneiforme. f, The os 
 pisiforme. g, Trapezium, h, Trapezoides. i, Magnum, k, 
 Unciforme. 1, The four metacarpal bones of the fingers, m, 
 The first phalanx, n, The second phalanx, o, The third 
 phalanx, p, The metacarpal bone of the thumb, q, The first 
 joint, r, The second joint. 
 
 Fig. 5 . The posterior View of the bones of the Left Hand. 
 
 The explication of Fig. 4. serves for this figure; the same 
 letters pointing out the same bones, though in a different view. 
 Fig. 6. The Upper Extremity of the Tibia, with the Semilunar 
 Cartilages of the Joint of the Knee, an*l some Ligaments. 
 
 a, The strong ligament which connects the rotulato the tu- 
 bercle of the tibia, bb, The parts of the extremity of the ti- 
 bia, covered with cartilage, which appear within the semilu- 
 nar cartilages, cc, The semilunar cartilages, d, The two 
 parts of what is called the cross ligament. 
 
 Fig. 7. The Posterior view of the Joint of the Right Knee. 
 
 a, The os femoris cut. b, Its internal condyle, c, Its ex- 
 ternal condyle, d, The back part of the tibia, e, The superior 
 extremity of the fibula, f, The edge of the internal semilunar 
 cartilage, g, An oblique ligament, h, A large perpendicular 
 ligament, i, A ligament connecting the femur and fibula. 
 Fig. 8. The Anterior view of the Joint of the Right Knee. 
 
 b, The internal condyle, c, Its external condyle, d, The 
 part of the os femoris, os which the patella moves, e, A per- 
 pendicular ligament. * fit 1 , The two parts of the crucial liga- 
 ments. gg, The edges of the two moveable semilunar carti- 
 lages. h, The tibia, i, The strong ligament of the patella. 
 
 k, The back part of it where the fat has been dissected away, 
 
 l, The external depression, m, The internal one. n, The 
 cut tibia. 
 
 Fie. 9. A View of the inferior part of the Bones of the 
 Right Foot. 
 
 a, The great knob of the os calcis. b, A prominence on its 
 outside, c, The hollow for the tendons, nerves and blood ves - 
 sels. d, The anterior extremity of the os calcis. e, Part of the 
 astragalus, f, Its head covered with cartilage, g, The internal 
 prominence of the os naviculare. h, The os cuboides. i, The 
 os cuneiform internum ; k, — Medium : 1, — Externum, m, 
 The metatarsal bones of the four lesser toes, n, The first — o, 
 The second — p, The third phalanx of the four lesser toes, q, 
 
438 Explanation of the Plates, of Osteology . 
 
 The metatarsal bones of the great toe. r, Its first — s, Its se- 
 cond joint. 
 
 Fig. 10. The Inferior Surface of the two large Sesamoid 
 Bones, at the first Joint of the Great Toe. 
 
 Fig. 11. The Superior View of the Bones of the Right Foot, 
 a, b, as in Fig. 9. c, The superior head of the astragalus. 
 
 d, &c. as in Fig. 9. 
 
 Fig. 12. The view of the Sole of the Foot, with its ligaments. 
 
 a, The great knob of the os calcis. b, The hollow for the 
 tendons, nerves, and blood vessels, c, The sheaths of the 
 flexores pollicis and digitorum long! opened, d, The strong 
 cartilaginous. ligament supporting the head of the astragalus. 
 
 e, h, Two ligaments which unite into one, and are fixed to 
 the metatarsal bone of the great toe. f, A ligament from 
 the knob of the os calcis to the metatarsal bone of the little 
 toe. g, A strong triangular ligament, which supports the 
 bones of the tarsus, i, The ligaments of the joints of the 
 five metatarsal bones. 
 
 Fig. 13. a, The head of the thigh bone of a child, b, The 
 lmamentum rotundum connecting it to the acetabulum, c, 
 The capsular ligament of the joint with its arteries injected, 
 d, The numerous vessels of the mucilaginous gland injected. 
 Fig. 14. The Back-view of the Cartilages of the Larynx, 
 with the Os Hyoides. 
 
 a, The posterior part of the base of the os hyoides. bb, Its 
 cornua, c, The. appendix of the right side, d, A ligament sent 
 out from the appendix of the left side, to the styloid process 
 of the temporal bone, e, The union of*the base with the left 
 cornu, ff, The posterior sides of (g) the thyroid cartilage, 
 hh, Its superior cornua, ii, Its inferior cornua, k, The cri- 
 coid cartilage. 11, The arytenoid cartilages, m, The entry into 
 the lungs, named glottis, n, The epiglottis, oo, The superior 
 cartilages of the trachea, p, Its ligamentous back part. 
 
 Fig. 15. The superior Concave surface of the Sesamoid Bones 
 at the first joint of the Great Toe, with their Ligaments, 
 a, Three sesamoid bones, b, The ligamentous substance in 
 which they are formed. 
 
/ 
 
Explanation of the Plates of the Muscles. 439 
 
 EXPLANATION OF PLATES VI. and VII. 
 
 PLATE VI. 
 
 Fig. I. The Muscles immediately under the common te- 
 guments on the anterior part of the body are represented on 
 the right side; and on the left side the Muscles are seen 
 which come in view when the exterior ones are taken away. 
 
