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 Physiology for the laboratory, 
 
 3 1924 003 145 798 
 
Copyright, 1900, by 
 BERTHA MILLARD BROWN 
 
 ALL EIGHTS RESERVED 
 
PREFACE. 
 
 It has seemed to me that there is needed a radical 
 change in the teaching of physiology. The old way qi 
 teaching physiology merely from the text-book has been 
 outgrown in most of the best schools. Many teachers are 
 in the next stage of development. They use the text- 
 book largely, but have experiments to illustrate the text. 
 That is, they use first the text-book, and secondly the 
 experiments. 
 
 It would seem that the logical way to teach the ele- 
 ments of physiology, as the elements of other sciences, 
 would be, first, to study the specimen and then to go to 
 the text-book for additional facts after we have thoroughly 
 laid the foundation with the specimens. The text-book 
 should be used, but the foundation must first be laid from 
 the study of the actual animals in the laboratory. This 
 has long been the method of teaching botany, chemistry, 
 and the other sciences. "Why should physiology be taught 
 so very differently ? Some have thought that the subject 
 was not one for experimental work in the high and normal 
 schools. But that can be easily disproved by visiting 
 some really good teaching in this subject. The student's 
 own body may be studied to a certain extent, and then 
 
iv PREFA CE. 
 
 the markets furnish us with the parts of many lower ani- 
 mals that may be used to teach the functions of corre- 
 sponding parts of the human body. 
 
 The ideal way to teach physiology, of course, would be 
 to give the specimen to the student and expect him to 
 discover for himself the structure and function of all the 
 parts. This was Agassiz's method. But this is hardly 
 practicable to-day. With so much to teach and so short 
 a time to do it, we must necessarily help the student. 
 We may call his attention to the important things to be 
 seen and then make sure that he has found them correctly. 
 With a large class, the simplest way to call attention to 
 the main points is by clear and well-written directions to 
 be used in the laboratory. We can only be sure that each 
 one finds the parts when he shows them to us, or we exam- 
 ine his carefully labeled drawings. The directions should 
 not be too full. They should simply point the way and 
 not describe the parts. That is the work of the student. 
 If the directions are too full, or the ordinary text-book is 
 used in the laboratory, the beginner is tempted to study 
 the text-book and disregard the specimen. 
 
 Too much stress cannot be laid on the importance of 
 gaining the first impressions from the specimens. This 
 has already been too long neglected in the teaching of 
 physiology. We must also bear in mind that we are not 
 teaching this subject merely for the sake of anatomy and 
 physiology as sciences, but for the sake of hygiene and 
 better ways of living. 
 
 Finding that much time may be lost in the laboratory 
 unless the work is carefully planned, I have found it con- 
 venient, in my own classes, to use a series of directions 
 
PREFACE. V 
 
 that may prove of service to some other teacher. All of 
 the experiments are simple and may be performed by 
 any student. Most of the apparatus is made by the 
 students, and no elaborate pieces are required. The other 
 supplies are such as may be obtained from the ordinary 
 market, or are similar to those found in any simple chem- 
 ical or physical laboratory. 
 
 I have to thank Mr. C. B. Wilson of the State Normal 
 School at Westfield, Mass., and Dr. Theodore Hough of 
 the Massachusetts Institute of Technology, for carefully 
 reading the manuscript and making some valuable sug- 
 gestions. B M B 
 
 Boston, Mass., April, 1900. 
 
The original of this book is in 
 the Cornell University Library. 
 
 There are no known copyright restrictions in 
 the United States on the use of the text. 
 
 http://www.archive.org/details/cu31924003145798 
 
CONTENTS. 
 
 CHAPTER PAGE 
 
 I. General Directions. The Microscope . . 1 
 
 II. The Cells 7 
 
 III. The Bones 9 
 
 IV. The Preparation oe a Skeleton . 16 
 V. The Joints . . 18 
 
 VI. The Muscles . ... .22 
 
 VII. The Blood . 31 
 
 VIII. The Circulation . .35 
 
 IX. Respiration .... . .49 
 
 X. The Teeth and the Tongue .... 55 
 
 XL Other Digestive Organs . . . .58 
 
 XII. Foods .... .... 67 
 
 XIII. Digestion . . . . .77 
 
 XIV. The Kidneys .87 
 
 XV. The Skin and Bodily Temperature . . 89 
 
 XVI. The Brain 94 
 
 XVII. The Spinal Cord and other Nerves . . . 106 
 
 XVIII. The Eye and Vision 113 
 
 XIX. The Ear and Hearing 125 
 
 XX. Some Dermal Sensations' 127 
 
 XXI. The Larynx and the Voice .... 130 
 
 XXII. Bacteria 134 
 
 Appendix ......... 147 
 
" What is the range and position of Physiological Science as a 
 branch of knowledge, and what is its value as a means of mental 
 discipline ? Its subject-matter is a large moiety of the universe ; 
 its position is midway between the physico-chemical and the social 
 sciences. Its value as a branch of discipline is partly that which it 
 has in common with all sciences — the training and strengthening 
 of common sense ; partly that which is more peculiar to itself — the 
 great exercise which it affords to the faculties of observation and 
 comparison ; and, I may add, the exactness of knowledge which it 
 requires on the part of those among its votaries who desire to extend 
 its boundaries." Huxley. 
 
 " The great benefit which a scientific education bestows, whether 
 as training or as knowledge, is dependent upon the extent to which 
 the mind of the student is brought into immediate contact with 
 facts — upon the degree to which he learns the habit of appealing 
 directly to Nature, and of acquiring through his senses concrete 
 images of those properties of things which are, and always will be, 
 but approximatively expressed in human language." Huxley 
 
PHYSIOLOGY FOE THE LABOEATOEY. 
 
 i. 
 
 GENERAL DIRECTIONS. 
 
 THE COMPOUND MICROSCOPE. 
 
 In studying the various parts of the human body, we 
 need to magnify some of them in order to see their struc- 
 ture. To do this, we shall need to use a compound 
 microscope. But, in the first place, it would be well to 
 study the microscope and learn how to use it properly. 
 
 A. The Parts of the Compound Microscope. 
 
 The parts of the compound microscope are the stand, the 
 objectives, and the eyepieces. 
 
 I. The Stand. 
 
 The stand is the largest part of the microscope and 
 includes all except the objectives and the eyepieces. It 
 has several divisions : 
 
 a. The foot. The foot is the horseshoe-shaped part on 
 which the rest of the microscope stands (Fig. 1, a). 
 
 b. The pillar. This is the vertical column that is fas- 
 tened to the base (Fig. 1, b). 
 
 l 
 
PHYSIOLOGY FOB THE LABORATORY. 
 
 c. The arm. The arm is attached to the upper part of 
 the pillar and supports the parts, d and e, of the micro- 
 scope (Fig. 1, c). 
 
 d. The body. This is the 
 short outer tube upheld by 
 the arm (Fig. 1, d). 
 
 e. The draw-tube. This is 
 the long tube within the body 
 to which the objectives and 
 the eyepieces are attached. It 
 is called the draw-tube, be- 
 cause in some microscopes it 
 can be lengthened and short- 
 ened to change the magnifica- 
 tion (Fig. 1, e). 
 
 f. The stage. This is the 
 part attached to the pillar, 
 below the body, on which the 
 slide that is to be examined is 
 placed (Fig. 1, /). 
 
 g. The diaphragm. Attached 
 to the lower side of the stage 
 is a circular piece, the dia- 
 phragm. It contains open- 
 ings of different sizes and 
 may be turned so that the 
 one of the desired size may 
 
 be brought under the opening in the centre of the stage 
 
 (Fig- l,g). 
 
 h. The clips. These are the two small metallic pieces, 
 one on either side of the stage, to hold in place the slide 
 
 FtG. 1. — The compound microscope. 
 a, foot ; 6, pillar; c, arm ; d, body; e, 
 draw-tube ; /, stage ; g, diaphragm ; 
 h, clips ; i, mirror ; k, milled head 
 for fine adjustment ; I, eyepiece ; 
 m, objective. 
 
GENERAL DIRECTIONS. 3 
 
 to be examined (Fig. 1, h). These are merely for con- 
 venience and are not always used. 
 
 i. The mirror. The mirror is below the stage (Fig. 1, i). 
 
 k. The milled head. This is at the upper end of the 
 pillar (Fig. 1, k). It is the fine adjustment to raise and 
 lower the body of the microscope and all the parts that the 
 body carries. Turn the milled head slowly and notice the 
 motion of the body of the microscope. 
 
 II. The Objectives and the Eyepieces. 
 
 a. There are several objectives and eyepieces, but the 
 objectives most often used are a low power No. 3 and a 
 higher power No. 7. The eyepieces most often used are 
 a low power No. 2 and a higher power No. 4. 
 
 b. The magnifications for the Leitz microscope are 
 approximately as follows : 
 
 Objective 3 
 
 Eyepiece 2 
 
 Diameters 70 
 
 « -3 
 
 « 4 
 
 105 
 
 7 
 
 2 
 
 440 
 
 7 
 
 4 
 
 625 
 
 c. An object should first be examined with the low 
 power, and afterward studied more carefully with the 
 high power. The lenses must be perfectly clean, since 
 the least dust or cloudiness obscures the image. For 
 wiping the lenses use a soft cloth, first breathing upon 
 the glass in order to dampen it. An old handkerchief is 
 useful. The lenses should never be touched with the 
 fingers, for they are apt to make ineffaceable marks. 
 
4 PHYSIOLOGY FOB THE LABORATORY. 
 
 B. The Use of the Microscope. 
 
 1. The stand is used with the ends of the horseshoe-foot 
 pointing away from the student. It is always kept in this 
 position, and any change in the light is overcome by a 
 change in the position of the mirror. 
 
 2. The light is obtained by turning the mirror so that 
 it will reflect the light from the sky upward through the 
 draw-tube ; the amount of light may be regulated by the 
 diaphragm. The sun should never be allowed to shine 
 directly on the mirror or on any other part of the microscope. 
 
 3. The proper focus is found by two adjustments. 
 
 a. The coarse adjustment is used first with both low and 
 high power to find the approximate focus. It is accom- 
 plished most easily by slowly twisting the entire draw-tube 
 while sliding it upward or downward with the fingers. 
 
 b. The fine adjustment is used to focus exactly, so that 
 the object shall be perfectly clear and distinct. It is 
 effected by turning the milled head on the upper end of 
 the pillar. 
 
 c. Never focus downward with the eye at the microscope, 
 as there is danger of touching the slide with the lens and 
 injuring both the slide and the lens. 
 
 d. If the object cannot be brought clearly into view b}"- 
 the adjustment, test the illumination by changing the 
 position of the mirror, examine the objective to make sure 
 that it is not wet, and finally examine the cover-glass. 
 
 e. Learn to keep both eyes open ; the strain upon them is 
 far less than if one eye is closed. If the object does not 
 
GENERAL DIRECTIONS. 5 
 
 show clearly, do not strain the eye to see it, but change 
 the focus by the fine adjustment. 
 
 4. Study the microscope until you are familiar with 
 the names and uses of the various parts. 
 
 5. Make a sketch of the microscope and carefully label 
 the parts. 
 
 Note. — The Leitz microscope and only the lenses that are most 
 frequently used are here described. The general description, how- 
 ever, -would apply to any other manufacture, but each kind has its 
 own system of magnification. 
 
 In the microscopes made by the Bausch and Lomb Optical Co., 
 the objectives and eyepieces are designated by their focal distances. 
 The low-power objectives range from a focal distance of 3 inches 
 (the lowest) to f inch. The higher objectives range from a focal 
 distance of \ inch to ■£$ inch (the highest). The eyepieces range from 
 a focal distance of 2 inches (a low power) to \ inch (a high power). 
 
 C. The Sketches and Records of Experiments. 
 
 I. Sketches. 
 
 All the more important observations should be recorded 
 by sketches. 
 
 a. The outlines may be first traced lightly. 
 
 b. When all the parts are drawn, the outlines may be 
 darkened with a hard pencil (H H H H) and the various parts 
 made clear when necessary by the use of colored crayons 
 or water colors. 
 
 c. Draw on a large scale and label neatly at the side of 
 the drawing. 
 
 d. Do not shade your drawings so as to conceal the 
 essential parts. 
 
b PHYSIOLOGY FOB THE LABORATORY. 
 
 II. The Recoup of Experiments. 
 
 After performing any experiment make a record of it in 
 the following order : 
 
 a. The materials used. 
 
 b. The apparatus used. 
 
 c. The experiment, or what was done. 
 
 d. The observation of what occurred. 
 
 e. The inference, or explanation." 
 
 III. The Instruments. 
 
 Each scholar should be provided with a set of instru- 
 ments consisting of : 
 
 1. A pair of scissors. 
 
 2. A pair of forceps. 
 
 3. A medium-sized scalpel. 
 
 4. Two needle-holders with needles. 
 
 Care should be taken to clean the instruments after 
 using them, to wipe, and to keep them dry. 
 
II. 
 
 THE CELL. 
 A. Simple Cells. 
 
 Material. A prepared slide showing large cells. 
 Apparatus. A compound microscope. 
 
 Study first with a low power and then with a high power 
 a prepared slide showing large cells, as the cells of the cast- 
 off skin of a newt, that have been stained. 
 
 Notice : 
 
 I. A Single Cell. 
 
 a. Its general shape. 
 
 b. The protoplasm, lightly stained. 
 
 c. The nucleus, deeply stained. 
 
 d. The nucleolus, a dark spot in the nucleus. 
 
 e. Deeply stained loops, or chromatin loops, may be scat- 
 tered through the protoplasm. This is the part that is 
 thought to bear the hereditary characteristics. 
 
 /. The cell-wall, when present, on the outside of the cell. 
 
 II. The Arrangement of the Cells. 
 
 a. What is the general arrangement ? 
 
 6. Are there any spaces between the cells ? 
 
 c. Sketch several cells and label all the parts. 
 
 7 
 
8 PHYSIOLOGY FOB THE LABORATORY. 
 
 B. Cells of Other Tissues. 
 
 Material. Prepared sections of skin, connective tissue, fatty tissue, 
 and cartilage. A section of skin from the roof of a rabbit's mouth 
 will show I, II, and III finely. 
 
 Apparatus. A compound microscope. 
 
 Examine, in the same way as in A, prepared sections 
 of the skin, connective tissue, fatty tissue, and cartilage. 
 
 Notice : 
 
 I. Epithelial Tissue. 
 
 a. Is it composed of cells or fibres ? 
 
 b. How are they arranged? 
 
 c. Notice the change in shape and structure as we pro- 
 ceed from the inside outward. 
 
 II. Connective Tissue. 
 
 a. Is it cellular or fibrous ? 
 
 b. What does its structure suggest as to its use ? 
 
 III. Fatty, or Adipose Tissue. 
 
 a. Where is it found ? 
 
 b. Compare the cells with those of epithelium. 
 
 c. Do you find any nucleus ? The protoplasm has been 
 changed to oil. 
 
 IV. Cartilage. 
 
 a. The scattered condition of cells. 
 
 b. Do you find nuclei or cell-wall? 
 
 c. The substance intervening between the cells is neither 
 cellular nor fibrous. 
 
III. 
 
 THE BONES. 
 A. The Shapes of Bones. 
 
 Materials. A human skeleton and human vertebrae of the dorsal, 
 lumbar, and cervical regions. Many different kinds of bones, as the 
 leg and wing bones of chickens, the shoulder-blades and skulls of 
 dogs and horses, bones of the ankle of sheep, and the vertebra? of 
 chickens. 
 
 Study the bones of the human skeleton when possible, 
 but the corresponding bones of other animals, as the dog, 
 horse, and chicken, may be used for some of the experi- 
 ments. 
 
 Select from the bones on the table : 
 
 a. A long bone. 
 
 1. What is its general shape? 
 
 2. Compare with the human skeleton and find other 
 
 long bones. 
 
 b. A tabular or plate-like bone, as the shoulder-blade. 
 
 1. What is its general shape ? 
 
 2. Compare with the human skeleton and find other 
 
 tabular bones. 
 
 c. A short bone, as one of the wrist bones, having about 
 the same diameter in every direction. 
 
10 PHYSIOLOGY FOB THE LABORATORY. 
 
 1. What is its general shape ? 
 
 2. Compare with the human skeleton and find other 
 
 short bones. 
 
 d. An irregular bone, such as the vertebra or any bone 
 except the three preceding kinds. 
 
 1. Find other irregular bones in the human skeleton. 
 
 B. The Gross Structure of a Long Bone. 
 
 Materials. A long bone, as the humerus or bone of the upper 
 arm ; a fresh long bone, as the bone of the leg of a sheep. This 
 should be sawed in halves longitudinally (lengthwise). Any butcher 
 will saw the bone when the material is purchased. 
 
 Study carefully any long bone, as the humerus or bone 
 of the upper arm. Most of the external parts may be 
 seen from a dried specimen. Then compare this with a 
 longitudinal section of a fresh bone and identify the 
 remaining parts. 
 
 I. The External Parts (of a long bone). 
 a. The shaft, or long central cylindrical portion. 
 
 1. The ridges on the surface : their use ? where do 
 
 they lead? 
 
 2. The round openings : where situated ? their use ? 
 
 3. The rough places : what is attached here ? 
 
 4. The periosteum, or covering on the fresh bone. 
 
 (1) How far does it extend ? 
 
 (2) What is the color and appearance of its 
 
 surface ? 
 
 (3) What is its use ? 
 
THE BONES. 11 
 
 b. The articular extremities. 
 
 1. How are these united to the shaft ? (See a bone 
 
 that has been boiled until the extremities have 
 separated from the shaft.) 
 
 2. The cartilage in the fresh bone. 
 
 (1) How far does it extend ? 
 
 (2) What is its texture and color? 
 
 3. The large prominences or knobs : their use ? 
 
 c. Sketch and label all the external parts. 
 
 II. The Internal Parts. 
 
 These may be seen from a longitudinal section of a fresh 
 bone of the leg of a sheep. 
 
 a. The hard bone on the outside. 
 
 1. Note the thickness in different parts of the bone. 
 
 2. Where is it thickest? Why? 
 
 3. Where is it thinnest? Why? 
 
 b. The spongy bone in the ends. 
 
 1. How far does it extend? 
 
 2. What is its color in the fresh bone? That is 
 
 due to the marrow within it. 
 
 c. The fine cavities and passages : their use ? 
 
 d. The medullary cavity in the centre. 
 
 1. What is its shape ? 
 
 2. How far does it extend ? 
 
 3. Which is stronger, a solid or a hollow shaft con- 
 
 taining the same amount of material ? 
 
 4. What, then, is the use of the medullary cavity? 
 
12 PHYSIOLOGY FOR THE LABORATORY. 
 
 e. The marrow is within the cavity. What is its color ? 
 "What is its use to the bone? 
 ' /. Make a sketch of the longitudinal section. 
 
 C. The Gross Structure of an Irregular Bone, a Vertebra. 
 
 Materials. A dorsal vertebra of the human skeleton or of a dog, 
 sheep, or other vertebrate. The axis, or second cervical vertebra, of 
 the human skeleton. The atlas, or first cervical vertebra, of the human 
 skeleton. The spinal column just taken from a fresh fish or a rabbit. 
 
 1. Examine carefully a human vertebra of the dorsal 
 region. If that is not possible, study the vertebra 
 of a cat, a dog, a bird, a sheep, or of any other of 
 the vertebrates. Identify the following parts when 
 present : 
 
 a. The centrum, or body, is the large solid part. 
 
 b. The neural arch is the bony arch on one side ; its use ? 
 Study the spinal column of the human skeleton and see 
 whether the arch is on the dorsal (back) or ventral (front) 
 side of the vertebral column. 
 
 c. The neural ring is formed by the neural arch and the 
 centrum. 
 
 d. The neural canal is the cavity within the ring. See a 
 fresh specimen of the spinal column of a fish and find what 
 is in the neural canal. 
 
 e. The. spinous process is the outward projection on the 
 dorsal side of the neural arch. 
 
 f. The transverse processes are projections at the side. 
 
 g. The anterior articular process is the projection by which 
 the vertebra joins the next vertebra above towards the 
 head. 
 
THE BONES. 13 
 
 h. The posterior articular process is the projection by which 
 the vertebra joins the next vertebra below. 
 
 i. Is there a medullary cavity in the vertebra ? 
 
 j. Is there any spongy bone ? 
 
 k. Does an irregular bone, then, have a medullary cavity 
 or spongy bone ? 
 
 I. Sketch a side and an end view of a vertebra. 
 
 2. Compare with the dorsal vertebra the following : 
 
 a. The axis, or second cervical (neck) vertebra, of the 
 human skeleton or of a sheep. The odontoid process is the 
 rounded prominence upon it. 
 
 b. The atlas, or first cervical vertebra. 
 
 c. "What parts are present and what parts are wanting 
 in each? 
 
 d. Place the axis in position on the atlas and find the 
 use of the odontoid process. 
 
 e. Sketch an end view of each. 
 
 D. The Chemical Composition of Bone. 
 
 Materials. A thin piece of bone about two inches long. Hydro- 
 chloric acid, ten per cent. Ammonium hydrate. A long, slender 
 bone, as a rib of a chicken. 
 
 Apparatus. A pair of Fairbanks standard scales. Bunsen burner. 
 A piece of wire gauze about six inches square. A tall, slender jar. 
 A ring-stand. 
 
 All bones are composed of animal and mineral matter. 
 
 I. The Mineral Mattee. 
 
 a. Weigh carefully a clean piece of bone. 
 
 b. Burn it on a' piece of sheet-iron over the flame of a 
 
14 PHYSIOLOGY FOR THE LABORATORY. 
 
 Bunsen burner until it turns white. Be very careful 
 neither to lose any of it nor to burn it too long. 
 e. What happens ? 
 
 d. Touch it ; what happens ? 
 
 e. What is its chief structure and general appearance ? 
 /. What have you left ? 
 
 g. Weigh it. 
 
 h. Calculate the amount of mineral matter in the bone. 
 i. What has become of the animal matter? 
 j. Calculate the amount of animal matter in bone. 
 k. Place the burned bone in dilute, ten per cent, hydro- 
 chloric acid. 
 
 I. What happens ? Why? 
 m. Add ammonium hydrate (ammonia) in excess. 
 n. What happens ? Why ? 
 
 The mineral matter consists of eighty-three per cent of 
 calcium phosphate, Ca 3 (P0 4 ) 2 , thirteen per cent of calcium 
 carbonate, CaCo 3 , and of other salts. The animal matter 
 consists mainly of an albuminoid, ossein, or collagen, which 
 may be converted by boiling with water into gelatin. 
 
 II. The Animal Mattek. 
 
 a. Place a long, slender bone, such as a rib-bone, in 
 dilute, ten per cent, hydrochloric acid in a tall, narrow 
 jar, and leave it for a day or longer according to the size 
 of the bone. Dilute nitric acid or vinegar may also be 
 used. 
 
 b. Touch it ; can you bend it ? 
 
 o. What are its characteristics now? 
 
 d. What has taken place? 
 
 e. What have you left ? 
 
THE BONES. 15 
 
 /. Where is the mineral matter? Prove it. 
 g. Burn this as you did the entire bone. What previous 
 experiment does this verify ? 
 
 E. The Microscopical Structure of Bone. 
 
 Material. A prepared slide showing a cross-section of a human 
 humerus. 
 
 Apparatus. A compound microscope. 
 
 Examine under the microscope a prepared cross-section 
 of a long bone, as the human fibula or humerus. 
 
 a. Notice with the low power : 
 
 1. The large Haversian canals that are cut across. 
 
 These are the passages for the blood-vessels. 
 
 2. The lamellae, or layers arranged concentrically 
 
 around the canals. 
 
 3. The lacuna;, or small cavities separating the 
 
 lamellae. What is their shape ? These were 
 once filled with living cells. Why are they 
 now black? 
 
 4. Sketch. 
 
 b. Notice, in addition, with high power: 
 
 1. The canaliculi, or wavy branches which run across 
 
 the lamellae. 
 
 (1) Where do they lead? 
 
 (2) What is their use ? 
 
 2. Sketch. 
 
IV. 
 
 THE PREPARATION OF A SKELETON. 
 
 A part of a skeleton, the wing or the leg of a fowl, 
 makes a good specimen to mount. This exercise may be 
 postponed until later, and some of the material obtained 
 for the study of muscles be utilized. The skeleton of an 
 entire animal may be prepared if each scholar will take 
 one- part. 
 
 Materials. A leg or wing of a chicken or bones to be mounted. 
 Ammonium hydrate. Borax. 
 
 Apparatus. Bunsen burner. Ring-stand. A piece of wire gauze 
 six inches square. Granite-ware stew-pan. Fine gimlet and wire 
 or cardboard, needle and thread. 
 
 In preparing bones, only general directions can be given, 
 as the kind, size, and condition of the bones determine, to 
 a certain extent, the details. 
 
 a. Much of the muscle and fat may first be removed 
 with scissors and scalpel. 
 
 b. Place the bones and the remaining debris in water 
 and boil until the muscles fall readily from the bones. If 
 a small amount of ammonium hydrate or borax be added 
 to the water, the process will be facilitated. To remove 
 the marrow from a long bone, bore a hole in either end 
 and thoroughly wash out the marrow. 
 
 c. Place in clean water and remove everything from the 
 
 16 
 
THE PMEPABATION OF A SKELETON. 17 
 
 bones. Take care that none of the bones are lost, and 
 notice the positions of the different bones. 
 
 d. "Wash the bones repeatedly in fresh water until per- 
 fectly clean and then place them on a board to dry. 
 
 e. Small bones may be sewed in their proper positions 
 on a piece of stiff cardboard. Large bones should have a 
 single hole bored at either end and be wired together. For 
 the positions of the holes,. study a skeleton that has been 
 set up. 
 
V. 
 THE JOINTS. 
 A. The Kinds of Joints. 
 Materials. The human skeleton. The student's body. 
 
 Study carefully the human skeleton and identify the 
 four kinds of joints. 
 
 a. A ball and socket joint, e.g. the hip-joint. 
 
 1. What are all the possible movements ? 
 
 2. What is the shape of the differentpartsof the joint? 
 
 3. Find other joints of this kind. 
 
 b. A hinge joint, e.g. the knee-joint. 
 
 1. How many movements has it? 
 
 2. Whatistheshape of the differentpartsof the joint ? 
 
 3. Find other hinge joints. 
 
 c. A pivot joint, e.g. between the first and second cer- 
 vical vertebrae. 
 
 1. What is the motion ? 
 
 2. How is the joint formed? 
 
 3. Can you find other pivot joints ? 
 
 d. A gliding joint, e.g. between the bones of the wrist, — 
 the carpal bones. 
 
 1. What is their motion ? 
 
 2. Find other joints of this kind. 
 
 18 
 
THE JOINTS. 19 
 
 B. A Ball and Socket Joint. 
 
 Material. A fresh hip-joint of an ox or sheep with the mem- 
 brane and muscles still attached. If the butcher saws it in halves 
 longitudinally, the different parts may be clearly seen. 
 
 Study carefully a large, fresh ball and socket joint, such 
 as the hip-joint of a sheep. 
 Identify : 
 
 a. The cavity, or acetabulum. What is its shape and 
 use? 
 
 b. The ball, or head of the long bone. What is its 
 shape and use ? 
 
 <?. The cartilage. 
 
 1. How far does it extend? 
 
 2. Feel of it. 
 
 3. Cut it. 
 
 4. What are its properties and uses ? 
 
 d. The ligaments bind the bones together. Find the use 
 and the properties of each. 
 
 1. The capsular ligament is a loose bag extending 
 
 all around the joint. 
 
 2. The round ligament passes from the acetabulum 
 
 to the head of the long bone. How does the 
 attachment of these ligaments allow motion at 
 the joint? 
 
 e. The tendons attach the muscles to the bones. How 
 do they differ in appearance from the ligaments ? 
 
 /. The synovial membrane is a thin layer of cells extend- 
 ing over the ligaments and cartilage. It is too thin to be 
 distinguished with the naked eye. 
 
20 . PHYSIOLOGY FOB THE LABORATORY. 
 
 g. The synovial liquid is found as soon as the capsular 
 ligament is cut. It is secreted by the synovial membrane. 
 
 1. Eub a little between your fingers. 
 
 2. What is its use ? 
 
 h. Sketch and label all the parts. 
 
 C. Some Other Joints. 
 Material. The fore leg of a lamb. 
 The joints of the fore leg of a lamb may be studied. 
 
 1. Compare the fore leg of the lamb with the upper limb 
 
 of man and find which joint you are studying. 
 Describe the way in which the bones fit together at 
 the joint, and explain how motion, in certain direc- 
 tions is prevented while it is allowed in others. 
 
 2. Identify the different parts of the joint that are named 
 
 under the ball and socket joint, except a and b. 
 Sketch. 
 
 D. The Microscopical Structure of Cartilage. 
 
 Material. A prepared slide of hyaline cartilage. 
 Apparatus. A compound microscope. 
 
