diff options
| author | nfenwick <nfenwick@pglaf.org> | 2025-01-27 18:36:55 -0800 |
|---|---|---|
| committer | nfenwick <nfenwick@pglaf.org> | 2025-01-27 18:36:55 -0800 |
| commit | eb07dee71785333aa9bdf84517dd22b7d44bc602 (patch) | |
| tree | 0c565d3783ae25bedfb0700d6290c0eae02ba405 /old/60949-0.txt | |
| parent | e89509048b28b38705d69cb93bad9c39dadffa6d (diff) | |
Diffstat (limited to 'old/60949-0.txt')
| -rw-r--r-- | old/60949-0.txt | 3606 |
1 files changed, 0 insertions, 3606 deletions
diff --git a/old/60949-0.txt b/old/60949-0.txt deleted file mode 100644 index caa9ee6..0000000 --- a/old/60949-0.txt +++ /dev/null @@ -1,3606 +0,0 @@ -Project Gutenberg's Notes on Veterinary Anatomy, by Charles J. Korinek - -This eBook is for the use of anyone anywhere in the United States and most -other parts of the world at no cost and with almost no restrictions -whatsoever. You may copy it, give it away or re-use it under the terms of -the Project Gutenberg License included with this eBook or online at -www.gutenberg.org. If you are not located in the United States, you'll have -to check the laws of the country where you are located before using this ebook. - -Title: Notes on Veterinary Anatomy - -Author: Charles J. Korinek - -Release Date: December 18, 2019 [EBook #60949] - -Language: English - -Character set encoding: UTF-8 - -*** START OF THIS PROJECT GUTENBERG EBOOK NOTES ON VETERINARY ANATOMY *** - - - - -Produced by The Online Distributed Proofreading Team at -http://www.pgdp.net (This file was produced from images -generously made available by The Internet Archive) - - - - - -Transcriber’s notes: - -The text of this e-book has been preserved as in the original, -including inconsistent capitalisation and hyphenation. Archaic and -inconsistent spellings have also been preserved except where obviously -misspelled in the original. A list of spelling corrections and -inconsistencies is appended at the end. Archaic phraseology has been -retained. Incorrect paragraph numbering on p. 17 has been corrected, -and several missing full stops have been inserted. - - - - - VETERINARY SCIENCE ASSOCIATION - OF AMERICA - - - NOTES ON - VETERINARY ANATOMY - - BY - - CHARLES J. KORINEK, V. S. - - _Graduate of the Ontario Veterinary College, in affiliation with - the University of Toronto, Canada. Hon. Member of the Ontario - Veterinary Medical Society. Ex. State Veterinarian for - Oregon. Ex. President of the Oregon State Veterinary Medical - Board of Examiners. Author of “The Veterinarian”. Principal - of the Veterinary Science Association of America. Sixteen - years of Practical Experience as a Veterinary Surgeon._ - - - [Illustration] - - - PUBLISHED BY THE - VETERINARY SCIENCE ASSOCIATION - OF AMERICA - - - COPYRIGHT 1917 - by the - VETERINARY SCIENCE ASSOCIATION - OF AMERICA - - - - -TABLE OF ILLUSTRATIONS. - - Page - - Plate I. Skeleton of the Horse 7 - - Plate II. Muscles of the Horse, superficial layer 29 - - Plate III. Muscles of the Horse, deep layer 31 - - Plate IV. Digestive and Urinary Organs of the Horse 37 - - Plate V. Heart and Chief Blood Vessels of the Horse 69 - - Plate VI. Nervous System of the Horse 73 - - Plate VII. Structure of the Horse’s Foot 78 - - - - -TABLE OF CONTENTS. - - Page - - Chapter I. Osteology, or Structure of the Bones 8 - - Chapter II. Arthrology, or Study of the Joints 21 - - Chapter III. Myology, or Study of the Muscular System 28 - - Chapter IV. Splanchnology, or Study of the Digestive, - Respiratory, Urinary and Generative Systems 38 - - Chapter V. Angiology, or Study of the Blood-Vascular - System, as the Heart, Arteries, Veins, - Lymphatic Vessels and Glands 67 - - Chapter VI. Neurology, or Study of the Nervous Tissue, - as the Brain, Spinal Cord and Their Nerves 73 - - Chapter VII. Aesthesiology, or the Study of the Organs of - Special Sense, as the Ear, Eye and Organs of - Sensation, as Skin, Hair, Foot, etc. 75 - - Chapter VIII. Embryology or Development of the Foetus 81 - - - - -PREFACE - - -There are a number of excellent works on Veterinary Anatomy, and many -of them will amply repay the student for the time taken to master -them, but for quick reference none seem to contain the wants of the -veterinary practitioner and student for which this humble little work -is primarily intended. - -It has been my endeavor to briefly describe each organ as found in the -healthy animal; its functions, etc., in a condensed yet complete form. -I am positive that the student or veterinary practitioner will find its -pages highly instructive as well as profitable and interesting. - -In compiling this work a few authorities have been consulted and -quoted, while it has not been practical to give individual credit for -the use of ideas and language, a general acknowledgement is here made: - - Veterinary Science, Hodgins and Haskett. - - Veterinary Anatomy, Strangeways. - - CHARLES J. KORINEK, V. S. - - - - -DESCRIPTIVE ANATOMY - - -Osteology is a term applied to that section of descriptive anatomy -which treats of the bones. _Arthrology_, to the consideration of the -joints or modes of union between the bones, while by _Myology_ is -meant the doctrine of the muscular system. _Splanchnology_ treats of -the viscera, _Angiology_ of the circulatory and absorbent systems. -_Neurology_ deals with the nervous system. _Aesthesiology_ with -the organs of sense; while _Embryology_, as before stated is the -consideration of the animal frame at periods preceding its birth. - -In this work the various departments are discussed in the order -here given. The structures which are the subject of the first three -divisions are sometimes classed together as the _Organs of Locomotion_; -for bones form the frame work of the body and often act as levers; the -joints connect the bones, permitting more or less motion between them; -while the muscles move the bones, and so produce motion of a part of -the body--or it may be locomotion, or change of situation in the entire -frame. - -In the study of comparative Anatomy the terms _analogy_ and _homology_ -are frequently met with. Although these words are unfrequently used -indiscriminately, the following differences should be noted. Organs -are said to be analogous when, though differing in structure, they -perform the same function; but when their functions are different, -which, in the broad sense, they correspond in structure or form, they -are said to be homologous. Thus the middle finger of the human hand is -the homologue of the anterior (front) digit of a horse, because they -have the same general structure, and relation to the rest of the limb; -but as the functions they perform are quite dissimilar, they cannot be -termed analogous. Again, the lungs of a mammal are analogous to the -gills of a fish, for, though they differ widely in structure, position -and form, and are therefore not homologous, their ultimate use is -the same--each of them being an apparatus in which is carried on the -process of purifying the blood. - - -DISSECTION. - -Students must dissect as many animals as possible, so as to familiarize -themselves with the _frame work or structure_, and the location of the -_digestive, nervous and blood systems_, as it will aid materially in -the art or process of determining the nature of various diseases. - -During cool weather an animal for dissecting purposes can be kept for a -considerable length of time without preservatives - -It is well to have a copy of Anatomy at hand when dissecting for -it will show the location of the various organs and explain their -functions. - -[Illustration: PLATE I. - -SKELETON OF HORSE--AFTER MEGNIN.] - - -EXPLANATION OF PLATE I - -SKELETON OF THE HORSE - - 1. Skull, or skeleton of the head. - 2. Cervical vertebræ or neck bones. - 3. Dorsal vertebræ or back bones. - 4. Lumbar vertebræ or loin bones. - 5. Sacral vertebræ or rump bones. - 6. Coccygeal vertebræ or tail bones. - 7. Pelvic or hip bones. - 8. Sternum or breast bone. - 9. Ribs. - 10. Scapula or shoulder blade. - 11. Humerus or shoulder bone. - 12. Radius or bone of the fore-arm. - 13. Ulna or bone of the fore-arm. - 14. Carpus or bones of the knee. - 15. Os Melacarpi Magnus, metacarpal, or cannon bone. - 16. Ossa Melacarpi Parva, or splint bones. - 17. Proximal Phalanx, os suffraginis, or large pastern bone. - 18. Great Sesamoid Bones. - 19. Medium Phalanx, os coronæ, or small pastern bone. - 20. Distal Phalanx, os pedis, or coffin bone. - 21. Os Naviculare, small sesamoid, or shuttle bone. - (This bone can be plainly seen Plate VII). - 22. Femur, or thigh bone. - 23. Patella, or stifle bone. - 24. Tibia, or leg bone. - 25. Fibula. (This bone is little developed in the horse.) - 26. Tarsus or hock bones. - 27. Metatarsus, or os metatarsi magnus. - 28. Ossa Metatarsi Parva, or splint bones of the hind leg. - -Names of joints placed according to numbers. - - I. Shoulder Joint. - II. Elbow Joint. - III. Carpus or knee joint. - IV. Fetlock Joint. - V. Pastern Joint. - VI. Coffin Joint. - VII. Hip Joint. - VIII. Stifle Joint. - IX. Tarsus or hock joint. - - - - -CHAPTER I. - -OSTEOLOGY. - - -STRUCTURE OF THE BONES--Bones are hard, yellow-white, insensitive -objects, which form the skeleton and give attachment to soft structures -(muscles, tendons and ligaments); they are of various sizes, forms and -densities. In the limbs the bones are ordinarily more or less long, -circular bodies, with expanded ends, effectually supporting the body, -supplying leverage and attachment for soft structures, and forming the -basis of all joints. Where cavities, such as the cranium, chest, and -pelvic, enclosing the organs requiring protection and support, the -bones tend to assume a flat, expanded form. - -Living bone is bluish pink, insensitive, and elastic; on exposure to -air it becomes diseased and blackened, very sensitive and painful; (the -teeth excepted) which are harder and of a higher specific gravity than -any other bone formation. - -Bones are composed of two kinds of substance--animal, which makes the -bone tough and flexible; earthy, which makes it hard and fragile. -In young animals the animal matter forms about one-half of the bone -substance; in the adult, it diminishes to about a third, while in old -animals it is still less; hence the bones of very old animals are -brittle, more liable to fracture and harder to mend. - -Bones in a six-year-old horse contained, Phosphate of Lime, 54.37 per -cent; Carbonate of Lime, 12.00 per cent; Phosphate of Magnesia, 1.83 -per cent; Soluble Salts, 0.70 per cent, or mineral matter, 68.90 per -cent. While they contain Cartilage, 27.99 per cent; Fat, etc., 3.11 per -cent, or animal matter 31.10 per cent. - -In bone tissue there are two modifications of texture, the _compact_ -and the _cancellated_. The former--hard, dense, and ivory-like, is -always situated externally; the latter porous and spongy lies within. - -Although the compact tissue appears uniformly dense, and destitute of -porosity, yet, if we transversely sectate the shaft of a long bone, and -examine it under the microscope, by transmitted light, it is found to -contain numerous round openings. These are called _Haversian canals_. -They transmit bloodvessels, and run in a longitudinal or slightly -oblique direction, opening on either the outer or inner surface of the -bone. - -The external (outer) surface of every bone is covered by a tough, -fibrous, inelastic membrane called periosteum, which can be seen by -examining the bone of an animal which has recently died. The only -exception to this is at the joints where one bone articulates with -another, and where a tendon or muscle plays over a bone; here we find -its place taken by articular cartilage. By its strength it sometimes -retains bones in contact after an oblique fracture; in the young, it -is thicker and more vascular than in the adult. Blood-vessels which -penetrate the periosteum pass directly to the bone; the outer surface -of the bone is always studded with numerous _foramina_ through which -these enter. - -The periosteum owing to its inelasticity, is, when inflamed, the seat -of intense pain; and should any part of it be stripped off, there is -every probability of the denuded bone dying and separating. - -CONTENTS OF BONE.