 A, The frontal muscle. B, The tendinous aponeurosis which 
 joins it to the occipital; hence both named occipitofrontalis . 
 C, Attollens aurem. D, The ear. E, Anterior auris. FF, Or- 
 bicularis palpebrarum. G, Levator labii superioris alaeque 
 nasi. H, Levator anguli oris. I, Zygomaticus minor. K, Zy- 
 gomaticus major. L 5 Masseter. M, Orbicularis oris. N, De- 
 pressor labii inferioris. O, Depressor anguli oris. P, Bucci- 
 nator. QQ, Platysma myoides. RR, Sterno-cleido-mastol- 
 deus. S, Part of the trapezius. T, Part of the scaleni. 
 
 Superior Extremity. — U, Deltoides. V, Pectoralis ma- 
 jor. W, Part of the latissimus dorsi. XX, Biceps flexor cu- 
 biti. YY, Part of the triceps extensor. ZZ, The beginning of 
 the tendinous aponeurosis, (from the biceps,) which is spread 
 over the muscles of the fore-arm. aa, Its strong tendon insert- 
 ed into the tubercle of the radius, bb, Part of the brachialis in- 
 ternus. c, Pronator radii teres, d, Flexor carpi radialis. e, 
 Part of the flexor carpi ulnaris. f, Palmaris longus. g, Apo- 
 neurosis palmaris. 3, Palmaris brevis. 1, Ligamentum carpi 
 annulare. 2 2, Abductor minimi digiti. h, Supinator radii lon- 
 gus. i, The tendons of the thumb, k, Abductor -pollicis. 1, 
 Flexor pollicis longus. mm, The tendons of the flexor sublimis 
 perforatus, profundus perforans,|andlumbricales. The sheaths 
 are entire in the right hand, — in the left cut open to show the 
 tendons of the flexor profundus perforating the sublimis. 
 
 Muscles not referred to — in the left superior extremity. — 
 n, Pectoralis minor, seu serratus anticus minor, o, The two 
 heads of (xx) the biceps, p, Coraco-brachialis. qq, The long 
 head of the triceps extensor cubiti. rr, Teres major, ss, Sub- 
 scapularis. tt, Extensores radiales. u, Supinator brevis, v, 
 The cut extremity of the pronator teres, w, Flexor sublimis 
 perforatus. x, Part of the flexor profundus, y. Flexor pol- 
 licis longus. z, Part of the flexor pollicis brevis. 4, Abduc- 
 tor minimi digiti. 5, The four lumbricales. 
 
 Trunk.— 6 , Serrated extremities of the serratus anticus ma- 
 
440 Explanation of the Plates of the Muscles , 
 
 jor. 7 7, Obliquus externus abdominis. 8 8, The linea alba. 
 9, The umbilicus. 10, Pyramidalis. 11 11, The spermatic 
 cord. On the left side it is covered by the cremaster- 12 12, 
 Rectus abdominis. 13, Obliquus internus. 14 14, &c. In- 
 tercostal muscles. 
 
 Inferior Extremities. — a a , The gracilis, b b. Parts of 
 the triceps, c c, Pectinalis. d d, Psoas magus, e e, Iliacus in- 
 ternus. /, Part of the glutasus medius. g, Part of the glutseus 
 minimus. li, Cut extremity of the rectus femoris. ii, Vastus 
 externus. k, Tendon of the rectus femoris. 1 1, Vastus inter- 
 nus. # Sartorius muscle. **. Fleshy origin of the tensor vaginas 
 femoris or membranosus. Its tendinous aponeurosis covers 
 («) the vastus externus on the right side, m in, Patella, nn, 
 Ligament or tendon from it to the tibia, o, Rectus femoris. 
 p, Crurasus. q q, The tibia, r r, Part of the Gemellus, or gas- 
 trocnemius externus. sss , Part of the soleus or gastrocnemius 
 internus. t, Tibialis auticus. u , Tibialis posticus, v v , Pero- 
 naei muscles, tv w, Extensor longus digitorurn pedis, a; a;, Ex- 
 tensor longus pollicis pedis, y, Abductor pollicis pedis. 
 
 Fig. 2. The Muscles, Glands, &c. of the Left Side of the 
 face and neck, after the common Teguments and Platys- 
 ma myoides have been taken off. 
 
 a, The frontal muscle, b, Temporalis and temporal arte- 
 ry. c, Orbicularis palpebrarum, d, Levator labii superioris 
 alaeque nasi, e, Lavator anguli oris, f, Zygomaticus. g, 
 Depressor labii inferioris. h, Depressor anguli oris, i, Buc- 
 cinator. k, Masseter. 1 1, Parotid gland, m, Its duct, n, 
 Sterno-cleido-mastoideus. o, Part of the trapezius, p, Ster- 
 no-hyoideus. q, Sterno-thyroideus. r, Omo-hyoideus. f, Le- 
 vator scapulae, tt, Scaleni. u, Part of the splenius. 
 
 Fig. 3. The Muscles of the Face and Neck in view after 
 the exterior ones are taken away, 
 aa, Corrugator supercilii. b, Temporalis, c, Tendon of 
 the levator palpebrae superioris. - d, Tendon of the orbicula- 
 ris palpebrarum, e, Masseter. f, Buccinator, g, Levator 
 anguli oris, h, Depressor labii superioris alseque nasi, i, Or- 
 bicularis oris, k, Depressor anguli oris. 1, Muscles of the 
 os hyoides. m, Sterno-cleido-mastoideus. 
 
 Fig. 4. Some of the Muscles of the Os Hyoides and Sub- 
 maxillary Gland. 
 
 a, Part of the masseter muscle, b, Posterior head of the 
 digastric, c, Its anterior head, d d, Sterno-hyoideus. e, Omo- 
 hyoideus. f, Stylo-hyoideus. g, Submaxillary gland in situ 
 

 
 f; c 
 
 
 A 
 
 i 
 
 v';c 
 
Anatomy 
 
Explanation of the Plates of the Muscles. 441 
 
 Fig. 5. The Submaxillary Gland and Duct. 
 
 a, Musculus mylo-hyoideus. b, Hyo-glossus. c, Submax- 
 Illary gland removed from its place, d, Its duct. 
 