 Study with the high power of a compound microscope a 
 prepared slide of a piece of hyaline cartilage. 
 
 Notice : 
 
 1. The cartilage cells. 
 
 a. What is their shape? 
 
 b. How are they arranged ? 
 
 c. What parts of the cell can you identify ? 
 
THE JOINTS. 21 
 
 2. The homogeneous material, or matrix, in which the cells 
 are embedded. Sketch. 
 
 E. The Relation of Cartilage to Bone. 
 
 Materials. A prepared slide of developing bone. Foetal bones 
 of some young animal. (Those of the pig are usually easy to obtain 
 from any butcher.) 
 
 Apparatus. A compound microscope. 
 
 Study : 
 
 1. Some of the long bones of the foetus. 
 
 a. Examine them both in the centre and at the ends. 
 Compare in structure and density. 
 
 b. Compare them in shape with the adult form. 
 
 c. Compare them with cartilage joining the ribs to the 
 breast-bone and with cartilage always present at the joints. 
 
 2. Examine the prepared slide of developing bone. 
 Notice : 
 
 a. The enlargement and rearrangement of cartilage cells. 
 
 b. The calcification of the matrix. 
 
 c. Sketch. 
 
VI. 
 
 THE MUSCLES. 
 
 A. The Parts of a Muscle. 
 
 Material. A chicken, pigeon, or fore leg of a lamb. 
 
 Examine the muscles of some small animal, as a chicken, 
 a pigeon, or the fore leg of a lamb. Dissect carefully one 
 entire muscle, but do not cut it away. 
 
 Notice : 
 
 a. The belly is the red central part. 
 
 1. What is its shape when contracted '! 
 
 2. What is its shape when relaxed? 
 
 b. The tendons are attached at either end. 
 
 1. What is their texture ? 
 
 2. What is their use ? 
 
 c. At how many places is a muscle attached ? 
 
 d. The origin is the less movable attachment of the 
 muscle. 
 
 e. The insertion is the more movable attachment of the 
 muscle. 
 
 /. Which is the origin and which is the insertion of 
 the muscle that you have dissected? 
 g. Sketch. 
 
 22 
 
THE MUSCLES. 23 
 
 B. The Gross Structure of a muscle. 
 
 Material. A piece of lean corned beef about two inches long. 
 
 Some of the parts of a muscle may be seen especially 
 well in a piece of corned beef. 
 
 a. The perimysium, or loose sheath, is on the outside of 
 the entire muscle. 
 
 1. Of what is it composed ? 
 
 2. What is its color? 
 
 3. What is its use ? 
 
 4. What relation does it bear to the tendons ? 
 
 5. Where do branch partitions from the perimysium 
 
 extend ? 
 
 b. A muscle is composed of many bundles of tissue or 
 fasciculi. 
 
 c. Smaller fasciculi unite to form a larger fasciculus. 
 
 d. The smaller fasciculi are composed of fibres. Tease 
 out a few fibres. Note their color, size, and shape. 
 
 e. The nerves are the fine white threads seen on the 
 outside and sometimes within the muscles. What is their 
 distribution and use? 
 
 /. The blood-vessels are the red or colorless thin-walled 
 vessels usually found with the nerves. 
 g. Is a muscle a tissue or an organ? Why? 
 h. Sketch both longitudinal and transverse views. 
 
 C. The Different Kinds of Muscles. 
 Material. A fowl. 
 
 In a common fowl the different kinds of muscles may 
 be found. The tendons of the muscles of the foot and of 
 
24 PHYSIOLOGY FOR THE LABORATORY. 
 
 the leg of a fowl should be dissected carefully, leaving 
 their attachments at both ends. By pulling the upper 
 ends of the tendons that are attached to the muscles of 
 the fore leg, the toes will move as in a living fowl, and 
 can be made to pick up objects. 
 
 Find as many as possible of the following kinds of 
 muscles. 
 
 a. A simple muscle is enlarged in the middle and tapers 
 towards either end. 
 
 b. A biceps muscle is divided into two parts at one end 
 so that it has three tendons. Find the biceps in the leg 
 of the fowl. 
 
 o. In a penniform muscle the tendon runs along the side 
 of the muscle. 
 
 d. The tendon runs down the middle of the muscle in 
 the bipenniform muscle. This kind may be found on the 
 breast of the fowl. 
 
 e. Sketch one of each kind. 
 
 D. The Microscopical Structure of Muscles. 
 I. Stkiated Muscle. 
 
 Material. A prepared slide of striated muscle. 
 Apparatus. A compound microscope. 
 
 Study under the compound microscope a prepared slide 
 of a few fibres of striated muscle that have been teased 
 apart. Frog's muscle shows the striations very plainly. 
 
 Notice : 
 
 a. A single fibre. 
 
 1. Its shape. 
 
 2. The striations that run across the cell. 
 
THE MUSCLES. 25 
 
 3. The nuclei. 
 
 4. The sarcolemma is the thin sheath on the outside. 
 
 Look for it where the fibre has been crushed 
 or bent. 
 
 5. The longitudinal divisions of the fibre into many- 
 
 small flbrillae are not always visible. 
 
 6. Sketch. 
 
 II. Striated Muscle. — A Cross-Sectioh. 
 
 Material. A slide showing a cross-section of striated muscle that 
 has been hardened in Flemming's fluid and stained in safranin. 
 Apparatus. A compound microscope. 
 
 Examine with the high power of a compound microscope 
 a cross-section of striated muscle. 
 
 Observe : 
 
 a. The arrangement of the fibres in the muscle. 
 
 b. The parts of a single fibre. 
 
 1. The polyhedral areas into which the entire fibre 
 
 is divided are the areas of Cohnheim. 
 
 2. Each area is a group of bundles of flbrillae. The 
 
 granular appearance of each area of Cohnheim 
 is due to the cut ends of the fibrillse. The 
 fibrillee are arranged in columns or bundles 
 which, taken together, make the fibre. 
 
 3. Surrounding each fibrilla and again around the 
 
 columns of fibrillee is a hyaline or slightly- 
 granular substance resembling protoplasm, 
 called sarcoplasm. 
 
 III. Plain Muscle. 
 
 Material. A prepared slide of the fibres of plain muscle. 
 Apparatus. A compound microscope. 
 
26 PHYSIOLOGY FOB THE LABORATORY. 
 
 Examine in the same way a piece of plain or non- 
 striated muscle. Identify the different parts of the fibre- 
 cell. Sketch. 
 
 E. Experiments on the Student's Body. 
 
 1. Examine carefully the back of your hand, bending and 
 
 extending the fingers one by one. 
 
 a. Find the different tendons or cords and follow them 
 outward. To what are they attached ? 
 
 Notice especially: 
 
 1. The arrangement at the knuckles. 
 
 2. The tendon of the little finger. How is it con- 
 
 nected with the tendon of the third finger? 
 Why? 
 
 b. Follow the tendons inward toward the arm. 
 
 1. Where do they lead ? Compare the tendons of 
 
 the thumb and the little finger. 
 
 2. Where are the muscles to which these tendons 
 
 are attached ? Verify by placing your fingers 
 on the muscles and bending the fingers' as far 
 back as possible. 
 
 e. Sketch. 
 
 d. Compare this with a drawing of the hand showing 
 the muscles and tendons. 
 
 2. Notice the mass of muscles at the base of the thumb. 
 
 Grasp a book tightly between the thumb and fore- 
 finger. What happens ? 
 
 3. Pin a piece of paper snugly around the upper arm. Lift 
 
 a weight to the shoulder. What happens ? Why? 
 
THE MUSCLES. 27 
 
 4. Standing with heels near together, rise on the toes 
 and then sink as far as possible, bending ankles 
 and knees. Repeat six or ten times. Explain. 
 
 F. The Way in which Muscles Act. 
 
 Materials. A frog. Ether. Cotton batting. 
 
 Apparatus. Ring-stand. Small induction coil. Battery. Wires, etc. 
 
 Etherize the frog, cut the spinal cord just back of the 
 head and destroy the brain with a probe. Lay bare the 
 gastrocnemius (calf) muscle in one hind leg with the nerve 
 leading to it (the sciatic nerve), and cut the several branches 
 of this nerve close to the backbone. 
 
 1. Stimulate the nerve, with a single shock, close to the 
 
 backbone and watch results. Does the result 
 follow instantaneously? Why? How long does 
 it take the muscle to recover its normal position ? 
 
 2. Stimulate at any point with a rapid succession of shocks. 
 
 What difference is there in the result? Call this 
 tetanus, and show its relation to convulsions and 
 cramp. How long does it take the muscle to recover? 
 
 3. Expose the muscle and nerve on the other hind leg, 
 
 cut, and repeat 1 and 2 to verify the results before 
 obtained, watching especially the interval which 
 elapses between stimulation and contraction. 
 
 4. Repeat the single shock stimuli many times at quite 
 
 short intervals, allowing the muscle to recover each 
 time. Note the decreasing strength of contraction 
 produced and the increasing length of time it takes 
 to recover. This is fatigue. 
 
28 PHYSIOLOGY FOB THE LABORATORY. 
 
 G. The Work of Muscles and Bones. Levers. 
 
 Apparatus. A wooden rod about a yard long. Weights of dif- 
 ferent sizes. A triangular prism of wood for a fulcrum. A spring- 
 balance. 
 
 Arrange the different parts to show the kinds of levers. 
 One weight will represent the "weight," and the spring- 
 balance will measure the power. Change the weight and 
 notice the effect on the power. The power arm is the 
 distance from the power to the fulcrum, and the weight 
 arm is the distance from the weight to the fulcrum. Find 
 the relation of the product of the power and the power 
 arm to the product of the weight and the weight arm. 
 
 Show the three kinds of levers : 
 
 a. When the fulcrum is between the power and the 
 weight. 
 
 h. When the weight is between the power and the ful- 
 crum. 
 
 c. When the power is between the weight and the ful- 
 crum. 
 
 H. The Lever in the Arm. 
 
 Note. — These problems maybe solved arithmetically or worked 
 out on Dr. Fitz's lever apparatus. 
 
 1. The bones of the forearm act as a lever. Part of the 
 power is the biceps muscle attached on the inside 
 just below the elbow. 
 
 a. Where is the weight ? the fulcrum ? 
 
 b. What is the length of the power arm ? of the weight 
 arm? 
 
 c. Which kind of lever is this ? 
 
THE MUSCLES. 29 
 
 d. How much power must be exerted to lift a weight 
 of twenty pounds resting on the hand, when the forearm 
 is in a horizontal position ? 
 
 2. The triceps muscle of the back of the arm does part 
 of the work of the arm. It is attached just back 
 of the elbow-joint. 
 
 a. Where is the weight ? the fulcrum ? 
 
 b. Which kind of lever is this ? 
 
 o. How much power must be exerted by the triceps 
 muscle to make the hand push twenty pounds? 
 
 I. The Lever in the Foot and Leg. 
 
 When standing on the toes, the bones of the foot act as 
 a lever. The power is in the muscles of the calf of the leg. 
 
 a. Where is the weight? How much is it? 
 
 b. How long are the power and the weight arms ? 
 
 e. Which kind of lever is this ? 
 
 d. How much power is required for a person weighing 
 125 pounds to stand on his toes ? How much is required 
 for you to stand on your toes ? 
 
 J. A Model of an Arm. 
 
 Note. — This is adapted from Woodhull's Home-Made Apparatus. 
 
 Apparatus. One piece of wood 4 in. x 3 in. x 1 in. 
 " " 9 in. x 1 in. x 1 in. 
 
 " " 4 in. x 1 in. x 1 in. 
 
 Three rubber bands. Six hooks. Four small strips of tin about an 
 inch long. 
 
 The general arrangement of the muscles in the arm may 
 be obtained from a model of wood with muscles of rubber 
 
30 
 
 PHYSIOLOGY FOB THE LABOBATOBY 
 
 bands. The model consists of three pieces of wood ; the 
 longest represents the humerus, the smallest represents 
 together the radius and the ulna, and the broadest repre- 
 sents the shoulder-bone, or scapula. A rubber band 
 
 Fig. 2. — A model of an arm. 
 
 attached at a below the elbow-joint and at b above the 
 shoulder-joint represents the biceps muscle. The rubber 
 band attached at e and / represents the triceps muscle^ 
 
 1. Adjust the three bands so that the arm hangs down 
 
 straight. Show how the muscles work in opposi- 
 tion to each other over the joints. How is the 
 joint made rigid? 
 
 2. Unfasten the band at e and /. What happens to the 
 
 arm ? What muscle causes this motion ? 
 
 3. Replace the rubber band ef and unfasten the band cd. 
 
 What happens to the arm ? What muscle does the 
 work? 
 
 4. If both ef and cd are unhooked, what is the position 
 
 of the arm ? What muscle causes this motion ? 
 
 5. Remove the piece of wood representing the scapula, 
 
 and readjust the muscles to represent the move- 
 ments of the foot. 
 
VII. 
 
 THE BLOOD. 
 
 A. The Structure of Blood. 
 
 Materials. A drop of human blood. To obtain a drop of blood, 
 tie a string or wind a handkerchief tightly around the finger and 
 wait a few minutes until the blood has collected in the finger. 
 Then with a clean needle make a prick near the nail. Let a drop 
 of blood fall on a glass slide. Spread out the blood very thin by 
 placing a second glass slide over the first and rubbing it about. 
 Then remove the second glass slide, place a cover-glass over the 
 blood and the slide is ready for examination. A prepared slide of 
 the blood of a frog. 
 
 Apparatus. Glass slides. Cover-glasses. Compound microscope. 
 
 I. The Human Blood. 
 
 Examine a drop of human blood under the microscope. 
 Notice : 
 
 a. The red corpuscles. What is their shape and arrangement? 
 
 b. The white corpuscles. What is their relative size and 
 shape ? What is their relative number ? 
 
 c. The delicate threads of fibrin. 
 
 d. Sketch. 
 
 II. The Fkog's Blood. 
 
 Study with the microscope a slide of the blood of the frog 
 prepared by double staining to show the nuclei of the red 
 
 corpuscles. 
 
 31 
 
32 PHYSIOLOGY FOR THE LABORATORY. 
 
 Notice : 
 
 a. The red corpuscles. What is their shape as shown 
 by a surface and an end view ? Do you find a nucleus ? 
 
 b. The white corpuscles (stained in the preparation). 
 What is their size and shape? What is the nature of 
 their contents? Have they any nucleus? 
 
 c. Sketch a corpuscle of each kind greatly enlarged. 
 
 III. The Blood op Othek Animals. 
 
 A few drops of a pigeon's or a hen's blood may be 
 obtained and compared with the two kinds already studied. 
 
 B. The Clotting of Blood. 
 
 Materials. Fresh blood from the market, or a frog. Chloroform. 
 Cotton batting. 
 
 Apparatus. Test-tube. Bell-jar. 
 
 I. The Clot. 
 
 Fresh blood of an animal recently killed may be had of 
 the butcher, or a frog may be killed and the blood col- 
 lected. To kill a frog, place it under a bell-jar with some 
 cotton batting saturated with chloroform. Wait until the 
 frog is stiff before dissecting. Then make an incision 
 along the ventral median line, cutting through the breast- 
 bone. Cut the blood-vessels leading to and from the heart 
 close to the latter, and collect the blood in a test-tube. 
 Pour out some of the blood into a smaller test-tube and 
 allow it to stand, taking care to cover it so that it cannot 
 dry. Watch it until changes take place. In case the 
 blood is obtained of the butcher, some of it should be 
 poured in a glass jar and allowed to coagulate. 
 
THE BLOOD. 33 
 
 Notice : 
 
 a. The clot. What is its color, shape, size, consistency, 
 and position ? 
 
 b. The serum or straw-colored liquid. Where is it 
 found? Compare it with the clot in quantity. Remove 
 the serum and notice the effect on the clot. 
 
 II. Fibrin. 
 
 Beat vigorously the remainder of the blood obtained of 
 the butcher, with a bundle of twigs or wires, for a few 
 minutes until some stringy elastic fibrin has collected upon 
 them. Remove the twigs with the fibrin, rinsing them as 
 much as possible in the whipped blood. 
 
 Notice: 
 
 a. The amount, form, and nature of the fibrin. Whence 
 did it come ? 
 
 b. What is its color? Rinse thoroughly under the 
 faucet and note again the color. To what was the former 
 color due? Compare with the color of clot in clotted 
 blood. Inferences. 
 
 e. The liquid which remains after the fibrin has been 
 removed. What part of the blood is it? What color 
 is it? 
 
 d. Allow this liquid to stand for some time. Does it 
 clot ? To what, then, was the clotting in the other blood 
 due ? Compare this liquid carefully with the serum. 
 
 III. The Composition of Blood Serum. 
 
 Material. Blood serum left after I. 
 
 Apparatus. Evaporating dish. Ring-stand. Wire gauze. Bun- 
 sen burner. Test-tube. 
 
34 PHYSIOLOGY FOB THE LABORATORY. 
 
 a. Allow any corpuscles that remain in the serum to 
 settle and pour off some of the clear liquid. Evaporate 
 this slowly to dryness. 
 
 1. How much residue is left? What does this 
 
 represent ? 
 
 2. Heat this residue as you did the bone until it is 
 
 all burned. Is anything left? What kind 
 of matter is it? 
 
 3. Moisten a piece of paper with serum and attempt 
 
 to dry it. What must have been present in 
 the serum ? Whence did it come ? 
 
 4. Boil a small amount about 10 c.c. of serum in a 
 
 test-tube. What change takes place ? What 
 does this show? 
 
 C. The Influence of the Presence or Absence of Oxygen on 
 the Color of Blood. 
 
 Material. Fresh blood in a small test-tube. The blood that was 
 left after experiment B may be used. 
 
 Apparatus. A small test-tube. A piece of glass tubing six 
 inches long. 
 
 Collect a small amount of blood in a test-tube. 
 
 a. What color is the blood ? 
 
 b. Is it arterial or venous ? 
 
 c. Breathe through a glass tube into the blood. 
 
 d. What occurs ? Explain. 
 
VIII. 
 
 THE CIRCULATION OF THE BLOOD. 
 
 A. The Heart and Related Organs. 
 
 Material. Obtain from the market the " pluck'' of a sheep, pig, 
 or calf. This includes the heart, lungs, trachea, and diaphragm. 
 Care should be taken to engage it beforehand, with the request that 
 it be left intact, or the heart will be punctured and there will be no 
 pericardium. 
 
 Study the entire specimen. 
 
 Identify : 
 
 a. The lungs. 
 
 b. The trachea, or windpipe leading to the lungs. 
 
 c. The oesophagus, a thin-walled tube near the trachea, 
 is sometimes cut away. 
 
 d. The heart. 
 
 e. The pericardium is the thin-walled bag in which the 
 heart is held. Does it fit closely to the heart ? Puncture 
 the pericardium, if it has not already been cut. 
 
 /. The pericardial liquid is within the pericardium. 
 
 g. The diaphragm is the muscular membrane just under 
 the heart. What is its shape and texture? Part of it 
 may be cut away. 
 
 h. Sketch all the parts to show the relation of one to 
 
 another. 
 
 35 
 
36 
 
 PHYSIOLOGY FOB THE LABORATORY. 
 
 B. The Parts of the Heart. 
 
 Materials. 
 
 removed. 
 
 The heart and lungs of a calf with the pericardium 
 
 Place the mass on the table with the heart uppermost 
 and with the point of the heart extending away from you. 
 
 Now you see the front of 
 the heart, or its ventral 
 surface. 
 
 Notice : 
 
 a. The apex, or the 
 point of the heart. 
 
 b. The base of the heart 
 is its large end. 
 
 e. The ventral surface, 
 or front of the heart, is 
 the side that is now upper- 
 most as it lies on the table. 
 
 d. The dorsal surface is 
 opposite the ventral. 
 Which is more convex? 
 
 e. The right side of the 
 ™ o tv *„,. ,. a, w a heart is on your right as 
 
 Fig. 3.— Diagram of the heart and large blood- J a 
 
 vessels. A, right ventricle ; B, left ventri- it lies On the table, 
 cle ; C, right auricle; D, left auricle; E, . ,_,, . ., « ,, 
 
 inferior vena cava ; F, superior vena cava ; J- J- n ® left Side 01 une 
 
 W and K, right and left innominate veins ; heart jg qq your left. The 
 R and N, right and left subclavian veins ; " 
 
 v and x, right and left jugular veins ; <?, two sides are separated by 
 
 pulmonary artery ; / and J, right and left TT.ru~.i- :~ ™ 4-u;~ 
 
 pulmonary veins ; H, aorta ; P, innominate * groove. What IS in this 
 
 artery ; S and Y, right and left carotid groove ? 
 
 arteries ; T and M, right and left sub- ° 
 
 clavian arteries. </. The right ventricle IS 
 
THE CIRCULATION OF THE BLOOD. 37 
 
 the large chamber of the heart on the right side of the 
 heart. (A in Fig. 3.) 
 
 h. The left ventricle is the corresponding chamber on 
 the left side. "Which ventricle has thicker walls ? Why ? 
 Do they both extend to the apex of the heart ? (B in 
 Fig. 3.) 
 
 i. The right and the left auricles are the thin-walled 
 pouches at the base of the heart. They may be partly 
 cut away in your specimen. (C and J) in Fig. 3.) 
 
 j. Sketch a dorsal and a ventral view of the heart. 
 
 C. The Blood-Vessels that Open into the Heart. 
 
 Materials. The heart and lungs of a calf, neither cut nor punc- 
 tured in any way, but with the pericardium removed. 
 
 Apparatus. A piece of glass tubing drawn out to a point for a 
 blowpipe or a metallic blowpipe. 
 
 Identify : 
 
 a. The inferior vena cava is the large vein that comes up 
 from the lower part of the body and carries the impure 
 blood into the right auricle. Look for it on the dorsal 
 side of the right auricle at its extreme left where it joins 
 the right ventricle. With a blowpipe inflate the auricle 
 through the inferior vena cava. (H in Fig. 3.) 
 
 b. The superior vena cava carries the blood from the upper 
 part of the body into the right auricle. Look for it close 
 beside a, but at the part of the right auricle that is farthest 
 from the apex of the heart. Follow it away from the 
 heart, as far as you can, to its source at the union of 
 the two innominate veins. With the blowpipe inflate the 
 auricle through this vein. (F in Fig. 3.) 
 
38 PHYSIOLOGY FOR THE LABORATORY. 
 
 c. The pulmonary artery leads from the base of the right 
 ventricle to the lungs. Look for it on the ventral side of 
 the heart between the two auricles. How far can you 
 trace it ? In what direction does it run ? Explain this 
 crossing. Does it carry arterial or venous blood? Why 
 is it called an artery? (See Cr in Fig. 3.) 
 
 d. The aorta is the large tube leading from the left ven- 
 tricle. Trace it from the heart and find the arch where it 
 turns to go to the lower part of the body. (See H in Fig. 3.) 
 
 e. The four pulmonary veins run from the lungs to the 
 left auricle. The two right pulmonary veins run close 
 along the dorsal surface of the right auricle. The two 
 left open at the extreme left of the auricle beneath the 
 arch of the aorta. (See I and J in Fig. 3.) 
 
 /. Indicate the openings of the blood-vessels in your 
 sketches of the heart. 
 
 g. Trace the path of the blood through the heart from 
 the superior and inferior venae cavse. 
 
 h. Indicate in your sketches of the heart the path of the 
 blood through it. 
 
 D. The Valves of the Heart. 
 
 Materials. The heart of the calf. Water. 
 Apparatus. A bulb syringe. A glass graduate. 
 
 I. The Tricuspid Valve. 
 
 Cut away most of the right auricle and with a bulb 
 syringe inject water or allow water from a faucet to flow 
 into the right ventricle. Notice the action of the valves 
 between the auricle and ventricle at the auriculo-ventricu- 
 lar orifice. Press on the ventricle to imitate its contrac- 
 
THE CIRCULATION OF THE BLOOD. 39 
 
 tion. Where does the water escape? Cut through the 
 wall of the ventricle from the base to the apex and spread 
 it open, exposing the tricuspid valve. 
 Notice : 
 
 a. The flaps. How many are there and how are they 
 arranged ? 
 
 b. How are they held in place ? The white cords are 
 called chordae tendime. 
 
 c. One end of these cords is attached to the edge of the 
 valve. To what is the other end attached? These are 
 the papillary muscles. Explain how they work. Why is 
 something of this sort necessary? 
 
 d. Sketch. 
 
 II. The Semilunar Valves at the Base op the 
 
 Pulmonary Artery. 
 
 Find where the pulmonary artery opens into the right 
 ventricle. Cut away enough of the wall of the ventricle 
 to see the opening from below. Pour water into the 
 artery and watch the .action of the valves. 
 
 Notice : 
 
 a. How many are there ? 
 
 b. What is their shape ? 
 
 c. What is their arrangement? 
 
 d. What effect did they have on the stream of water? 
 
 e. What effect did the water have on them? 
 /. Sketch. 
 
 III. The Mitral or Bicuspid Valve. 
 
 Remove the left auricle, noticing from the inside where 
 the pulmonary veins open into it. Inject water into the 
 
40 PHYSIOLOGY FOB THE LABORATORY. 
 
 left ventricle as you did into the right and compare the 
 valves with those of the right ventricle. 
 
 IV. The Semilunar Valves at the Base of the 
 Aorta. 
 
 Find the opening of the aorta into the left ventricle and 
 study the semilunar valves as you did those at the base 
 of the pulmonary artery. 
 
 E. The Valves in the Veins. 
 
 Material. The heart and blood-vessels of a ca]f. 
 Apparatus. Knitting needle. 
 
 If the veins are still attached to the specimen, try to 
 find the valves in them by passing down a small probe, as 
 a knitting needle. 
 
 a. In what direction is the blood flowing in the veins ? 
 In what direction do the valves prevent flow ? 
 
 b. Compare their action with that of the semilunar 
 valves in the arteries. 
 
 Remove the heart and reserve the lungs and trachea 
 for study another time. 
 
 F. The Beating of the Heart. 
 
 Materials. A frog. Chloroform. 20 o.o. normal salt solution. 
 Apparatus. Watch crystal. Watch. Bunsen burner. 
 
 Kill a frog with chloroform, and as soon as it is dead and 
 the limbs are stiff make a cut along the ventral median 
 line, cutting through the breast-bone. Take care not to 
 
THE CIRCULATION OF THE BLOOD. 41 
 
 cut any large blood-vessels. Cut open, carefully, the peri- 
 cardium and watch the action of the beating of the heart. 
 Observe : 
 
 a. The alternate beats of the two auricles and the ven- 
 tricle. 
 
 b. The synchronous beats of the two auricles. 
 
 o. The ventricle during contraction is pale, and its apex 
 is thrown forward and upward. 
 
 d. The pause or systole before the auricle contracts. 
 
 e. Count the beats in a minute. 
 
 /. Remove the heart from the body and place it in 
 normal salt solution in a watch crystal, and see if it still 
 beats. 
 
 g. Apply a gentle heat and watch the effect. 
 
 h. Count the number of beats. 
 
 i. Apply ice and watch the effect. 
 
 j. Count the number of beats. 
 
 G. The Circulation in the Web of the Foot of a Frog. 
 
 Material. A live frog or tadpole. 
 
 Apparatus. Glass slides. Cover-glasses. Piece of cork two inches 
 square. Cloth. Pins. Compound microscope. 
 
 To show the circulation in the web of the foot of the 
 frog, the foot should be spread out perfectly smooth and 
 held in place. Take a very thin piece of cork about two 
 inches square, and cut a hole about half an inch in diameter 
 in the centre of it. Lay a glass slide over the opening. 
 Spread out the foot on the slide over the opening, and 
 secure it there by pinning narrow strips of cloth across 
 the ends of the toes. The frog may be kept quiet by 
 
42 PHYSIOLOGY FOB THE LABORATORY. 
 
 wrapping it in a moist cloth and then in tea-lead, leaving 
 one foot exposed. Cover the foot with a cover-glass, taking 
 care to have water beneath it. 
 
 A tadpole is often easier to manage than a frog. Lay 
 a tadpole on a glass slide and keep it still by winding a 
 piece of moist cloth loosely around both the tadpole and 
 slide. Cover the end of the tail with a cover-glass, tak- 
 ing care that there is water under the cover-glass. 
 
 Study under the microscope the circulation of blood 
 through the capillaries of the web of a frog's foot or the 
 tail of a tadpole. 
 
 Notice : 
 
 a. The capillaries, or small thin-walled blood-vessels. 
 
 b. The red corpuscles carried along in the stream. What 
 is their shape and color"? 
 
 c. The white corpuscles. What is their movement and 
 position in the stream of blood? 
 
 d. At a branch in the capillaries, see how the red cor- 
 puscles are bent out of shape, and then resume their normal 
 shape. 
 
 e. The cells in the epidermis. 
 
 f. The black pigment cells. 
 
 g. What is the color of the blood in a small vein or 
 artery ? 
 
 h. Sketch. 
 