--Red marrow is found in the extremities or near the -ends of bones, white marrow is found in the shaft. - -CLASSES OF BONES.--Bones are classed as long, flat, and irregular. -Long or cylindrical bones are found in the limbs or extremities, and -serve as levers and pillars for traveling and to support the body. -Descriptively, a long bone is divisible into a center or _shaft_ and -two ends or extremities. Flat bones are found where visceral organs -need protection. As the shoulder or scapula and ribs, to protect the -heart and lungs; pelvic or hip bones, to protect the rectum and -urinary and genital organs; also the cranial bones, to protect the -vital organ called the brain. Irregular bones are found in the spinal -column and in the joints, such as the knee or carpus, hock or tarsus, -where great strength is required. They usually possess many angles and -indentations, with surfaces for articulation and tendonous attachment, -and consist of a thin, dense, external (outer) case of compact bone -enclosing cancellated tissue. In proportion to their size they present -a much larger extent of articular surface and greater mechanical -strength than any other class. - -1. SKULL, or skeleton of the head, the most anterior (forward) part -of the horse’s skeleton, articulates with the first cervical vertebra -(or atlas), from which it is suspended by its posterior (or back part) -extremity, its anterior (forward) extremity being free. Its position -varies with the attitude of the animal; but in our descriptions we -shall always suppose it to be placed in a horizontal position. - -In the young animal the skull is composed of a number of bones, all of -which, with the exception of the lower jaw, the teeth, the bones of the -tongue, and ossicles of the ear, become united by ossification (growing -together) in the adult. - -In speaking of the different points of importance in connection with -the head bones of the horse, and other animals, suppose a cross or -longitudinal section of the head is made. It will be noticed that it is -full of cavities or sinuses. The uses of these are to lighten the head -and also to warm the air as it passes into the nostrils, on its way -down to the lungs. It will also be found full of foramen or small holes -through which the nerves from the brain and various blood vessels pass -to the organs situated in the head, such as the tongue, lips and the -various glands in and around the head. - -Then there are the cavities in which the eyes are situated, one on each -side of the head, called the orbital fossa. In examining this fossa you -will find a small opening or foramen, through which the optic nerve -passes in coming from the brain to the eye. This is the nerve of sight. -Then the most important part of all to consider is the cranial cavity -in which that very important organ is situated called the brain, which -controls all the various functions and movements of the body. - -Another important point is the situation of the ear drum. It is -situated in the hardest bone found in the whole skeleton, called the -petrosal. The nerve that gives the function called hearing comes from -the brain down to the petrosal bone and enters by a small foramen or -hole into the drum of the ear to give hearing. This nerve is called the -auditory nerve. - -2. CERVICAL VERTEBRAE OR NECK BONES.--These bones are seven in number. -The first and second bones proceeding from the head receive special -names. The first one is called the atlas, from which the head is -suspended and to which it is attached; it somewhat resembles the body -of a bird with wings extended. The second bone receives the name -of dentata. This is the bone which allows the head to turn in any -direction, hence it is sometimes called the axis or pivot of the neck. -Between these two bones, on the upper surface, is the only place where -the spinal cord is not covered with bone, a spot about three-fourths of -an inch in diameter. The next four bones receive no name, and are about -the same in size and length. The last, or the seventh bone, is only -about one half the length of the preceding ones and receives no special -name. - -3. DORSAL VERTEBRAE OR BACK-BONE.--Dorsal bones are eighteen in number. -The chief point of interest about them are the height of the spines on -the upper surface of the bones. These large spines form the withers of -the horse, as will be noticed in the skeleton. On either side of these -bones the ribs are attached, 18 pairs corresponding with the number of -bones in this region. - -4. LUMBAR VERTEBRAE (or the bones which form the skeleton of -the loins). These bones are six in number, and they are situated -immediately above the kidneys. - -5. SACRAL VERTEBRAE OR RUMP BONES.--There are five of these bones in -the young horse, but in the adult they unite as a single bone, somewhat -triangular-shape. These are situated between the upper hip bones and -help to form the rump. Beneath these bones the bladder is situated. - -6. COCCYGEAL VERTEBRAE OR TAIL BONES.--These are 18 to 20 in number. -There is no complete canal, like in the previous vertebraes, for -enclosure of the spinal cord. - -7. PELVIC OR HIP BONES.--The pelvic bones are flat, but somewhat -irregularly-shaped, and they form the sides, floor, and part of the -roof of the pelvic cavity. Above they are connected with the sacrum, -and below united to each other, in the adult, by ossification (union -of bone). In the young animal, as above stated, and especially in the -foetus, each side consists of three parts, which retain their names of -ilium, ischium, and pubis, even after union by ossification. They all -three meet in the acetabulum, or articular cavity for the femur or hip -bone. - -8. STERNUM OR BREAST BONE.--This bone is small and short in the horse -and is situated on the lower surface of the chest cavity. The principle -points to be noted in this bone are that of its softness, and that the -first eight pairs of ribs are attached to it on either side. This bone, -in the horse resembles the keel and cut-water of a boat. - -9. RIBS.--In the horse the ribs usually number eighteen on each side. -They extend in a series of arches of varying curvature from the dorsal -vertebrae above, towards the sternum and sides of the abdomen below. -Their shape, in a great measure, determines the conformation or -shape of the thorax or chest cavity; they protect its contents, and -materially aid in its contraction and expansion. They are continued -downward and forward by a small piece of cartilage or gristle, and are -just slightly attached to the breast bone or sternum; these are called -the false ribs. Note that, starting with the first rib, they get longer -until the ninth rib is reached; they then get shorter, the last rib -being only a few inches long. - -10. SCAPULA OR SHOULDER BLADE.--The scapula is a flat bone situated on -the antero-lateral (front side) surface of the thorax or chest cavity, -it is triangular in shape, the base being turned upwards. The inferior -or lower extremity articulates with the humerus or shoulder bone. - -11. HUMERUS OR SHOULDER BONE.--The humerus is a long bone extending -from the scapula to the radius and ulna in an oblique direction -downwards and backwards. Like all long bones it possesses a shaft and -two extremities and two articular surfaces. - -12. RADIUS, OR BONE OF THE FORE-ARM.--The radius is a long bone, and -occupies a vertical position between the humerus and the carpus. - -13. ULNA, OR BONE OF THE FORE-ARM.--The ulna is an irregular bone, -in form triangular, with the base uppermost, and is placed on the -supero-posterior or (upper and back) part of the radius. - -14. CARPUS, OR KNEE.--The carpus, knee or wrist, as it is incorrectly -termed in quadrupeds, is composed of seven and often of eight small, -irregular bones arranged in two rows of three each, one above the -other, the seventh being at the back of the three in the upper row, -and the eight, when present, in a similar position with respect to the -lower row. Their names are as follows: scaphoid, lunar bone, cuneiform -bone, trapezium, trapezoid, os magnus, unciform, pisiform, which is not -always present. - -15. OS METACARPI MAGNUS, METACARPAL OR CANNON BONE.--The large -metacarpal, or cannon bone, is a long, straight bone, placed in a -vertical direction. Its superior or upper extremity articulates with -the carpus and its inferior or lower extremity articulates with the os -suffraginis and the two sesamoids. - -16. OSSA METACARPI PARVA, OR SPLINT BONES.--The two small metacarpal, -or splint bones, tuberous in form (marked or covered with projections) -at the carpus and tapering distally (lower portion), are attached to -the large bone, one on each side of its posterior (back) surface, by -ligaments in the young animal, and by ossification (union of bone) in -most grown up, and in all old animals. - -17. PROXIMAL PHALANX, OS SUFFRAGINIS, OR LARGE PASTERN BONE.--The os -suffraginis, or large pastern bone, passes obliquely downwards and -forwards, and articulates with the cannon bone above, and the median -phalanx or os coronae below. It belongs to the class of long bones. - -18. GREAT SESAMOID BONES.--These bones, two in number, are placed side -by side at the postero-inferior (back and lower) part of the metacarpus -and postero-superior (back and upper) part of the os suffraginis; they -are irregular in shape, their back parts are covered with cartilage, -for the passage of the flexor tendons of the digit or the last four -bones of the limb. Their superior or upper surface is roughened, and -their sides, which are grooved for the reception of the suspensory -ligament. (This is called the fetlock joint.) - -19. MEDIAN PHALANX, OS CORONAE, OR SMALL PASTERN BONE.--The second -phalanx, os coronae, or small pastern bone, has no marrow canal, and -belongs to the class of irregular bones. It is inclined, like the os -suffraginis, obliquely downwards and forwards, and is partly covered -by the hoof. The upper portion of this bone articulates with the os -suffraginis and the two sesamoids, the lower part articulates with the -os pedis. - -20. DISTAL PHALANX, OS PEDIS, OR COFFIN BONE.--The third, or ungual -phalanx, os pedis, or coffin bone, is an irregular bone situated within -the hoof, and, when in a healthy state, corresponding somewhat to it in -shape, being semilunar in form, with the convexity to the front. This -bone is very hard and porous, having many openings for the transmission -of arteries and veins. In this bone we notice the wall, the sole, the -tendonous surface, the articular surface, and the alae or wings. This -bone articulates with os coronae superiorly (upper) and posteriorly it -articulates with the os navicular bone. - -21. OS NAVICULARE.--The naviculare, third or small sesamoid, or shuttle -bone, is an irregular bone, situated with its long axis transversely, -behind and below the os coronae, and behind the os pedis, with both -of which it articulates, the articulation of the three forming the -so-called _coffin_ joint. The lower surface of this bone is important -as it is covered with cartilage, and together form a kind of a pully -over which plays the great flexor perforans muscle. The remaining -portion of the anterior limb or front leg, will be considered under -anatomy of the foot. The navicular bone can be plainly seen on Plate -VII, anatomy of the foot. - -22. FEMUR OR THIGH BONE.