 Plate VII. 
 
 Fig. 1. The Muscles immediately under the common te- 
 guments on the posterior part of the body, are represented on 
 the right side ; and on the left side the Muscles are seen 
 which come in view when the exterior ones are taken away. 
 
 Head. — AA, Occipito-frontalis. B, Attollens aurem. C, 
 Part of the orbicularis palpebrarum. D, Masseter. E, Ptery- 
 goideus interims. 
 
 Trunk. — Right side. FFF, Trapezius seu cucullaris. 
 GGGG, Latissimus dorsi. H, Part of the obliquus externus 
 abdominis. 
 
 Trunk. — Leftside. I, Splenius. K, Part of the cotnplexus. 
 L, Levator scapulas. M, Rbomboides. NN, Serratus posticus 
 inferior. O, Part of the longissimus dorsi. P, Part of the 
 sacro-lumbalis. Q, Part of the semi-spinalis dorsi. R, Part of 
 the serratus anticus major. S, Part of the obliquus internus 
 abdominis. 
 
 Superior Extremity. — Right side. T, Deltoides. U, 
 Triceps extensor cubiti. V, Supinator longus. WW, Ex- 
 tensores carpi radialis longior and brevior. XX, Extensor 
 carpi ulnaris. YY, Extensor digitorum communis. Z, Ab- 
 ductor indicis. 12 3, Extensores pollicis. 
 
 Superior Extremity. — Left side, a, Supra Spinatus. b, 
 Infraspinatus, c, Teres minor, d, Teres major, e, Tri- 
 ceps extensor cubiti. ff, Extensores carpi radialis. g, Supi- 
 nator brevis, h, Indicater. 12 3, Extensores pollicis. i, Ab- 
 ductor minimi digiti. k, Interossei. 
 
 Inferior Extremity. — Right side. 1, Glutseus maximus. 
 m, Part of the Glutseus medius. n, Tensor vaginae femoris. o. 
 Gracilis, pp, Adductor femoris magnus. q, Part of the vastus 
 internus. r, Semimembranosus, s, Semitendinosus. t, Long 
 head of the biceps flexor cruris, uu, Gastrocnemius externus 
 seu gemellus, v, Tendo Achillis. w, Soleus seu gastrocne- 
 miusfeternus. xx, Peronasus longus and brevis, y, Tendons 
 of the flexor longus digitorum pedis; — and under them *flexor 
 brevis digitorum pedis, z, Abductor minimi digiti pedis. 
 
 Inferior Extremity. — Left side, m, n, o, pp, q, r, s, t , v, 
 ww , xx, y, z, Point the same parts as in the right side, a, Pyri- 
 formis. bb, Gemini, cc, Obturator internus. d, Quadratus fe- 
 moris. e, Coceygaeus. /, The short head of the biceps flexor cru- 
 ris. gg, Plantaris. /i 3 Popliteus. i, Flexor longus pollicis pedis , 
 
 Vol. n. 56 
 
442 Explanation of the Plates of the Muscles „ 
 
 Fig. 2. The Palm of the Left Hand after the common Tegu- 
 ments are removed, to show the Muscles of the Fingers, 
 a, Tendon of the flexor carpi radialis. b, Tendon of the flex- 
 or carpi ulnaris. c, Tendons of the flexor sublimis perforatus, 
 profundus perforans and lumbricales. d, Abductor pollicis. 
 ee, Flexor pollicis longus. f. Flexor pollicis brevis, g, Palma- 
 ris brevis, h, Abductor minimi digiti. i, Ligamentum carpi- 
 annulare. k, A probe put under the tendons of the flexor di~ 
 gitorum sublimis; which are performed by 1, the flexor digito- 
 rum profundus, mmmm, Lumbricales. n, Abductor pollicis. 
 Fig. 3. A fore-view of the foot and Tendons of the flexores 
 Digitorum. 
 
 a, Cut extremity of the tendo Achillis. b, Upper part of the 
 astragalus, c, Os calcis. d, Tendon of the tibialis anticus. e, 
 Tendon of the extensor pollicis longus. f, Tendon of the 
 peroneus brevis, g, Tendons of the flexor digitorum longus, 
 with the non us Vesalii. hh, The whole of the flexor digitorum 
 brevis. 
 
 Fig. 4. Muscles of the Anus, 
 aa, An outline of the buttocks, and upper part of the thighs, 
 b, The testes contained in the scrotum, cc, Sphincter ani. 
 d, Anus, e, Levator ani. ff, Erector penis, gg, Accelera- 
 tor urinae. h, Corpus cavernosum urethrae. 
 
 Fig. 3. Muscles of the Penis. 
 
 aa, b, d, ee, ff, h, point the same as in fig. 4. c, Sphincter 
 ani. gg, Transversalis penis. 
 
 EXPLANATION of PLATES VIII. IX. and X. 
 
 Plate VIIL 
 
 Fig. 1. Shows the Contents of the Thorax and Abdomen In 
 
 situ. 
 
 l, Top of the trachea, or windpipe. 2 2, The internal ju- 
 gular veins. 3 3, The subclavian veins. 4, The vena cava de- 
 scendens. 5, The right auricle of the heart. 6, The right ven- 
 tricle. 7, Part of the left ventricle. 8, The aorta descendens. 
 9, The pulmonary artery. 10, The right lung, part of which, 
 is cut off to show the great blood vessels. 11, The left lung 
 entire. 12 12, The anterior edge of the diaphragm. 1313, 
 The two great lobes of the liver. 14, The ligamentum rotun- 
 dum. 15, The gall bladder. 16, The stomach. 1717, The 
 jejunum and ilium. 18, The spleen. 
 