THE CIRCULATION OF THE BLOOD. 43 
 
 H. Experiments on the Student's Body. 
 Apparatus. A watch. A rubber band, or piece of twine. 
 
 1. Find the pulse in different places. 
 
 a. In the wrist. 
 
 b. In the thumb. 
 
 c. In front of the ear, or the side of the face. 
 
 d. Under the knee. Cross one knee over the other and 
 watch the foot of the crossed knee. Explain. 
 
 e. On the temple. 
 
 2. Count your pulse standing, sitting, lying down, and 
 
 after running. How soon is the pulse normal after 
 running ? 
 
 3. Trace the veins and arteries on the back of the hand 
 
 and in the wrist. How can you distinguish between 
 the veins and the arteries ? 
 
 4. Tie a rubber band tightly around your finger. Ex- 
 
 plain the result. 
 
 5. Press with a finger on the skin, and then lift the finger. 
 
 6. Listen for the sounds of the heart of another person. 
 
 I. The Demonstration of the Principles of Circulation. 
 I. Upon what Cibculation Depends. 
 
 a. The beat of the heart. 
 
 b. The peripheral resistance, or the resistance to the 
 
 flowing of the blood in the capillaries. 
 e. The long stretch of elastic tubing or blood-vessels. 
 
44 PHYSIOLOGY FOB THE LABORATORY. 
 
 II. The Normal Flowing of the Blood. 
 
 Material. Water, which may be slightly colored red if preferred. 
 Apparatus. A small force-pump. Two wooden pails. 
 660 cm. pure rubber tubing, 12 m.m. in diameter. 
 \% m. " " " 6 m.m. " " 
 
 560 cm. » " " 5 m.m. " " 
 
 Three-way glass connecting tubing, F-shape. Six large size, 
 
 12 m.m. in diameter, length of one arm 90 m.m. 
 Eight medium size, 6 m.m. in diameter, length of one arm 
 
 65 m.m. 
 Two medium size, T-shape tubing, 6 m.m. in diameter, length 
 
 of one arm 65 m.m. 
 Sixteen small size, 4 m.m. in diameter, length of one arm 
 
 60 m.m. 
 64 cm. glass tubing 12 m.m. in diameter. 
 192 cm. " " 4 m.m. " " 
 Two pinch-cocks. 
 35 cm. of glass rod 2 m.m. in diameter, or pieces of a fine 
 
 sponge. 
 
 By means of an apparatus made of glass and rubber 
 tubing, the principal phenomena of the circulation of the 
 blood may be demonstrated. A small force-pump con- 
 nected with one end of the apparatus represents the action 
 of the heart. The large rubber tubing of one half of the 
 apparatus represents the arteries, and of the other half the 
 veins. The small passages in the sponge within the small 
 tubing, between the two parts, represent the capillaries 
 and cause the peripheral resistance. The difference in 
 structure between the arteries and the veins may be more 
 clearly shown, if the arteries are made of very elastic pure 
 rubber tubing, and the veins made of less elastic tubing 
 which has some linen fibres in its walls. The outlet at H 
 
THE CIRCULATION OF THE BLOOD. 
 
 45 
 
 represents an injury to an artery, and a cor- 
 responding outlet in the other half represents 
 an injury to a vein. 
 
 a. Connect the pump with the large ar- 
 tery, and slowly force the air out of the set 
 of tubes, and water, slightly colored red, into 
 the tubes. Imitate the action of the heart 
 with seventy-two slight strokes a minute. 
 Watch the circulation of the water through 
 the tubing. 
 
 b. Hold in the hand a large artery and 
 feel and count the pulse. Feel the pulse in 
 a small artery. How do the two compare ? 
 Feel of a capillary. Is there any pulse? 
 Feel of a small vein and then a large vein 
 for the pulse. Where is the pulse most 
 prominent? Where is it least felt? 
 
 o. Remove the stop-cock at If and con- 
 tinue the action of the pump. Is the out- 
 flow continuous or intermit- 
 tent? How does the blood flow 
 from an injury in an artery ? 
 
 d. Remove the correspond- 
 ing stop-cock in the large vein, 
 and replace the stop-cock in 
 the artery. Continue the 
 action of the pump. Is the 
 outflow continuous or inter- 
 mittent ? How does the blood 
 flow from an injury in a vein ? 
 
 e. How does the flowing of 
 
 M 
 
 A 
 
 E, 
 
 H u 
 
 ffffffn 
 
 halfway g| Mill 
 
 Fig. 4. — One fourth of the apparatus 
 to illustrate the circulation of the 
 Wood. 1, 2, and 3 are of the 12m.m. 
 rubber tubing ; 4 is of 6 m.m. rubber 
 tubing ; 5 and 6 are of 5 m.m, rubber 
 tubing; A and B are the 12 m.m. 
 three-way, y-shaped, connecting glass 
 tubing ; E is a three-way, T-shaped, 
 glass tube ; -Fis the 4 m.m. three-way, 
 y-shaped, glass tubing ; D is a three- 
 way, 7*-shaped, connecting glass tube; 
 C is the connector made from 12 m.m. 
 glass tubing, drawn down to fit the 
 rubber tubing 6 m.m. in diameter ; 
 g is of the 4 m.m. glass tubing, which 
 is filled with pieces of fine sponge, 
 or with pieces of glass rod 2 m.m. in 
 diameter. 
 
46 PHYSIOLOGY FOR THE LABORATORY. 
 
 the blood near the pump compare with the flow in the large 
 tube at the opposite end of the apparatus ? What is true 
 of the flowing of the blood in the large arteries and veins ? 
 
 III. The Use op the Peripheral Resistance. 
 
 Material. Water. A small force-pump. 
 
 Apparatus. One metre of pure rubber tubing 12 m.m. in diameter. 
 
 Connect with the pump a long piece of elastic rubber 
 tubing, and intermittently force water through it. Is the 
 outflow intermittent or continuous? Compare with the 
 result obtained when the peripheral resistance is present as 
 in II c. What is the effect of the peripheral resistance ? 
 What is the advantage of a continuous flowing of blood 
 in the body ? 
 
 IV. The Use of the Elastic Walls of the Tubes. 
 
 Material. Water. 
 
 Apparatus. A small force-pump. 
 
 50 cm. of glass tubing 12 m.m. in diameter. 
 6 cm. of rubber tubing 12 m.m. in diameter. 
 
 Connect with the pump a piece of glass tubing, and 
 intermittently force water through it. Is the outflow in- 
 termittent or continuous? 
 
 J. A Model to Show the Action of the Semilunar Valves. 
 
 Material. A piece of thick manila paper, three inches by six and 
 a half inches, strong enough for sewing, and flexible enough to bend 
 easily. A piece of white cloth about the same size. Water. 
 
 Apparatus. Two glasses. Needle and thread. 
 
 A model of the base of the aorta and the semilunar 
 valves may be made of paper and cloth. The piece of 
 
THE CIRCULATION OF THE BLOOD. 
 
 47 
 
 paper, rolled so that the short ends lap half an inch, repre- 
 sents the aorta. The three valves are nearly semicircular 
 in shape, like the outlines in dotted lines in Fig. 5. Each 
 one is two inches wide and two and a half inches deep. 
 These valves are left free at their upper edges, which 
 should be flat on the paper, and are sewed along the 
 
 Fig. 5. — A model of the semilunar valves, 
 
 continuous line marked A A A A. After the valves are 
 sewed in place, roll the paper so that B comes at C and 
 sew. Make the model twice the size of Fig. 5. 
 
 1. Hold the model in the position corresponding to the 
 
 aorta in the body. Are the valves placed upward 
 or downward on the walls of the aorta? 
 
 2. Pour water through the tube to imitate the flowing 
 
 of the blood through the aorta. 
 
 a. What is the position of the valves ? 
 
 b. What is the effect of the valves on the stream of 
 water or blood ? 
 
48 PHYSIOLOGY FOB THE LABORATORY. 
 
 3. Imitate in a similar manner any backward pressure 
 in the blood. 
 
 a. What is the effect of the water or blood on the 
 valves ? 
 
 b. What is the action of the valves ? 
 
 e. What is the effect of the valves on the stream of 
 water or blood? 
 
 d. Is your model perfect? If not, what condition of 
 the valves does it illustrate? 
 
IX. 
 
 RESPIRATION. 
 
 A. The Lungs of a Sheep. 
 
 Materials. The lungs and trachea of a sheep. A glass of water. 
 Apparatus. Blowpipe. Twine. 
 
 Study the lungs and trachea that have been reserved 
 from a former exercise. 
 
 I. The Different Parts. 
 
 
 Notice : 
 
 
 a. The lungs. 
 
 
 l. Their shape. 
 
 
 2. Their size. 
 
 
 3. Their color. 
 
 
 4. Their weight as compared with water. 
 
 Cut off 
 
 a small piece and place in water. 
 
 Explain 
 
 its action. 
 
 
 b. The trachea. 
 
 1. Its shape. 
 
 2. Its size. 
 
 8. The cartilaginous rings. "What is their size, shape, 
 and position. Do the rings reach entirely 
 around the trachea? Why? 
 
 4. The lining membrane. 
 49 
 
50 PHYSIOLOGY FOB THE LABORATORY. 
 
 5. The two branches, or the right and the left bronchus. 
 
 6. Sketch both the lungs and the trachea. 
 
 c. Insert a blowpipe in the bronchus leading to the 
 uncut lung, and tie a stout cord around it so tightly that 
 no air can escape and inflate. Note the size of the lung 
 before and after inflation. .Of what kind of tissue must 
 it be composed? 
 
 d. Dissect carefully one bronchus until its branches or 
 bronchial tubes are found. Dissect one of the large 
 bronchial tubes to the surface of the lung. 
 
 II. The Supply op Blood. 
 
 Find where the pulmonary artery and a pulmonary vein 
 enter one lung, and trace them as far as possible through 
 the lung. Make a sketch of a portion of the lung dissected 
 to show a bronchial tube, a vein, and an artery. 
 
 B. The Changes in the Air during Respiration. 
 
 Materials. Lime-water, about 250 e.o. Hydrochloric acid. 
 
 Apparatus. A thermometer. A glass tumbler. A bottle con- 
 taining about 500 cc. A rubber stopper with two holes. Glass 
 tubing to fit the holes in the stopper. 
 
 I. The Change in Temperature. 
 
 a. Take the temperature of the air in the room. 
 h. Take the temperature of expired air by breathing on 
 the bulb of a thermometer. 
 
 II. Moisture in Expired Air. 
 
 a. Breathe on a cold glass. 
 
 b. What happens ? Explain. 
 
RESPIRATION. 
 
 51 
 
 III. Carbon Dioxide in Expired Air. 
 
 a. Breathe through a tube into a glass of lime-water. 
 
 b. What occurs ? Explain and write the reaction. 
 o. What occurs when hydrochloric acid is added? 
 d. What does this prove ? 
 
 IV. Test the Air of an Ordinary Room for Car- 
 
 bon Dioxide. 
 
 Use a bottle with a rubber stopper 
 fitted with two pieces of glass tubing, 
 each bent at a right angle. One piece 
 of the tubing should reach nearly to 
 the bottom of the bottle, the other just 
 below the stopper. (See Fig. 6.) 
 
 a. Fill the bottle half full with lime- 
 water. 
 
 b. Draw the air out of the bottle 
 through the short tubing. 
 
 c. What happens ? Why ? 
 
 Fro. 6. — Apparatus for 
 testing air for car- 
 bon dioxide. 
 
 C. Experiments on the Student's Body. 
 Apparatus. A watch. A tape-measure. 
 
 I. The Number of Respirations. 
 
 Count the number of respirations in a minute under 
 ordinary conditions. Count the number after running. 
 
 II. The Size of the Chest during Respiration. 
 
 Measure the chest by passing a tape across the chest 
 and around just under the arms to the middle of the back. 
 
52 
 
 PHYSIOLOGY FOR THE LABORATORY. 
 
 Take a long, deep inspiration, hold the breath, and 
 measure again. 
 
 Give some idea of the difference in cubic capacity, which 
 this difference in circumference represents. 
 
 D. Models to Illustrate the Principles of Breathing. 
 
 Note. — Adapted from Hints for Teachers of Physiology by 
 Professor Bowditeh. 
 
 I. The Vbbtical Enlargement op the Thoeax. 
 
 Apparatus. A glass bottle without the bottom, or a lamp- 
 chimney. A piece of rubber dam about half an inch larger than 
 the lower part of the chimney. A toy rubber balloon used by small 
 boys, called a "squawker," or another piece of 
 rubber dam about six inches in diameter. A 
 rubber stopper, with two holes in it, to fit the 
 upper end of the chimney. About twelve inches 
 of glass tubing to fit the holes in the stopper. 
 A pinch-cock. Linen thread. Three inches of 
 rubber tubing to fit the glass tubing. A stout 
 rubber band. 
 
 The apparatus should be put together 
 very carefully, as in Fig. 7, to prevent 
 the escape of air. 
 
 a. The chimney represents the chest 
 cavity. 
 
 b. With an elastic band fasten over the lower end of 
 the chimney a piece of rubber dam to represent the 
 diaphragm. 
 
 e. Into the upper end of the chimney fit the rubber 
 stopper containing two pieces of glass tubing, each bent at 
 a right angle. Attach the toy balloon (or the trachea and 
 
 Pig. 7. — A model to 
 show the vertical 
 enlargement of the 
 thorax. 
 
RESPIRATION. 
 
 53 
 
 lungs may be substituted in the place of the balloon) to 
 the inner end of one piece of the glass tubing. Slip a 
 piece of rubber tubing three inches long over the outer 
 end of the other piece of glass tubing, and put the pinch- 
 cock on the rubber tubing. 
 
 d. Partially exhaust the air from the bottle by sucking 
 through the rubber tubing, then close the pinch-cock. 
 This represents the condition in the thorax. 
 
 e. Lower and raise the rubber diaphragm. Notice what 
 occurs and explain. 
 
 II. The Dorso-Ventral Enlargement or the 
 Thorax. 
 
 Apparatus. Six pieces of cardboard or thin wood six inches long 
 and one inch wide. Two light rubber bands. Eight fasteners. 
 Four hooks. 
 
 Fasten four parallel pieces of stiff cardboard at right 
 angles to two parallel bars so that they may be moved at 
 the fastenings. Place the hooks at 1, 2, 
 3, and 4 (Fig. 8) so that a line connecting 
 1 and 2 shall be at right angles to one 
 connecting 3 and 4. The elastic bands 
 shall be so short as to be put on the 
 stretch when placed over the hooks. The 
 longest piece represents the spinal col- 
 umn. The shortest piece represents the FlG - 8 -~ A model to 
 
 , show the dorso-ven- 
 
 sternum. The three or four pieces of trai enlargement of 
 equal length, movable at either end, rep- the thorax - 
 resent the ribs. The band 1—2, running obliquely down- 
 ward and forward, represents the external intercostal 
 
54 PHYSIOLOGY FOB THE LABORATORY. 
 
 muscles. The band 3-4, running obliquely downward and 
 backward, represents the internal intercostal muscles. 
 
 a. Stretch a band over the hooks 1-2. What change is 
 there in the position of the horizontal pieces of cardboard? 
 What effect does the contraction of the external intercostal 
 muscles have on the ribs and on the chest cavity ? 
 
 b. Remove the band from hooks 1-2 and stretch it over 
 hooks 3—4. What change is there in the position of the 
 pieces of cardboard? What is the effect of the contrac- 
 tion of the internal intercostal muscles ? 
 
 III. The Lateral Enlargement op the Thorax. 
 
 In the body the ribs are curved, instead of being straight 
 as represented in Fig. 8, and as they rise during inspiration, 
 they also bulge outward, thus increasing at the same time 
 the lateral dimension of the chest cavity. 
 
X. 
 
 THE ORGANS OF DIGESTION. — THE TEETH 
 AND THE TONGUE. 
 
 A. The Parts of a Tooth. 
 Material. A human incisor tooth. 
 
 Specimens of the different kinds of human teeth may 
 be obtained of a dentist. 
 
 Study an incisor tooth with reference to the different 
 parts. 
 
 Observe : 
 
 a. The crown is the upper part seen in the mouth. 
 
 b. The root, or fang, is the part embedded in the jaw- 
 bone. 
 
 c. The neck is a narrow part between the crown and 
 the root, embraced by the edge of the gum. 
 
 d. The hole is at the tip of the root. What is its use ? 
 
 e. Sketch a side view. 
 
 B. The Structure of a Tooth. 
 
 Material. A slide showing a longitudinal section of a human 
 incisor tooth. 
 
 Apparatus. A magnifying glass. A compound microscope. 
 
 1. Study with a magnifying glass a prepared microscopical 
 slide of a longitudinal section of an incisor tooth. 
 55 
 
56 PHYSIOLOGY FOR THE LABORATORY. 
 
 Observe : 
 
 a. In the centre is the pulp cavity, which is filled during 
 life with a soft pulp containing blood-vessels and nerves. 
 
 b. The dentine is the hard part around the pulp cavity. 
 
 c. The enamel covers the dentine on the crown. How 
 far does it extend? 
 
 d. The cement covers the dentine on the root. How far 
 does it extend? 
 
 e. Sketch. 
 
 2. Study the same slide with the compound microscope, 
 and observe the structure of the different parts. 
 
 C. The Different Kinds of Teeth. 
 
 Materials. An incisor, a canine, a bicuspid, and a molar tooth. 
 
 1. Identify the following kinds of teeth : 
 
 a. The incisor with a wedge-shaped crown. 
 
 b. The canine with a pointed crown. 
 
 c. The bicuspid, or premolar, with a cuboidal crown. 
 
 d. The molar with an irregular crown. 
 
 e. Sketch one tooth of each kind. 
 
 2. Compare the parts in the different teeth. 
 
 a. How many cusps or points has each ? 
 
 b. How many fangs has each ? 
 
 3. Arrange them on the table as they are in the jaw. 
 
 4. A dental formula is often used as a short method to 
 
 indicate the number of teeth. The numerator 
 indicates the number of teeth in one side of the 
 
THE TEETH AND THE TONGUE. 57 
 
 upper jaw, and the denominator the number in one 
 side of the lower jaw; as, If, C3J-. If indicates 
 that there are two incisor teeth in one side of the 
 upper jaw and three in one side of the lower jaw. 
 
 a. Write the formulae for the premolar and the molar 
 teeth. 
 
 b. What are the wisdom teeth ? 
 
 D. The Teeth of the Lower Animals. 
 
 Materials. The teeth of a horse or cow. The teeth of a cat or 
 dog. 
 
 1. Study the teeth of an herbivorous animal and compare 
 
 them with the human teeth. 
 
 2. Study the teeth of a carnivorous animal and compare 
 
 them with both the preceding. 
 
 E. The Tongue. 
 Apparatus. A hand-mirror. 
 
 With a hand-mirror examine your own tongue. 
 Notice : 
 
 a. The small papillae that cover most of the upper sur- 
 face of the tongue are the filiform papillae. 
 
 b. The larger papillae that are scattered occasionally 
 over the surface are the fungiform papillae. 
 
 c. The very large papillae, or the circumvallate papillae, are 
 situated as far back on the tongue as you can see. How 
 are they arranged? 
 
 d. Sketch. 
 
XI. 
 OTHER ORGANS OF DIGESTION. 
 
 The Digestive Organs of the Rabbit. 
 A. The General Plan of the Body — Preliminary. 
 
 Materials. A live rabbit. Chloroform. Cotton batting. Water. 
 Apparatus. An air-tight jar or box just large enough to hold 
 the rabbit. 
 
 Kill the rabbit by placing it in an air-tight box with 
 some cotton batting saturated with chloroform. When 
 ready for dissection, lift the skin of the ventral side and 
 make a cut along the median line from near the base of 
 the tail forward to the breast-bone. Cut through the 
 skin, and also through the body-wall. At the posterior 
 and anterior ends of the slit make cross-cuts extending 
 nearly around to the spinal column on either side and lay 
 back the flaps of the skin. 
 
 Notice : 
 
 a. The larger cavity at the posterior end of the body 
 is the abdominal cavity and contains all the visceral 
 organs. 
 
 b. The smaller cavity toward the anterior end of the 
 body is the thoracic cavity. 
 
 58 
 
OTSES, ORGANS OF DIGESTION. 59 
 
 o. The large circular muscle is the diaphragm and sepa- 
 rates the thoracic and the abdominal cavities. 
 d. Sketch. 
 
 B. The Alimentary Canal. 
 
 I. The Teeth. 
 
 Examine the teeth and compare them with the human 
 teeth. 
 
 a. How many incisor teeth are there ? 
 
 1. What is peculiar about them ? 
 
 2. What is the purpose of this ? 
 
 b. How many canine teeth has the rabbit? 
 
 c. Find the premolar teeth. 
 
 d. Are there any molar teeth? 
 
 e. What is the dental formula of the rabbit? 
 
 II. The Mouth, or Buccal Cavity. 
 Notice its general shape and size. 
 
 III. The Pharynx, or Throat Cavity. 
 
 a. Can you find the nasal openings on the dorsal surface ? 
 
 1. How many are there? 
 
 b. Look carefully on the sides for the openings into 
 the Eustachian tubes. Pass a bristle along one tube into 
 the middle ear. 
 
 c. On the ventral surface of the pharynx look for the 
 opening into the windpipe, — the glottis. Which way 
 does the lid, or epiglottis, open ? 
 
60 PHYSIOLOGY FOR THE LABORATORY. 
 
 d. Find the opening into the gullet, or oesophagus. Is 
 it ventral or dorsal to the glottis ? 
 
 e. Sketch. 
 
 IV. The (Esophagus. 
 
 Trace the tube from its opening in the pharynx to the 
 stomach. 
 
 a. Through what cavity does it pass ? 
 
 b. Through what part of the cavity ? 
 
 c. Through what muscle does it extend ? 
 
 d. Is it the same size throughout? 
 
 Xote. — A few minutes may well be spent in identifying and 
 reviewing the lungs, trachea, heart, and main blood-vessels, since the 
 organs are here intact. 
 
 V. The Stomach. 
 
 The stomach will be found just beneath the diaphragm. 
 
 a. What is its shape and color? 
 
 b. What is its position in relation to the surrounding 
 organs ? 
 
 c. Does the oesophagus open into the broad or the 
 narrow end of the stomach? 
 
 d. This opening between the oesophagus and the stomach 
 is the cardiac orifice, and this end of the stomach is the 
 cardiac end of the stomach. 
 
 1. Is it on the right or the left side of the 
 
 body? 
 
 2. Why is it called the cardiac end of the stomach ? 
 
 e. From which end of the stomach does the small intes- 
 tine lead? The opening between the intestine and the 
 
OTHER ORGANS OF DIGESTION. 61 
 
 stomach is the pyloric orifice, and this is the pyloric end of 
 the stomach. 
 
 1. On which side of the body is this end of the 
 
 stomach ? 
 
 2. What lies between the pyloric end of the stomach , 
 
 and the diaphragm ? 
 
 VI. The Small Intestine. 
 
 The small intestine extends from the stomach to the large 
 intestine. 
 
 a. Is it the same size throughout? 
 
 b. "What is its position in relation to the other organs ? 
 
 c. What holds it in position ? 
 
 d. What color is it? 
 
 VII. The Large Intestine. 
 
 The remaining part of the alimentary canal is the large 
 intestine. It is composed of three parts — the ccecum, the 
 colon, and the rectum. 
 
 a. The smaller intestine opens into the side of the large 
 intestine, leaving one end of the latter free in the body 
 cavity. This free end is the ccecum, and is much larger in 
 the rabbit than in man. What color is it ? 
 
 l. Opening from the end of the ccecum is a small 
 tube, the vermiform appendix. Inflammation of 
 this part causes appendicitis. 
 
 b. The colon begins at the opening from the small intes- 
 tine, and extends nearly to the end of the alimentary 
 canal. It is the longest part of the large intestine.. 
 
62 PHYSIOLOGY FOR THE LABORATORY. 
 
 1. What is its position in the abdominal cavity? 
 
 2. Is it the same size throughout? 
 
 3. What color is it ? 
 
 c. Near the end of the alimentary canal the colon 
 passes into the rectum. 
 
 VIII. The Livek. 
 
 There are several glands along the alimentary canal 
 that aid in digestion, the largest of which is the liver. 
 
 a. How many lobes has the liver? 
 
 b. Are they all of the same size? 
 
 c. What is their position ? 
 
 IX. The Gall Bladder. 
 
 Raise the lobes of the liver and find the small gall bladder. 
 It is often green in color. Look for the common bile duct 
 leading from the liver and gall bladder to the small intestine. 
 
 X. The Spleen. 
 
 Near the broad end of the stomach find the spleen, an 
 elongated dark-red body held in place by the thin mem- 
 brane or mesentery. 
 
 XI. The Pancreas. 
 
 Another gland, a pale-red pancreas, lies in the mesentery 
 in a fold of the small intestine. Look for the opening of 
 the pancreatic duct on the inner wall of the intestine about 
 a foot from the pyloric orifice. Pass a probe into the duct. 
 
 XII. The Mesentery. 
 
 Spread out the intestines and notice the mesentery. 
 
OTHER ORGANS OF DIGESTION. 63 
 
 a. What is its use ? 
 
 b. What do you find in it ? 
 
 c. Has it any connection with the peritoneum, or lining 
 of the abdominal cavity? 
 
 XIII. The Entire Alimentary Canal. 
 
 Remove the entire alimentary canal and straighten it 
 out on the table. 
 
 a. Measure the various parts. 
 
 b. How do they compare one with another ? 
 
 <?. How do they compare with the length of the body 
 cavities ? 
 
 d. Sketch. 
 
 C. A Detailed Study of the Different Organs. 
 
 Material. A dissected rabbit. 
 Apparatus. A magnifying glass. 
 
 With the scissors make a small cut in the walls of the 
 oesophagus, the stomach, the small and large intestines. 
 Wash out the contents. 
 
 Study : 
 
 I. The Wall of the (Esophagus. 
 
 a. The muscular coat on the outside. 
 
 b. The mucous lining within. 
 
 II. The Wall of the Stomach. 
 
 a. The muscular coat on the outside. 
 
 b. The mucous coat. Look with the magnifying glass 
 for shallow pits over the surface of the mucous lining. 
 These contain the openings of the gastric glands that will 
 
64 PHYSIOLOGY FOB THE LABORATORY. 
 
 be seen later with the compound microscope. In what 
 part of the stomach are they most numerous? 
 
 III. The Wall of the Small Intestine. 
 
 a. The muscular coat. 
 
 b. The mucous lining. 
 
 c. Look for irregular folds running transversely around the 
 intestine called the valvulae conniventes. What is their use ? 
 
 d. With a magnifying glass examine carefully the sur- 
 face of the mucous lining, until you find small conical 
 elevations, or villi. 
 
 e. Sketch. 
 
 IV. The Wall of the Large Intestine. 
 
 a. The muscular coat. 
 
 b. The mucous lining. What do you find on this ? 
 Compare with the small intestine. 
 
 D. The Microscopical Structure of the Alimentary Canal. 
 
 Materials. Microscopical slides showing cross-sections of the walls 
 of the stomach, the small intestine, the pancreas, and of the liver. 
 Apparatus. Compound microscope. 
 
 I. The Microscopical Structure of the Wall of 
 the Stomach. 
 
 Examine with the compound microscope a cross-section 
 of the wall of the pyloric end of the stomach. 
 Notice : 
 a. The muscular coat. 
 
 1. Which way do the fibres extend? 
 
 2. How thick is the coat compared with the thick- 
 
 ness of the entire wall? 
 
OTHER ORGANS OF DIGESTION. 65 
 
 b. The mucous coat. 
 
 1. How thick is this coat? 
 
 2. Do you find the shallow pits on the surface? 
 
 3. The long tubes opening on the inner surface are 
 
 the gastric glands. 
 
 c. The submucous coat lies between the mucous and 
 the muscular coats. What do you find here? 
 
 d. Sketch. 
 
 II. The Microscopical Structure op the Wall 
 of the Small Intestine. 
 
 Examine with the compound microscope a cross-section 
 of the wall of the small intestine that has been injected. 
 
 Notice : 
 
 a. The muscular coat. 
 
 1. How thick is it? 
 
 2. Which way do the fibres extend? 
 
 b. The mucous coat. 
 
 1. Is it as thick as that of the stomach ? 
 
 2. Do you find the villi? Notice the blood-vessels 
 
 in them. The lacteal is the large vessel in 
 the centre of each villus. 
 
 3. The tubular glands opening on the inner surface 
 
 are the crypts of Lieberkiihn. 
 
 c. The submucous coat is just beneath the mucous coat. 
 What does this contain ? 
 
 d. Sketch. 
 
66 PHYSIOLOGY FOB THE LABORATORY. 
 
 III. The Microscopical Structure op the Pan- 
 
 creas. 
 Examine a cross-section of pancreas. 
 Observe : 
 
 a. The arrangement of the cells in circular groups. Each 
 group is a cross-section of an alveolus, or tube formed by 
 secreting cells. 
 
 b. A small opening, or duct, is in the centre of each alve- 
 olus, but is hardly visible, being filled by spindle-shaped 
 cells. 
 
 c. The alveoli are grouped around larger ducts to form 
 lobules, which in turn unite to form the lobes of the pancreas. 
 
 d. The lobes, the lobules, and the alveoli are bound 
 together by connective tissue carrying the blood-vessels. 
 
 e. Sketch and label the various parts. 
 