--The os femoris, femur or thigh bone, the -largest, thickest, and strongest bone in the body, belongs to the class -of long bones, and is placed in a direction obliquely downwards and -forwards, articulating with the cup-shaped cavity in the pelvic or hip -bones superiorly (or upper), and with the tibia and patella inferiorly -(or below). This bone is roughened for the attachment of the powerful -muscles of the hip. - -23. PATELLA, OR STIFLE BONE.--This, the kneepan or stifle bone, is -placed in front of the pully-shaped groove of the femur. It is very -compact, its front surface being irregular, round and very much -roughened, for ligamentous attachment, and its posterior (or back) -surface very smooth to articulate with the groove in the femur, -presenting two depressions divided by a ridge, the inner being the -larger, and in the fresh state enlarged still more by projecting -cartilaginous lip, or elevation. The patella increases the power of the -hind leg, and it is this bone that causes stifle joint lameness when it -slips out of the groove in which it glides normally. - -24. TIBIA, OR LEGBONE.--The tibia or leg bone, is a long bone, larger -at its upper than its lower end, situated between the femur and the -astragalus, slanting downwards and backwards. This bone is three-sided, -possessing outer, inner and back surfaces, all of which are wider above -than below. This bone gives attachment to the flexor muscles of the hip. - -25. FIBULA.--This is a long slender bone, little developed in the -horse, and is an appendage to the tibia, being attached to the outer -side of that bone, and extending from its head to its lower third, to -which it is affixed by a ligament; the space between the two bones is -called the tibial arch. The fibula gives attachment to the peroneus -muscle, the muscle that is supposed to be severely contracted when an -animal is affected with string-halt. - -26. TARSUS, OR HOCK BONES.--The tarsus, or hock, corresponding to the -ankle-joint of a man, is composed of six irregular compact bones, -situated between the lower end of the tibia and the superior or upper -extremity of the metatarsus; they are arranged in two series; one -consisting of the cuboid and three cuneiform bones, the magnum, medium, -and parvum, corresponds to the lower row or carpal bones; the other -upper series consists of the astragalus and calcaneum; the first, -forming with the bone above the mobile portion of the joint, may be -said to correspond to the upper row of carpal bones, while the latter, -being the lever bone, corresponds to the trapezium. These bones, like -those of the carpus, are thickly covered with cartilage on their -articular surfaces, which acts as a protection against concussion. -It is these bones that become diseased and united when an animal is -affected with bone spavin. The calcaneum bone which forms the prominent -part, termed the point of the hock, and corresponds to the heel-bone -of man. This bone gives attachment to the calcaneo-cuboid ligament, and -it is this ligament that is sprained or ruptured in curb of the hock. - -28. METATARSUS, OR OS METATARSI MAGNUM.--This bone presents the same -general appearance as the large metacarpal or cannon bone, from which -it differs principally in being about one-sixth longer and flattened -from side to side. It is rounded and more prominent in front. This -bone articulates above with the tarsus bones, and its lower portion -articulates with the os suffraginis. - -28. OSSA METATARSI PARVA, OR SPLINT BONES OF THE HIND LEG.--These also -present the same general form as the small metacarpal bones of the -front leg; the outer is the longest and largest, and has the largest -head, with two surfaces which articulates with the cuboid bone; the -inner one has also three articular surfaces, two for small, and one for -the middle cuniform bones. The two surfaces on each head articulate -with corresponding ones on the large metatarsal bone. The remaining -bones of the hind extremity, viz.: the three phalanges, with their -three accessory bones, so closely resemble the corresponding bones -of the fore extremity, that it seems at first sight difficult to -distinguish one from the other; the chief differences being, that the -first phalanx of the hind extremity is longer; its upper end larger, -and its lower end smaller, than in the fore extremity. - - -COMPARATIVE OSTEOLOGY. - -In this section we shall endeavor to point out where the skeleton of -the domesticated animals, other than the horse, differ from the typical -skeleton of the latter in any important particular. The following -descriptions are therefore in all cases comparisons, where comparison -is possible, between the typical skeleton and the skeleton in question. - - -RUMINANTIA. - -(Cud Chewing Animal.) - -In this class we take the ox as the animal which represents the best -for our purpose, the family of ruminating or cud-chewing animals, as -cattle, sheep and goats. - -THE SKULL OR CRANIUM.--In the skull of the ox an important feature is -the development of the frontal or forehead bone, which extends from -below the eyes to the back of the skull, forming the entire forehead -and crest or top, in the middle of which is the forehead tuberosity or -knob-like elevation, which is very large in hornless animals. Springing -from the sides of the top are two processes, varying in size and shape, -but corresponding to the shape of the horns, which they support. - -VERTEBRAE.--The true vertebral column is made up of 26 bones divided -into seven cervical or neck-bones, 13 dorsal or back-bones, and six -lumbar or loin bones. - -CERVICAL OR NECK-BONES.--The bodies of these bones are shorter than -those of the horse, but same in number. - -DORSAL OR BACK-BONES.--These bones are longer than in the horse, but -have the same general form. It gives attachment to 13 ribs on each -side in the same manner as those of the horse. - -LUMBAR OR LOIN BONES.--The lumbar vertebrae are longer and thicker than -in the horse, their bodies being more round on the sides and lower -surfaces. - -SACRUM, OR RUMP BONES.--The sacrum is larger and more arched, and the -upper surface more round than in the horse. - -COCCYGEAL OR TAIL BONES.--The tail bones are from 15 to 20 in number, -are strong and rougher than those of the horse. - -PELVIS OR HIP BONES.--The pelvis is larger, but presents the same -general appearance as in the horse. - -In studying the bones of the limbs in ruminants, the only point of -difference is in bones below the knee. The large metacarpal bone -presents a vertical groove down its front, which marks the original -division of the bone into two bones. The lower extremity is divided by -a deep groove into two articulations, each resembling the single one -of the horse. The outer one being always the smaller, a rudimentary -metacarpus is placed on the back and outer surface. The pasterns and -sesamoids in either limb are double, one set forming each digit; they -are small and narrow, the coffin bone resembles half of that of the -horse, equally divided. - -In the aged ruminant, two bones are commonly found in the heart, -and may be termed the cardiac bones. They are found related with -auriculo-ventricular rings. In shape they present three angles, three -borders, and two surfaces. The left bone is somewhat smaller than the -right. - - -OMNIVORA. - -Animals eating both vegetable and animal food. - -The omnivora are represented in veterinary anatomy by the hog. - - -CARNIVORA. - -An order, suborder, or family of mammals, especially wild animals, -including the dog and cat, etc. Animals that eat flesh. - -In this order our description alludes mostly to the dog. - - -AVES. - -The scope of the present work will allow only very brief treatment of -this part of the subject. - -Of or pertaining to Birds, Poultry, Etc. - -The bone tissue or substance of birds are exceedingly compact and hard, -white in color; and some of the bones are pneumatic, or contain air -instead of marrow, notably these are bones of the skull, the sternum -or breast bone, and the upper bones of the limbs. There are a great -variety in the amount of pneumaticity or air possessed by the skeleton -of different species, but it is not necessarily determined by the -flying power of the animal. - - - - -CHAPTER II. - -ARTHROLOGY. - - -What is known regarding the articulations of bones of joints. The -several bones which form the skeleton are united by means of certain -soft structures, forming a number of articulations or joints, the study -of which is termed arthrology. - -Before considering the different forms of joints, it will be advisable -to describe briefly the various tissue, other than bone, which enter -into and contributes towards their formation. These are chiefly -cartilage, connective and elastic substance or tissues, and fat. - -In health, one bone never comes directly in contact with another, -cartilage or fibrous tissue being always interposed; an exception to -this exists in the adult skull, most of the bones of which become -firmly united by ossification of the interposed soft material. - -CARTILAGE.--Cartilage, known also by the familiar name of gristle, is -a firm, bluish-white elastic animal substance, somewhat transparent, -resilient, and flexible, possessing great cohesive power. That which -forms the original basis of the bony framework is termed temporary, -and that which persists in the adult, permanent cartilage; the former -disappears as it is replaced by bone, but the latter, of which alone we -have to treat here, never under normal circumstances become ossified. -Cartilage consists of corpuscles or cells, usually embedded in an -intercellular substance. - -The articular cartilage is important as it encrusts the articular -surfaces of bones, helping to form joints by supplying smooth, elastic -cushions, which diminishes both concussion and friction. - -CONNECTIVE TISSUE (White fibrous tissue.)--In one form or another this -tissue is found in all parts of the body. The chief varieties are the -areolar and the fibrous; the former serving as a connecting medium, and -support to the various organs, and to the structures of which they are -formed. It appears as a loose, transparent mesh, its interwoven bundles -forming spaces termed the areolar or cells. - -Connective tissue contains nerves and blood-vessels, for the supply of -neighboring structures as well as for its own nourishment. When healthy -it is little sensitive to pain. - -YELLOW ELASTIC TISSUE.--This differs from the white or connective -tissue in being yellow, elastic, and not so tough or strong. Its fibers -are usually large but when mixed with the white tissue in tendons the -size diminishes. - -Yellow elastic tissue is found nearly pure in the ligamentum nuchae, -and tunica abdominis, the coats of the largest arteries and elsewhere. -The lungs contain a large quantity of this tissue. - -When white fibrous tissue is boiled gelatine is obtained, which is not -the result of boiling the yellow elastic tissue. - -ADIPOSE TISSUE.--Fat or adipose tissue consists of cells containing an -oily material, and arranged in isolated groups, or slightly separated -by meshes of areolar tissue. It is found in many parts of the body, and -varies greatly in quantity; in joints it occurs between the ligaments, -and serves the purpose of a packing material, while in the form of -medulla or marrow it occupies the cavities of bones. In fat cell a -nucleus is very rarely visible. - -LIGAMENTS.