ANj\ T oMY 
 

Explanation of the Plates of the Muscles. 443 
 
 Fig. 2. Shows the organs subservient to the Chylopoietic Vis- 
 cera, — with those of Urine and Generation. 
 
 11, The under side of the two great lobes of the liver, a, 
 Lobulus spigelii. 2, The ligamentum rotundum. 3, The gall- 
 bladder. 4, The pancreas. 5, The spleen. 6 6, The Kid- 
 neys. 7, The aorta descendens. 8, Vena cava ascendens. 
 9 9, The renal veins covering the arteries. 10, A probe un- 
 der the spermatic vessels and a bit of the inferior mesentric 
 artery, and over the ureters. 1 1 11, The ureters. 12 12, The 
 iliac arteries and veins. 13, The intestinum rectum. 14, 
 The bladder of urine. 
 
 Fig. 3. Shows the Chylopoietic Viscera, and Organs subser- 
 vient to them, taken out of the body entire. 
 
 AA, The under side of the two great lobes of the liver. B, 
 Ligamentum rotundum. C, The gall-bladder. D, Ductus 
 cysticus. E, Ductus hepaticus. F, Ductus communis chole- 
 dochus. G, Vena portarum. H, Arteria hepatica. I, The 
 stomach. KK, Vense and arterise gastro-epiploicae, dextrae 
 and sinistrae. LL, Venae and arteriae coronariae ventriculi. 
 M, The spleen. NN, Mesocolon, with its vessels. 000, In- 
 testinum colon. P, One of the ligaments of the colon, which 
 is a bundle of longitudinal muscular fibres. QQQQ, Jejunum 
 and ilium. RR, Sigmoid flexure of the colon with the liga- 
 ment continued, and over. S, The intestinum rectum. TT, 
 Levatores ani. U, Sphincter ani. V, The place to which 
 the prostate gland is connected. W, The anus. 
 
 Fig. 4. Shows the Heart of a Foetus at the full time, with 
 the Right Auricle cut open to show the Foramen Ovale, or 
 passage between both Auricles. 
 
 a, The right ventricle, b, The left ventricle, cc, The out- 
 er side of the right auricle stretched out. dd, The posterior 
 side, which forms the anterior side of the septum, e, The 
 foramen ovale, with the membrane or valve which covers the 
 left side, f, Vena cava inferior passing through, g, A por- 
 tion of the diaphragm. 
 
 Fig. 5. Shows the Heart and Large Vessels of a Foetus at 
 the full time. 
 
 a, The left ventricle, b, The right ventricle, c, A part of 
 the right auricle, d, Left auricle, ee, The right branch of the 
 pulmonary Artery, f, Arteria pulmonalis. gg, The left branch 
 of the pulmonary artery, with a number of its largest branches 
 dissected from the lungs, h, The canalis arteriosus, i, The 
 arch of the aorta, kk, The aorta descendens. 1, The left sub- 
 
444 Explanation of the Plates of the Muscles. 
 
 clavian artery, m, The left carotid artery, n, The right caro- 
 tid artery. o, The right subclavian artery, p, The origin of the 
 right carotid and right subclavian arteries in one common 
 trunk, q, The vena cava superioror descendens. r, The right 
 common subclavian vein, s, The left common subclavian vein. 
 
 N. B. All the parts described in this figure are to be found 
 in the adult, except the canalis arteriosus. 
 
 Plate IX. 
 
 Fig. 1 . Exhibits the more superficial Lymphatic Vessels of 
 the Lower Extremity. 
 
 A, The spine of the os ilium. B, The os pubis, c, The 
 iliac artery. D, The knee. E, E, F, Branches of the crural ar- 
 tery. G, The musculus gastrocnemius. H, The tibia. I, The 
 tendon of the musculus tibialis anticus. On the outlines, a, 
 A lymphatic vessel belonging to the top of the foot, b, Its 
 first division into branches, c, c, c, Other divisions of the 
 same lymphatic vessel, d, A small lymphatic gland, e, The 
 lymphatic vessels which lie between the skin and the muscles 
 of the thigh, ffj Two lymphatic glands at the upper part of 
 the thigh below the groin, gg, Other glands, h, A lympha- 
 tic vessel which passes by the side of those glands without 
 communicating with them; and bending towards the inside of 
 the groin at (i,) opens into the lymphatic gland (k.) 11, 
 
 Lymphatic glands in the groin, which are common to the lym- 
 phatic vessels of the genitals and those of the lower extremi- 
 ty. m, n, A plexus of lymphatic vessels passing on the in- 
 side of the iliac artery. 
 
 Fig. 2. Exhibits a Back-view of the Lower Extremity dis- 
 sected so as to show the deeper-seated Lymphatic Vessels 
 which accompany the Arteries. 
 
 A, The os pubis. B, The tuberosity of the ischium. C, That 
 part of the os ilium which was articulated with the os sacrum. 
 
 D, The extremity of the iliac artery appearing above the groin. 
 