 IV. The Microscopical Structure op the Liver. 
 Examine in the same way a cross-section of liver. 
 Observe : 
 
 a. The hepatic cells of which the liver is everywhere 
 composed. What parts of the cell can you distinguish? 
 How are they arranged? 
 
 b. An hepatic veinlet is seen in section in the centre of 
 each group or lobule of hepatic cells. Whither does this 
 blood-vessel lead? 
 
 c. Branches of the portal vein and hepatic artery may be 
 traced in the connective tissue between the lobules. 
 
 d. The bile ducts are small tubes lined with a single 
 layer of cuboidal cells. What is their use? 
 
 e. Sketch. 
 
XII. 
 
 FOODS. 
 
 All foods consist primarily of water, proteids or protein, 
 fats, carbohydrates, and inorganic salts. 
 
 A. Water in Foods. 
 
 Materials. Potato. Carrot. Turnip. Cabbage. Apple. 
 Apparatus. Oven. Standard Fairbanks scales. 
 
 I. Water in Potatoes. 
 Experiment: 
 
 1. Wash a potato thoroughly and dry it. 
 
 2. Weigh it. 
 
 3. Heat it in an oven or on the radiator until com- 
 
 pletely dried. Take care not to burn it. 
 
 4. Weigh it again. 
 
 5. Calculate the per cent of water in potato. 
 
 II. Water in Other Vegetables. 
 Experiment : 
 
 1. In the same way examine carrot, turnip, onion, 
 
 cabbage, or apple, and calculate the per cent 
 of water. 
 
 2. Compare your result with a list of food com- 
 
 positions. 
 
 67 
 
68 PHYSIOLOGY FOR TEE LABORATORY. 
 
 B. Carbohydrates in Foods — Starch. 
 
 I. The Iodine Test foe Staech. 
 
 Materials. A few grains of starch. An aqueous or alcoholic 
 solution of iodine. Water. 
 
 Apparatus. A test-tube. Bunsen burner. 
 
 Experiment : 
 
 1. Thoroughly mix the starch with about lOc.c. of 
 
 cold water. 
 
 2. Dilute, boil, and cool. 
 
 3. Add a few c.e. of iodine solution. 
 
 4. Dilute again if the color is very dark. Boil 
 
 and cool. 
 
 II. Staech in Potato. 
 
 Materials. Potato. Water. Iodine solution (either aqueous or 
 alcoholic) . 
 
 Apparatus. Evaporating dish. Knife. Bunsen burner. 
 
 Experiment : 
 
 1. Wash thoroughly a potato and peel it. 
 
 2. Grate or slice it very thin and wash in an 
 
 evaporating dish. 
 
 3. Collect the white sediment. 
 
 4. Boil some of this with water. 
 
 5. Test for starch with iodine. 
 
 III. The Stktjctuee oe the Staech Geains of the 
 
 Potato. 
 
 Materials. A few starch grains just washed from a potato. 
 Apparatus. Glass slide. Cover-glass. Compound microscope. 
 
FOODS. 69 
 
 Mount a drop of water containing a few grains of starch 
 and examine with the compound microscope. 
 
 Observe : 
 
 a. The shape of the grains. 
 
 b. Their concentric structure. 
 
 c. The hilum or centre of the curves. 
 
 d. Sketch. 
 
 Run a drop of iodine solution under the cover-glass and 
 notice the change in the grains of starch. 
 
 IV. Starch in Other Foods. 
 
 Materials. Beans. Peas. Oatmeal. Tapioca. Farina. Rice. 
 Cornstarch. Sago. Barley. Indian meal. Wheat flour. Rye. 
 Crackers. Bread. Iodine solution. 
 
 Apparatus. Test-tubes. Test-tube rack. Filter-paper. Funnel. 
 Evaporating dish. Bunsen burner. 
 
 Experiment : 
 
 Examine for starch one of the following : 
 
 Beans, peas, oatmeal, tapioca, farina, rice, cornstarch, 
 sago, barley, Indian meal, wheat flour, rye, crackers, and 
 bread. 
 
 1. Make a paste by grinding and mixing with cold 
 
 water. 
 
 2. Add hot water and thoroughly mix. 
 
 3. Filter when necessary. 
 
 4. Test the filtrate for starch with the iodine test. 
 
70 PHYSIOLOGY FOB THE LABORATORY. 
 
 Carbohydrates in Foods — The Sugars. 
 
 V. Test foe Dextrose, Gbape Sugae — Fehling's 
 
 Solution. 
 
 Materials. 15 c.c. of Fehling's solution, which is a solution of 
 alkaline potassio-tartrate of copper K !! Cu(C 1 H 4 6 ) ! ,. Three grapes. 
 Water. 
 
 Apparatus. Test-tubes. Bunsen burner. Mortar and pestle. 
 Funnel and filter-paper. 
 
 Experiment : 
 
 1. Boil 15 c.c. of Fehling's solution in a test-tube. 
 
 If no yellow color appears, the solution is in 
 good condition. 
 
 2. Thoroughly mix with water in a mortar three or 
 
 four grapes. 
 
 3. Filter. 
 
 4. Test the filtrate for a reducing sugar as follows : 
 6. Add 1 c.c. of the filtrate to the Fehling's solu- 
 tion and boil. What color is the precipitate 
 cuprous oxid, CiijO? The sugar acts as a 
 reducing agent and changes the cupric salt 
 to a cuprous salt. This is characteristic of 
 dextrose, but there are other sugars, as maltose 
 and lactose (milk-sugar), that reduce metallic 
 salts, although in a less degree. 
 
 VI. Test foe Dexteose — Baefoed's Solution. 
 
 Materials. 15 c.c. of Barfoed's solution, which is a solution of 
 acetate of copper in water acidulated with acetic acid. 5 c.c. of a 
 solution of dextrose. 
 
 Apparatus. Test-tubes. Bunsen burner. 
 
FOODS. 71 
 
 Experiment : 
 
 To the Barfoed's solution in a test-tube add the solu- 
 tion of dextrose and boil. What color is the precipitate ? 
 What is it ? This test distinguishes dextrose from lactose, 
 maltose, and cane-sugar, which do not reduce Barfoed's 
 solution when boiled with it for a short time. 
 
 VII. Saccharose, Cane-Sugar, and Fehling's Solu- 
 
 tion. 
 
 Materials. A few grains of cane-sugar. 15 c.c. of Fehling's solu- 
 tion. Water. 
 
 Apparatus. Test-tubes. Bunsen burner. 
 
 Experiment : 
 
 1. Boil the Fehling's solution in a test-tube. 
 
 2. Dissolve the sugar in 10 c.c. of water. 
 
 3. Add the solution of sugar to the Fehling's solu- 
 
 tion and boil. What happens ? Does saccha- 
 rose reduce Fehling's solution? 
 
 VIII. The Action op Hydrochloric Acid upon 
 Saccharose, Cane-Sugar. 
 
 Materials. 100 c.c. of a strong solution of cane-sugar. 10 c.c. of 
 strong hydrochloric acid. 15 c.c. of Fehling's solution. 
 
 Apparatus. A glass flask. Bunsen burner. Ring-stand. Wire gauze. 
 
 Experiment : 
 
 1. To the solution of cane-sugar in the flask add 
 
 the hydrochloric acid. 
 
 2. Boil one hour or more and cool. 
 
 Caution. ' Never add hot caustic soda or potash to an acid. 
 
 3. Test 5 c.c. of the boiled solution for a reducing 
 
 sugar. 
 
72 PHYSIOLOGY FOB THE LABORATORY. 
 
 * 
 
 IX. The Action of Hydrochloric Acid upon Starch. 
 
 Materials. A few grains of starch. 2c.c. of hydrochloric acid. 
 15 c.c. of Fehling's solution. Water. 
 
 Apparatus. Test-tubes. Bunsen burner. 
 
 Experiment : 
 
 1. Mix the starch with 5 c.c. of water. 
 
 2. Add the hydrochloric acid. Boil and cool. 
 
 3. Add the Fehling's solution and boil. What 
 
 occurs? Into what has some of the starch 
 been changed? 
 
 X. Examine Foods for Dextrose. 
 
 Examine maple sugar, syrup, molasses, dates, and 
 prunes for dextrose. 
 
 XI. The Taste of the Sugars. 
 
 Taste a small amount of dextrose, saccharose, and lactose 
 and determine which is the sweetest. 
 
 C. Proteids in Foods. 
 I. General Tests for Proteids. 
 
 Egg-albumin, or the white of an egg, is a proteid. Try 
 the following tests for proteids upon some raw white of 
 egg diluted with water. 
 
 a. Mrst test : Xanthoproteic Reaction. 
 
 Materials. 5 c.c. of egg-albumin diluted with water. 5 c.c. of 
 concentrated nitric acid. 5 c.c. of ammonium hydrate. 
 
 Apparatus. Test-tubes. Test-tube rack. Bunsen burner. 
 
 Experiment : 
 
 Add the nitric acid to the proteid and heat. What 
 
FOODS. 73 
 
 happens ? Cool under the faucet and add the ammonium 
 hydrate. What happens ? The color is characteristic. 
 
 b. Second test : Piotrowski's Reaction. 
 
 Materials. 5 c.c. of proteid solution. 10 c.c. of a concentrated 
 solution of sodium hydrate. 2-3 drops of a one per cent solution of 
 cupric sulphate. 
 
 Apparatus. Test-tubes. Test-tube rack. Bunsen burner. 
 
 Experiment : 
 
 To the proteid solution add the sodium hydrate and 
 then the cupric sulphate. What color is obtained ? Boil. 
 What change is there in the color ? This test detects the 
 smallest traces of all proteids. 
 
 c. Third test. 
 
 Materials. 5 c.c. of proteid solution. 5 c.c. of acetic acid. 3-4 
 drops of potassium ferrocyanide. 
 Apparatus. Test-tubes. 
 
 Experiment : 
 
 To the proteid solution add the acetic acid and then 
 the ferrocyanide. What occurs ? 
 
 II. Examine Milk foe Pkoteids. 
 
 Materials. 10 c.c. of milk. 40 c.c. of water. 5 c.c. of acetic 
 acid or vinegar. 10 c.c. of lime-water. 10 c.c. of a concentrated 
 solution of sodium hydrate. 2-3 drops of a dilute solution of cupric 
 sulphate. 
 
 Apparatus. Test-tubes. Test-tube rack. Bunsen burner. Filter- 
 paper. Funnel. 
 
 Experiment : 
 
 1. Dilute the milk with the water and add the 
 acetic acid. What happens? This precipi- 
 tate is the proteid, casein. 
 
74 PHYSIOLOGY FOB THE LABORATORY. 
 
 2. Filter. What is the filtrate ? 
 
 3. Add a little of the casein to water and shake. 
 
 Is the casein soluble in water? 
 
 4. Add a little of the casein to lime-water and 
 
 shake. Is it soluble? 
 
 5. Test milk by the second method above for 
 
 proteid. 
 
 6. Boil some milk. Does the casein coagulate? 
 
 Compare, this result with the action of heat 
 upon egg-albumin. 
 
 III. Test Cheese foe Proteids. 
 
 Materials. A small piece of cheese. 25 c.c. of lime-water. 10 c.c. 
 of sodium hydrate (concentrated). 2 or 3 drops of cupric sulphate. 
 
 Apparatus. Test-tube. Filter-paper. Funnel. Bunsen burner. 
 Evaporating dish. 
 
 Experiment : 
 
 1. Thoroughly mix a small piece of cheese with 
 
 about 25 c.c. of lime-water. 
 
 2. Filter. Is the proteid in the precipitate or 
 
 filtrate ? 
 
 3. Test for proteid by the second test above. 
 
 4. From what is cheese made? 
 
 5. What proteid is in milk ? 
 
 6. What proteid is in cheese ? 
 
 IV. Examine Muscle foe Peoteids. 
 
 Materials. A piece of lean beef. 25 c.c. of 10 per cent solution 
 of ammonium chloride. Lime-water. 20 c.c. of a concentrated solu- 
 tion of sodium hydrate. 4-6 drops of cupric sulphate. Alcohol, 75 
 per cent solution. 
 
 Apparatus. Evaporating dish. Filter-paper. Test-tube. Bun- 
 sen burner. Funnel. 
 
FOODS. 75 
 
 Experiment : 
 
 1. Thoroughly wash and mince a piece of lean 
 
 beef. 
 
 2. Save the washings and test for proteid. 
 
 3. Mix the meat with ammonium chloride. The 
 
 ammonium chloride dissolves the proteid, 
 myosin, in the muscje. 
 
 4. Filter. Is the myosin in the precipitate or 
 
 filtrate ? 
 
 5. Test part of the filtrate for proteids by the 
 
 second test. 
 
 6. Add alcohol to part of the filtrate until a pre- 
 
 cipitate is formed. Myosin is insoluble in 
 alcohol. What is the precipitate? 
 
 7. Heat in a test-tube some of the solution of 
 
 myosin. Notice what change takes place, 
 and compare the result with the effect of 
 heat upon egg-albumin and casein. 
 
 D. Fats in Foods. 
 I. An Emulsion. 
 
 Materials. Water. 5 c.c. of olive oil. 2 small pieces of butter. 
 An egg. 
 
 Apparatus. Test-tubes. Evaporating dish. Bunsen burner. 
 
 Experiment : 
 
 1. Add 2 c.c. of oil to about 10 c.c. of water. 
 
 What occurs? Why? 
 
 2. Add a piece of butter to 10 c.c. of water. What 
 
 occurs ? Why ? Why does cream rise ? 
 
 3. Repeat experiment 2 with melted butter. 
 
76 PHYSIOLOGY FOB THE LABORATORY. 
 
 4. Melt the butter and add it to the white of an 
 egg. Beat them together. Add the water 
 and beat again. Does the butter and water 
 mix? Why? This is an emulsion. Of what 
 advantage is it in digestion ? 
 
 II. The Emulsion of Fat in Milk. 
 
 Materials. 1-2 c.c. of nrijk. 
 
 Apparatus. A glass slide. A cover-glass. Compound microscope. 
 
 Mount a drop of milk and examine under the microscope. 
 
 Notice : 
 
 a. The fat globules. 
 
 b. The liquid. 
 
 c. Sketch. 
 
 d. In what form is the fatty portion of the milk? Is 
 this an advantage or a disadvantage in digestion? Why? 
 Compare the results obtained from C. II, and infer what 
 it is that renders milk so valuable as a food. 
 
 III. The Extraction op Fat prom Foods. 
 
 Materials. Indian meal. Whole wheat flour. Common flour. Benzine. 
 Apparatus. Evaporating dish. Filter-paper. Funnel. 
 
 Extract the fat from the Indian meal, whole wheat 
 flour, and common flour. 
 Experiment : 
 
 1. Mix the Indian meal with benzine or ether. 
 
 2. Filter and allow a drop of the filtrate to evapo- 
 
 rate on a piece of clean glass. What is left? 
 Prove that this contains fat. What, then, is 
 one of the food constituents of Indian meal? 
 
 3. Test in the same way the whole wheat and com- 
 
 mon flour. Which contains the most fat? 
 
XIII. 
 DIGESTION. 
 
 The Effect of the Digestive Fluids on Foods. 
 A. The Saliva. 
 
 I. The Microscopical Examination of Saliva. 
 
 Material. Saliva. 
 
 Apparatus. A test-tube. A glass slide and cover-glass. A com- 
 pound microscope. 
 
 Collect half a test-tube of, saliva. Mount a drop on the 
 glass slide and examine with the compound microscope. 
 
 Notice : 
 
 a. The epithelial cells. Where did they come from ? 
 
 b. Possibly, debris of food. 
 
 c. Forms of bacteria. 
 
 II. The Effect of Saliva on Stakch. 
 
 Materials. Potato starch. Saliva. 
 
 Apparatus. Warm water-bath, or one made of a large beaker. 
 A Bunsen burner. A ring-stand. A piece of wire gauze six inches 
 square. A thermometer. Test-tubes and rack. 
 
 Prepare a warm water-bath by filling the beaker to a 
 depth of three or four inches with water, and placing it 
 on the wire gauze on the ring-^tand, over the Bunsen 
 burner. Stand the thermometer in the water and keep 
 it at a temperature of 42° C. 
 
 77 
 
78 PHYSIOLOGY FOB THE LABORATORY. 
 
 Experiment : 
 
 1. Make a dilute starch paste of pure potato starch 
 
 and boil for a few minutes. One grain of 
 starch to 200 c.c. of water is sufficient. 
 
 2. Dilute 5 c.c. of saliva with 25 c.c. of water. 
 
 3. Place one of the following solutions in each of 
 
 three test-tubes : 
 
 (1) 20 c.c. of starch paste. 
 
 (2) 20 c.c. of diluted saliva. 
 
 (3) 5 c.c. of saliva and 15 c.c. of starch 
 
 paste. 
 
 4. Place in the warm bath for ten minutes and then 
 
 test each for maltose. What is the effect of 
 saliva on starch ? Why was the mixture kept 
 at a temperature of 42° C. ? 
 
 B. The Gastric Juice. 
 I. The Preparation op Artificial Gastric Jttcce. 
 
 Materials. £ a gram of " pepsin. 2 c.c. of strong hydrochloric 
 
 acid. 50 c.c. of water. 
 
 Apparatus. A small beaker. A warm water-bath and ther- 
 mometer. 
 
 The essential constituents of gastric juice are hydrochloric 
 acid, pepsin, and rennin. As far as we know, the action of 
 rennin is confined to the curdling of milk, so that a solution 
 of pepsin, slightly acidulated with hydrochloric acid, rep- 
 resents the action of the normal gastric juice on proteids. 
 
 Experiment : 
 
 Mix the water, the acid, and the pepsin in the beaker 
 and place this in a warm water-bath. Insert the ther- 
 
DIGESTION. 79 
 
 mometer and keep the temperature at 100° F. or 42° C. 
 The body temperature is about 38° C. 
 
 II. The Action op Gasteic Juice on Peoteids. 
 
 Materiajs. Egg-albumin. Artificial gastric juice. Water. 
 Apparatus. Evaporating dish. Glass stirring rod. Test-tubes 
 and rack. Warm water-bath and thermometer. 
 
 Caution. Label all of your test-tubes. 
 
 Experiment : 
 
 1. (Preliminary) Heat some water in an evaporating 
 
 dish. Into this drop a little well-shaken egg- 
 albumin and stir constantly. 
 
 2. Add a small piece of the coagulated albumin, 
 
 not minced, to 10 c.c. of gastric juice. Keep 
 it cool and still. 
 
 3. Add a small piece of the egg-albumin, minced, to 
 
 10 c.c. of gastric juice. Place it in the water- 
 bath but keep it still. 
 
 4. Add the same amount of minced egg-albumin 
 
 to 10 c.c. of gastric juice. Keep at 42° C, but 
 shake often to imitate the action of the stomach. 
 Compare the three results at the end of two 
 hours. What three conditions aid digestion ? 
 
 III. Aee both Acid and Pepsin Necessary to 
 
 Digestion ? 
 
 Materials. Coagulated egg-albumin. Water. Dilute hydrochloric 
 acid. Pepsin. 
 
 Apparatus. Test-tubes. Warm water-bath. 
 
 Place a small piece of coagulated egg-albumin in each 
 of four test-tubes. 
 
80 PHYSIOLOGY FOB THE LABORATORY. 
 
 Experiment : 
 
 1. To the first test-tube add 10 c.c. of water. 
 
 2. To the second test-tube add 10 c.c. of dilute 
 
 hydrochloric acid. 
 
 3. To the third test-tube add 10 c.c. of pepsin and 
 
 water. 
 
 4. To the fourth test-tube add 10 c.c. of pepsin 
 
 and dilute hydrochloric acid. 
 6. Place all the test-tubes in the warm bath and 
 notice the results at the end of one or two 
 hours. 
 
 IV. The Action of Gastkic Juice on Milk. 
 
 Materials. 10 c.c. of milk. 10 c.c. of water. A few grains of 
 pepsin. Rennet. 
 
 Apparatus. Test-tubes. Warm water-bath. 
 
 When the milk reaches the stomach it is first acted 
 upon by the rennin and then by the pepsin and hydro- 
 chloric acid. 
 
 Experiment : • 
 
 1. The action of the rennin. (Rennin is the essen- 
 
 tial element of rennet, which is obtained from 
 the fourth stomach of the calf.) Add 4 or 5 
 drops of rennet to the milk in a test-tube, 
 and allow it to stand a few minutes in the 
 warm water-bath. What is the curd and the 
 whey ? What is the action of rennin on milk ? 
 
 2. The action of pepsin. Mix the curdled milk, 
 
 the pepsin, and water in a test-tube and place 
 it in the warm water-bath. Look at it every 
 fifteen minutes. What takes place ? 
 
DIGESTION. 81 
 
 3. The action of pepsin and hydrochloric acid. To 
 part of the above mixture add a few drops 
 of hydrochloric acid and keep it in the water- 
 bath. Compare the two at the end of two 
 or three hours. Have both the proteid and 
 the fat constituents been acted upon ? What 
 shows this? What is the action of gastric 
 juice on milk? 
 
 C. The Pancreatic Juice. 
 
 I. The Preparation oe Artificial Pancreatic 
 
 Juice. 
 
 Materials. 100 o.e. of water. 15 grains of sodium carbonate, 
 baking soda. 5 grains of pancreatin. 
 
 Apparatus. A small beaker. A water-batli and thermometer. 
 
 The essential elements of pancreatic juice are trypsin, 
 amylopsin, steapsin, and rennin. Trypsin acts upon the 
 proteids, amylopsin upon the carbohydrates, and steapsin 
 upon the fats. The action of rennin is to coagulate what- 
 ever casein may have escaped coagulation by the gastric 
 juice. 
 
 Experiment : 
 
 In the small beaker mix the pancreatin with the aqueous 
 solution of sodium carbonate. Place in the water-bath 
 and keep it at 42° C. 
 
 II. The Action of Pancreatic Juice on Fats. 
 Pancreatic juice acts upon fats, starch, and proteids. 
 
 Materials. 5 c.c. of olive oil. A tablespoonf ul of flour. 5 c.c. 
 of melted butter. 20 c.c. of artificial pancreatic juice. 
 
82 PHYSIOLOGY FOB THE LABORATORY. 
 
 Apparatus. Evaporating dish. Test-tubes and rack. Warm 
 water-bath. 
 
 Experiment : 
 
 1. Recall the experiments on fats in food. 
 
 2. Make an emulsion with olive oil, flour, and water. 
 
 3. To 10 c.c. of warm artificial pancreatic juice add 
 
 1 c.c. of olive oil. Shake. 
 
 4. To 10 c.c. of warm pancreatic juice add 1 c.c. of 
 
 melted butter. Shake and allow to stand in 
 the warm water-bath. What is the action 
 of pancreatic juice on fats as far as you can 
 judge from these experiments? Compare with 
 results in B. IV. 
 
 III. The Action of Panckeatic Juice on Pkoteids. 
 
 Materials. 15 c.c. of artificial pancreatic juice. A piece of raw 
 lean beef cut in small pieces. 
 
 Apparatus. Test-tube. Warm water-bath. 
 
 Experiment : 
 
 Into 15 c.c. of pancreatic juice drop the small pieces of 
 beef. Place the test-tube in the warm, water-bath and 
 watch from time to time. Compare this action with that 
 of the gastric juice. 
 
 IV. The Action op Pancreatic Juice on Milk. 
 
 Materials. 40 c.e. of milk. 20 c.c. of warm pancreatic juice. 
 30 c.c. of acetic acid, 5 c.c. of hydrochloric acid. 
 Apparatus. Test-tubes. Warm water-bath. 
 
 Experiment : 
 
 l. To 20 c.c. of milk add 5 c.c of hydrochloric, acid 
 and shake. What is the precipitate ? Filter 
 
DIGESTION. 83 
 
 and wash the precipitate two or three times. 
 Add some of this coagulated casein to 10 c.c. 
 of pancreatic juice and place in the warm 
 water-bath. Normally, what curdles the milk? 
 What is the effect of the pancreatic juice on 
 the curd? 
 
 2. Mix 20 c.c. of the milk and 10 c.c. of pan- 
 
 creatic juice. Place in the warm bath and 
 watch for results. After an hour what has 
 occurred? The precipitate is casein. Is it 
 in fine particles or in solid clots? 
 
 3. This experiment is to be performed after the 
 
 milk has been digested in experiment 2 for 
 an hour. Place in one test-tube 10 c.c. of 
 fresh milk and in another 10 c.c. of the milk 
 of experiment 2. Add to each the same 
 amount, about 15 c.c. of acetic acid or vinegar. 
 In which is the clot more firm ? Milk is often 
 treated with pancreatin or " peptonized " for 
 children and invalids. Why ? 
 
 D. Absorption of the Soluble Products of Digestion. 
 
 After the food has been acted upon by the various 
 digestive fluids of the alimentary canal, it is ready to 
 supply nourishment to the body. The products of diges- 
 tion, then, must in some way pass through the walls of 
 the alimentary canal and pass into the blood, in order to 
 reach the various organs of the body. Just how these 
 substances are able to pass through the walls of the intes- 
 tine has long been a question among physiologists. It is 
 
84 PHYSIOLOGY FOB THE LABORATORY. 
 
 now thought that the epithelial membrane, composed of a 
 single layer of cells, takes an active part in the absorption 
 of the soluble products of digestion. The laws that 
 control living cells are probably different from those of 
 ' imbibition ' and ' osmosis ' with a dead membrane. But 
 as these physical laws may aid in absorption they should 
 not be disregarded. 
 
 I. The Epithelial Cells. 
 
 Review the microscopical slide showing a section of 
 the wall of the small intestine. Recall particularly the 
 epithelial cells, their shape, size, arrangement, and the 
 number of layers. 
 
 II. Diffusion. 
 
 Materials. 20 c.o. of water. 10 c.o. of oil. 5 c.c. of ink. 
 Apparatus. Test-tubes. 
 
 Experiment : 
 
 1. Shake 10 c.c. of water and 10 c.c. of oil together. 
 
 Do they mix or diffuse ? 
 
 2. Shake the water and ink. Do they mix ? What 
 
 is meant by diffusion ? Why do the water and 
 ink diffuse while the water and oil do not? 
 
 III.. Osmosis. 
 
 Materials. Two eggs. A cup of vinegar. Dextrose. 
 Apparatus. A large beaker. Tape-measure. 
 
 Experiment : 
 
 1. Measure the circumference of an egg around 
 the short axis and around the long axis, and 
 make a record of the measurements. 
 
DIGESTION. 85 
 
 2. Place the egg in dilute acetic acid or vinegar, 
 
 and leave it a day or two until all the lime in 
 the shell has been dissolved. 
 
 3. Wash and place it in a solution of dextrose. 
 
 4. After a day or two measure the circumference 
 
 in the same places as before and compare 
 these measurements with those first taken. 
 What does the difference show? 
 
 5. Test the second egg for dextrose. 
 
 6. Test the egg that has been in the dextrose solu- 
 
 tion for dextrose. 
 
 7. What has taken place in the first egg ? 
 
 IV. Imbibition. 
 
 A. Capillary Imbibition. 
 
 Materials. Any colored solution, as red ink. Blotting-paper. 
 Apparatus. Glass tubing of different sizes. 
 
 Experiment : 
 
 1. Place a few pieces of glass tubing of different 
 
 sizes in a glass of red ink and note the result. 
 
 2. Suspend a strip of filter-paper or blotting-paper 
 
 so that one end dips in the red ink. Leave 
 for some time. What happens? Why? 
 
 B. Molecular Imbibition. 
 
 Materials. Glue. Water. 
 Apparatus. A small beaker. 
 
 Experiment : 
 
 1. Soak a piece of glue in cold water for about 
 half an hour. Compare this with a piece of 
 the dry glue and explain the difference. 
 
86 PHYSIOLOGY FOB THE LABORATORY. 
 
 2. Put a rubber cot on a finger and allow it to 
 
 remain for some time. Explain the result. 
 
 3. Explain the condition of the hands after they 
 
 have been in warm water for some time. 
 
 4. Explain the uncomfortable feeling produced by 
 
 wearing rubber shoes or boots for a long time. 
 
XIV. 
 
 THE KIDNEYS. 
 
 A. The Kidney of a Sheep. 
 
 Material. A kidney of a sheep. This may be obtained at any 
 market. 
 
 Cut away most of the fat surrounding the kidney and 
 any other tissues that may be attached, but leave the ureter 
 and blood-vessels untouched. 
 
 I. The External Parts. 
 Notice : 
 
 a. The shape of the kidney. 
 
 b. The size. 
 
 o. The tube or ureter leading from the kidney. 
 
 d. The blood-vessels. 
 
 e. The fat. What is its use ? 
 /. The thin skin on the outside. 
 
 g. The hilus, or deep fissure on the inner border. Where 
 does it lead? 
 h. Sketch. 
 