--Ligaments are dense, fibrous, connecting structures. They -exist in most articulations, and are made up principally of white -fibrous tissue. There are two kinds--capsular or bursal, and funicular -or binding ligaments. - -Capsular ligaments are membranous structures enclosing true joints. -They consist of a dense interlacement of fibers attached to bones, -round the edges of the articular cartilages; some regard them as a -continuation of the periosteum or the covering of bone. They are never -closely applied, their use being to form cavities round the joints, -enclosing and protecting the synovial or lubricating apparatus inside. - -Funicular or binding ligaments consist of rounded or flattened cords, -or bands of fibrous tissue, passing from one bone to another, firmly -attached to roughened portions of their surfaces. They hold the bones -in their places, at the same time allowing the requisite amount of -motion in the joints. Ligaments which are situated between bones are -often termed interosseous. Annular ligaments are those which bind -down and protect the tendons of muscles in certain joints, converting -grooves in the bones into channels or tubes which are lined with -synovial membrane, and through which the tendons play. - -Some ligaments are composed almost entirely of yellow elastic tissue, -such as the ligamentum nuchae (the elastic ligament of the neck) and -the ligaments connecting the vertebral arches (arches between the bones -of the spinal column). - -SYNOVIAL MEMBRANES.--These are thin membranes lining the capsular -ligaments of joints, or they are interposed elsewhere between -structures which move one upon another, and which would otherwise be -injured by the friction. Near the borders of articular cartilages -the membrane is generally found as a projecting fold, the projection -being due to a small pad of fat, interposed between the membrane and -the capsular ligament. These projections were once erroneously termed -synovial glands, but their use is probably to assist in forcing the -synovia between the opposing surfaces of cartilage. - -SYNOVIA.--Synovia or joint oil, is a viscid, transparent fluid, -colorless, or pale yellow, physically resembling oil, but it contains -very little fatty material, consisting chiefly of albumen, salts -and water; it is secreted by the cells of the inner surface of the -synovial membrane. When an animal is in active exertion, there is a -greater demand for joint oil than when at rest, consequently there is -an increased secretion of it. - -CLASSES OF JOINTS.--Joints may be divided into three -classes--Immovable, movable and mixed. - -MOTION IN JOINTS.--The following terms express the various movements -allowed by joints--_Extension_ tends to bring two bones as nearly into -a straight line as the structure of the joint will permit; _flexion_ is -the reverse of this, and diminishes the angle that extension increases; -_abduction_ expresses the outward movement of a limb or bone from the -central line of the body; _adduction_ is the reverse action; rotation -signifies the partial _revolution_ of a bone or number of bones, as it -were, on their own axis; _circumduction_ implies the movement of the -lower end of a bone or limb, where it describes a curve, as the bow -of a circle, _ellipse_, etc. The term gliding explains itself, and is -peculiar to movable and other joints having no frictional surfaces. - -Important points of joints to be considered will be described on Plate -I by Roman figures to correspond with those given below. - - -JOINTS OF THE FRONT LEG. - -I. SHOULDER JOINT.--This joint is formed by the lower end of the -scapula, or shoulder blade, and the upper end of humerus or shoulder -bone. This is a ball-and-socket joint, and is held in its place by -ligaments and muscles. This belongs to the class of rotation joints, -its action is outward, inward, backward and forward. - -II. ELBOW JOINT.--This joint is formed by the lower part of the humerus -and the upper portion of the radius and ulna. It is covered with -ligaments and muscles similar to the above mentioned joint. This is -a hinge joint the action of which is only forward and backward, or -flexion and extension. It has no lateral movement. - -III. CARPUS OR KNEE JOINT.--This joint has been explained very -thoroughly in the previous chapter. There are three separate articular -surfaces in this joint. This joint has a large capsular ligament, -and has binding ligaments one above the other, the seventh being at -the back of the three in the upper row, and the eight, when present, -in a similar position with respect to the lower row. Thus there are -three separate articular surfaces in this joint. The upper surface of -the carpus articulates with the radius; this forms the hinge joint -of the knee and is where flexion and extension takes place. Another -articulation between the upper and lower carpus bones give slight -motion to the knee, but not so much as the upper articular surface. -Between the lower surface of the lower row of carpus bones and the -upper extremity of the metacarpal, or cannon bones, is another -articular surface which gives motion to the knee. This joint has a -large capsular ligament, and has binding ligaments inside and outside. -In addition to the flexion and extension movement the knee joint -possesses, it also serves as a cushion and relieves concussion of the -fore limb. - -IV. FETLOCK JOINT.--This joint is formed above by the lower portion -of the metacarpal, or cannon bone, and below by the part of the os -suffraginis or the large pastern bone. At the back of this joint -there are two small bones called the sesamoid bones. This joint has a -capsular and two lateral binding ligaments. The motion of this joint is -a backward and forward or flexion and extension, same as that of the -knee. - -V. PASTERN JOINT.--This joint is situated just above the hoof, and is -formed by the lower end of the os suffraginis or large pastern bone -and the upper end of the os coronae or small pastern bone. It has a -capsular and lateral binding ligaments, same as the fetlock joint. It -also has the same motion as the fetlock joint, and is often the seat of -what is termed a high ringbone. - -VI. COFFIN JOINT.--This joint is situated within the hoof. It is formed -above by the lower end of the os coronae or small pastern bone, and -below by the upper surface of the os pedis or coffin bone. Immediately -behind this joint, and articulating with the two mentioned bones, is -the navicular, or shuttle bone--it gets its name from its likeness to -the shuttle of a sewing machine. This bone when diseased is the seat of -navicular disease, or coffin-joint lameness. The action of this joint -is very slight forward and backward. - - -JOINTS OF THE HIND LEG. - -VII. HIP JOINT. The hip joint is formed by the pelvis and femur bone. -This is a true ball-and-socket joint similar to the shoulder joint. It -has a capsular, and is called the round ligament, in the joint, holding -the head or ball on the femur in the socket of the pelvis. This can be -seen plainly by examining the joint. This round ligament is important, -as it often becomes strained, being the seat of hip joint lameness. It -is also held together by the strong muscles of the hip. Its motion is -rotation similar to that of the shoulder joint. - -VIII. STIFLE JOINT.--This joint is formed above by the lower end of the -femur, or hip bone, and the upper end of the tibia or thigh bone. These -two bones in front form a pulley-like surface on which the patella, -or stifle bone, is situated. This bone, when the joint is in motion, -glides up and down over the pulley-like surface. It sometimes becomes -displaced, and this is termed dislocation of the patella or stifle -bone. This is an important point to notice about this joint. It has a -capsular and lateral, or binding ligament, which hold the stifle bone -to its place as it plays upon the pulley-like process of this joint. -The action of this joint is only forward and backward or flexion and -extension. It has no lateral or side motion. - -IX. TARSUS OR HOCK JOINT.--This joint contains six bones. The two upper -bones, one of which is a pulley-like bone placed in front, and the -other placed behind, forms that portion of the hock which is called -the point of the hock to which the muscles of the gambe are attached. -It can be easily seen or felt. The upper surface of these two bones -articulate with the lower portion of the tibia or thigh bone, and forms -a true articulation of the hock joint. This part is what gives most of -the motion to the joint. Below these are three other small, irregular -bones, placed one upon the other, having an articular surface between -them. Immediately behind these three small bones is what is called the -cuboid bone. This bone also articulates with the three small irregular -bones, helping to form the articular surface of the hock. The lower -articular surface helps to give a small amount of motion to the joint. -This joint is the seat of bone or bog spavin due to severe sprains, or -poorly conformed joints. - -Fetlock, pastern and coffin joints of the hind leg are so closely -allied to those of the fore leg that it is not worth while -discriminating between them. - - - - -CHAPTER III. - -MYOLOGY. - - -The branch of anatomy which treats of the muscular system is called -Myology. - -Muscles are the active organs of motion, or locomotion, each being -separated from the other by a thin delicate membrane made up of -connective tissue, which forms a sheath for the muscle. A muscle is -divided into two parts, viz.: muscular and tendinous. The muscular -part is the larger of the two. It is sometimes called the belly of -the muscle or flesh. This part is known as muscular tissue, and has a -reddish, meaty color. At both ends of the muscle there is a tendinous -part, or the hard, white portion of the muscle which becomes attached -to the bone. All muscles are attached to two or more places of -different bones, and when contracted, the joints of the body are moved. -They are well supplied with nerves, which give strength and feeling, -and also well supplied with small blood vessels, from which the muscle -is fed. Muscles are found in separate groups, all of which have -different actions to perform. There are two kinds of muscles--voluntary -and involuntary. The voluntary muscles are under the control of the -will of the animal; example--the muscles of the head, neck, back, hip -and legs. The involuntary muscles are beyond control of the animal, -and will act even though the animal were asleep--such as those of the -heart, the large muscular curtain which separates the chest cavity from -the abdominal cavity, which is one of the great muscles of breathing; -also the muscles around the chest which assist in breathing. - -[Illustration: PLATE II. - -MUSCLES OF THE HORSE--SUPERFICIAL LAYER--AFTER MEGNIN.] - - -EXPLANATION OF PLATE II. - -MUSCLES OF THE HORSE. - -This illustration shows the superficial muscles of the body after the -skin and panniculus carnosis muscle has been carefully removed. This -muscle is spread over the greater part of the body, which is related -externally with the skin; internally with the superficial layer of -muscles. Its action corrugates the skin, and thus enables the animal -to expel or shake off insects and irritating bodies, its use being -thus protective to some extent; it also supports and binds down the -superficial muscles. - -SUPERFICIAL LAYER. - -The panniculus and tunica abdominalis are removed. - - 1. Abducens. - 2. Retrahentes muscles. - 2´. Attollens maximus. - 2´´. Attollens anticus. - 3. Temporalis. - 4. Nasalis longus. - 5. Orbicularis palpebrarum. - 6. Levator labii superioris alæque nasi. - 7. Dilatator naris lateralis. - 8. Orbicularis oris. - 9. Zygomaticus. - 9´. Buccinator. - 10. Depressor labii inferioris. - 11. Masseter. - 12. Levator humeri. - 13. Trapezius cervicalis. - 14. Trapezius dorsalis. - 15. Latissimus dorsi. - 18. Pectoralis parvus. - 19. Pectoralis magnus. - 20. Sterno-maxillaris. - 23. Subscapulo-hyoideus. - 24. Antea-spinatus. - 25. Teres externus. - 26. Postea-spinatus. - 30. Caput medium of the triceps. - 31. Caput magnum extensor brachii. - 33. Extensor metacarpi magnus. - 34. Humeralis obliquus. - 35. Extensor pedis. - 36. Flexor metacarpi externus and medius. - 37. Flexor metacarpi internus. - 46. Cervical - 47. Dorsal serratus magnus. - 48. Rhomboideus longus. - 49. Superficialis costarum. - 50. Splenius. - 52. Intercostales. - 54. Tensor fasciæ latæ. - 55. Triceps abductor femoris. - 56. Gluteus externus. - 61. Biceps rotator tibialis. - 62. Rectus femoris. - 63. Vastus externus. - 65. Gastrocnemius externus. - 68. Flexor pedis perforans. - 69. Peroneus. - 70. Extensor pedis. - 71. Flexor metatarsi. - 72. Flexor pedis accessorius. - 74. Obliquus abdominis externus. - -VOLUNTARY MUSCLES.