 E, The knee. FF, The two cut surfaces of the triceps muscle, 
 which was divided to show the lymphatic vessels that pass 
 through its perforation along with the crural artery. G, The 
 edge of the musculus gracilis. H, The gastrocnemius and so- 
 leus much shrunk by being dried, and by the soleus being se- 
 parated from the tibia to expose the vessels. I, The heel. K, 
 The sole of the foot. L, The superficial lymphatic vessels 
 passing over the knee, to get to the thigh. On the outlines ; 
 M, The posterior tibial artery, a, A lymphatic vessel accom- 
 panying the posterior tibial artery, b, The same vessel cross- 
 ing the artery, c, A small 1 vmphatic gland, through which this 
 
 4 
 
Explanation of the Plates of the Muscles. 445 
 
 deep-seated lymphatic vessel passes, d, The lymphatic vessel 
 passing under a small part of the soleus, which is left attached 
 to the bone, the rest being removed. e, The lymphatic vessel 
 crossing the popliteal artery, f, g, h, Lymphatic glands in the 
 ham,, through which the lymphatic vessel passes, i, The lym- 
 phatic vessel passing with the crural artery, through the perfo- 
 ration of the triceps muscle, k, The lymphatic vessel, after it 
 has passed the perforation of the triceps, dividing into branches 
 which embrace the artery (1.) m, A lymphatic gland belonging 
 to the deep-seated lymphatic vessel. At this place those vessels 
 pass to the fore part of the groin where they communicate with 
 the superficial lymphatic vessel, n, A part of the superficial 
 lymphatic vessel appearing on the brim of the pelvis. 
 
 Fig. 3. Exhibits the Trunk of the Human Subject prepared 
 to show the Lymphatic Vessels and the Ductus Thoracicus. 
 
 A, The neck. BB, The two jugular veins. C, The vena 
 cava superior. DDDD, The subclavian veins. E, The begin- 
 ning of the aorta, pulled to the left side by means of a ligature, 
 in order to show the thoracic duct behind it. F, The branches 
 arising from the curvature of the aorta. GG, The two carotid 
 arteries. HH, The first ribs. II, The trachea. KK, The spine. 
 LL, The vena azygos. MM, The descending aorta. N, The 
 cceliac artery, dividing into three branches. 0, The superior 
 mesenteric artery. P, The right crus diaphragm atis. QQ, The 
 two kidneys. R, The right emulgent artery. SS, The external 
 iliac arteries, g, d, The psoas muscles. T, The internal iliac 
 artery. U, The cavity of the pelvis. XX, The spine of the os 
 ilium. YY, The groins, a, A lymphatic gland in the groin, 
 into which lymphatic vessels from the lower extremity are seen 
 to enter, bb, The lymphatic vessels of the lower extremities 
 passing under Poupart’s ligament, cc, A plexus of the lympha- 
 tic vessels lying on each side of the pelvis, d, The psoas muscle 
 with lymphatic vessels lying upon its inside, e, A plexus of 
 lymphatics, which having passed over the brim of the pelvis at 
 (c,) naving entered the cavity of the pelvis, and received the 
 lymphatic vessels belonging to the viscera contained in that ca- 
 vity, next ascends and passes behind the illiac artery to (g.) f 
 Some lymphatic vessels of the left side passing over the upper 
 part of the os sacrum: to meet those of the right side, g, The 
 right psoas, with a large plexus of lymphatics lying on its inside. 
 M, The plexus lying on each side of the spine. Hi, Spaces 
 occupied by the lymphatic glands, k, The trunk of the lacteals 
 lying on the under side of the superior mesenteric artery. /, The 
 same dividiug into two branches, one of which passes on each 
 
446 Explanation of the Plates of the Muscles. 
 
 side of the aorta; that of the right side being seen to enter the 
 thoracic duct at ( m .) m, The thoracic duct beginning from 
 the large lymphatics, n, The duct passing under the lower 
 part of the crus diaphragmatis, and under the right emulgent 
 artery, o, The thoracic duct penetrating the thorax, p, Some 
 lymphatic vessels joining that duct in the thorax, q, The tho- 
 racic duct passing under the curvature of the aorta to get to 
 the left subclavian vein. The aorta being drawn aside to show 
 the duct, r, A plexus of lymphatic vessels passing upon the 
 trachea from the thyroid gland to the thoracic duct. 
 
 Plate X. 
 
 Fig. 1 . Represents the Under and Posterior Side of the 
 Bladder of Urine, &c. 
 
 a, The bladder, bb, The insertion of the ureters, cc, The 
 vasa deferentia, which convey the semen from the testicles to 
 dd. The vesiculae seminales, — and pass through e. The pros- 
 tate gland, to discharge themselves into f. The beginning of 
 the urethra. 
 
 Fig. 2. A transverse Section of the Penis. 
 
 gg, Corpora cavernosa penis, h, Corpus cavernosum ure- 
 thrae. i. Urethra, k, Septum penis. 11, The septum be- 
 tween the corpus cavernosum urethrae and that of the penis. 
 
 Fig. 3. A Longitudinal Section of the Penis. 
 
 mm, The corpora cavernosa penis, divided by o, The sep- 
 tum penis, n, The corpus cavernosum glandis, which is the 
 continuation of that of the urethra. 
 
 Fig. 4. Represents the Female Organs of Generation. 
 
 a, That side of the uterus which is next to the os sacrum. 
 1, Its fundus. 2, Its cervix, bb, The fallopian or uterine 
 tubes, which open into the cavity of the uterus; — but the other 
 end is open within the pelvis, and surrounded by c c, The fim- 
 briae. d d, The ovaria. e, The os internum uteri, or mouth 
 of the womb, ff, The ligamentum rotundum, which passes 
 without the belly, and is fixed to the labia pudendi. gg, The 
 cut edges of the ligamenta lata, which connect the uterus to 
 the pelvis, h. The inside of the vagina, i, The orifice of the 
 urethra, k, The clitoris surrounded by (1,) The praeptium. 
 mm, The labia pudendi. nn, The nympbae. 
 