 II. The Internal Parts. 
 
 Cut the kidney in halves longitudinally, making the 
 cut through the hilum and parallel to the broad side of 
 the kidney. 
 
 87 
 
88 PHYSIOLOGY FOB THE LABORATORY. 
 
 Notice : 
 
 a. The pelvis is the widened end of the ureter. 
 
 b. The cups, or calices, are the smaller cavities that unite 
 to form the pelvis. 
 
 c. The cortical portion is the outer part of the wall of 
 the kidney. What is its color and structure ? 
 
 d. The medullary portion is within the cortex. It is 
 divided into separate pyramidal portions, called the pyra- 
 mids of Malpighi. How does it compare in color and 
 structure with the cortex? 
 
 e. Sketch. 
 
 III. The Microscopical Structure of the Kidney. 
 
 Material. A prepared radial section of injected kidney. 
 Apparatus. A compound microscope. 
 
 Examine under a low power and determine : 
 
 a. The uriniferous tubules, or small tubes, compose the 
 larger part of the medullary and cortical portions. Each 
 tube is very complicated and is composed of straight and 
 convoluted parts. It arises in a Malpighian body (see b) 
 and after passing through the cortical and medullary 
 portions, finally opens at the apex of a pyramid. 
 
 b. The Malpighian bodies are small spherical bodies in the 
 cortical portion of the kidney. Each one is composed of 
 a network of capillary blood-vessels, surrounded by a thin 
 membrane which narrows to form the beginning of a tubule. 
 The fluid is secreted in the capsule and in a part of the 
 tubules. 
 
XV. 
 
 THE SKIN AND BODILY TEMPERATURE. 
 
 A. The Gross Structure of the Skin. 
 
 I. The Skin on the Hand. 
 
 Apparatus. A magnifying glass. 
 
 Examine with a magnifying glass the skin of the palm 
 of the hand. 
 
 Notice : 
 
 a. The larger furrows, or creases. What is their cause ? 
 
 b. The smaller ridges, or papillae-, and the small furrows. 
 How are they arranged ? 
 
 c. The small openings. These are the openings of the 
 perspiratory, or sweat, glands. How are they arranged ? 
 
 d. Sketch. 
 
 II. The Two Layeks of the Skin. 
 
 Apparatus. A sewing needle. 
 
 Carefully insert a needle under the outer skin of your 
 finger. 
 Notice : 
 
 a. The two layers of the skin. 
 
 b. The outer, dead skin, or epidermis. 
 
 1. What is its color ? 
 
 2. Has it blood-vessels or nerves ? 
 
90 PHYSIOLOGY FOB THE LABORATORY. 
 
 c. The inner, true skin, or dermis. Has it blood-vessels 
 or nerves ? 
 
 III. A Blistbe. 
 
 When you have a water-blister, insert a needle under 
 the outer skin and find the liquid that collects between 
 the two layers of the skin. Whence does this liquid 
 come ? Why does it not exude through the pores of the 
 sweat glands ? 
 
 IV. Attachment of the Skin. 
 
 Try to lift the skin up away from the underlying tis- 
 sues in the following places : back of the hand, cheek, 
 forehead, neck, palm of hand, and fingers. What differ- 
 ences in the mode of the attachment in the different 
 places ? Why should the skin be so firmly attached to 
 the palms and the fingers ? 
 
 B. Finger-Prints. 
 
 Material. Printer's ink and paper. 
 
 Spread a film of thin printer's ink on a piece of paper, 
 glass, or a stamping pad. Place the under surface of the 
 last joint of a finger on the ink and then on a piece of 
 clean paper. Study the print and find the arrangement of 
 the small ridges. 
 
 a. Are they in an arch, a loop, or a whorl ? What is 
 their use ? 
 
 b. Make a print of all your fingers and thumbs and 
 compare the results with those of others. 
 
THE SKIN AND BODILY TEMPERATURE. 91 
 
 C. The Microscopical Structure of the Skin. 
 
 Material. A microscopical slide showing a cross-section of the 
 skin of the head. 
 
 Apparatus. A compound microscope. 
 
 With the compound microscope examine a prepared 
 slide showing a cross-section of the skin of the head, and 
 find as many as possible of the following parts. 
 
 Notice : 
 
 a. The epidermis. 
 
 1. Its thickness. 
 
 2. The three layers of cells. 
 
 (1) The outer layer of elongated horny cells. 
 
 In which direction are they elongated ? 
 Have they any nuclei ? What is their 
 relation to dandruff? 
 
 (2) The second layer of rounded cells. 
 
 (3) The third layer of columnar cells. In which 
 
 direction are these cells elongated? 
 Have they any nuclei? Compare 
 with the outer layer and determine 
 the relative amount of life in the 
 two layers. Inferences. 
 
 b. The dermis. 
 
 1. Its thickness. 
 
 2. Its structure. 
 
 3. The hair. 
 
 (l) The root of the hair is the part embedded 
 in the skin. 
 
92 PHYSIOLOGY FOB THE LABORATORY. 
 
 (2) The stem of the hair is the part outside 
 
 of the skin. Is this stem solid or 
 
 hollow? Is it one piece or made up 
 of parts? 
 
 (3) The follicle is the depression in the skin 
 
 that contains the root. What relation 
 do the walls of the follicle bear to the 
 dermis and epidermis ? 
 
 (4) A modified papilla is at the base of the 
 
 follicle over which the root of the 
 hair fits. 
 
 4. The sebaceous, or oil, glands. 
 
 (l) Their shape and size. 
 
 (2). Where do their ducts open ? 
 
 5. The perspiratory, or sweat, glands are the tubular 
 
 glands. 
 Find: 
 
 (1) The body of the gland. What is its posi- 
 
 tion, shape, size, and structure. 
 
 (2) The gland duct. Follow its course through 
 
 the epidermis. 
 
 D. The Temperature of the Body. 
 I. The Normal Temperature. 
 
 Apparatus. A physician's thermometer. 
 
 Place a physician's thermometer under the tongue in 
 the mouth. Close the lips, hold the thermometer there 
 for five minutes, and then read the temperature. 
 
THE SKIN AND BODILY TEMPERATURE. 93 
 
 II. Variations in the Temperature. 
 
 Apparatus. A physician's thermometer. 
 
 Take the temperature at different times, when very 
 warm and when cold. 
 
 III. The Regulation oe the Temperature. 
 
 Material. Ether or alcohol. 
 
 Pour a few drops of ether or alcohol on the hand. How 
 does it feel ? Why ? How do a dog and a cat cool off ? 
 How does a person ? 
 
XVI. 
 
 THE NERVOUS SYSTEM. 
 
 The Brain. 
 
 The nervous tissues of the body may be divided into 
 several parts; the brain, the spinal cord, the nerves, the 
 ganglia, and the sympathetic nerves and ganglia. 
 
 A. The Brain of a Sheep. 
 
 Materials. The head of a sheep. Cotton batting. Potassium 
 bichromate. Formalin or formaldehyde. A human brain if pos- 
 sible. 
 
 Apparatus. A meat-saw. Bone forceps. Glass jar. 
 
 The head of a sheep, a rabbit, or of some other verte- 
 brate may be obtained and the brain be taken from it. In 
 order to obtain the brain in good condition the roof of the 
 skull must be removed. With a meat-saw, cut across the 
 front of the skull just back of the eyes, and then saw, 
 backward along either side of the head, just above the 
 ears to the opening in the skull where the spinal cord 
 joins the brain. Carefully remove the large, nearly tri- 
 angular piece of bone. With the handle of a scalpel, 
 slowly free the brain with its coverings from the skull. 
 Take care not to cut the roots of the cranial nerves close 
 to the brain, but preserve them as long as possible. Wrap 
 the brain in a piece of cotton batting to prevent its weight 
 
 94 
 
THE NERVOUS SYSTEM. 95 
 
 from flattening it against the side of the jar while soft, 
 and immerse it in the following liquid to harden. 
 
 Potassium bichromate 10 grams. 
 
 Formalin or formaldehyde 40 per cent . . . 15-20 c.c. 
 Water 500 c.c. 
 
 Allow it to remain in this liquid two weeks, and then 
 remove and wash it in running water for two or three 
 hours. If it is not sufficiently hard, let it stand over- 
 night in a mixture of 350 c.c. of 5 per cent formalin and 
 150 c.c. of 95 per cent alcohol. If a fresh brain be placed 
 in this latter mixture, it will harden throughout, with no 
 appreciable shrinkage, to the consistency of India rubber 
 within thirty-six hours, but there will be no differentiation 
 of white and gray matter. 
 
 The potassium bichromate colors the cellular (gray) 
 tissue, but has no effect upon the fibrous (white) tissue, 
 while alcohol bleaches both tissues. 
 
 I. The Bkain as a Whole. 
 
 a. What is its position, size, and shape ? 
 
 b. The surfaces of the brain. 
 
 1. The dorsal surface is the upper or more rounded 
 
 surface. 
 
 2. The ventral surface is the lower or flatter surface. 
 
 3. The anterior end is more rounded than the 
 
 posterior. 
 
 II. The Coverings of the Brain. 
 
 a. The dura mater is the thick outer covering. 
 
 1. Is it attached to the brain ? 
 
 2. Is it close to the brain? 
 
96 PHYSIOLOGY FOR THE LABORATORY. 
 
 3. What is its relation to the long median fissure 
 
 and to the fissure between the cerebrum and 
 cerebellum ? 
 
 4. "What is its use ? 
 
 b. The pia mater is the thin inner membrane. 
 
 1. What is on this membrane ? 
 
 2. "What is its function ? 
 
 c. The arachnoid is between the two. It is a thin mem- 
 brane just outside the pia mater, and bridges across the 
 fissures. 
 
 III. The General Parts. 
 
 Carefully remove the dura mater, but the pia mater may- 
 remain on the brain to protect it. 
 
 a. The cerebrum is the large anterior part of the brain. 
 This is the fore-brain. 
 
 b. The cerebellum or smaller division may be seen on the 
 dorsal surface posterior to the cerebrum. Trace it around 
 toward the ventral surface. 
 
 c. The pons Varolii is the band that extends across ven- 
 trally from one side of the cerebellum to the other. 
 
 d. The medulla oblongata, or spinal bulb, is beneath the 
 cerebellum, posterior to the pons Varolii. Push the cere- 
 bellum gently forward to find the dorsal surface of the 
 medulla, b, c, and d constitute the hind-brain. 
 
 e. The crura cerebri, or peduncles of the cerebrum, are on 
 the ventral side, just anterior to the pons Varolii. 
 
 1. Where do their nerve fibres come from ? 
 
 2. Whither do they lead ? 
 
THE NERVOUS SYSTEM. 97 
 
 /. The corpora quadrigemina are situated on the dorsal 
 side. Gently press backward the cerebellum and look 
 forward under the cerebrum for them. 
 
 1. How many parts are there? 
 
 2. What is their shape ? 
 
 3. Are they all of the same size ? e and / are in 
 
 the mid-brain. 
 
 g. Sketch larger than life-size a dorsal, a ventral, and a 
 lateral view of the entire brain, showing the exact relation 
 of the parts, and label each. 
 
 IV. A Detailed Study of. the Parts oe the 
 Brain. 
 
 a. The cerebrum, or fore-brain. 
 
 1. The two cerebral hemispheres, the right and the 
 
 left. 
 
 (1) Their general shape. 
 
 (2) How are they separated? 
 
 (3) How are they connected? 
 
 2. The irregular swellings are called convolutions. 
 
 (l) Is there any definite arrangement ? Com- 
 pare the two sides of the same specimen, 
 and then compare your specimen with 
 another. 
 
 3. The fissures are the depressions between the 
 
 convolutions. Locate the principal fissures 
 on each hemisphere, 
 
 (l) The median fissure lies between the two 
 hemispheres. 
 
98 PHYSIOLOGY FOB THE LABORATORY. 
 
 (2) The fissure of Sylvius is on the lateral sur- 
 
 face of the hemisphere. It begins about 
 one third the distance from the anterior 
 to the posterior end and runs upward 
 and backward. 
 
 (3) The fissure of Rolando begins at the median 
 
 fissure on the dorsal surface of the brain 
 and runs downward and forward in front 
 of the fissure of Sylvius. 
 
 (4) The parieto-occipital fissure also begins at 
 
 the median fissure, but posterior to the 
 fissure of Rolando, and runs across the 
 hemisphere. 
 
 4. Find the lobes resulting from these fissures. 
 
 (1) The frontal lobe is at the anterior part of 
 
 the brain. 
 
 (2) The occipital lobe is at the posterior part. 
 
 (3) The parietal lobe lies between the two along 
 
 the median line. 
 
 (4) The temporal lobe is on the side below the 
 
 fissure of Sylvius. How many convo- 
 lutions are there in each lobe? 
 
 5. The olfactory lobes are the two small elongated 
 
 lobes on the ventral surface of the hemi- 
 spheres at the anterior end. 
 
 b. The hind-brain. 
 
 l. The cerebellum. 
 
 (1) Its shape. It consists of a central and 
 two lateral parts. 
 
rmmz UmsflaStvoua srsd f J , ' ara ' N ' 99 
 
 (2) Its structure. Are there any convolutions 
 
 and fissures ? Is it divided into hemi- 
 spheres ? 
 
 (3) Its relative size. Compare with the 
 
 human brain. 
 2. The medulla oblongata, or spinal bulb. 
 
 (1) Its shape. Raise the cerebellum, push it 
 
 gently forward, and remove the thin 
 epithelial covering from the dorsal side 
 of the medulla. 
 
 (2) The fourth ventricle is the chamber in the 
 
 medulla. What is its shape ? Where 
 does it open posteriorly ? 
 
 (3) The diverging posterior columns, or pyramids, 
 
 are on either side of the fourth ven- 
 tricle. 
 
 (4) The restiform bodies, a rounded eminence 
 
 in each column. Anteriorly find where 
 they pass into the inferior peduncles of 
 the cerebellum. 
 
 (5) The superior peduncles of the cerebellum, 
 
 one on each side, proceed from the 
 cerebellum and pass beneath the poste- 
 rior corpus quadrigenlinum of the same 
 side. 
 
 (6) On the under, or ventral, surface of the 
 
 medulla notice two cords, the anterior 
 pyramids. Compare them with the pos- 
 terior pyramids. 
 
 (7) The pons Varolii. In which direction do 
 
 its fibres run? Follow its fibres on 
 
100 PHYSIOLOGY FOB THE LABORATORY. 
 
 each side into the middle peduncles of 
 the cerebellum. 
 
 e. The mid-brain. 
 
 1. The optic tracts are two bundles of fibres coming 
 
 obliquely forward over the front part of the 
 peduncles and meeting in the centre to form 
 the optic chiasma. What is the meaning of 
 this crossing ? What relation does it bear to 
 the optic nerves and the sensation of light? 
 
 2. The tuber cinereum is the small triangular or 
 
 nearly quadrilateral area at the anterior part 
 of the crura cerebri in the angle of diver- 
 gence of the optic tracts. 
 
 3. The infundibulum extends from the tuber cinereum 
 
 to the pituitary body that may have been 
 torn off in removing the brain from the skull. 
 Notice the cavity in the infundibulum. 
 
 4. The pineal gland is the small body above the 
 
 corpora quadrigemina. 
 
 5. Sketch the details in your dorsal, ventral, and 
 
 lateral views of the brain. 
 
 B. The Motor and Sense Areas. 
 
 The surface of the cerebrum has been partly mapped 
 out into motor and sense regions. These are divided into 
 areas for the muscle-groups belonging to different members 
 of the body, the foot, the arm, etc. The stimulation of 
 a certain part of an area for the arm results in movements 
 of extension, the stimulation of another part of the area 
 results in flexion of the arm. Moreover, each area may 
 
THE NERVOUS SYSTEM. 
 
 101 
 
 be marked off into centres which control the motion of a 
 smaller group of muscles, as of a part of the arm. The 
 area of the arm would thus be the sum total of centres for 
 the various movements of which all the parts of the arm 
 are capable. The areas affect the movements of the 
 muscles of the opposite side of the body, so that stimu- 
 lating the area of the arm on the right cerebral cortex 
 will result in movements of the left arm. Locate the 
 main motor and sense areas from the following diagram. 
 
 Ant. 
 
 Fig. 9. — The left cerebral hemisphere. Sy is the Assure of Sylvius; lio, the 
 fissure of Rolando ; P.O., the parietooccipital fissure ; H, the area for hear- 
 ing ; V, the area for vision ; S, the area for smelling. 
 
 C. The Cranial Nerves. 
 
 If the cranial nerves have been severed close to the 
 brain, they should be studied in the interior of the skull. 
 Observe carefully the points of exit of the roots of the 
 nerves. 
 
 a. The olfactory nerves arise from the olfactory lobes. 
 
 b. The optic nerves arise from the optic tracts just 
 anterior to the crura cerebri. 
 
102 PHYSIOLOGY FOB THE LABORATORY. 
 
 c. The motor oculi, or motor nerves of the eye, arise from 
 the inner surfaces of the crura cerebri in front of the 
 pons Varolii. 
 
 d. The pathetici curve around the front edge of the 
 pons ; they originate a little posterior to the corpora 
 quadrigemina. 
 
 e. The trigeminals are large and conspicuous and. arise 
 from the sides of, the pons. 
 
 f. The abducens arise just posterior to the pons. 
 
 g. The facial nerves are seen at the lower edge of the 
 pons, nearly in a line with the fifth pair. 
 
 h. The auditory nerves are just outside the seventh pair, 
 and cling to the lateral surface of the medulla. The 
 glossopharyngeal, the pneumogastric, the spinal accessory, and 
 the hypoglossal, each arises by several roots which form a 
 line on the lateral part of the medulla. Consult a draw- 
 ing of the human brain. 
 
 i. Add the nerves to your ventral view of the brain. 
 
 D. The Interior of the Brain. 
 
 I. A Longitudinal Section. 
 
 Make a median longitudinal section of the entire brain, 
 taking great care that it is exactly in the median line. 
 
 Identify : 
 
 a. All the parts that you have seen on the dorsal and 
 ventral surfaces. 
 
 5. The gray matter constitutes the outer layer, or cortex. 
 Is it composed of cells or fibres ? How is it arranged with 
 reference to the fissures ? How thick is it ? 
 
THE NERVOUS SYSTEM. 103 
 
 c. The white substance is in the centre. Is it cellular or 
 fibrous? How is it arranged ? 
 
 d. The corpus callosum, a flat, thick band of white tissue 
 curved under at either end and situated in the lower part 
 of the cerebral hemispheres. 
 
 e. The cavities of the brain, four of / 1 [—\ — l 
 which can be easily distinguished. Y-l—y-j—ii 
 
 1. The lateral ventricles are in the ^ fc-F.M. 
 
 right and left cerebral hemi- 
 spheres. They will be found ' "" ' m 
 after cutting the horizontal \ [>XS. 
 sections (Fig. 10, I and H). 
 
 2. The third ventricle is dorsal to the \ j "' " 
 
 optic tracts. (Fig. 10, III.) 
 
 3. The foramen of Monroe is the 
 
 passage from the lateral to 
 the third. It is reshaped. 
 
 *■ Fig. 10. — A diagram 
 
 (Fig. 10, F.M.) of the ventricles 
 
 4. The fourth ventricle is in the me- ofttetaain - 
 
 dulla oblongata, and is merely covered by the 
 membranes of the spinal cord. (Fig. 10, IV.) 
 6. The aqueduct of Sylvius leads from the third to 
 the fourth ventricle. (Fig. 10, A.S.) 
 f. Sketch. 
 
 II. A Horizontal Section. 
 
 Cut away the dorsal surface of one hemisphere in thick 
 horizontal sections nearly down to the corpus callosum, 
 noting the arrangement of white and gray matter. Make 
 a shallow, vertical cut into the corpus callosum, parallel 
 with the median fissure and about half an inch from it. 
 
104 PHYSIOLOGY FOB THE LABORATOBY. 
 
 a. Pull up the outer edge of this cut and find a hollow 
 space, the lateral ventricle. 
 
 b. Cut off its roof and look for the corpus striatum, pro- 
 jecting from the floor at the anterior end. 
 
 c. Sketch. 
 
 III. Another Horizontal Section. 
 
 Cut off another section just below the corpus callosum 
 so as to pass through the corpus striatum and the optic 
 thalamus. 
 
 Notice : 
 
 a. The gray matter around the margin and its relation 
 to the convolutions. What, then, is the purpose of the 
 convolutions ? 
 
 b. The size and shape of the fissure of Sylvius and the 
 average depth of the fissures between the convolutions. 
 
 c. Sketch. 
 
 IV. A Transverse Section. 
 
 Cut the other hemisphere transversely halfway between 
 the pons and the optic chiasma. 
 
 Notice on the cut surface : 
 
 a. The shape of the fissure of Sylvius. 
 
 b. The gray matter composing the optic thalamus and 
 the corpus striatum. 
 
 o. Sketch. 
 
 V. The Cerebellum. 
 
 Cut the peduncles of the cerebellum and remove it. 
 Cut one half transversely at the centre and determine the 
 relative number and depth of the fissures. 
 
THE NERVOUS SYSTEM. 105 
 
 a. The white substance. How is it arranged ? 
 
 b. The gray substance. How thick is it ? 
 
 e. A gray mass, the corpus dentatum, is in the centre of 
 the white substance in each lateral lobe. 
 d. Sketch. 
 
 VI. The Medulla Oblongata. 
 
 Make a transverse section of the medulla and note the 
 arrangement of the gray matter within. Make another 
 through the pons, and note the arrangement of the fibres 
 which compose it. 
 
 E. The Microscopical Structure of the Brain. 
 
 Material. A prepared section of the cerebral cortex of the human 
 brain. 
 
 Apparatus. A compound microscope. 
 
 Examine a prepared section of the human brain. 
 
 The Nerve Cells. 
 Note: 
 
 a. Their size, shape, and structure. 
 
 b. Protoplasmic or branched processes are called dendrites. 
 
 c. The unbranched process, or axon, is continued as the 
 axis cylinder of a nerve fibre. Each nerve cell with all 
 its processes, both dendrites and axons, is called a neuron. 
 Do all cells possess both kinds? 
 
 d. Draw cells showing all these parts. 
 
 e. How do nerve cells differ from epithelial and muscle 
 cells ? 
 
XVII. 
 
 THE NERVOUS SYSTEM. 
 
 The Spinal Cord. 
 
 A. The Gross Structure of the Spinal Cord. 
 
 Material. The spinal cord of a calf or some large animal. This 
 may be easily obtained at the large markets. It is only necessary 
 to ask the butcher to save, when he cuts the animal for the market, 
 the long spinal cord that is inside the backbone. 
 
 Study the entire cord or a long piece of it. 
 
 Notice : 
 
 a. The general shape, its length and diameter. Locate 
 the cervical and lumbar swellings in the regions of the 
 neck and the lower part of the back. What causes 
 them? 
 
 b. The roots, or attachments, of the spinal nerves. 
 
 1. How are they arranged? 
 
 2. How near together are they? 
 
 e. Sketch. 
 
 B. The Microscopical Structure of the Spinal Cord. 
 
 Material. A microscopical slide showing a cross-section of a 
 spinal cord. 
 
 Apparatus. A magnifying glass. A compound microscope. 
 
 106 
 
TBE NERVOUS SYSTEM. 107 
 
 I. The Spinal Cord Slightly Magnified. 
 
 Study with a magnifying glass a microscopical slide of 
 a cross-section of a spinal cord. 
 
 Notice : 
 
 a. Its general shape. 
 
 b. The anterior, ventral fissure is the deep indentation on 
 one side. 
 
 c. The posterior, dorsal fissure is on the opposite side. 
 
 d. The membranes around the cord. How many are there ? 
 
 e. The white substance is just within the membranes. 
 Distinguish the anterior, lateral, and posterior columns. 
 
 f. The gray substance is within the white substance. 
 What is its shape ? Find the anterior and posterior cornua. 
 
 g. The* canal is in the centre of the gray substance. 
 What is its size? 
 
 h. The cerebro-spinal fluid was within the canal. 
 
 i. The roots of the nerves. Which roots are they, the 
 anterior or the posterior? 
 
 j. The blood-vessels. What is their relation to the septa 
 or extensions of the pia mater into the cord ? 
 
 k. Sketch. 
 
 II. The Spinal Cord Highly Magnified. 
 
 Study the section with the high power of the com- 
 pound microscope. 
 
 Notice in the gray substance : 
 a. The nerve cells. 
 . 1. The shape. 
 
 2. The cell protoplasm. 
 
 3. The nucleus. 
 
108 PHYSIOLOGY FOB THE LABORATORY. 
 
 4. The nucleolus. 
 
 5. The fibres leaving the cells. Is there an axon? 
 
 Look for branching fibres. 
 
 b. The network of fibres. 
 
 c. Compare with the cells of the brain. 
 
 d. Sketch. 
 
 C. The Structure of Different Parts of the Spinal Cord. 
 
 Material. Microscopical slides showing cross-sections of the 
 spinal cord in the cervical, dorsal, and lumbar regions. 
 Apparatus. A magnifying glass. 
 
 Examine the sections of the different regions of the 
 spinal cord. 
 
 Notice : 
 
 a. Their comparative size and shape. Is the difference 
 due to the gray or white substance ? What shows this ? 
 
 b. The comparative number of cells in the anterior 
 cornua. What does this signify? 
 
 o. The comparative amounts of gray and white sub- 
 stance. To what is this due? 
 
 d. In the cervical region note the division of the pos- 
 terior columns into a median and lateral part separated by 
 connective tissue. 
 
 e. Make sketches showing typical sections from these 
 three regions. 
 
 D. The Spinal Nerves. 
 
 Materials. A frog. Chloroform. Formalin, 5 per cent. Cotton 
 batting. 
 
 Apparatus. Glass jar. Bell-jar. 
 
THE NERVOUS SYSTEM. 109 
 
 Kill a frog and keep it in 5 per cent formalin for three 
 or four days. Cut open the body cavity along the ventral 
 surface, lay aside the intestines, and look for the spinal 
 nerves at the back of the body cavity. 
 
 Notice : 
 
 a. Their number and arrangement with reference to 
 the vertebrae. 
 
 b. Their roots, the anterior and posterior. What is the 
 size and structure of each ? On which is the ganglion ? 
 
 c. Their distribution. To what portions of the body do 
 they extend ? 
 
 E. Nerve Fibres. 
 
 Materials. A frog. Chloroform. Normal salt solution. Cotton 
 batting. 
 
 Apparatus. Bell-jar. 
 
 Cut off a quarter of an inch of a perfectly fresh nerve, 
 and put it on a slide without any liquid. Press one end 
 against the slide, and tease out the other end by passing 
 a needle lengthwise through the fibres. Spread the fibres 
 out like a fan, add a drop of normal salt solution, and 
 cover. 
 
 Notice : 
 
 a. The relative size and arrangement of the nerve fibres. 
 
 b. The connective tissue running amongst and around the 
 fibres. 
 
 c. The primitive sheath is a thin, transparent covering on 
 the outside. 
 
 d. The medullary sheath, also transparent, is inside the 
 primitive sheath and consists of a fatty substance. 
 
110 PHYSIOLOGY FOB THE LABORATORY. 
 
 e. The axon, or axis cylinder, is in the centre. Add a 
 drop of chloroform and look for this along the centre of 
 the fibres. These are called medullated or white fibres. 
 Distinguish from them the non-medullated or gray fibres; 
 where are the latter found? 
 
 /. Look for nuclei along the nerve fibre. 
 
 g. Sketch a single fibre and show all these parts. 
 
 F. A Nerve Ganglion. 
 
 Material. A prepared section of a nerve ganglion. 
 Apparatus. A compound microscope. 
 
 Examine a section of a nerve ganglion. 
 
 Notice : 
 
 a. The size and general shape. 
 
 b. The outer coat, its thickness and structure. 
 
 c. The nerve cells. 
 
 1. What is their size and shape ? 
 
 2. Have they any nucleus ? 
 
 3. Compare them with those seen in the brain. 
 
 d. The fibres. Do any of them join the cells? Are 
 they nerve fibres? 
 
 e. Sketch. 
 
 G. The Functions of the Spinal Cord. (Reflex Action.) 
 
 I. The Knee-Jerk. 
 
 Sit with one knee crossed over the other. With the 
 tips of the fingers, strike the crossed knee just below the 
 knee pan. Notice the motion of the foot. Was the action 
 voluntary ? Trace the course of the nerve impulse. 
 
THE NERVOUS SYSTEM. 
 
 Ill 
 
 II. The Reflex Action of the Spinal Cord of a 
 Fkog. 
 
 Materials. A frog. Chloroform. Hydrochloric acid. Cotton batting. 
 Apparatus. Bell-jar. Ring-stand. 
 