--The voluntary muscles are in groups. The first -muscle we will call the student’s attention to, after removing the -skin, is the panniculus carnosus (not shown in Plate I), which is a -thin muscle, and almost entirely covering the body, which is sometimes -accidentally removed by a careless person in skinning the animal. The -action of this muscle is to shake the skin when flies or other objects -bother the horse. This muscle is not shown in Plate I it having been -removed in order to show the more important ones. - -HEAD MUSCLES.--At the head there is a group of muscles which assist in -chewing, or masticating, the food. - -GULLET OR PHARYNX MUSCLES.--Around the throat is another set of -muscles, sometimes called the muscles of the gullet, or pharynx, which -assist in swallowing. - -NECK MUSCLES.--The neck muscles are divided into two groups, one on -each side. The action of these is to raise and lower the head, also to -turn the neck and head from side to side. - -MUSCLES OF THE BACK.--The muscles of the back are generally divided -into two groups, one above the spinal column and the other below. The -muscles above the spine assist the animal in running, jumping and -rearing. The muscles below the spine are sometimes called the psoae, or -lumbar, muscles, situated below the lumbar bones, or the bones of the -small of the back. The action of these muscles is to assist the animal -in getting up. These muscles are important, for when paralyzed the -horse cannot use his hindquarters. Below these muscles are the kidneys. - -HIP OR GLUTEAL MUSCLES.--The muscles of the hip are very large, filling -in around the hip bones. The action of these is much the same as those -of the back, as they assist in jumping, running, rearing and in flexing -and extending the hind leg. - -[Illustration: PLATE III. - -MUSCLES OF THE HORSE--DEEP LAYER--AFTER MEGNIN.] - - -EXPLANATION OF PLATE III. - -MUSCLES OF THE HORSE. - -_Deep Layer._ - - 1. Temporalis. - 1. Stylo-maxillaris. - 2. Rectus capitis anticus major. - 3. Sterno-thyro-hyoideus. - 4. Sterno-maxillaris. - 5. The Trachea. - 6. Scalenus. - 7. Splenius. - 8. Funicular part of ligamentum nuchæ. - 9. Rhomboideus longus. - 10. Cervical. - 15. Costal serratus magnus. - 11. Cartilage of prolongation. - 12. Rhomboideus brevis. - 13. Transversalis costarum. - 14. Longissimus dorsi. - 15. Serratus Magnus. - 16. External intercostals. - 17. Internal intercostals. - 18. Rectus abdominis. - 19 19. Pectoralis magnus. - 20. Postea-spinatus minor. - 21. Flexor brachii. - 22. Humeralis obliquus. - 22´. Caput parvum (of triceps extensor brachii). - 23. Extensor suffraginis. - 24. Extensor metacarpi magnus divided. - 25. Extensor metacarpi obliquus. - 25´. Its tendon. - 26, 28. Flexor pedis perforans and perforatus. - 29. Obliquus abdominis internus. - 30. Gluteus maximus. - 31. Erector coccygis. - 32. Curvator coccygis. - 33. Depressor coccygis. - 34. Rectus femoris. - 35. Vastus externus. - 36. Part covered by triceps abductor. - 37. Biceps rotator tibialis. - 38. Gastrocnemius externus. - 39. Plantaris. - 40. Flexor pedis perforans. - 41. Peroneus. - 42. Flexor metatarsi. - 43. Extensor pedis (cut across). - -TAIL OR COCCYGEAL MUSCLES.--Here there are four that are important, -one situated on the upper side of the tail when straight out, the -action of which is to raise the tail; two, one on each side of the -tail, have the power of drawing the tail to either side; the fourth is -situated under the tail and is the smallest one of the four. Its action -is to draw the tail down. - -ABDOMINAL MUSCLES.--The abdominal or belly muscles, are four large, -flat muscles on each side of the abdomen. The outer edge of these -muscles is attached to the outer ends of the false ribs, also to the -processes of the lumbar bones and the outer angles of the pelvic or -hip bones. They unite below to what is called the linea alba, a hard, -white fibrous cord. They pass back in the center of the belly and are -attached to the front of the pelvic bones, called the lower bones of -the pelvic cavity. About ten inches from where it is attached here, -passing forward, is a small slit or hole, which is called the navel, -or umbilical opening. Here the navel vessels pass in and out during -the foetus life, or before the colt is foaled. This is a point of -importance to note, for sometimes at the time of birth this opening -does not close and allows the bowels to come down and form what is -known as umbilical or navel rupture. - -Before finishing the description of this group of muscles a very large, -important ligament should be noted, which is found spread all over the -abdomen of the horse. It is of a yellowish color and about one-eighth -of an inch thick, attached in front to the back of the breast bone and -to the pelvic bones behind. This is the first structure seen after -removing the skin from the abdomen. This ligament gives great support -to the organs contained in the abdominal cavity. The action, or uses, -of the abdominal muscles are to support the organs contained in the -abdominal cavity, to flex the back-bone and assist in passing of the -feces. In the mare these muscles assist in parturition, or foaling. - -SHOULDER MUSCLES.--The shoulder muscles are very large and powerful. -There are only three of great importance. Two situated on the outside -of the scapula or shoulder blade are important, as they are muscles -affected in the disease called shoulder sweeny. The other important one -is that which passes down over the shoulder joint through the groove -or pulley-like surface on the humerus, or shoulder bone. This is a -long, powerful muscle, attached above to the lower end of the scapula, -or shoulder blade, passing down through the groove mentioned, and is -attached to the upper and front part of the radius or fore arm bone. -Its chief point of importance rests in its action in raising the front -leg, where it passes over the pulley-like surface mentioned, when it -becomes injured or diseased; it is the seat of shoulder joint lameness. - -MUSCLES OF THE FRONT LEG.--Muscles of the front leg, from the shoulder -down, are divided into two separate kinds, the extensor and flexor -muscles. The extensor muscles are those which bring the leg forward. -These muscles above are attached to the bones around the elbow joint, -passing down in front of the arm bones. About three inches above the -knee they become changed into the tendinous part of the muscles, or -what is called the cords of the leg. Some of them are attached to the -bones about the knee joint, while others pass over the front of the -joint and are held down to their place by a band or ligament, forming -a loop, as it were, for the tendinous portion of the muscle to glide -into when the leg is in action. Each one of these loops through which -the muscles pass are supplied with a synovial membrane to secrete the -synovia, or oil, which lubricate it during action, the same as in the -joint. This is a point of importance, as sometimes, on account of -injury or strain of this part of the joint through which the muscles -play there may be found a small, puffy enlargement containing oil -secreted by the synovial membrane. This disease is called bursal -enlargement. - -The flexor muscles are situated at the back part of the leg, attached -above to the back part of the elbow joint, passing downwards at the -back part of the leg. About two or three inches above the back part -of the knee joint they become tendinous, and from there down to the -back part of the coffin bone, where two of the principle muscles are -attached; these form what is known as the back tendons, or cords, of -the leg. Some of them become attached to the back part of the knee, -same as the muscles on the front part of the leg, while the other two -principal tendons pass through a loop formed by ligaments, the same as -those mentioned in the front part of the knee. In tracing these tendons -down from the knee to the fetlock, notice that they pass through -another larger loop or sheath formed at the back of the fetlock, where -some of the fibers are attached, while others continue down at the back -part of the pastern bones, and are attached to the os pedis or coffin -bone. These tendons are important, because when they are strained the -fact is spoken of as the strain of the back tendons. The action of -these muscles is to flex the leg, bend the knee, pastern joints and -fetlock. - -MUSCLES OF THE HIND LEG.--These are also divided into two groups, -extensor and flexor. The extensor muscles are situated in front of -the hind leg. They are attached above, around the stifle joint, and -pass downward in front of the tibia, or thigh bone, one being attached -to the front part of the hock. The other passes through sheaths, or -loops, supplied by a synovial membrane, formed by ligaments, to hold -the muscles firm in front while the leg is in action. In tracing them -down, in front of the shin bone to the fetlock, note that they pass -through loops, or sheaths, and continue down in front of the pastern -bones to where they are attached. The action of these is to bring the -leg forward. - -The flexor muscles of the hind legs are attached, above, around the -back part of the stifle joint. In tracing them down it will be found -that they become tendonous. Two of the principal ones pass down to -that part of the hock joint, which forms the point known as the cap. -These form what is called the gambe of the leg, and are partly attached -at the point of the hock, and other part passing down to the fetlock -joint through a loop, or sheath, along the back part of the pastern -bones, and are attached to the os pedis or coffin bone of the foot. -This muscle, from the hock down, forms one of the back tendons of the -hind leg. Another important muscle is found passing down underneath -those already mentioned, through a loop, or sheath, at the back part of -the hock, where it is supplied with a synovia sac. This is a point of -importance, because when it becomes sprained it is the seat of what is -called thoroughpin. It then passes down the back part of the shin bone -beneath the other tendons already mentioned, through the loop at the -fetlock to the back part of the os pedis or coffin bone, where it is -attached. The action of these muscles are to flex or bend the fetlock -and raise the hock joint in traveling. - -INVOLUNTARY MUSCLES.--Involuntary muscles, or muscles not under the -control of the will. The first to notice are those of breathing or -respiration. They form a group situated about the chest in such a way -as to be the means of increasing or decreasing the size of the chest -cavity. When these muscles expand the chest cavity is enlarged, causing -the air to rush into the lungs, known an inspiration. On the other -hand, when these muscles contract the air is expelled from the lungs, -known as expiration. - -The diaphragm is a muscular curtain which separates the chest from the -abdominal cavity. It also assists greatly in drawing the air in, when -it contracts. This muscle also assists in passing faeces, and in the -mare foaling. It separates the heart and lungs from the bowels, liver -and stomach. This muscle should be carefully examined by the students. -It can be seen by opening any dead animal. - -There is one muscle which is both voluntary and involuntary. It is -situated in the penis, surrounding the urethra, or the tube, which -carries the urine from the bladder to the penis in the male animal. -Its action is voluntary while the animal is passing urine. It is -involuntary during sexual intercourse, forcing the semen down through -the penis. - -[Illustration: PLATE IV. - -DIGESTIVE AND MALE URINARY APPARATUS OF A HORSE--AFTER MEGNIN.] - - -EXPLANATION OF PLATE IV - -DIGESTIVE APPARATUS OF THE HORSE - - 1. Mouth. - 2. Pharynx. - 3. Œsophagus. - 4. Diaphragm. - 5. Spleen. - 6. Stomach (left sac). - 7. Duodenum. - 8. Liver (upper extremity). - 9. Great colon. - 10. Cæcum. - 11. Small intestine. - 12. Floating colon. - 13. Rectum. - 14. Anus. - 15. Left kidney and ureter. - 16. Bladder. - 17. Urethra. - _a._ Hard palate. - _b._ Tongue. - _c._ Soft palate. - _d._ Trachea. - _e._ Pulmonary artery (divided). - _f._ Heart. - _g._ Posterior aorta. - - - - -CHAPTER IV. - -SPLANCHNOLOGY. - - -Study of large interior organs in any of the four great bodily cavities -especially those in the abdomen. - -DIGESTIVE ORGANS OF THE HORSE.