 Fig. 5. Shows the Spermatic Ducts of the Testicle filled 
 with Mercury. 
 
 A, The vas deferens. B, Its beginning, which forms the 
 
/< w . 
 
 Akat omt 
 
A N ATOMY 
 
Explanation of Vie Plates of the Muscles . 447 
 
 posterior part of the epididymis. C, The middle of the epi- 
 didymis, composed of serpentine ducts. D, The head or an- 
 terior part of the epididymis unravelled, e e e e, The whole 
 ducts which compose the head of the epididymis unravelled, 
 f f, The vasa deferentia. g g, Rete testis, h h, Some recti- 
 linear ducts which send off the vasa deferentia. i i, The sub- 
 stance of the testicle. 
 
 Fig. 6. The right Testicle entire, and the Epididymis filled 
 with Mercury. 
 
 A, The beginning of the vas deferens. B, The vas deferens 
 ascending towards the abdomen. C, The posterior part of the 
 epididymis, named globus minor. D, The spermatic vessels 
 enclosed in cellular substance. E, The body of the epididy- 
 mis. F, Its head, named globus major. G, Its beginning from 
 the testicle. H, The body of the testicle, enclosed in the tu- 
 nica albuginea. 
 
 EXPLANATION of PLATE XI. 
 
 This plate represents the Heart in situ, all the large Arte- 
 ries and Veins, with some of the Muscles, &c. 
 
 Muscles, &c. — Superior Extremity. — a, Masseter. b, 
 Complexus. C, Digastricus. d, Os hyoides. e, Thyroid gland, 
 f, Levator scapulae, g, Cucullaris. h h, The clavicles, cut. i. 
 The deltoid muscle, k, Biceps flexor cubiti. cut. 1, Coraco- 
 brachialis. m, Triceps extensor cubiti. n, The heads of the 
 pronator teres, flexor carpi radiales, and flexor digitorum sub- 
 limis, cut. o, The flexor carpi-ulnaris, cut at its extremity. 
 
 p, Flexor digitorum profundus, q, Supinator radii longus, 
 cut at its extremity, r, Ligamentum carpi transversale. s, 
 Extensores carpi radiales. t, Latissimus dorsi. u, Anterior 
 edge of the serratus anticus major, vv, The inferior part of 
 the diaphragm, ww, Its anterior edge cut. xx, The kidneys, 
 y, Transversus abdominus. z, Os ilium. 
 
 Inferior Extremity. — a, Psoas magnus. b, Iliacus inter- 
 nus. c, The fleshy origin of the tensor vagina femoris. dd } 
 The ossa pubis cut from each other, e, Musculus pectineus 
 cut from its origin, f, Short head of the triceps abductor fe- 
 moris cut. g, The great head of the triceps, h, The long 
 head cut. i, Vastus internus. k, Vastus externus. I, Cru- 
 reus. m, Gemellus, n, Soleus. o, Tibia, p, Peroneus longus. 
 
 q, Peroneus brevis, r, Fibula. 
 
 Heart and Blood-vessels. — A, The heart, with the co- 
 ronary artery and veins. B, The right auricle of the heart. C, 
 The aorta ascendens. D, The left subclavian artery. E, The 
 
448 Explanation of the Plates of the Muscles. 
 
 left carotid artery. F, The common trunk which sends oft' the 
 right subclavian and right carotid arteries. G, The carotis ex- 
 terna. H, Arteria facialis, which sends off the coronary arte- 
 ries of the lips. I, Arteria temporalis profunda. K, Aorta de- 
 scendens. LL, The illiac arteries, which sends oft' MM, The 
 femoral or crural arteries. N. B. The other arteries in this 
 figure have the same distribution as the veins of the same 
 name : — And generally, in the anatomical plates, the descrip- 
 tion to be found on the one side, points out the same parts in 
 the other. 1, The frontal vein. 2, The facial vein. 3, Vena 
 temporalis profunda. 4, Vena occipitalis. 5, Vena jugulads 
 externa. 6, Vena jugularis interna, covering the arteria caro- 
 tis communis. 7, The vascular arch on the palm of the hand, 
 which is formed by, 8, The radial artery and vein, and, 9, 
 The ulnar artery and vein. 10 10, Cephalic vein. 1 1, Basilic 
 vein, that on the right side cut. 12, Median vein. 13, The 
 humeral vein, which, with the median, covers the humeral ar- 
 tery. 14 14, The external thoracic or mammary arteries and 
 veins. 15, The axillary vein, covering the artery. 16 16, The 
 subclavian veins, which, with (6 6) the jugulars, form, 17, The 
 vena cava superior. 18, The cutaneous arch of veins on the 
 fore part of the foot. 19, The vena tibialis antica, covering the 
 artery. 20, The vena profunda femoris, covering the artery. 
 21, The upper part of the vena saphena major. 22, The fe- 
 moral vein. 2323, The illiac veins. 24 24, Vena cava infe- 
 rior. 25 25, The renal veins covering the arteries. 26 26, 
 The diaphragmatic veins. 
 
 EXPLANATION of PLATE XII. 
 
 Fig. 1 . Represents the Inferior part of the Brain; — the An- 
 terior part of the whole Spine, including the Medulla Spina- 
 lis; — with the origin and large portions of all the Nerves. 
 