 Etherize a frog, and as soon as it is unconscious sever 
 the brain from the spinal cord by a cut across the back of 
 the neck. With a probe destroy the brain and suspend 
 
 Fig. 11. —A diagram o£ the reflex action of the spinal cord. 
 
 the frog from an iron stand. By pinching with the 
 forceps, gently stimulate one foot of the frog. Give a 
 more vigorous stimulus and compare the result with that 
 previously obtained. 
 
112 PHYSIOLOGY FOB THE LABORATORY. 
 
 Repeat the same experiment, using a small piece of 
 paper wet in dilute hydrochloric acid as a stimulus. Ex- 
 plain and give the path of the nerve impulse. Destroy 
 the spinal cord by passing a needle down the spinal 
 column and repeat the same experiments. 
 
 By a comparison of the results obtained, infer one of 
 the normal functions of the spinal cord in the frog. 
 
 H. The Sympathetic System. 
 
 Material. A frog that has been in 5 per cent formalin for three 
 or four days. The same frog that was studied for the spinal nerves 
 may be used. 
 
 Lay open the body cavity and push aside the intestines 
 and other organs. 
 
 I. The Situation of the Sympathetic System, and 
 
 its Connection with the Ceeebro-Spinal 
 System. 
 
 Just back of the kidneys find a row of small nerve 
 fibres, which run transversely from the spinal nerves to 
 the chain of pigmented, sympathetic ganglia close to the 
 dorsal surface and along beside the vertebrae. 
 
 II. Its Structure. 
 Notice : 
 
 a. The two rows of sympathetic ganglia. 
 
 b. The nerves connecting the ganglia. 
 
 c. The sympathetic trunks which arise from the ganglia 
 and connecting nerves. 
 
 d. The distribution of its nerves to the digestive, circu- 
 latory, and excretory organs. 
 
XVIII. 
 THE EYE AND VISION. 
 
 A. The Eye of an Ox. 
 
 Materials. The eye of an ox may be easily obtained at the mar- 
 ket. Care should be taken to obtain a fresh specimen. Potassium 
 bichromate, 1 per cent solution. 
 
 Apparatus. A small glass jar. 
 
 The Parts of the Eye. 
 
 a. The muscles on the outside of the eye. 
 
 1. How many do you find? 
 
 2. Where are they attached? 
 
 3. What is the use of each ? 
 
 b. Do you find anything else on the outside of the eye ? 
 What is its function ? 
 
 e. Remove the muscles and fat and find the optic nerve. 
 
 1. Is it in the axis of the eye ? 
 
 2. Can you determine whether your specimen is 
 
 the right or the left eye? 
 
 d. Sketch a front and a side view. 
 
 e. The cornea is the transparent coat on the front of the 
 eye. 
 
 /. The sclerotic coat is the white or gray opaque coat 
 that is continuous with the cornea. The cornea and the 
 sclerotic coat form the outer covering of the eye. 
 
 113 
 
114 PHYSIOLOGY FOE THE LABORATORY. 
 
 g. The conjunctiva is a thin membrane over the cornea. 
 It is a continuation of the mucous membrane lining the 
 eyelids. In removing the eye, the conjunctiva is cut 
 through where it passes from the eyelids to the sclerotic 
 coat. 
 
 h. The aqueous humor is found in the anterior chamber 
 of the eye by cutting through the cornea about a quarter 
 of an inch from the junction of the cornea with the 
 sclerotic coat. 
 
 i. Find the iris. 
 
 1. What color is it? 
 
 2. What is its shape? 
 
 3. Where is it attached? 
 
 j. The pupil, or opening. 
 
 1. How is it formed? 
 
 2. What is its shape ? 
 
 3. How does its shape change ? 
 
 k. At a short distance posterior to the cornea, cut 
 through the sclerotic coat, being careful not to cut too 
 deeply. The pigmented membrane beneath it is the 
 choroid coat. How are the sclerotic and choroid coats 
 connected? Remove a strip of the sclerotic coat one 
 quarter of an inch broad, stretching from the cornea to 
 the optic nerve. 
 
 1. What color is its inner surface ? 
 
 2. The pale fibres of the ciliary muscle may be seen 
 
 in the front part of the choroid close to the 
 cornea. Where do they arise? How far 
 backward do they extend? 
 
THE EYE AND VISION. 115 
 
 I. With forceps, carefully lift the choroid coat about 
 halfway between the optic nerve and the cornea and cut 
 through it. Beneath it the retina, a thin membrane, will 
 be seen. The pigment layer of the retina will probably 
 be torn away with the choroid. 
 
 m. The vitreous humor, which occupies the posterior cav- 
 ity of the eye, may be seen by tearing away a piece of the 
 retina. What are its characteristics ? 
 
 n. Hold the eye so that the cornea is underneath. Look 
 through the vitreous humor and see the longitudinal folds 
 of the choroid coat. These are the ciliary processes. 
 
 o. The ora serrata is the uneven line at the level of the 
 commencement of the ciliary processes. The retina ceases 
 along this line. 
 
 p. Turn the eye with the iris uppermost and cut away 
 the thin edge of the iris. Find the lens. Make a slit in 
 the membrane over the lens and remove it from its capsule. 
 Find how far the lens capsule extends. How is it held 
 in place? 
 
 q. Study the lens. 
 
 1. Its shape, size, and transparency. 
 
 2. Are its two faces alike ? 
 
 3. Lay the lens over some writing and notice the 
 
 result. 
 
 4. Place the lens in a 1 per cent solution of potas- 
 
 sium bichromate, and study the structure at 
 the end of a week. 
 
 r. The blind spot is the place where the optic nerve joins 
 the retina. It may be found by removing the posterior 
 half of the eye. 
 
116 PHYSIOLOGY FOB THE LABORATORY. 
 
 s. The blood-vessels of the eye may sometimes be seen 
 in the choroid coat radiating from the blind spot after 
 removing the retina. 
 
 t. Make a diagram of a median vertical longitudinal 
 section, showing the position of the coats, the lens, the 
 chambers, and the humors of the eye. 
 u. Label all of the parts that are shown in your sketches. 
 
 B. The Human Eye. 
 Apparatus. A hand-mirror. 
 Study your own eyes with a hand-mirror. 
 
 a. The eyebrows. 
 
 1. - Their position. 
 
 2. The direction of the hair. 
 
 8. The thickness and the color of the hair. 
 
 4. The hairless place above the bridge of the nose. 
 
 b. The eyelids. 
 
 1. Their number. Do you see the remnant of 
 
 another lid at the inner corner? , 
 
 2. The union of the mucous membrane and the 
 
 skin on the edge of the eyelid. 
 
 3. The openings on the edge of the lower lid. 
 
 (1) How many are there? 
 
 (2) What is their use ? 
 
 4. The larger opening on the slight elevation near 
 
 the inner angle of the lower lid is the open- 
 ing into the nasal duct. 
 
 5. Do you know any animals that have three eye- 
 
 lids ? Do you know any that have no eyelids ? 
 
THE EYE AND VISION. 117 
 
 c. The eyelashes. 
 
 1. Their position. 
 
 2. Their length and shape. , 
 
 d. The sclerotic coat. "What is its color ? 
 
 e. The iris. 
 
 1. What is its color? 
 
 2. What is its shape ? 
 
 3. How does it change with a varying amount of 
 
 light? 
 
 4. What is an albino ? 
 
 /. The pupil. 
 
 1. What is it? 
 
 2. What is its shape, size, and color? 
 
 3. Compare the pupil with that of the cat, the dog, 
 
 and other animals. 
 g. Sketch. 
 
 C. The Formation of the Image. 
 
 Apparatus. A double convex lens on a stand. A ground glass 
 screen. A candle in a stand. A wooden rod on -which the lens, 
 screen, and candle may slide. 
 
 I. The Image on Glass. 
 
 Arrange the lens, the candle-flame, and the screen so 
 that the image of the flame may fall on the screen. 
 Compare the image of the flame with the flame. 
 
 Notice : 
 
 a. The size of the image. 
 
 b. The position of the image. 
 
 c. The distance of the image from the lens. 
 
118 PHYSIOLOGY FOB THE LABORATORY. 
 
 II. The Image on the Retina. 
 
 Materials. The eye of an albino rabbit. Care should be taken to 
 have it freshly excised, with the cornea still clear, or the experiment 
 will fail. A piece of black paper about six inches square. A candle. 
 
 Roll the black paper into the form of a tube, and place 
 the rabbit's eye. in it with the cornea directed forwards. 
 Hold the eye in front of a candle-flame, and look for the 
 image of the flame shining through the retina, choroid, and 
 sclerotic coats. Move the flame and watch the image. 
 
 D. Accommodation. 
 
 Close one eye and hold up both forefingers, the one 
 about six inches, the other about eighteen inches, from 
 the open eye. Look steadily at the nearer finger. Is the 
 image of it clear or indistinct? Do you see clearly the 
 finger farther away? Look steadily at the finger farther 
 away. Is its image distinct? How is the image of the 
 nearer finger ? Can you focus on the nearer finger with- 
 out an effort? 
 
 E. Defects in Vision. 
 
 Materials. Snellen's cards of test-types including the card for 
 astigmatism. 
 
 I. Nearsight and Farsight. 
 
 With the aid of Snellen's test-types, examine your 
 own eyes and determine if they are normal. You should 
 be able to read type of this size ^™ at a distance of 
 sixteen feet. L. 
 
 What is nearsightedness, or myopia ? What is farsight- 
 edness, or hypermetropia ? How may each be corrected 
 by the use of glasses ? 
 
THE EYE AND VISION. 119 
 
 II. Astigmatism. 
 
 Test your own eyes for astigmatism with a card having 
 lines of the same brilliancy radiating from the centre, or 
 with the face of the clock. Astigmatism is present if 
 some of the lines are more distinct or brighter than 
 others. 
 
 Astigmatism is usually caused by unequal curvatures 
 of the cornea. 
 
 F. Changes in the Iris and the Pupil. 
 
 Material. A living cat. 
 
 Apparatus. A gas-jet or lamp. A hand-mirror. A piece of 
 cardboard about six inches square. 
 
 I. Changes in the Size op the Pupil. 
 
 Sit opposite a light and study the pupils of the eyes 
 in a hand-mirror. Place a hand over one eye and notice 
 the diameter of the pupil of the other. Suddenly remove 
 the hand from the eye while watching the pupil of the 
 open eye. What change do you observe? 
 
 II. The Rate op Movement op the Ieis. 
 
 a. The human eye. 
 
 Close the left eye, and with the right look through a 
 pin-hole in a card at a white shade of a lighted lamp. 
 Notice the size of the circular visual field, or the amount 
 of space visible at one time. Is it very bright? Open 
 the left eye. What change is there in the visual field? 
 Again close the left eye and note the change in the shape 
 and brilliancy of the visual field. 
 
120 PHYSIOLOGY FOB THE LABORATORY. 
 
 b. The eye of a cat. 
 
 Study the eyes of a cat during sudden changes in the 
 amount of light. 
 
 G. Binocular Vision. 
 
 While holding a pencil about a foot in front of the 
 eyes, look at a distant object. How does the pencil 
 appear? Close the right eye. What change is there? 
 Close the left eye and open the right. 
 
 H. The Blind Spot. 
 Marriott's experiment: 
 
 With the following figure find the blind spot in your 
 own eye. Close the right eye and hold the figure about 
 ten inches in front of the left eye. Look steadily at the 
 
 cross with the left eye and gradually draw the page 
 toward the eye. Do you find a place where the circle 
 disappears? The image then falls on the entrance of the 
 optic nerve, or the blind spot. 
 
 I. The Yellow Spot. 
 
 Clark-Maxwell's experiment: 
 
 Material. Chrome alum, a strong solution. 
 Apparatus. A glass bottle with flat sides. 
 
THE EYE AND VISION. 
 
 121 
 
 Place a clear, strong solution of chrome alum in a glass 
 bottle with flat sides. Close the eyes for a few minutes 
 and then look through the solution when held between 
 one eye and a white cloud. A rosy spot should be seen 
 in a green field of vision. The pigment in the yellow 
 spot on the retina absorbs the blue-green rays, and so the 
 remaining rays which pass through the alum give a pink 
 color. 
 
 J. Irradiation. 
 
 a. In Fig. 13 look at the white spot on the black 
 ground, and at the black spot on the white ground. 
 Which spot appears larger? 
 
 I. In Fig. 14 look at the four squares, two white and 
 two black. Which looks larger, the white or the black? 
 What is meant by irradiation? 
 
 K. Imperfect Visual Judgments. 
 
 a. Make three round black dots, 
 1, 2, and 3, of the same size and in 
 the same line, so that 1 and 3 are equi- 
 distant from 2. Make several other 
 dots of the same size between- 1 and 2. 
 Which now appear to be farther apart, 1 and 2 or 2 and 3 ? 
 
 b. Make two squares of equal size with very light out- 
 
 PlG. 14. 
 
122 
 
 PHYSIOLOGY FOB THE LABORATORY. 
 
 lines. In one draw parallel horizontal lines, and in the 
 other parallel vertical lines. How do the two squares 
 
 ito. 15. 
 
 now compare in size and shape? Which would make a 
 person look taller, vertical or horizontal lines? 
 
 c. Look at the rows of letters, s, and the figures, 8. 
 
 s s s s ss s 
 
 8 8 8 8 8 8 8 
 
 Fig. 16. 
 
 Do the upper and the lower halves appear to be of the 
 same size? Invert the page and look again. 
 
 d. Zollnee's Lines. Make six parallel vertical lines. 
 Do they appear parallel? Draw short parallel oblique 
 lines across them, so that those on adjacent verticals 
 
 Fig. 17. 
 
THE EYE AND VISION. 123 
 
 shall point in opposite directions. How do the parallel 
 lines now look? 
 
 e. Do the long lines appear to be of the same length in 
 Fig. 18? Measure them. 
 
 < > > < i 1 
 
 >CZ~X XX 
 
 Fig. IS. 
 
 L. Color-Blindness. 
 
 Material. A large assortment of skeins of worsteds of different 
 colors, shades, and tints. A color-blind person. 
 
 Place a large assortment of the shades and tints of 
 different colored worsteds in a good light. Select a light 
 green skein and ask the person to be examined to select 
 all the skeins of the same color whether lighter or darker. 
 A color-blind person will select shades and tints of other 
 colors. Select a bright red skein and ask the person to 
 point out other skeins of the same color. The red-blind 
 person will select green and gray ; the green-blind person 
 will select red and gray. Do not ask the person to name 
 colors. 
 
 M. Mixing of Color Sensations. 
 
 Apparatus. Rotary apparatus for color-disks. The Bradley 
 Color Wheel and Maxwell Disks. 
 
 On a rotating disk place a blue and a yellow disk in 
 such proportions as to obtain gray or white when rotated. 
 Why does it not make green ? Try different combinations 
 of colors. 
 
124 PHYSIOLOGY FOB THE LABORATORY. 
 
 W. After-images. 
 
 I. Positive Aptee-Images. 
 
 Apparatus. A gas-jet with a white globe. 
 
 Rest the eyes by closing them, and then suddenly open 
 the eyes and look for a few seconds at the gas-jet. Now 
 close the eyes again and notice what you see. 
 
 II. Negative Aftee-Images. 
 
 Material. Papers of different colors, as red and blue. 
 
 Experiment : 
 
 1. Look steadily for half a minute or longer at a 
 
 small white square on a black ground. Then 
 slip a piece of white paper over the whole 
 and notice the image. 
 
 2. Look steadily at a bright red square on a black 
 
 ground, and then slip a piece of white paper 
 over them. What color is the after-image ? 
 
 3. Obtain the after-images with other colored papers. 
 
 These images are due to fatigue of the retina 
 and brain. What relation do the colors of 
 the after-images bear to the colors of the 
 paper. 
 
XIX. 
 
 THE EAR AND HEARING. 
 
 A. The Ear. 
 
 Material. The ear of some animal, as a dog, or a large model of 
 the human ear. 
 
 Study a large model of the human ear. 
 Note: 
 
 I. The External Ear. 
 
 a. The concha, or expansion on the outside of the head. 
 
 b. The passage leading into the head, or external auditory 
 meatus. 
 
 c. The drum, or tympanic membrane at the inner end of 
 the passage. 
 
 II. The Tympanum, or Middle Ear. 
 
 a. The Eustachian tube leads from the middle ear to the 
 pharynx. What is its use ? 
 
 b. The three bones of the ear. 
 
 1. The malleus, or hammer, is in contact with the 
 
 drum. 
 
 2. The incus, or anvil-bone, rests against the malleus. 
 
 3. The stapes, or stirrup-bone, is the innermost bone. 
 
 125 
 
126 PHYSIOLOGY FOB THE LABORATORY. 
 
 III. The Internal Ear, or Labyrinth. 
 
 The Internal Ear, or Labyrinth, is protected by the 
 temporal bone of the skull. 
 
 a. The vestibule is the middle part. 
 
 b. The semicircular canals are on one side of the ves- 
 tibule. 
 
 c. The cochlea, a spirally coiled tube, is on the opposite 
 side of the vestibule. 
 
 IV. The Path of the Sound Waves. 
 
 Trace the path of the sound waves through the drum, 
 the tympanic bones, the liquids in the labyrinth to the 
 auditory nerve. 
 
 B. A Test for Hearing. 
 
 Apparatus. A watch. 
 
 a. Sit in a chair and have some one hold a ticking 
 watch at the side of one ear. How far can the watch be 
 carried before it ceases to be audible? Test the other 
 ear to see if it is equally acute. 
 
 b. Hold a ticking watch between the teeth and notice 
 how loud it ticks. Close both ears and notice the result. 
 Repeat and uncover one ear. 
 
 C. Location of Sound. 
 
 Apparatus. Two rods of iron to make a distinct sound. 
 
 Blindfold a person and see how well sounds in front, 
 at the back, and at the sides may be located. 
 
XX. 
 
 SOME DERMAL SENSATIONS. 
 Touch, Smell, and Taste. 
 A. The Sense of Touch. 
 
 I. Location of Touch. 
 
 Close the eyes and have some one touch some part of 
 the body. Can you name the part" touched? 
 
 II. The Sensibility op the Skin. 
 
 Apparatus. A pair of dividers, 
 
 Apply the blunted points of a pair of dividers simul- 
 taneously to some part of the body, as the finger tips, the 
 back of the hand, and the back of the neck. Determine 
 the distance between the two points that is necessary in 
 order that the points may be felt as two. Compare your 
 results with those given in any physiology. 
 
 III. Aristotle's Experiment. 
 
 Cross the middle finger over the forefinger, and with 
 the crossed ends rub along the bridge of the nose. What 
 is the sensation felt? 
 
 B. The Sense of Temperature. 
 
 Materials. Iron rods. Pieces of fur, silt, wood, and metallic 
 rods. Water. 
 
 Apparatus. Bunsen burner. Large beakers or basins. 
 
 127 
 
128 PHYSIOLOGY FOB THE LABORATORY. 
 
 I. Perception op Temperature. 
 
 a. Close the eyes and have some person touch different 
 parts of the body with cold and warm rods. How are the 
 sensations different? 
 
 b. With fur, wood, and metal of the same temperature 
 test the body. Which feels colder? Why? 
 
 II. Estimation op Temperature. 
 
 Plunge the hand into water of different temperatures 
 and so learn to judge the temperature of water. How hot 
 can you endure the water? Can the hands or the feet 
 endure warmer water? Plunge one hand into hot water, 
 the other in cold, and then both into warm water. What 
 is the sensation in each hand ? 
 
 i 
 
 C. The Sense of Pressure. 
 
 Apparatus. Weights of different sizes. 
 
 Estimation op Weights. 
 
 a. Lift weights of different magnitude until you are 
 able to judge some of the more common, as a pound, 
 three pounds, etc. 
 
 b. Hold a pound weight in the hand. Add a few 
 ounces. What is the least difference that you are able 
 to perceive? 
 
 D. The Senses of Taste and Smell. 
 
 Materials. Sugar, vinegar, salt, pepper, apple, potato, onion, 
 ammonia, and cabbage. 
 
SOME DERMAL SENSATIONS. 129 
 
 I. The Location op the Sense op Taste. 
 
 Place a little sugar on the tip and on the back of the 
 tongue. Where is it sweeter? Repeat with acetic acid 
 or vinegar and salt, and determine where they are more 
 sharply tasted. 
 
 II. The Difference between Taste and Smell. 
 
 Close the eyes and nostrils and try to distinguish be- 
 tween salt and pepper, apple and potato. 
 
 Which of the following have taste, and which have 
 odors, — onion, sugar, salt, vinegar, carrot, dilute ammo- 
 nia, and cabbage? 
 
XXI. 
 
 THE LARYNX AND THE VOICE. 
 A. The Larynx. 
 
 Material. The larynx of a calf or a sheep. If possible, obtain 
 a specimen of the larynx with the tongue and surrounding organs 
 still attached. 
 
 I. The Different Organs of the Specimen. 
 Identify : 
 
 a. The trachea, or windpipe. 
 
 b. The larynx, or cartilaginous box, at the upper end of 
 the trachea. 
 
 c. The oesophagus, or gullet, a muscular walled tube run- 
 ning parallel with the trachea. Notice how it is attached 
 to the larynx. 
 
 d. The tongue. How is it held in place ? 
 
 e. The hyoid bones, at the root of the tongue, holding it 
 in position. Where are they attached? 
 
 /. Some glands may be present in your specimen. 
 g. Sketch. 
 
 II. The Trachea. 
 
 Review the structure of the trachea. 
 
 III. The Larynx. 
 
 Remove the fat, the blood-vessels, the lower part of the 
 
 130 
 
THE LARYNX AND THE VOICE. 131 
 
 oesophagus, most of the tongue, the muscles of 'the pharynx, 
 and so expose the larynx. 
 
 Notice : 
 
 a. The general size and shape. 
 
 b. The front or ventral surface is easily identified by the 
 projection in the cartilage called the Adam's apple. 
 
 c. The epiglottis is the lid at the upper opening. 
 
 1. "What" is its shape? 
 
 2. Raise it. 
 
 3. Press it down and see how it closes the opening. 
 
 4. Cut it to find its structure. 
 
 d. The vocal cords are the two elastic pads seen when 
 looking into the larynx. Notice them when closed and 
 when open. 
 
 e. The mucous membrane lines the larynx. Notice how 
 it also lines the oesophagus. 
 
 /. The cartilages. 
 
 l. The large cartilage on the ventral side extend- 
 ing backward and comprising most of the 
 larynx is the thyroid cartilage. 
 
 (1) What is the exact shape ? 
 
 (2) The hyoid bone is attached to its upper 
 
 dorsal corner. 
 
 (3) At the lower dorsal corner, the thyroid is 
 
 articulated with the cricoid cartilage. 
 Notice carefully the articulation. 
 
 (4) The Adam's apple is on this cartilage. 
 
 2. The cricoid cartilage can be found on the ventral 
 side just below the thyroid. , It resembles one 
 
132 PHYSIOLOGY FOB THE LABOBATOBY. 
 
 ' of the cartilaginous rings of the trachea and 
 might easily be mistaken for one. Move it 
 up and down to see that it is separate from 
 the thyroid and the trachea. Trace it around 
 to the dorsal side underneath the lower pos- 
 terior corner of the thyroid cartilage. How 
 far on the dorsal side does it extend ? What 
 is its exact shape? How is it articulated 
 with the thyroid cartilage? 
 
 3. On the dorsal side above the cricoid cartilage on 
 either side is an arytenoid cartilage. It is con- 
 cealed by the muscles and the vocal cord, 
 but its exact shape can be found after dis- 
 secting the muscles. 
 
 g. The muscles. 
 
 1. A crico-thyroid muscle is on either side of the 
 
 dorsal surface extending from the thyroid to 
 the corresponding cricoid cartilage. 
 
 (1) Where is it attached on each cartilage? 
 
 (2) What is its use ? 
 
 (3) Dissect it away and find how the motion 
 
 of the thyroid is limited. 
 
 2. The posterior crico-arytenoid muscles are on the pos- 
 
 terior surface of the cricoid, one at either 
 side. They extend diagonally upward to 
 the corresponding arytenoid cartilages. Dis- 
 sect away the attachment on the thyroid 
 cartilage, pull the muscle, and note the effect 
 on the arytenoid cartilage and on the vocal 
 cord. 
 
THE LARYNX AND THE VOICE. 133 
 
 3. The lateral crico-arytenoid stretches from the lateral 
 
 portion of the upper edge of the cricoid, up- 
 ward and backward to the arytenoid cartilage. 
 Disarticulate the thyroid and cricoid of one 
 side, push aside the thyroid without injury to 
 the muscles, and this muscle can be readily 
 seen. Pull the muscle and note the result. 
 
 4. The arytenoid muscle may be found by cutting 
 
 away the tissue above the cricoid cartilage at 
 the back of the arytenoid cartilages. Cut 
 through the middle and also see where it is 
 attached to the arytenoid cartilages. Find 
 where the arytenoid cartilages articulate with 
 the cricoid. Pull the arytenoid muscle and 
 find its use. 
 
 5. The thyro-arytenoid muscle extends from the ven- 
 
 tral surface of the thyroid across to the aryte- 
 noid. Cut it at its origin, dissect it loose, 
 and prove its effect on the vocal cord. 
 
 h. Sketch a dorsal, a ventral, and a lateral view of the 
 larynx. 
 
 i. Carefully examine from the inside the muscles of 
 the opposite side, showing the effect of each on the vocal 
 cords. 
 
 j. Remove all the muscles and find the exact shape of 
 the cartilages. 
 
 k. Make a paper model of the cartilages of the larynx. 
 
XXII. 
 
 THE BACTERIA. 
 
 A. The Harmless or Non-Pathogenic Bacteria. 
 
 Materials. Nutrient gelatin made of 500 grms. of lean beef, 
 finely minced, 1 litre of water, 100 grms. of gold-label gelatin, 10 
 grms. of peptone, 5 grms. of salt, and sodium carbonate. One egg. 
 
 Apparatus. Steam sterilizer, or kettle for steaming. Hot-air 
 sterilizer, or oven for sterilizing with gas stove. Double boiler. 
 Stirring rod. Funnel.. Filter-paper. King-stand. Bunsen burner. 
 Litmus paper. Cotton-batting. Two glass flasks holding 500 c.c. 
 each. 
 
 To make the nutrient gelatin, mix the beef with the 
 water and allow it to stand about twelve hours. Filter 
 through "cheese-cloth," and to the filtrate or meat-water 
 add the gelatin, peptone, and water. Mix thoroughly in 
 the double boiler and heat for about half an hour. Neu- 
 tralize by adding sodium carbonate, till red litmus paper 
 just turns blue. Boil for about an hour, add an egg to 
 clarify and settle the albuminous matter, and boil a few 
 minutes longer. Filter while hot through filter-paper 
 into sterilized flasks and plug with cotton. Care should 
 be taken to keep the unfiltered gelatin hot, and to wet the 
 filter-paper with hot water before beginning to filter. 
 Sterilize the gelatin in' a steam generator twenty-five 
 minutes a day for three days in succession. If the gela- 
 tin is found to be acid at the beginning of filtration, it 
 
 134 
 
THE BACTERIA. 135 
 
 should be neutralized again and boiled for fifteen minutes. 
 If thoroughly sterile, this nutrient gelatin should keep a 
 long time. 
 
 I. Bacteria in Water and Ice. 
 
 Materials. 3 c.c. of water from tne faucet. 20 c.c. of nutrient 
 gelatin. A small piece of ice. 
 
 Apparatus. Two sterilized Petri dishes. (Caution. Keep the 
 dishes covered, and do not remove the cover till your materials are 
 ready to use.) 
 
 a. Pour the water into one of the Petri dishes, and then 
 add 10 c.c. of the nutrient gelatin which has been warmed 
 and so become liquid. Cover as soon as possible, to pre- 
 vent the bacteria in the air from falling, into the gelatin. 
 Mix the gelatin and the water by gently rotating the dish. 
 Label the dish carefully, giving the material examined, 
 the date, and your name on a piece of paper placed under 
 the dish. Keep in a darkened place at about the tempera- 
 ture of 24° C. Watch from day to day, and as the colonies 
 of bacteria appear, study them. In performing the experi- 
 ments alone, several check experiments should be made, 
 but the results of the other members of the class will 
 serve as check experiments. 
 
 Notice : 
 
 1. The number of colonies. Each colony started 
 
 from a single bacterium in the water. How 
 many bacteria were there in the water ? 
 
 2. The shape of the colonies as seen from the sur- 
 
 face and from the side. What effect do they 
 have on the gelatin ? 
 
136 PHYSIOLOGY FOB THE LABORATORY. 
 
 s. The color of the colonies. What colors do you 
 find? 
 
 b. Ice may be examined by melting it and examining 
 the water obtained, as in a. 
 
 1. Should ice be placed directly in drinking water ? 
 
 Why not? 
 
 2. How may drinking water be cooled? 
 
 II. Bacteria in Milk. 
 
 Materials. 3 c.c. of fresh milk. 10 c.c. of nutrient gelatin. 
 Apparatus. A sterilized Petri dish. 
 