--The digestive organs comprise the -alimentary canal and the accessories by which the alimentary matter is -received and subjected to specific actions, which adapt it for purposes -of nutrition. Digestion, therefore, embraces the collective operations -and changes which the food undergoes in the alimentary canal. - -The whole digestive track from the mouth to the anus which is situated -just below the tail, is sometimes called the alimentary canal. - -The mouth is an oval cavity at the commencement of the alimentary or -digestive canal. In front of the mouth are the lips, one above and -one below; at the sides are the cheeks. The mouth is lined with what -is known as the mucous membrane, in which are several small openings, -from the glands, which are situated about the mouth. Through these the -saliva is poured. On the upper part of the mouth the mucous membrane -is thrown into ridges, or folds, from 18 to 20 in number. This is a -point of importance in connection with bleeding a horse with lampas. It -is never safe to bleed back of the third bar because there is a large -artery which runs down through the roof of the mouth and enters the -hole in the bone just before it reaches this bar. The tongue, which has -the chief nerves of the sense of taste, is situated in the mouth; this -organ also has a very important part to perform in masticating the food -and mixing it with saliva. The teeth, which also take a very active -part in the masticating of food, are dealt with under the heading of -“Teeth.” - -SALIVARY GLANDS.--These glands secrete the saliva that is poured into -the mouth while the animal is eating. There are only three pairs of -much importance. One large pair, one on each side of the throat below -the ears, known as the parotid glands, fill up the space between the -jaw bone and the neck. This pair has tubes passing around and under the -lower jaw and up into the cheek muscles entering the mouth opposite -the fourth molar tooth. These tubes, known as steno’s ducts are about -an eighth of an inch in diameter and convey the saliva from the -glands into the mouth. The next pair are situated under the pair just -mentioned. Their tubes enter into the bottom part of the mouth. The -third pair are situated under the tongue, one on each side. They pour -their secretion into the mouth by several small openings near the front -under the tongue. This can be seen by examining the under surface of -the tongue closely. This is very important fluid in connection with the -digesting of the food. - -The gullet is a cavity situated just back of the mouth. It is chiefly -made up of muscles which perform the act of swallowing the food. It is -lined with the continuation of the mucous membrane of the mouth. - -The oesophagus, or the continuation of the gullet, is a tube extending -from the gullet to the stomach, and is used to convey the food to -that organ. It is made up of two coats, the muscular and the mucous. -The former contains fibers which, when once the food enters the tube, -contract behind it, forcing it down to the stomach. Its lining is a -continuation of the mucous membrane of the mouth and the gullet. In -tracing the oesophagus or tube down the neck from the gullet, note -that it passes down the left side of the neck, entering the thoracic, -or chest cavity, between the lungs over the heart through the large -muscular curtain known as the diaphragm, then enters the stomach an -inch or two after passing the diaphragm. - -THE STOMACH.--This organ is very small in the horse in comparison with -that of the ox. It holds only about four gallons, and is situated -just back of the curtain which separates it from the lungs. It lies -mostly to the left side. The walls of the stomach being composed of -three coats. That on the outside is called the serous membrane, a name -applied to membranes which line closed cavities, such as the abdominal -cavity. The inside lining is a continuation of the mucous membrane -lining the organs before mentioned. The lining in the left part of -the stomach or the part where the food is prepared for digestion is -the same color as that of the mouth. The lining of the right part -of the stomach, which is the true digestive part, is of a deep red -color resembling velvet, and when placed under a microscope has the -appearance of a honey-comb. When the stomach is empty this membrane is -thrown into loose folds. Several small openings may be noticed through -which the gastric juice and pepsin from the glands, situated in the -walls of the stomach, enters. These are very important fluids as they -assist greatly in digesting the food. The third coat is known as the -muscular coat already mentioned. Its action is to give the stomach a -churning motion, rolling the food around and mixing it with the juices. -The opening to the stomach is guarded by a valve which prevents the -food from passing back through the gullet. There is also a valve at -the opening of the bowels, preventing any coarse, undigested food -from entering them. The stomach is held in its place by five large -ligaments, and is well supplied by blood-vessels and nerves. Digestion -of the food takes place very quickly in the horse in comparison to -other animals. Frequently a change of food or working too soon after -eating will interfere with the digestion, thus setting up what is known -as indigestion. This is a very painful disease in the horse. After the -food is acted upon by the juices in the stomach it changes into what -is known as chyme, which passes into the bowels. - -THE BOWELS.--They are divided into two parts--the large and small. - -The small bowels are 72 feet in length, about one inch in diameter, -and are made up of three coats, same as the stomach. The serous coat -on the outside contains small glands which secrete an oily material -to lubricate the outside of the bowels, which comes in contact with -the inner wall of the abdominal cavity. The muscular coat, made up of -muscular fibers, is situated between the other two coats, the same -as in the stomach; its action is to contract the bowels, giving them -motion to convey the food along through them. The mucous coat is a -continuation of the mucous coat of the stomach. Along this coat are -found small glands known as villi lacteal; these absorb the nourishment -from the food as it passes along through the bowels and pours it into -the blood. The small intestines or bowels are attached on the upper -side to what is known as the mesentery, which is attached above to the -roof of the abdominal cavity. It can be seen in any of the smaller -animals upon examination. About six inches from the stomach, in the -bowels, are found two openings. One of these receive the hepatic duct, -a tube for the purpose of carrying the bile from the liver to be poured -in on the food as it passes through the bowels. The other opening is -for the duct of the gland known as the pancreas. It secretes a clear -fluid known as the pancreatic juice. These juices act on the food -in the first part of the small intestines, changing it into chyle. -After this, the action of the rest of the intestines is to absorb the -nourishment out of the food as it is passing back. The small intestines -and stomach, when in a healthy condition, should be found empty one -hour after food has been eaten. The small bowels or intestines are -situated mostly on the left side just behind the stomach. - -The large bowels have three coats, the same as the small ones. The -first part of the large bowels is known as the blind bowel or caecum, -and is about three feet in length; this is generally the first thing to -protrude when opening a horse’s abdominal cavity. Its use is to act as -a reservoir to hold the water and fluid of the food; from this organ -the water and fluid parts are mostly taken up into the system. The next -part of the large bowels is known as the large colon; it lays along -the floor of the abdominal cavity, is about nine feet in length and -is doubled on itself three times. In this bowel the solid part of the -food is found. Here digestion is brought about by the contraction and -expansion of the muscles of the bowel and the nourishment taken from -it, after which it is worked back out of this bowel and enters what is -known as the floating colon. This is about ten feet in length and about -two inches in diameter, or double the size of the small bowel. It is -thrown into folds or pleats, and as that portion of the food containing -no nourishment passes through it is worked into balls which pass back -and are emptied into the rectum or back bowel. This is situated at the -back part of the abdominal and pelvic cavity back of the small bowels -or intestines and like them, is suspended by a fold paritoneum. - -The rectum or back bowel is sometimes known as the straight bowel. -It is about 18 inches long and forms the last part of the bowels or -intestines. Its coats are a continuation of those of the large bowel, -but each is thicker and heavier. Above this bowel are the bones of the -sacrum, below it, in the horse the bladder and other small glands. -Below the rectum of the mare are situated the womb and the vagina, the -latter being the passage into the womb from the outside. The bones -which help to form the pelvic cavity are situated at the sides, and -at the back immediately under the tail is what is known as the annus. -The use of the rectum is to hold the balls as they pass back from the -floating colon. When the rectum becomes so full that there is pressure -on the sides of the wall thus stimulating the nerves the muscular coat -contracts and forces the contents back towards the annus. At the same -time the muscles of the annus dilate, causing the faeces to pass out. - -ACCESSORY ORGANS OF DIGESTION.--In the abdominal region these organs -are the Liver, the Pancreas, and the Spleen. - -The Liver is the largest gland in the body and is situated between the -stomach and the diaphragm. The liver of the horse weighs from ten to -twelve pounds. It is of a dark brown color, well supplied with blood -and nerves, and is held in place by several strong ligaments. A bitter, -greenish colored fluid called the bile is secreted from the liver and -emptied into the digestive system, where it plays an important part -in its action on the food. There is no gall bladder in the horse, but -simply a tube passing from the liver to the small bowel into which it -empties the bile about six inches back of the stomach. It is important -to note that it is in this tube that gall stones sometimes collect. - -The Pancreas is another very important gland. It is of a grayish, fatty -color, and may be found near the roof of the abdominal cavity in front -of the kidneys. The Pancreas secretes a clear, colorless fluid called -the pancreatic juice. This fluid, like the bile from the liver, also -plays an important part in the digestion of food. It is carried down -from the Pancreas by a duct or tube emptying into the small bowel just -back of that of the liver. - -The Spleen is a long, flat gland about fifteen inches in length, -situated along the left side of the stomach and to which it is closely -attached. It is of a grayish red color and feels quite soft. It is -ductless, there being no secretion passing from it. The function of -this gland is not clearly understood, but by many it is supposed to -regulate the temperature of the stomach during the process of digestion -and to act as a reservoir for the blood. Some speak of it as the -burying ground of the red corpuscles. It is well supplied with blood -vessels and nerves and weighs about two pounds in an average sized -horse. - - -RUMINANTIA. - -DIGESTIVE SYSTEM.