 AA, The anterior lobes of the cerebrum. BB, The lateral 
 lobes of the cerebrum. CC, The two lobes of the cerebellum. 
 D, Tuber annulare. E, The passage from the third ventricle 
 to the infundibulum. F, The medulla oblongata, which sends 
 off the medulla spinalis through the spine. GG, That part of 
 the os occipitis which is placed above (HH) the transverse 
 processes of the first cervical vertebra. II, &c. The seven 
 cervical vertebrae, with their intermediate cartilages. KK, 
 &c. The twelve dorsal vertebrae, with their intermediate car- 
 tilages. LL, &c. The five lumbar vertebrae, with their inter- 
 mediate cartilages. M, The os sacrum. N, The os coccygis. 
 
Ill* 
 
 
Explanation of the Plates of the Muscles . 449 
 
 Nerves. — 1 1, The first pair of nerves, named olfactory 9 
 which go to the nose. 2 2, The second pair named optic , which 
 goes to form the tunica retina of the eye. 3 3, The third pair, 
 named motor oculi ; it supplies most of the muscles of the 
 eye-ball. 4 4, The fourth pair, named pathetic , — which is 
 wholly spent upon the musculus trochlearis of the eye. 5 5, 
 The fifth pair divides into three branches. — The first, named 
 ophthalmic, goes to the orbit, supplies the lachrymal gland, and 
 sends branches out to the forehead and nose. — The second, 
 named superior maxillary, supplies the teeth of the upper 
 jaw, and some of the muscles of the lips. — The third, named 
 inferior maxillary, is spent upon the muscles and teeth of the 
 lower jaw, tongue, and muscles of the lips. 6 6, The sixth 
 pair, which after sending oft' the beginning of the intercostal 
 or great sympathetic, is spent upon the abductor oculi. 7 7, 
 The seventh pair, named auditory, divides into two branches.-- 
 The largest, named portio mollis , is spent upon the internal 
 ear. The smallest, portio dura , joins to the fifth pair within 
 the internal ear by a reflected branch from the second of the 
 fifth ; and within the tympanum, by a branch from the third 
 of the fifth, named chorda tympuni. — >Vid. fig. 3. near B 8 8, 
 &c. The eighth pair, named par vugum, — which accompanies 
 the intercostal, and is spent upon the tongue, larynx, pharynx, 
 lungs, and abdominal viscera. 9 9, The ninth pair, which are 
 spent upon the tongue. 10 10, &c. The intercostal, or great 
 sympathetic, which is seen from the sixth pair to the bottom 
 of the pelvis on each side of the spine, and joining with all 
 the nerves of the spine; — In its progress supplying the heart, 
 and, with the par vagum, the contents of the abdomen and 
 pelvis. 1111, The accessorius, which is spent upon the ster- 
 no-cleido-mastoideus and trapezius muscles. 12 12, The first 
 cervical nerves; — 13 13, The second cervical nerves; — both 
 spent upon the muscles that lie on the neck, and teguments 
 of the neck and head. 1414, The third cervical nerves, which, 
 after sending off, (15 15, &c.) the phrenic nerves to the dia- 
 phragm, supply the muscles and teguments that lie on the 
 side of the neck and top of the shoulder. 16 16, The brachial 
 plexus, formed by the fourth, fifth, sixth, seventh cervicals, 
 and first dorsal nerves : which supply the muscles and tegu- 
 ments of the superior extremity. 17 17, The twelve dorsal, 
 or proper intercostal nerves, which are spent upon the inter- 
 costal muscles and some of the large muscles which lie upon 
 the thorax. IS 18, The five lumbar pairs of nerves, which 
 supply the lumbar and abdominal muscles, and some of the 
 teguments and muscles of the inferior extremity. 19 19. The 
 Vol. ii, 57 
 
450 Explanation of the Plates of the Muscles, 
 
 sacro-sciatic or posterior crural nerve, formed by the two in- 
 ferior lumbar, and three superior of the os sacrum. This large 
 nerve supplies the greatest part of the muscles and teguments 
 of the iuferior extremity. 20, The stomachic plexus, formed 
 by the eighth pair. 21 21, Branches of the solar or cceliae 
 plexus, formed by the eighth pair and intercostals, which sup- 
 ply the stomach and chylopoietic viscera. 22 22, Branches of 
 the superior and inferior mesenteric plexuses, formed by the 
 eighth pair and intercostals, which supply the chylopoietic vis- 
 cera, with part of the organs of urine and generation. 23 23, 
 Nerves which accompany the spermatic cord. 24 24, The hy- 
 pogastric plexus, which supplies the organs of urine and gene- 
 ration within the pelvis. 
 
 Fig. 2, 3, 4, 5, Show different Views of the Inferior part of the 
 Brain, cut perpendicularly through the Middle, — with the 
 Origin and large Portions of all the Nerves which pass but 
 through the Bones of the Cranium,— and the three first 
 Cervicals. 
 
 A, The anterior lobe. B, The lateral lobe of the cerebrum, 
 C, Onehrf the lobes of the cerebellum. D, Tuber annulare. 
 
 E, Corpus pyramidale, in the middle of the medulla oblongata, 
 
 F, The corpus olivare, in the side of the medulla oblongata, 
 
 G, The medulla oblongata. H, The medulla spinalis. 
 Nerves.— 1 23 45 6 7 8 and 9, Pairs of Nerves. 10 10, 
 
 Nerves accessorius, which comes from — 11, 12, and 13, The 
 three first cervical nerves. 
 
 EXPLANATION of PLATE XIII. 
 
 Fig. 1. Shows the Lachrymal Canals, after the Common Te- 
 guments and Bones have been cut away, 
 a, The lachrymal gland, b, The tivo puncta lachrymalia, 
 from which the two lachrymal canals proceed to c, The lach- 
 rymal sac. d, The large lachrymal duct, e, Its opening into 
 the nose, f, The carunca lachrymal is. g, The eye-ball. 
 