 Pour the milk and then the warm nutrient gelatin into 
 a Petri dish. Mix the water and gelatin and label the 
 culture. Keep in a warm, dark place and watch from day 
 to day for the appearance of the colonies. Compare these 
 colonies with those obtained from the examination of 
 drinking water. Study these in the same way. 
 
 III. Bacteria in Dust. 
 
 Materials. A little dust gathered from the floor, the top of the 
 door, or back of a picture. 10 c.c. of nutrient gelatin. 
 
 Apparatus. A sterilized Petri dish. A compound microscope. 
 
 a. Pour the warm nutrient gelatin into the dish and 
 scatter a little dust over it. Place in a warm room and 
 watch for the appearance of the colonies. Compare these 
 with the colonies obtained from the examination of water 
 and milk. 
 
 b. Mount a little dust in water on a glass slide and 
 examine with the compound microscope. What do you 
 find? 
 
THE BACTERIA. 137 
 
 IV. Bacteria in the Am. 
 
 Material. 30 c.c. of nutrient gelatin. 
 Apparatus. 3 sterilized Petri dishes. 
 
 a. Pour 10 c.c. of the warm nutrient gelatin into a Petri 
 dish, and allow it to stand for two minutes uncovered and 
 exposed to the air of the room. Then cover and place 
 with the other tests. Study the colonies as they appear. 
 
 b. Test in the same way the air of a room before and 
 after sweeping and compare your results. 
 
 1. Why are hardwood floors more healthful than 
 
 carpets ? 
 
 2. Which is better, a cloth or a feather duster? 
 
 Why? 
 
 V. Bacteria in Vinegar. 
 
 Materials. A few c.c. of mother-of-vinegar. 
 
 Apparatus. A compound microscope, glass slide, and cover-glass. 
 
 Mount a few drops of mother-of-vinegar on a glass slide, 
 examine with the microscope, and study the bacteria. 
 
 Notice : 
 
 a. Their size, shape, and motion. 
 
 b. In what are the bacteria embedded? This mass of 
 jelly is called a zooglea. It is formed by many individuals 
 whose cell-walls have become mucilaginous. If the mass 
 is membranous, as in the mother-of-vinegar, it is called 
 mycodenna, or fungus-skin. 
 
 VI. The Microscopical Examination of Bacteria. 
 
 Materials. Colonies of bacteria obtained from samples of water 
 and milk. 
 
 Apparatus. A compound microscope. 
 
138 PHYSIOLOGY FOB THE LABORATORY. 
 
 Mount on a glass slide a drop of the liquid containing 
 bacteria. Cover with a cover-glass and examine with high 
 power. 
 
 Notice : 
 
 a. The size of the bacteria. 
 
 b. Their shape and motion. 
 
 B. The Pathogenic Bacteria. 
 
 Materials. Prepared slides of cultures of the bacteria that pro- 
 duce typhoid fever, diphtheria, consumption, and splenic fever. 
 Apparatus. A compound microscope. 
 
 Examine with the microscope prepared slides of bacillus 
 typhi abdominalis (typhoid fever), bacillus diphtheriae (diph- 
 theria), bacillus tuberculosis (consumption), and bacillus 
 anthracis (splenic fever). Study as in A. VI. Do you 
 find any cilia? 
 
 a. "What other diseases are caused by bacteria ? 
 
 b. How is the body able to combat the bacteria? 
 
 c. What is susceptibility to disease ? 
 
 d. What is immunity from disease ? 
 
 e. Is consumption hereditary? Explain the most com- 
 mon " cures " for consumption. 
 
 /. What is one method of treatment for diphtheria ? 
 g. What is antitoxine ? How is it obtained ? 
 h. What js vaccination? Give reasons for and against 
 it. 
 
THE BACTERIA. 139 
 
 C. Putrefaction. 
 The Cause of Putrefaction. 
 
 Materials. 300 c.c. of hay infusion. To make hay infusion, 
 pour hot water on hay, allow it to stand a few hours and then filter 
 through paper. 
 
 Apparatus. 3 glass flasks. Cotton-batting. Cork to fit one 
 
 Pour 100 c.c. of hay infusion into each flask and boil 
 for an hour. Allow the first flask to stand uncorked. 
 Cork the second air-tight while boiling. Plug the third 
 with cotton-batting while boiling. Allow the three to 
 stand side by side on the table and watch from day to 
 day. Explain the results. 
 
 a. Why will preserves keep in a thick syrup? 
 
 b. Why are pickles preserved in vinegar? 
 e. Why does tripe keep in brine ? 
 
 d. Explain the conditions in canned beef. 
 
 D. Conditions Necessary for the Growth of Bacteria. 
 I. Heat. 
 
 Materials. 300 c.c. of fresh milk. Ice. 
 
 Apparatus. 3 bottles. Hot water-bath. Bunsen burner. 
 
 a. Pour 100 c.c. of fresh milk in one bottle. Cork it 
 and place it on ice. 
 
 b. Pour 100 c.c. of the milk in another bottle. Cork it 
 and allow it to stand on the table. 
 
 o. Boil for an hour the other 100 c.c. of milk in the 
 third bottle, plug the bottle with cotton-batting and allow 
 it to stand on the table. 
 
140 PHYSIOLOGY FOB THE LABORATORY. 
 
 d. Compare the three from day to day. Souring of 
 milk is due to the presence of certain bacteria. They 
 convert the milk sugar into lactic acid which gives the 
 sour taste and curdles the milk. 
 
 1. In which of the three bottles is the best growth 
 
 of bacteria? 
 
 2. What is the effect of extreme heat and cold 
 
 upon bacteria? 
 
 3. Why does food keep in refrigerators? 
 
 4. Does frozen beef decay? Why not? 
 
 II. Moisture. 
 
 Material. 10 c.c. of nutrient gelatin. 
 Apparatus. A Petri dish. 
 
 Pour 'the warm nutrient gelatin into a Petri dish and 
 allow it to stand uncovered for several days. 
 
 a. Do the colonies of bacteria appear ? 
 
 b. How long do they grow? 
 
 c. What happens to them? 
 
 d. What happens to the bacteria if the disk is placed in 
 a windy place ? 
 
 e. Are the bacteria blown about when moist or dry? 
 This is a common source of infection in contagious 
 diseases. 
 
 /. Should infected matter from the sick room be allowed 
 to dry? 
 
 g. What should be done with it ? Is moisture necessary 
 to the growth of bacteria ? 
 
 h. Why does ham keep? 
 
THE BACTERIA. 141 
 
 III. Light. 
 
 Materials. 10 c.c. of nutrient gelatin. 
 Apparatus. A sterilized Petri dish. Black paper. 
 
 Pour the liquid nutrient gelatin into the dish and expose 
 it two or three minutes to the air. Why? Cover and 
 paste a piece of black paper over half of the dish and 
 expose it to strong sunlight in an ordinary room. Watch 
 it from day to day and notice the result. Explain. 
 
 a. Is light or darkness more favorable to the growth of 
 bacteria ? 
 
 b. Which are more healthful, sunny or dark rooms? 
 Why? 
 
 c. What three conditions have you found essential to 
 the growth of bacteria? 
 
 E. Milk. 
 
 Since milk is a good food and furnishes, proper nutri- 
 ment for the growth of bacteria, it becomes a serious matter 
 to keep milk free from bacteria. 
 
 I. The Contamination of Milk. 
 
 a. Sources of contamination. 
 
 b. Prevention of contamination. 
 
 c. Laws in regard to handling milk by milk-men. 
 
 d. Adulteration of milk. 
 
 1. Why is milk adulterated? 
 
 2. What chemicals are most often used? 
 
 II. The Preservation op Milk. 
 
 a. Preservatives. Sometimes various chemicals are added 
 to prevent, souring. What is used for this purpose ? 
 
142 , PHYSIOLOGY FOE THE LABORATORY. 
 
 b. The sterilization of milk. 
 
 l. Recall experiment D. I. How long did the 
 boiled milk keep sweet? How does boiling 
 affect the taste of milk? If the milk is 
 heated hot enough to kill all the infectious 
 germs, a scum appears on the top which is 
 the albumin of the milk coagulated by heat. 
 A boiled taste is also acquired which is 
 objectionable to some persons, though very- 
 pleasant to others. Milk thus heated is a 
 little less digestible than fresh milk. If a 
 high degree of heat is used, the sugar is 
 scorched, and this forms a brown sediment 
 on the bottom of the dish. 
 
 c. The Pasteurization of milk. 
 
 Materials. Milk. Water. 
 
 Apparatus. Pasteurizing apparatus or tin pail. Thermometer. 
 Bunsen burner. Stand. Bottles. Cotton-batting. 
 
 The Pasteurization of milk may be easily done in any 
 home. 
 
 Fill one or more bottles nearly full of milk and plug 
 with dry, clean cotton-batting. The apparatus for Pas- 
 teurizing consists of a large tin pail which has a false tin 
 bottom perforated with holes. The cover should fit tightly 
 and have a thermometer held in place by a cork in an 
 opening. Place the bottles in an upright position in the 
 pail and fill the pail with enough water to rise above the 
 milk in the bottles. Close the pail and heat over a Bunsen 
 burner until the water is 155° F. (if in winter) or 180° 
 (in summer). Then remove the pail and keep tightly cov- 
 
THE BACTERIA. 
 
 143 
 
 ered for half an hour. A cloth over the pail will help to 
 retain the heat. Take out the milk bottles, cool as quickly 
 as possible in cold water or on ice, and keep in a cold 
 
 Fig. 19. — Apparatus for Pasteurizing Milk. 
 
 place. The cotton plugs should be kept dry and not 
 removed until the milk is to be used. 
 
 a. Taste the milk to determine if its flavor has been 
 changed. 
 
 b. Keep the bottles at the ordinary temperature of the 
 room. How long does the milk keep before souring? 
 
 c. Is the milk germ free ? Prove it. 
 
 F. Disinfection. 
 
 By disinfection we mean killing all the bacteria and 
 their spores. Bacteria may be killed in several ways. 
 
 I. The Action of Chemicals. 
 
 Materials. 2 c.c. of a (1 to 1000) solution of corrosive sublimate. 
 4 c.c. of milk. 20 c.c. of nutrient gelatin. 
 Apparatus. Two sterilized Petri dishes. 
 
144 PHYSIOLOGY FOR THE LABORATORY. 
 
 a. Pour 10 c.c. of the warm nutrient gelatin into a 
 sterilized Petri dish. Add the corrosive sublimate and 
 thoroughly mix it with the gelatin by rotating the dish. 
 Add 2 c.c. of the milk and mix it with the gelatin. 
 
 b. Pour 10 c.c. of the warm gelatin into the other Petri 
 dish. Add 2 c.c. of the milk. Place the two dishes 
 under the same conditions of heat and light and watch 
 for results from day to day. Explain. 
 
 - l. What other chemicals are used as disinfectants ? 
 
 2. How do they disinfect? 
 
 3. What danger is there in their use ? 
 
 4. When may chemicals be safely used as disin- 
 
 fectants ? 
 
 5. When may they not be used ? 
 
 II. The Effect of Heat. 
 
 a. Recall experiment A. I. b. 
 Does freezing kill bacteria? 
 
 b. Recall experiments C. I and D. I. 
 
 Does boiling or exposure for three quarters of an hour 
 at 100° C. by means of steam kill bacteria? 
 
 ' c. Some foods and liquids would be injured by exposure 
 for three quarters of an hour to so high a temperature as 
 100° C. How was the nutrient gelatin sterilized? This 
 method is called discontinuous sterilization. The gelatin was 
 subjected to a temperature of 56° C. for three or four hours 
 on three successive days. 
 
 1. Were all the bacteria killed on the first day? 
 
 What happened to the spores? 
 
 2. What took place on the second and third days ? 
 
THE BACTERIA. 145 
 
 d. l. Recall experiment E. 
 
 2. Is Pasteurized milk sterile ? 
 
 e. How were the flasks and Petri dishes sterilized? 
 This method is hot-air sterilization. The objects need to be 
 subjected to a temperature of 150° C. for three quarters 
 of an hour in dry air. What kind of objects are best 
 sterilized in this way ? 
 
 G. Purification of Water. 
 Read upon the following subjects : — 
 
 1. Purification of water by sand filtration. Describe 
 
 a filtration plant such as is used to filter the 
 drinking water of the city of Lawrence, Mass., 
 or Albany, N. Y. 
 
 2. Domestic filters. Their efficiency. 
 
 3. Sterilization of water by heat. 
 
 4. Purification of water by sedimentation. 
 
 5. Purification of water by agitation with solid par- 
 
 ticles and subsequent subsidence. 
 
 6. Chemical precipitation. 
 
 7. Purification of sewage. 
 
 H. Epidemics. 
 
 Give the history of one epidemic, either of typhoid fever 
 or of diphtheria. 
 
 a. Its cause and extent. 
 
 b. Its means of spreading. 
 
 c. Remedies. 
 
APPENDIX. 
 
 A LIST OF SPECIMENS NEEDED. 
 
 1. A human skeleton. 
 
 2. Pieces of bone to burn. 
 
 3. Slender (rib) bone to place in acid. 
 
 4. Long bones. 
 
 5. Tabular bones. 
 
 6. Short bones. 
 
 7. . Irregular bones or vertebrae. 
 
 Note. — Numbers 4, 5, 6, and 7 may be obtained at the market, from 
 the table, or found already cleaned in the fields. Partial skeletons of a 
 dog, a horse, a bird, or a cow are very useful. 
 
 8. The axis and atlas. 
 
 9. A fresh long bone sawed longitudinally. 
 
 10. Part of a skeleton to clean and mount. 
 
 11. A ball-and-socket joint of an ox, a hip-joint. 
 
 12. The fore leg of a sheep. 
 
 13. Postal bones of some young animal, as a pig. 
 
 14. A chicken or fowl. 
 
 15. A small piece of corned beef. 
 
 16. Presh blood. 
 
 17. The heart and lungs of a sheep. 
 
 18. Frogs. 
 
 19. Different kinds of human teeth. 
 
 20. A kidney of a sheep. 
 
 21. The brain of a sheep. 
 
 147 
 
148 APPENDIX. 
 
 22. The spinal cord of some large animal. 
 
 23. The eye of an ox. 
 
 24. The larynx of a calf or sheep. 
 
 25. A living cat. 
 
 26. A rabbit. 
 
 27. Saliva. 
 
 28. The teeth of horse, dog, and cat. 
 
 29. A few drops of human blood. 
 
 Note. — The skeleton and other bones may be obtained of Ward's 
 Natural History Establishment, Rochester, N. Y. 
 
 A LIST OF MICROSCOPICAL SLIDES. 
 
 1. 
 
 Circulation of the blood in the web of the foot of a frog. 
 
 2. 
 
 Cross-section of 
 
 adipose tissue. 
 
 3. 
 
 a 
 
 it 
 
 (C 
 
 a human humerus bone. 
 
 4. 
 
 it 
 
 a 
 
 tt 
 
 developing bone. 
 
 5. 
 
 ii 
 
 n 
 
 a 
 
 the skin of the head. 
 
 6. 
 
 a 
 
 tt 
 
 " 
 
 the spinal cord, cervical region. 
 
 7. 
 
 tt 
 
 it 
 
 a 
 
 the spinal cord, dorsal region. 
 
 8. 
 
 a 
 
 a 
 
 a 
 
 the spinal cord, lumbar region. 
 
 9. 
 
 a 
 
 it 
 
 u 
 
 the brain. 
 
 10. 
 
 a 
 
 a 
 
 u 
 
 a nerve ganglion. 
 
 11. 
 
 a 
 
 Li 
 
 a 
 
 a tooth. 
 
 12. 
 
 a 
 
 it 
 
 a 
 
 the wall of the stomach. 
 
 13. 
 
 a 
 
 it 
 
 a 
 
 the small intestine. 
 
 14. 
 
 a 
 
 a 
 
 tt 
 
 the liver. 
 
 15. 
 
 a 
 
 a 
 
 tt 
 
 a muscle. 
 
 16. 
 
 a 
 
 ce 
 
 tt 
 
 the pancreas. 
 
 17. A radial section of kidney. 
 
 18. Fresh human blood, a few drops. 
 
 19. Hyaline cartilage. 
 
 20. Milk. 
 
APPENDIX. 149 
 
 21. Plain muscle fibres. 
 
 22. Potato starch grains. 
 
 23. Saliva. 
 
 24. Slide of bacillus typhi abdominalis. 
 
 25. " " » diphtherias. 
 
 26. " " " tuberculosis. 
 
 27. " " " anthracis. 
 
 28. Stained corpuscles of the blood of the frog. 
 
 29. Striated muscle fibres. 
 
 30. Typical cells, as the cells in the cast-off skin of a newt 
 
 or frog. 
 
 Note. — Numbers 1, 18, 20, 22, and 23 may be prepared before the 
 class exercise. The other slides may be obtained of Bausch & Lomb 
 Optical Company, Rochester, N. Y. 
 
 
 A LIST OF MODELS, 
 
 1. 
 
 A manikin. 
 
 2. 
 
 A model of the brain. 
 
 3. 
 
 " " " " eye. 
 
 4. 
 
 " " " " ear. 
 
 5. 
 
 " " " " heart. 
 
 6. 
 
 A wooden model of the arm. 
 
 7. 
 
 A model of the valves of the aorta. 
 
 8. " " " " chest to show the vertical enlargement. 
 
 9. " " to show the dorso-ventral enlargement of the 
 
 chest. 
 
 10. The circulation apparatus of glass and rubber tubing. 
 
 11. The lever apparatus. 
 
 12. A paper model of the larynx. 
 
 Note. — The models numbers 6, 3, 8, 9, and 12 are to be made by the 
 student. Most of the other models may be obtained of Ward's Natural 
 History Establishment, Rochester, N. Y., or of Mr. Charles H. Ward, 
 Rochester, N. Y. 
 
150 
 
 APPENDIX. 
 
 A LIST OF CHEMICALS AND OTHER SUPPLIES. 
 
 1. 
 
 Acetic acid. 
 
 30. 
 
 Beans. 
 
 2. 
 
 Alcohol. 
 
 31. 
 
 Beef, lean. 
 
 3. 
 
 Ammonium chloride. 
 
 32. 
 
 Bread. 
 
 4. 
 
 Ammonium hydrate. 
 
 33. 
 
 Butter. 
 
 5. 
 
 Barfoed's solution. 
 
 34. 
 
 Cabbage. 
 
 6. 
 
 Benzine. 
 
 35. 
 
 Cane sugar or saccharose, 
 
 7. 
 
 Borax. 
 
 36. 
 
 Carrot. 
 
 8. 
 
 Chloroform. 
 
 37. 
 
 Cheese. 
 
 9. 
 
 Chrome alum. 
 
 38. 
 
 Corn meal. 
 
 10. 
 
 Corrosive sublimate. 
 
 39. 
 
 Cornstarch. 
 
 11. 
 
 Cupric sulphate, 10 per 
 
 40. 
 
 Crackers. 
 
 
 cent solution. 
 
 41. 
 
 Dates. '-— _ 
 
 12. 
 
 Fehling's solution. 
 
 42. 
 
 Dextrose. 
 
 13. 
 
 Formalin. 
 
 43. 
 
 Eggs. 
 
 14. 
 
 Gelatin, gold label. 
 
 44. 
 
 Farina. 
 
 15. 
 
 Hydrochloric acid. 
 
 45. 
 
 Glue. 
 
 16. 
 
 Iodine. 
 
 46. 
 
 Grapes. 
 
 .17. 
 
 Lime-water. 
 
 47. 
 
 Ice. 
 
 18. 
 
 Nitric acid. 
 
 48. 
 
 Indian meal. 
 
 19. 
 
 Normal salt solution. 
 
 49. 
 
 Lactose. 
 
 20. 
 
 Pancreatin, Fairchild's. 
 
 50. 
 
 Maple sugar. 
 
 21. 
 
 Pepsin, Fairchild's. 
 
 51. 
 
 Maple syrup. 
 
 22. 
 
 Peptone. 
 
 52. 
 
 Milk. 
 
 23. 
 
 Potassium bichromate. 
 
 53. 
 
 Molasses. 
 
 24. 
 
 Potassium ferrocyanide. 
 
 54. 
 
 Oatmeal. 
 
 25. 
 
 Bennet. 
 
 55. 
 
 Olive oil. 
 
 26. 
 
 Sodium hydrate. 
 
 56. 
 
 Onions. 
 
 27. 
 
 Sodium carbonate. 
 
 57. 
 
 Peas. 
 
 
 
 • 58. 
 
 Pepper. 
 
 
 
 28. 
 
 Apples. 
 
 59. 
 
 Potato. 
 
 29. 
 
 Barley. 
 
 60. 
 
 Prunes. 
 
APPENDIX. 151 
 
 61. Eice. 66. Tapioca. 
 
 62. Rye. 67. Turnips. 
 
 63. Sago. 68. Vinegar and mother-of- 
 
 64. Salt. vinegar. 
 
 65. Starch. 69. Whole wheat flour. 
 
 Note. — " Barfoed's Solution. Make a solution of neutral acetate of 
 copper containing 1 part of the salt to 15 parts of water. To 200 c.c. of 
 tliis solution add 5 c.c. of a 38 per cent solution of acetic acid. 
 
 Fehling's Solution. Solution A. 34.64 grams of pure crystalline 
 cupric sulphate are powdered and dissolved in 500 c.c. of distilled water. 
 Solution B. In another vessel dissolve 173 grams of Rochelle salts 
 (sodio-potassium tartrate) in 100 c.c. of pure caustic soda, sp. gr. 1.34, 
 and add water to make 500 c.c. Keep the two solutions separate in 
 stoppered bottles, and mix them as required. On mixing equal quanti- 
 ties of A and B, a clear deep blue fluid is obtained." — Stirling's Practi- 
 cal Physiology. 
 
 A LIST OF APPARATUS. 
 
 1. A compound microscope giving a magnification of about 
 
 six hundred diameters. 
 
 2. A hand magnifying glass ; the tripod is convenient. 
 
 3. A set of instruments for each student, composed of — 
 
 1. One scalpel, No. 5435 (Cat., Fifteenth Edition) ; 
 
 2. One pair of scissors, No. 5585 ; 
 
 3. One pair of forceps, No. 5825 ; 
 
 4. One blowpipe, No. 5910 ; 
 
 5. Two needle holders, No. 5970. 
 
 4. Pencils, hard and medium. 
 
 5. Colored crayons, red, blue, yellow, and green. 
 
 6. Air-tight box for killing rabbit. (The crock for waste 
 
 material may be used.) 
 
152 APPENDIX. 
 
 7. Beakers. 16. Cotton-batting. 
 
 8. Bell-jar. 17. Cotton, white. 
 
 9. Bulb syringe. 18. Cover-glasses. 
 
 10. Bunsen burner. 19. Double boiler. 
 
 11. Bone forceps. 20. Double convex lens. 
 
 12. Candle and stand. 21. Evaporating dish. 
 
 13. Cardboard. 22. Fasteners. 
 
 14. Colored paper. 23. Filter-paper. 
 
 15. Colored worsteds. 24. Force-pump. 
 
 25. Fulcrum, or triangular prism of wood. 
 
 26. Funnel. 
 
 27. Fur, a small piece. 
 
 28. Gimlet. 
 
 29. Glass bottles. 
 
 30. Glass bottle with flat sides. 
 
 31. Glass flasks, two, 500 c.c. each. 
 
 32. Glass rods, 35 cm., of 2 m.m. in diameter. 
 
 33. Glass rods, for stirring rods. 
 
 34. Glass slides. 
 
 35. Glass tubing. 
 
 Three-way glass connecting tubing, Y-shape. 
 
 Six large size, 12 m.m. in diameter, length of one 
 
 •arm, 90 m.m. 
 Eight medium size, 6 m.m. in diameter, length of 
 
 one arm, 65 m.m. 
 Two medium size, T-shaped, 6 m.m. in diameter, 
 
 length of one arm, 65 m.m. 
 Sixteen small size, 4 m.m. in diameter, length of 
 
 one arm, 60 m.m. 
 
 36. Glass tubing of different sizes. 
 
 37. Glass tubing, 50 cm. 12 m.m. in diameter. 
 
 38. Granite-ware stew-pan. 
 
 39. Ground-glass screen. 
 
APPENDIX. 153 
 
 40. Hot-air sterilizer or oven. 
 
 41. Knitting needle or probe. 
 
 42. Litmus paper. 
 
 43. Lamp-chimney. 
 
 44. Meat-saw. 
 
 45. Mortar and pestle. 
 
 46. Needles and thread. 
 
 47. Pair of dividers. 
 
 48. Pasteurizing apparatus or tin pail. 
 
 49. Petri dishes. 
 
 50. Pinch-cocks. 
 
 51. Pins. 
 
 52. Ring-stand. 
 
 53. Pods of wood and metal. 
 
 54. Eotary apparatus with color disks. Bradley Color Wheel 
 
 and Maxwell Disks. 
 
 55. Rubber dam. 
 
 56. Rubber tubing. 
 
 660 cm. pure rubber tubing, 12 m.m. in diameter. 
 1£ metre pure rubber tubing, 6 m.m. in diameter. 
 560 cm. pure rubber tubing, 5 m.m. in diameter. 
 
 57. Ruler or tape-measure. 
 
 58. Scales, Fairbanks' Standard! 
 
 59. Sheet-cork. 
 
 60. Sponge. 
 
 61. Spring-balance. 
 
 62. Steam sterilizer or kettle for steaming. May use the 
 
 Pasteurizing apparatus. 
 
 63. Test-tubes. 
 
 64. Test-tube rack. 
 
 65. Test-types for testing eyes. 
 
 66. Thermometer, chemical. 
 
 67. Thermometer, physician's. 
 
 «f 
 
154 APPENDIX. 
 
 68. Twine. 
 
 69. Watch-crystals. 
 
 70. Water-bath. 
 
 71. Weights of different sizes. 
 
 72. Wire, fine. 
 
 73. Wire-gauze. 
 
 74. Wooden pail. 
 
 75. • Wooden rods for levers. 
 
 76. Dr. Fitz's lever apparatus. 
 
 Note 1. — References as to the kind of apparatus are to the catalogues 
 of Bausch and Lomb Optical Company. 
 
 Note 2. — When time permits there are other more difficult experi- 
 ments that may be introduced as class exercises. The apparatus for 
 such experiments may be obtained of the Waltham Clock Co., "Waltham, 
 Mass. 
 
 REFERENCE BOOKS. 
 
 An American Text-Book of Physiology. W. H. Howell. W. B. 
 
 Saunders, Philadelphia. 
 A Text-Book of Physiology. M. Foster. The Macmillan Company. 
 The Human Body. The Advanced Course and the Briefer Course. 
 
 H. N. Martin. Henry Holt & Co. 
 Lessons in Elementary Physiology. T. H. Huxley. The Macmil- 
 lan Company. 
 Human Physiology. J. C. Dalton. Lea Brothers & Co. 
 Anatomy. Henry Gray. (Latest revision.) Lea Brothers & Co. 
 The Essentials of Histology. E. A. Schafer. Lea Brothers & Co. 
 Hints for Teachers of Physiology. Guides for Science Teaching, 
 
 No. XIV. H. P. Bowditch. D. C. Heath & Co. 
 Foods: Nutritive Value and Cost. Department of Agriculture, 
 
 Washington, D. C. 
 Food as a Factor in Student Life. Mrs. Ellen H. Richards and 
 
 Marion Talbot. The University of Chicago Press. 
 Prize-Essay. The Five Food Principles. Mrs. M. H. Abel. Henry 
 
 Lomb, Rochester, N. Y. 
 
APPENDIX. 155 
 
 Finger Prints. Francis Galton. The Macmillan Company. 
 
 Chemistry of Cookery. W. M. Williams. D. Appleton & Co. 
 
 The Physiology of Bodily Exercise. Fernand Lagrange. D. Apple- 
 ton & Co. 
 
 The Making of the Body. Mrs. S. A. Barnett. Longmans, Green 
 &Co. 
 
 A Course of Elementary Practical Physiology and Histology. Fos- 
 ter & Langley. The Macmillan Company. 
 
 Outlines of Practical Physiology. William Stirling. Blakiston, 
 Son & Co., Philadelphia. 
 
 A Handbook of Simple Experiments in Physiology. Charles H. 
 Stowell. Silver, Burdett & Co. 
 
 Practical Physiology. J. M. Callahan. A. Flanagan, Chicago. 
 
 Practical Zoology. Buel P. Colton. D. C. Heath & Co. 
 
 Home-Made Apparatus. Woodhull. E. L. Kellogg & Co., N. Y. 
 
 Laboratory Exercises in Anatomy and Physiology. J. E. Peabody. 
 Henry Holt & Co. 
 
 Bapteria and Their Products. S. Woodhead. Charles Scribner's 
 Sons. 
 
 Our Secret Friends and Foes. P. F. Frankland. E. and J. B. 
 Young & Co., N. Y. 
 