--The lips of an ox are thick and hard. The upper has -no hair on it and varies in color with the color of the animal. When -cattle are in good health this space is always moist. - -The cheeks on the inside are covered by many small rough processes, -which give them a very rough appearance. - -The Tongue of the ox is stronger than that of the horse and is more -movable. It is very thick and heavy at the back, pointed at the front -end and the upper part of it is very rough. It is by means of the -tongue that the ox takes most of the food into the mouth. - -The Salivary glands are similar to those of the horse. - -The Teeth differ very much from those of the horse. - -The ox has no front teeth in the upper part of his mouth, their place -being taken by a pad of cartilage or gristle. This pad takes the place -of the upper row of front teeth. The lower row of teeth press against -it when the animal is cropping grass. This accounts for the fact that -cattle do not do as well on short grass as horses. - -The front teeth in the lower jaw also differ from those of the horse. -They are eight in number, chisel-shaped, and are loosely set in the gum. - -The molars, or back teeth, are similar to those of the horse, only -they are smaller and not so smooth on their upper surface. The ox has -twenty-four molars or back teeth, and eight incisors or front teeth, -making thirty-two in all. - -The Gullet of the ox is much larger than that of the horse. - -The Oesophagus or tube, which carries the food down from the mouth to -the stomach is well developed, the fibers in it being very strong and -possessing a double action. When the animal is eating they carry the -food from the mouth to the stomach, and when chewing the cud they act -the very opposite, carrying the food from the stomach back into the -mouth. - -THE STOMACH.--The student will do well to give some time to the study -of this important organ of the ox, as it is very frequently the seat of -disease. - -The stomach has a capacity of fifty-two gallons and is divided into -four separate and distinct compartments: the Rumen or Paunch, the -Reticulum or Honey Comb, the Omasum or Many-plies, and the Abomasum or -the true Stomach. In the first three of these the food undergoes a sort -of preparatory process, while in the fourth the process of digestion is -complete. - -The Rumen or paunch is very large, and in an aged animal fills -three-quarters of the abdominal cavity. It lies up against the left -side of the wall of the abdomen, where it is attached and held to its -place by the ligaments. Its situation being an important matter, as -many diseases of the rumen, or paunch, are first noticed on the left -side. Tapping for bloating is always done on the left side because -of this fact. The walls of the paunch of an ox resemble those of the -stomach of the horse, but are not so sensitive, and stand a great deal -of abuse before inflammation sets in. The paunch has two openings, both -of which are at the front; through one the food enters, while through -the other it passes out into the next division. - -The Reticulum, or honey comb, is the smallest division and resembles a -honey comb in appearance. This part has little to do with preparing the -food. It is provided with two openings, one in front, where the food -enters, the other at the back, where it passes through into the third -division. In the reticulum, or honey comb, the food is softened further -by the water that the animal drinks which passes directly into the -second division. The food is here pressed into balls and prepared to be -forced back into the mouth to be further masticated. - -The Omasum, or many-plies, is the second largest division of the -stomach. When full it is ovoid in shape. It is placed just behind the -second division and at the right side of the paunch. The inside is full -of folds, or layers of membrane, into which all the coarse parts of the -food pass and roll about until it is fine and well prepared to pass -into the last division. When this part of the stomach becomes deranged -and the food becomes dry and hard between the folds, the disease called -impaction of the many-plies, or dry murrain, is the result. - -The Abomasum, or fourth stomach, is the true digestive part. In it the -food is completely digested. The walls are redder in color than those -of the three first divisions and contain the glands which secrete the -acids and gastric juices. This stomach has two openings, one through -which the food enters and the other through which it passes into the -small bowels. - -The Bowels, or intestines, of the ox are divided into large and small -bowels. This, together with their structure and action resembles that -of the horse. The small bowels are only half the size of the horse, -being about one-half inch in diameter, and about one hundred and fifty -feet in length. The large bowels are not nearly so long as those of the -horse and are thirty-five feet in length. - -The Liver of the ox resembles that of the horse, except that it is -provided with a gall bladder which resembles a pear in shape. This acts -as a sac in which to store the gall during the time it is not required -in digestion. When digestion is going on the wall of the gall sac -contracts and forces the gall down to the food. The other glands, the -pancreas and spleen, resemble those of the horse. The juices from these -glands have the same action in cattle as they have in the horse. - -RUMINATION, OR CHEWING THE CUD.--Food when first taken into the mouth -of a ruminant is but lightly masticated and mixed with the saliva from -the salivary glands, after which it is swallowed, passing through the -oesophagus into the rumen or paunch (first stomach). This division -acts as a reservoir or storehouse for food thus eaten quickly. When -the animal has time, so to speak, he lies down or stands quietly and -completes the process of mastication of his food by chewing the cud. -This peculiar act is performed as follows: After being softened and -moistened by warmth, the food passes from the rumen or paunch into -the second division--the reticulum, honey comb or second stomach. In -this small globe-like compartment the food is moistened and compressed -into pellets--the cud. By a peculiar reverse action of the oesophagus -or gullet these pellets are taken back into the mouth for further -mastication or chewing. When re-mastication is completed it is again -swallowed, but this time it passes directly into the omasum, many-plies -or third stomach, and thence to the fourth or true stomach. - -PROCESS OF DIGESTION AFTER RUMINATION.--Following rumination which, -strictly speaking, is the first step in the digesting process, the food -passes into the third stomach. The fine parts pass right along to the -fourth stomach while the coarser parts are drawn between the folds of -the membrane in this division and worked about until it is fine and -ready to pass into the fourth stomach, where it becomes fully digested -by the action of acids and gastric juices which are secreted in this -part. It then passes into the small bowels, and is acted upon by the -bile from the liver and the pancreatic juice from the pancreas. These -juices are emptied into the first part of the small bowels through -little ducts or tubes, which lead from the glands down to the bowels, -just on the same principle as that of the horse. After this, throughout -the rest of the bowels, the nourishment of the food is taken into the -system by means of little glands which are situated in the coating of -the bowels. The nourishment when once in the blood goes to supply the -different parts of the body, while the part containing no nourishment -or undigested passes off through the back bowels in the form of feces. - - -TEETH. - -Teeth are objects situated in the upper and lower jaws. They are made -of the same tissues as bone but contain 10-1/2 per cent. more of earthy -salts. This fact accounts for their extreme hardness. Unlike bone they -can stand exposure to air and friction without becoming diseased. Teeth -are used to masticate or chew the food, and because of the constant -change in their formation and appearance they serve as a guide in -telling the age of the horse. - -There are three hard structures that enter into the formation of the -teeth--Dentine or Ivory, Enamel, and Cementum, or Crusta Petrosa. - -The Dentine, or ivory, is situated in the upper part around the pulp or -nerve cavity. It is of yellowish color and largely supplied with nerves -which pass through it from the pulp cavity. - -The Enamel is the hardest substance of the tooth, and covers the -outside of all the exposed part. This substance is characterized by its -whiteness and, unlike the dentine, contains no blood vessels or nerves. -If part of the enamel is broken off it is never replaced, and the tooth -below the broken part generally becomes decayed. - -The Cementum, or crusta petrosa, is found in the fang or root and the -parts situated below the gum. It is the softest part of the tooth. - -Teeth may be simple or compound. Simple as in the dog, where the entire -exposed surface is covered by a solid cap of enamel, which alone is in -wear; compound or complex, as in the horse, where various tissues are -in wear. A tooth consists of the following anatomical parts: The body, -or crown, that part above the gum; the table, the part that comes into -wear on the top; the neck, the part to which the gums are attached; and -the fangs or roots, the parts situated down in the bone. - -There are three kinds of teeth found in the horse, the incisors, the -canine and the molars. - -The Incisors, or front teeth, situated in the front part of the mouth -just inside the lips, are twelve in number, six above and six below. - -The Canine, or bridle teeth, are often absent in the mare. They are -four in number, two in the upper and two in the lower jaw, one on -each side about two inches back from the incisor teeth. They are from -a quarter to three-quarters of an inch above the gum, are round and -pointed and of no particular use. They resemble the eye teeth of other -animals. - -The Molars, or back teeth, are twenty-four in number, six on each side -in the upper and six on each side in the lower jaw. With these the food -is ground and masticated. - -Wolf Teeth are two small, round, pointed temporary teeth which vary in -size in different animals, situated one on each side in front of the -molars or back teeth in the upper jaw. - -TEMPORARY AND PERMANENT TEETH.