 Fig. 2, An interior View of the Coats and Humours of the 
 
 Eye. 
 
 a a a a, The tunica sclerotica cut in four angles, and turned 
 back, bbbb, The tunica clioroides adhering to the inside of 
 the sclerotica and the ciliary vessels are seen passing over — 
 cc. The retina which covers the vitreous humour, dd, The 
 ciliary processes, which were continued from the choroid coat, 
 a e, The iris f, The pupil. 
 
Anatomy plate xm . 
 
Explanation of the Plates of the Muscles. 451 
 
 Fig. 3. Shows the Optic Nerves, and Muscles of the Eye. 
 a, a. The two optic nerves before they meet, b, The two 
 optic nerves conjoined, c, The right optic nerve, d, Muscu- 
 lus. attollens palpebrse superioris. e, Attollens oculi. f, Ab- 
 ductor. gg, Obliquus superior, or trochlearis. h, Abductor, 
 i, The eye-ball. 
 
 Fig. 4. Shows the Eye-ball with its Muscles, 
 a, The optic nerve, b, Musculus trochlearis. c, Part of 
 the os frontis, to which the trochlea or pulley is fixed through 
 which, — d, The tendons of the trochlearis pass, e, Attollens 
 oculi. f, Adductor oculi. g, Abductor oculi. h, Obliquus in- 
 ferior. i, Part of the superior maxillary bone to which it is 
 fixed, k, The eye-ball. 
 
 Fig. 5. Represents the Nerves and Muscles of the Right 
 Eye, after part of the Bones of the orbit have been cut 
 away. 
 
 A, The eye-ball. B, The lachrymal gland. C, Musculus 
 abductor oculi. D, Attollens. E, Levator palpebras superi- 
 oris. F, Depressor oculi. G, Abductor. H, Obliquus superior, 
 with its pulley. I, Its insertion into the sclerotic coat. K, 
 Part of the obliquus inferior. L, The anterior part of the os 
 frontis, cut. M, The crista galli of the ethmoid bone. N, 
 The posterior part of the sphenoid bone. 0, Transverse spi- 
 nous process of the sphenoid bone. P, The carotid artery, 
 denuded where it passes through the bones. Q, The carotid 
 artery within the cranium. R, The ocular artery. 
 
 Nerves.— a a, The optic nerve,—- b, The third pair, c, Its 
 joining with a branch of the first branch of the fifth pair, to 
 form 1, — The lenticular ganglion, which sends off the ciliary 
 nerves, d. ee, The fourth pair, f, The trunk of the fifth pair, 
 g, The first branch of the fifth pair, named ophthalmic, h, 
 The frontal branch of it. i, Its ciliary branches, along with 
 which the nasal twig is sent to the nose, k, Its branch to the 
 lachrymal gland. 1, The lenticular ganglion, m, The second 
 branch of the fifth pair, named superior maxillary, n, The 
 third branch of the fifth pair, named inferior maxillary, o, 
 The sixth pair of nerves — which sends oft' p, The beginning 
 of the great sympathetic, q, The remainder of the sixth pair, 
 spent on c, The abductor oculi. 
 
 Fig. 6. Represents the head of a youth, where the upper part 
 of the cranium is sawed off, —to show the upper part of the 
 brain, covered by the pia mater, the vessels of which are 
 minutely filled with wax. 
 
 AA, The cut edges of the upper part of the cranium. B. 
 

 452 Explanation of ike Plates of the Muscles. 
 
 The two tables and intermediate diploe. BB, The two hemi- 
 spheres of the cerebrum. CC, The incisure made by the falx, 
 D, Part of the tentorium cerebello super expansum. E, Part 
 of the falx, which is fixed to the crista galli. 
 
 Fig. 7. Represents the parts of the External Ear, with the 
 Parotid Gland and its Duct. 
 
 a a, The helix, b, The antihelix, c. The antitragus, d, The 
 tragus, e, The lobe of the ear. f, The cavitas innominata. g, 
 The scapha. h, The concha, i i, The parotid gland, k, A 
 lymphatic gland, which is often found before the tragus. 1, 
 The duct of the parotid gland, m, its opening into the mouth. 
 Fig. 8. A view of the posterior part of the external ear, mea- 
 tus auditorius, tympanum with its small bones and Eusta- 
 chian tube, of the right side. 
 
 a, The back part of the meatus, with the small ceruminous 
 glands, b, The incus, c, Malleus, d, The chorda tympani. e, 
 Membrana tympani. f, The Eustachian tube, g, Its mouth 
 from the fauces. 
 
 Fig. 9. Represents the anterior part of the right external ear, 
 the cavity of the tympanum — it9 small bones, cochlea, and 
 semicircular canals. 
 
 a, The malleus, b, Incus, with its long leg, resting upon 
 the stapes, c, Membrana tympani. d, e, The Eustachian tube 
 covered by part of — f f, The Musculus circumilexus palati. 1, 
 2, 3, The three semicircular canals. 4, The vestibule. 5, The 
 cochlea. 6, The portio mollis of the seventh pair of nerves. 
 Fig. 10. Shows the muscles which compose the fleshy sub- 
 stance of the Tongue. 
 
 a a, The tip of the tongue, with some of the papillse mini- 
 mse. b, The root of the tongue, c, Part of the membrane of 
 the tongue, which covered the epiglottis, d d, Part of the mus- 
 culus hyo-glossus. e, The lingualis. f, Genio-glossus. g g. 
 Part of the stylo-glossus. 
 

 JgT 
 
 I 
 
 Wistar 
 
 1827 
 
 v. 2