 The Story of the Bacteria. T. M. Prudden. G-. P. Putnam's Sons. 
 
 The Story of Germ Life. H. W. Conn. D. Appleton & Co. 
 
INDEX. 
 
 A. 
 
 Abducens, 102. 
 Absorption, 83, 84. 
 Accommodation, 118. 
 Acetabulum, 19. 
 Acetic acid, 73, 83, 85, 129. 
 Adam's apple, 131. 
 Adjustment, 3, 4. 
 After-images, 124. 
 Agitation, 145. 
 Air, 5Q, 51, 137. 
 Albino, 117, 118. 
 Albumin, 142. 
 Albuminoid, 14. 
 Alcohol, 75, 93, 95. 
 Alveolus, 66. 
 Ammonium chloride, 75. 
 
 hydrate, 14, 16, 73, 129. 
 Amylopsin, 81. 
 Animals, 117. 
 Antitoxine, 138. 
 Aorta, 38, 39. 
 Apex of heart, 36. 
 Apparatus, 151-154. 
 Appendix, 61, 147-155. 
 Apple, 67, 129. 
 Aqueduct of Sylvius, 103. 
 Arachnoid membrane, 96. 
 Arch, 90. 
 Areas, motor, 100, 101. 
 
 sense, 100, 101. 
 
 Aristotle's experiment, 127. 
 Arm, 2, 26, 29, 100, 101. 
 Artery, 38, 39, 43, 44, 50, 66. 
 Articular extremities, 11. 
 
 process, 12, 13. 
 Astigmatism, 119. 
 Atlas, 12, 13. 
 Auricles, 37, 38, 41. 
 Axis, 12, 13, 113. 
 
 cylinder, 105, 110. 
 Axon, 105, 110. 
 
 B. 
 
 Bacillus, anthracis, 138. 
 
 diphtheria, 138. 
 
 tuberculosis, 138. 
 
 typhi abdominalis, 138. 
 Back, 106. 
 
 Bacteria, 77, 134-145. 
 Baking powder (see sodium car- 
 bonate). 
 Barley, 69. 
 Base of heart, 36. 
 Bausch & Lomb Optical Co. , 5, 149. 
 Beans, 69. 
 Beats of heart, 41. 
 Beef, 23, 75, 82, 134, 139, 140. 
 Belly of a muscle, 22. 
 Benzine, 76. 
 Biceps, 24, 28. 
 Bicuspid, 39, 56. 
 
 157 
 
158 
 
 INDEX. 
 
 Bile duct, 62, 66. 
 Binocular vision, 120. 
 Bipenniform, 24. 
 Blind spot, 115, 116, 120. 
 Blister, 90. 
 Blood, 31, 48. 
 
 arterial, 34. 
 
 circulation, 35. 
 
 clotting, 32. 
 
 color, 34: 
 
 flowing, 44. 
 
 human, 31. 
 
 of frog, 31. 
 
 of hen, 32. 
 
 of pigeon, 32. 
 
 principles of circulation, 43. 
 
 structure, 31. 
 
 venous, 34. 
 
 -vessels, 23, 37, 43, 65, 87, 88, 
 89, 107, 116, 130. 
 Bodies, restiform, 99. 
 Body, 26, 43, 51, 57, 58, 100, 127, 
 128, 138. 
 
 of the compound microscope,2. 
 
 of gland, 92. 
 
 pituitary, 100. 
 Bone, 9, 10, 11, 12, 13, 14, 15. 
 
 anvil, 126. 
 
 developing, 21. 
 
 hard, 11. 
 
 hyoid, 130, 131. 
 
 irregular, 9. 
 
 long, 9. 
 
 microscopical structure, 15. 
 
 short, 9. 
 
 spongy, 11, 13. 
 
 stirrup, 126. 
 
 tabular, 9. 
 
 tympanic, 126. 
 Books of reference, 154, 155. 
 Borax, 16. 
 
 Brain, 94-105, 108, 110, 111, 124. 
 Bread, 69. 
 Breathing, 52. 
 Brine, 139. 
 Bronchial tubes, 50. 
 Bronchus, 50. 
 Bulb, spinal, 96, 99. 
 Butter, 75, 76, 81. 
 
 Cabbage, 67, 129. 
 Calcium carbonate, 14. 
 
 phosphate, 14. 
 Calf, 29, 106, 130. 
 Calices, 88. 
 Canal, 107, 126. 
 
 alimentary, 59, 63, 83. 
 Canaliculi, 15. 
 Candle-flame, 117 f 118. 
 Cane-sugar (see saccharose). 
 Canine, 56, 59. 
 Capillaries, 42, 44. 
 Carbohydrates, 67, 72, 81. 
 Carbon dioxide, 51. 
 Cardboard, 16, 17. 
 Cardiac orifice, 60. 
 Card-test, 119. 
 Carnivorous animals, 57. 
 Carpal bones, 18. 
 Carpets, 137. 
 Carrot, 67, 129. 
 Cartilage, 8, 11, 19, 20, 21. 
 
 arytenoid, 132, 133. 
 
 cricoid, 131, 133. 
 
 thyroid, 131, 132, 133. 
 Casein, 73, 74, 81, 83. 
 Cat, 93, 117, 119, 120. 
 Cavity, abdominal, 58, 63. 
 
 body, 109, 112. 
 
 buccal (see mouth). 
 
INDEX. 
 
 159 
 
 Cavity of bone, 11. 
 
 of brain (see ventricles). 
 
 thoracic, 58. 
 Cells, 7, 8, 15, 66, 91, 102, 103. 
 
 cartilage, 20. 
 
 epithelial, 77, .84, 105. 
 
 hepatic, 66. 
 
 muscle, 105. 
 
 nerve, 105, 107, 108, 110. 
 Cell-wall, 7. 
 Cement, 56, 
 Centres, 101. 
 Centrum, 12. 
 
 Cerebellum, 96, 97, 98, 99, 100, 104. 
 Cerebral hemispheres, 97, 103. 
 Cerebrum, 96, 97, 100. 
 Cervical region, 108. 
 
 swellings, 106. 
 Chamber of eye, 114, 115, 116. 
 Check experiments, 135. 
 Cheek, 90. 
 Cheese, 74. 
 
 Chemicals, 141, 143, 150, 151. 
 Chest, 51, 52. 
 Chiasma, optic, 100, 104. 
 Chicken, 22. 
 
 Chloroform, 108, 109, 110, 111. 
 Chordae tendinse, 39. 
 Choroid coat, 114, 115, 118. 
 Chromatin loops, 7. 
 Chrome alum, 120, 121. 
 Cilia, 138. 
 Circle, 120. 
 
 Circulation, principles of, 43. 
 Clark-Maxwell's experiment, 120. 
 Clips, 2. 
 Clock, 119. 
 Clot, 33, 83. 
 Cloud, 121. 
 Coat, 110, 116. 
 Cochlea, 126. 
 
 Ccacum, 61. 
 
 Cohnheim, areas of, 25. 
 
 Collagen, 14. 
 
 Colon, 61. 
 
 Colonies, 135, 136, 140. 
 
 Color, 123, 136: 
 
 Color-blindness, 123. 
 
 -disks, 123. 
 Column, spinal (see vertebral 
 
 column). 
 Columns, posterior, 99, 108. 
 Compositions of food, 67. 
 Concentric structure, 69. 
 Concha, 125. 
 Conjunctiva, 114. 
 Consumption, 138. 
 Contamination, 141. 
 Contents, vii. 
 Convolutions, 97, 104. 
 Cord (see tendons). 
 Cord, spinal, 94, 103, 106, 107, 108, 
 110, 111, 112. 
 
 vocal, 131, 132, 133. 
 Cornea, 113, 114, 115, 118, 119. 
 Cornstarch, 69. 
 Cornua, 107, 108. 
 Corpora quadrigemina, 97, 99, 100, 
 
 102. 
 Corpus callosum, 103, 104. 
 
 striatum, 104. 
 Corpuscles, red, 31, 42. 
 
 white, 31, 42. 
 Cortex, 88, 101, 102. 
 Cot, rubber, 86. 
 Coverings, 95. 
 Crackers, 69. 
 Cream, 75. 
 Creases, 89. 
 Cross, 120. 
 Crown of tooth, 55. 
 Crura cerebri, 96, 100, 101, 102. 
 
160 
 
 INDEX. 
 
 Crypts of Lieberkuhn, 65. 
 
 Culture, 136. 
 
 Cupric sulphate, 73, 74. 
 
 Curd, 80, 83. 
 
 Curdle, 140. 
 
 D. 
 
 Dates, 72. 
 Debris of food, 67. 
 Defects in vision, 118. 
 Dendrites, 105. 
 Dentatum corpus, 105. 
 Dentine, 56. 
 Dermis, 90, 91, 92. 
 Dextrose, 70, 71, 72, 84, 85. 
 Diaphragm, 2, 4, 35, 52, 59, 61. 
 Diffusion, 84. 
 Digestion, 55-66. 
 
 organs of, 58, 76, 77-86, 112. 
 Diphtheria, 138, 145. 
 Directions, general, 1-6. 
 Diseases, 138, 140. 
 Disinfectants, 144. 
 Disinfection, 143. 
 Distribution, 109. 
 Dog, 93, 117, 125. 
 Drawings, 5. 
 
 Draw-tube of compound micro- 
 scope, 2, 4. 
 Drum, 126, 126. 
 Duct, 66, 92, 116. 
 Dust, 136. 
 Duster, 137. 
 
 Ear, 94, 125, 126. 
 Egg, 72, 75, 76, 84, 85. 
 
 -albumin, 72, 74, 75, 79. 
 Elbow-joint, 29. 
 
 Emulsion, 75, 76. 
 Enamel, 56. 
 Epidemic, 145. 
 Epidermis, 42, 89, 91, 92. 
 Epiglottis, 59, 131. 
 Ether, 76, 93. 
 Eustachian tubes, 59, 125. 
 Examination of object, 3. 
 Experiments, records of, 6. 
 Extension, 100. 
 Eye, 4, 113-124, 129, 134. 
 Eyebrows, 116. 
 Eyelashes, 117. . 
 Eyelids, 114, 116. 
 Eyepieces, 1, 3. 
 
 F. 
 
 Farina, 69. 
 Farsight, 118. 
 Fasciculi, 23. 
 Fat, 67, 75, 113. 
 
 globules, 76, 81, 82, 87, 130. 
 Fatigue, 27, 124. 
 Fever, splenic, 138. 
 
 typhoid, 138, 145. 
 Fibres, 8, 102, 103, 105, 108, 114. 
 
 medullated or white, 110. 
 
 nerve, 109, 112. 
 
 non-medullated or gray, 110. 
 Fibrillse, 25. 
 Fibrin, 31, 33. 
 Fibula, 15. 
 Field, visual, 119. 
 Figures, 122. 
 Filters, 145. 
 Filtration, 145. 
 Finger, 26, 90, 118, 127. 
 
 -prints, 90. 
 Fissure, 96, 97, 102, 104. 
 
 dorsal, 107. 
 
INDEX. 
 
 161 
 
 Fissure, median, 103. 
 
 of Rolando, 98. 
 
 of Sylvius, 98. 
 
 parieto-ocoipital, 98. 
 
 ventral, 107. 
 Flexion, 100. 
 Floors, 137. 
 Flour, wheat, 69, 76, 81, 82. 
 
 whole wheat, 76. 
 Fluid, 77, 88, 107. 
 Focus, 4. 
 Fcetus, 21. 
 Follicle, 92. 
 Foods, 67, 76. 
 Foot, 1, 29, 100, 111, 128. 
 Foramen of Monroe, 103. 
 Forearm, as lever, 28. 
 Fore-brain, 96. 
 Forehead, 90. 
 Fore leg of lamb, 20. 
 Formalin or formaldehyde, 95, 108, 
 
 109, 112. 
 Formula, dental, 56, 59. 
 Fowl, 16, 23, 24. 
 Frog, 27, 31, 32, 40, 41, 108, 111, 
 
 112. 
 Fulcrum, 28. 
 
 G. 
 
 Gall bladder, 62. 
 Ganglia, 94, 109, 110. 
 Gas-jet, 124. 
 Gastric glands, 63, 65. 
 
 juice, 78, 79, 80, 81, 82. 
 Gastrocnemius muscle, 27. 
 Gelatin, 14, 134, 135, 136, 137, 
 
 140, 141, 143, 144. 
 Germ, 142, 143. 
 Gimlet, 16. 
 Gland, 62, 63, 65, 66, 130. 
 
 Glasses, 118. 
 Globe, 124. 
 Glottis, 59, 60. 
 Glue, 85. 
 Grapes, 70. 
 Gullet, 130. 
 
 H. 
 
 Hair, 91, 116. 
 
 Hairless place, 116. 
 
 Ham, 140. 
 
 Hammer, 125. 
 
 Hand, 26, 43, 89, 90, 127, 128. 
 
 Haversian canals, 15. 
 
 Head of bone, 19. 
 
 Hearing, 125, 126. 
 
 Heart, 35, 36, 37, 38, 40, 43. 
 
 Heat, 143, 144. 
 
 Herbivorous animals, 57. 
 
 Hereditary characteristics, 7. 
 
 Hilum, 69. 
 
 Hilus, 87. 
 
 Hind-brain, 96, 98. 
 
 Hip-joint, 18, 19. 
 
 Humerus, 10, 15, 30. 
 
 Humor, 114, 115, 116. 
 
 Huxley, viii. 
 
 Hydrochloric acid, 13, 14, 71, 72, 
 
 78, 79, 80, 81, 82, 112. 
 Hypermetropia, 118. 
 
 Ice, 135, 136. 
 Image, 117, 120, 124. 
 Imbibition, 84, 85. 
 Immunity, 138. 
 Impulse, nerve, 110, 112. 
 Incisor, 56, 59. 
 Incus, 125. 
 
162 
 
 INDEX. 
 
 Infection, 140. 
 Infundibulum, 100. 
 Infusion, 139. 
 Ink, 84, 85, 90. 
 Insertion of muscle, 22. 
 Instruments, 6. 
 Intestine, 109, 112. 
 
 large, 61, 63, 64. 
 
 small, 61, 63, 64, 84. 
 Iodine, 68, 69. 
 Iris, 114, 117, 119. 
 Irradiation, 121. 
 
 J- 
 
 Joints, 18-21. 
 
 ball and socket, 18, 19. 
 
 gliding, 18. 
 
 hinge, 18. 
 
 muscles of, 30. 
 
 pivot, 18. 
 Judgments, imperfect visual, 121, 
 122. 
 
 K. 
 
 Kidney, 87, 88, 112. 
 Knee, 110. 
 
 -jerk, 110. 
 
 -joint, 18. 
 
 pan, 110. 
 Knuckles, 26. 
 
 L. 
 
 Labyrinth, 126. 
 Lacteal, 65. 
 Lactic acid, 140. 
 Lactose, 70, 71, 72, 140. 
 Lacunae, 15. 
 Lamb, fore leg, 22. 
 
 Lamellse, 15. 
 Lamp, 119. 
 Larynx, 130-133. 
 Leg, 29. 
 
 Leitz microscope, 3. 
 Lens, 3, 115, 116, 117. 
 
 capsule, 115. 
 Letters, 122. 
 Levers, 28, 29. 
 Lieberkuhn, crypts of, 65. 
 Ligaments, 19. 
 
 capsular, 19, 20. 
 
 round, 19. 
 Light, 4, 100, 141. 
 Lime, 85. 
 
 -water, 73, 74. 
 Liquid, 90, 126. 
 Liver, 62, 66. 
 Lobe, frontal, 98. 
 
 lateral, 105. 
 
 occipital, 98. 
 
 olfactory, 98. 
 
 parietal, 98. 
 
 temporal, 98. 
 Lobes, 66. 
 Lobules, 66. 
 Loop, 90. 
 
 Lumbar swellings, 106. 
 Lungs, 35, 49, 53. 
 
 M. 
 
 Magnification, 2, 3. 
 Malleus, 125. 
 Malpighian bodies, 88. 
 Maltose, 70, 71, 78. 
 Marriott's experiment, 120. 
 Marrow, 11, 12. 
 Mater, dura, 95. 
 pia, 96, 107. 
 Matrix, 21. 
 
INDEX. 
 
 163 
 
 Matter, gray, 102, 103, 104. 
 
 infected, 140. 
 
 mineral, 13. 
 
 white, 103. 
 Meal, Indian, 69, 76. 
 Meatus, external auditory, 125. 
 Medulla oblongata, 96, 99, 102, 
 
 103, 105. 
 Medullary cavity, 11, 13. 
 
 portion, 88. 
 Membrane, epithelial, 84. 
 
 mucous, 114, 116, 131. 
 
 of cord, 107. 
 Mesentery, 62. 
 Microscope, 1-5. 
 Mid-brain, 100. 
 
 Milk, 73, 76, 78, 80, 81, 82, 83, 
 136, 139, 141, 142, 143, 144, 145. 
 Milk-men, 141. 
 
 -sugar (see lactose). 
 Milled head, 3, 4. 
 Mirror, 3, 4. 
 
 Mitral valve (see bicuspid valve). 
 Model of arm, 29, 30. 
 
 chest, 52, 53, 54. 
 
 circulation, 44, 45, 46. 
 
 ear, 125. 
 
 larynx, 133. 
 
 lever, 28, 29. 
 
 valves of aorta, 46, 47. 
 Moisture, 140. 
 Molar, 56, 59. 
 Molasses, 72. 
 Motor oculi, 102. 
 Mouth, 59. 
 Mucous coat, 64, 65. 
 Muscles, 16, 22-30. 
 
 action of, 27. 
 
 arytenoid, 132. 
 
 ciliary, 114. 
 
 crico-arytenoid, 132. 
 
 Muscles, crico-thyroid, 132. 
 
 gross structure, 23. 
 
 groups, 100, 101. 
 
 kinds, 23. 
 
 microscopical structure, 24. 
 
 of eye, 113. 
 
 papillary, 39, 74. 
 
 simple, 24. 
 
 thyro-arytenoid, 133. 
 Muscular coat, 64, 65. 
 Mycoderma, 137. 
 Myopia, 118. 
 Myosin, 75. 
 
 N. 
 
 Nasal openings, 59. 
 Nearsight, 118. 
 Neck, 55, 90, 106, 111, 127. 
 Nerves, 23, 89, 94. 
 
 auditory, 102, 126. 
 
 cranial, 101. 
 
 facial, 102. 
 
 glosso-pharyngeal, 102. 
 
 hypoglossal, 102. 
 
 olfactory, 101. 
 
 optic, 100, 101, 113, 115, 120. 
 
 pneumogastric, 102. 
 
 spinal, 109, 112. 
 
 spinal accessory, 102. 
 
 sympathetic, 94, 112. 
 
 trunks of, 112. 
 Network, 108. 
 Neural arch, 12. 
 
 canal, 12. 
 
 ring, 12. 
 Neuron, 105. 
 Newt, 7. 
 
 Nitric acid, 14, 74. 
 Normal salt solution, 109. 
 Nose, bridge of, 116, 127. 
 
164 
 
 INDEX. 
 
 Nostril, 129. 
 
 Nucleolus, 7, 108. 
 
 Nucleus, 7, 25, 31, 91, 107, 110. 
 
 0. 
 
 Oatmeal, 69. 
 
 Objectives of compound micro- 
 scope, 1, 3. 
 Odors, 129. 
 
 O3sophagus, 35, 60, 63, 130, 131. 
 Oil, glands, 92. 
 
 olive, 82, 84. 
 Onion, 67, 129. 
 Openings, 10, 89, 116. 
 Ora serrata, 115. 
 Organs, 112, 130. 
 
 circulatory, 112. 
 
 digestive, 58, 112. 
 
 excretory, 112. 
 Origin of muscle, 22. 
 Osmosis, 84. 
 Ossein, 14. 
 Outflow, 46. 
 Ox, 113. 
 
 Oxid cuprous, 70. 
 Oxygen, 34. 
 
 P. 
 
 Pail, 142. 
 
 Palm of hand, 89, 90. 
 Pancreas, 66, 131. 
 Pancreatic juice, 81, 83. 
 Pancreatin, 81, 83. 
 Papers, 124. 
 Papilla, 57, 89, 92. 
 Paste, starch, 78. 
 Pasteurization, 142. 
 Pathetici, 102. 
 
 Peduncles, 96, 99, 100, 104. 
 
 Pelvis, 88. 
 
 Penniform, 24. 
 
 Pepper, 129. 
 
 Pepsin, 78, 79, 80, 81. 
 
 Peptone, 134. 
 
 Peptonized, 83. 
 
 Pericardial liquid, 35. 
 
 Pericardium, 35, 41. 
 
 Perimysium, 23. 
 
 Periosteum, 10. 
 
 Peritoneum, 63. 
 
 Person, 93, 123, 126. 
 
 Perspiratory glands, 89, 92. 
 
 Pharynx, 59. 
 
 Pickles, 139. 
 
 Pigeon, 22. 
 
 Pillar of the compound micro- 
 scope, 1. 
 
 Pineal gland, 100. 
 
 Piotrowski reaction, 72. 
 
 Pits, 65. 
 
 Pituitary l)ody, 100. 
 
 Plain muscle, 25, 26. 
 
 Pluck, 35. 
 
 Pons Varolii, 96, 99, 102, 104, 105. 
 
 Potassium bichromate, 95, 113, 
 115. 
 
 ferrocyanide, 73 
 
 Potato, 67, 68, 129. 
 
 Pound, 128. 
 
 Power, 28. 
 
 Precipitation, 145. 
 
 Preface, iii-v. 
 
 Premolar, 59. 
 
 Preservatives, 141. 
 
 Preserves, 139. 
 
 Pressure, 128. 
 
 Process, 13, 115. 
 
 Processes, branched (see dendrites). 
 
 Products of digestion, 83. 
 
INDEX. 
 
 165 
 
 Prominences, 11. 
 Proteids, 67, 72-75, 78, 81. 
 Protein (see proteid). 
 Protoplasm, 7, 8, 107. 
 Prunes, 72. 
 Pulp cavity, 66. 
 Pulse, 43, 45. 
 Pump, 45. 
 
 Pupil, 114, 117, 119. 
 Purification, 145. 
 Putrefaction, 139. 
 Pyloric orifice, 61. 
 Pyramids, 99. 
 
 of Malpighi, 88. 
 
 R. 
 
 Rabbit, 94. 
 
 Radius, 30. 
 
 Rays, 121. 
 
 Record of experiments, 5, 6. 
 
 Rectum, 61, 62. 
 
 Reducing agent, 70. 
 
 sugar, 71. 
 Reflex action, 110, 111, 112. 
 Rennet, 80. 
 Rennin, 78, 80, 81. 
 Resistance, peripheral, 43. 
 
 use of, 46. 
 Respiration, 49-54. 
 
 number of, 51. 
 Retina, 115, 116, 118, 121, 124. 
 Rice, 69. 
 Ridges, 10, 89. 
 Rings, cartilaginous, 49. 
 Rods, 128. 
 Rooms, 141. 
 Root, 91, 92. 
 
 of nerves, 101, 106, 107, 109. 
 
 of tooth, 55. 
 Rough places on bone, 10. 
 
 S. 
 
 Saccharose, 71, 72. 
 
 Saliva, 77, 78. 
 
 Salt, 129. 
 
 Salts, 67, 70. 
 
 Sarcolemma, 25. 
 
 Sarcoplasm, 25. 
 
 Scapula, 30. 
 
 Sclerotic coat, 113, 114, 117; 118. 
 
 Screen, 117. 
 
 Sebaceous glands, 92. 
 
 Sediment, 142. 
 
 Sedimentation, 145. 
 
 Semilunar valves, 39. 
 
 Sensations, 123, 127-129. 
 
 Septa, 107. 
 
 Serum, 33, 34. 
 
 Sewage, 145. 
 
 Shade, 119. 
 
 Shaft of a long bone, 10, 11. 
 
 Sheath, 109. 
 
 Sheep, 94, 130. 
 
 Shoes, rubber, 86. 
 
 Shoulder-blade, 9. 
 
 -bone (see scapula). 
 
 -joint, 30. 
 Skeleton, 9, 10, 16, 17, 18. 
 Sketches, 5. 
 Skin, 87, 89-93, 127. 
 Skull, 94, 100, 101. 
 Slides, microscopical, 148. 
 Smell, 127-129. 
 Sodium carbonate, 81, 134. 
 
 hydrate, 73, 74. 
 
 Barfoed's, 70, 71. 
 Solution, Fehling's, 70, 71, 72. 
 Sound, 126. 
 
 Souring of milk, 140, 141, 143. 
 Specimens, 147, 148. 
 
166 
 
 INDEX. 
 
 Spinous process, 12. 
 Spleen, 62. 
 Spores, 143, 144. 
 Spot, 121. 
 Spring-balance, 28. 
 Squares, 120, 121. 
 Stage, 2. 
 
 Stand of the compound micro- 
 scope, 1, 4. 
 Staples, 125. 
 
 Starch," 68, 69, 72, 77, 81. 
 Steapsin, 81. 
 Stem of hair, 92. 
 Sterilization, 134, 142, 144, 145. 
 Stimulus, 111, 112. 
 Stomach, 60, 63, 64, 79, 80., 
 Striations of muscle, 24, 25. 
 Sublimate, corrosive, 143, 144. 
 Submucous coat, 65. 
 Subsidence, 145. 
 Substance, gray, 105, 107, 108. 
 
 white, 103, 105, 107, 108. 
 Sugar, cane (saccharose), 71, 72, 
 129. 
 
 grape (dextrose), 70, 71, 72, 
 85, 84. 
 
 maple, 72. 
 
 milk (lactose), 70, 71, 72, 140, 
 142. 
 
 reducing, 71. 
 Summer, 142. 
 Sunlight, 141. 
 Susceptibility, 138. 
 Sweat glands, 89, 90. 
 Sweeping, 137. 
 Sweet, 142. 
 Swellings, 106. 
 Synovial liquid, 20. 
 
 membrane, 19, 20. 
 Syrup, 72, 139. 
 System, cerebro-spinal, 112. 
 
 System, nervous, 94-112. 
 
 sympathetic, 112. 
 Systole, 41. 
 
 Tadpole, 42. 
 
 Tapioca, 69. 
 
 Taste, 127-129, 142. 
 
 Teeth, 55, 59, 126. 
 
 Temperature, 50, 89-93, 127, 128. 
 
 Tendons, 19, 22, 24, 26. 
 
 Test for hearing, 126. 
 
 Test-types, Snellen's, 118. 
 
 Tetanus, 27. 
 
 Thalamus, optic, 104. 
 
 Thermometer, 142. 
 
 Thorax, 52, 53, 54. 
 
 Throat (see pharynx). 
 
 Thumb, 26, 90. 
 
 Tissue, cellular, 95. 
 
 connective, 8, 66, 108, 109. 
 
 epithelial, 8. 
 
 fatty, 8. 
 
 fibrous, 95. 
 
 nervous, 94. 
 Toes, 27. 
 
 Tongue, 53, 57, 129, 130, 131. 
 Touch, 127. 
 
 Trachea, 35, 49, 52, 130, 132. 
 Tracts, optic, 100, 101, 103. 
 Transverse processes, 12. 
 Triceps, 29, 30. 
 Trigeminals, 102. 
 Tripe, 139. 
 Trypsin, 81. 
 Tuber cinereum, 100. 
 Tubules, 88. 
 Turnip, 67. 
 Tympanum, 125. 
 Type, 118. 
 
INDEX. 
 
 167 
 
 u. 
 
 Ulna, 30. 
 Ureter, 87, 88. 
 Uriniferous tubules, 88. 
 Use of the microscope, 4. 
 
 V. 
 
 Vaccination, 138. 
 
 Valve, 38, 39, 40, 46. 
 
 Valvulse conniventes, 64. 
 
 Vein, 38, 39, 40, 43, 44, 50. 
 
 Veinlet, hepatic, 66. 
 
 VenEB cavae, 37, 38. 
 
 Ventricle, of brain, 99, 103, 104. 
 
 of heart, 36, 37, 38, 41. 
 Vertebra, 12, 112. 
 Vertebral column, 12, 112. 
 Vestibule, 126. 
 Villi, 64, 65. 
 Vinegar, 14, 73, 83, 84, 85, 129, 
 
 137, 139. 
 Vision, 113-124. 
 Voice, 130-133. 
 
 W. 
 
 Watch, 126. 
 
 Water, 67, 128, 135, 136, 145. 
 
 Waves, sound, 126. 
 
 Weight, 28, 128. 
 
 Whey, 80. 
 
 Whorl, 90. 
 
 Windpipe, 130. 
 
 Winter, 142. 
 
 Wire, 16. 
 
 Wisdom teeth, 57. 
 
 Worsteds, 123. 
 
 Wrist, 9, 18, 43. 
 
 Yellow spot, 120. 
 
 Z. 
 
 Zanthoproteic reaction, 72. 
 Zollner's lines, 122. 
 Zobglea, 137. 
 
Bureau Nature Study, 
 O^inmVEKsrry. Ithaca. N. Y.