--The horse has two sets of teeth. The -milk are temporary and are those that the colt sheds; while those that -come in and remain without being shed are called the permanent teeth. -The cutting of the teeth of the foal varies, but at or within nine -days after birth he has four front teeth, two in the center above and -two below, and in the back part of the mouth twelve molars. At from -seven to nine weeks four more incisors or front teeth appear, one at -each side of the two center teeth in each jaw. At nine months he gets -the last of his milk or temporary teeth, these being the corner teeth, -two in the upper side and two in the lower side of the jaw. At this -time he has his full set of milk temporary teeth, consisting of twelve -molars or grinders and twelve incisors or front teeth, six above and -six below, making twenty-four in all. As the colt advances in age he -sheds all these teeth. He then commences to get permanent teeth. When -the age of one year is reached, four permanent molars appear, two in -each jaw, one on each side, behind the three temporary teeth. At two -years of age he gets four more back molars, one on each side of each -jaw. When the age of two years and nine months is reached the two -middle teeth of the temporary incisors, or front teeth of each jaw -fall out, and are replaced by two permanent incisors in each jaw; thus -at the age of three years these four permanent incisors are up and in -wear. At this age, the first eight molars, two on each side of each -jaw, are shed and replaced by eight permanent molars. At four years of -age he sheds four more front or incisor teeth next to those shed at -three years, and these are replaced by four more permanent incisors or -front teeth. At this age, too, he sheds the four remaining temporary -molars, or grinders, which are replaced by four more permanent molars. -He also gets four more permanent molars at the back of the mouth. Thus -at the age of four years the colt has a full set of permanent molars, -consisting of six on each side of each jaw, making twenty-four in all. -At five years of age he sheds the four remaining temporary incisors or -front teeth, which are replaced by four permanent incisors, known as -the corner teeth. It is important to become familiar with the time at -which the colt sheds his different teeth, for sometimes the caps or -shells of the teeth do not fall off when they should. These should be -watched, for they greatly interfere with feeding and should be removed -with forceps. At five years of age the canine or bridle teeth make -their appearance; thus at the age of five years the colt has all his -teeth or what is known as a full mouth. - -The following table shows the various changes taking place in the -mouth of the horse from the time of birth up to the age of five years: - -Hence the horse has-- - - --Incisors-- Canine --Molars-- - Age Temporary Permanent Temporary Permanent - At or soon after birth 4 0 0 12 0 - 9 weeks 8 0 0 12 0 - 1 year 12 0 0 12 4 - 2 years 12 0 0 12 8 - 3 years 8 4 0 4 16 - 4 years 4 8 0 0 24 - 5 years 0 12 4 0 24=40 - - The table given below indicates the various changes which occur in - the mouths of ruminants, and more particularly in the mouth of the ox: - - -RUMINANTS - - --Incisors-- --Molars-- - Age Temporary Permanent Age Temporary Permanent - At or soon after - birth 4 0 12 0 - 2 weeks 6 0 1 year 12 4 - 3 weeks 8 0 2 years 8 12 - 2 years 6 2 3 years 4 16 - 3 years 4 4 - 4 years 2 6 4 and 5 years 0 24=32 - 5 years 0 8 - - A table giving the number and variety of teeth as they occur in - the domestic animals and in man may be serviceable as one of handy - reference, and is herewith appended: - - Incisors Molars Canine Bicuspid Total - 4 6 2 4 - Man -- -- -- -- = 32 - 4 6 2 4 - - 6 12 2 0 - Horse -- -- -- -- = 40 - 6 12 2 0 - - 0 12 0 0 - Ox -- -- -- -- = 32 - 8 12 0 0 - - 6 12 2 0 - Dog -- -- -- -- = 42 - 6 14 2 0 - - 6 14 2 0 - Pig -- -- -- -- = 44 - 6 14 2 0 - - 6 8 2 0 - Cat -- -- -- -- = 30 - 6 6 2 0 - - The dental formula of the ox is the same as that of all ruminants. - - -RESPIRATORY SYSTEM OF THE HORSE. - -ORGANS OF RESPIRATION.--By the action of these organs certain chemical -and physical changes take place in the blood, the chief of these -consisting of absorption of oxygen from, and giving off carbonic -acid to the atmospheric air, the former change being necessary for -the elaboration of the fluid, the latter for the elimination of a -substance which, if retained, would prove injurious. The organs of -respiration are invariably adapted to the wants of the animal and the -medium in which it lives. Thus insects breathe by air-tubes, opening -on the surface of the body; in the oyster breathing is performed by -fringes; in fishes by gills; in the mammalia by means of elastic -air-receptacles, called lungs, which are enclosed in special cavities, -and communicate with the atmosphere by means of an air-tube. - -In the horse, who breathes only through his nose, the organs of -respiration are the nostrils, nasal-chambers, larynx, trachea, and in -the thoracic cavity, the bronchi, bronchial tubes, and the lungs. - -NOSTRILS.--The nostrils are two openings, one on each side of the nose. -They are held open by the aid of cartilage and muscles. About one and -one-half inches up the nostril on the under side is a small opening -about the size of a grain of shot. Through this opening the duct or -tube which carries the tears down from the eyes empties into the nose. -The nostril is lined with a thin, delicate skin which changes into -mucous membrane as it passes up into the chambers of the head. - -NASAL CHAMBERS.--These give passage to the air from the nostril into -the larynx. There are two of these chambers, divided in the center by a -thin partition or cartilage called the septum nasi. These communicate -with the sinuses of the head. The horse cannot breathe through the -mouth on account of the formation of the throat, and this compels him -to always breathe through the nostrils. This is a point which should be -remembered. - -LARYNX.--This is a cavity made of cartilage. It gives passage to the -air and also the organ of voice. It is situated in the floor of the -gullet. This cavity has an opening on its upper side, guarded by a -valve, which is always opened except when the animal is swallowing -food or water. When the food is being swallowed it passes over the -valve which closes the opening while the food passes over it. This is -important, for if the valve does not close properly, thus allowing -either food or water to drop into the windpipe, the animal will have a -fit of coughing. This is sometimes referred to as “the food going down -the wrong way.” On the outside of this cavity of cartilage are found -several small muscles which help to hold it in its place. It is lined -inside by a continuation of the same membrane as that of the chambers -of the head. The vocal cords which come into play when the animal is -whinnying are found along the inside of this cavity. These cords are -not nearly so well marked as in the human being, and if they or the -cartilage of the larynx become affected it generally gives rise to the -disease called wind-broken or roaring. - -TRACHEA (Windpipe).--This is a tube which conveys the air down from -the larynx to the bronchial tubes in the lungs. It is made up of forty -or fifty rings of cartilage which are united to each other by strong -elastic ligaments. They give to the windpipe its flexibility, that is, -the power to bend in any direction almost like a piece of elastic. From -the larynx the windpipe enters the chest where it terminates into two -small tubes, one going to the right lung and one to the left. These are -called the bronchial tubes. - -BRONCHIAL TUBES AND AIR CELLS.--These are made up of the same material -as that of the windpipe, but are only about half the size. After -passing into the substance of the lungs they break up into small tubes -which pass all through the lungs and terminates into what is known as -the air-cells. These small tubes and air cells are lined inside by a -very thin mucous membrane, a continuation of the membrane lining the -other organs already mentioned. Just inside this thin mucous membrane -is found the capillary network of the lungs, and while the blood is -slowly passing through this network of vessels it gives off to the air -in the air cells carbonic acid gas and takes in the oxygen from the -pure air while it is in the lungs. - -LUNGS.--Lungs are the most important organs of respiration. They are -spongy, yellowish organs, two in number, one situated on the right -side, and the other on the left. The right lung is the largest because -of the left one having a hollow in its side for the heart. The lungs -are separated by a partition known as the mediastinum, by the heart -which is in the folds of this partition, and also the large blood -vessels and oesophagus. They are made up of light elastic tissue and -are full of air cells and tubes. While the animal is alive they are -very large and fill up nearly the whole chest cavity, but after death -they collapse and are not nearly so large. Between the lungs and -the ribs is found a serous membrane called the pleura or the lining -membrane of the chest. It is made up of two folds, one being attached -around the outer surface of the lungs, while the other is attached to -the ends of the ribs at the side and at the back to the large curtain -which separates the lungs from the bowels. The little glands situated -in this membrane secrete an oily fluid which serves to lubricate these -parts while the lungs are working in the chest so as not to cause -friction. When this membrane becomes inflamed from a chill or injury it -sets up the disease called pleurisy. - -RESPIRATION.--The number of respirations per minute varies with the -different classes of animals; as a rule, the larger the animal the -slower the respiration. - - The horse 8 to 10 - Cattle 12 to 15 - Sheep and goats 12 to 20 - The dog 15 to 20 - Swine 10 to 15 - -The rate of breathing is increased from the process of digestion -immediately after eating, or may increase from exercise. - - -RESPIRATORY SYSTEM OF THE OX. - -The nostrils are narrow and capable of little dilation compared to -those of the horse. The nasal chambers differ chiefly in there being -an additional turbinated bone. The nasal chambers communicate with the -mouth, therefore cattle can breathe through the mouth to a certain -extent. The larynx is simpler in construction, the true vocal cords -being only slightly developed. The trachea or windpipe presents no -important variation. We may note the presence of a third bronchus, -which passes to the right lung to supply a lobe which is wanting in the -horse. - -The Thoracic Cavity is relatively smaller in the ruminants, and the -pleurae present a very important deviation from the arrangement found -in the solipede--viz., the back or posterior mediastinum is imperforate -and strong, completely separating one pleural sac from the other. This -arrangement exists in all the domesticated mammals but the solipede. -The left lung is divided into two lobes, the right into four, the front -one recurving over and almost covering the front of the heart. The -interlobular or cellular tissue is exceedingly thick, the separation -between the lobules being distinctly visible. This arrangement explains -perfectly the special nature of pneumonic lesions in the large -ruminants. - - -URINARY SYSTEM OF THE HORSE. - -The organs of this system secrete the urine from the blood, and excrete -or expel it from the body. These organs are chiefly the kidneys, -ureters, bladder and urethra. The urine, which is a watery fluid, is -secreted by the kidneys, and carried off by their ducts, the ureters, -to a special reservoir, the bladder, where it accumulates and from -which it is finally expelled at intervals through the urethra. - -The kidneys are two compound tubular glands, one on the right side and -one on the left side, and are situated just below the small of the back -(sublumbar region), the right one being the fartherest ahead. In shape -they are long and narrow and resemble the liver in color. In cutting -one of the kidneys open, it is found to be full of glands and tubes, -which secrete the urine from the blood while it is passing through the -kidneys. These tubes pass to the center of the kidneys, where they -empty the urine into what is called the pelvis. The glands are largely -supplied with blood vessels and nerves. The use of the kidneys are to -secrete the urine from the blood, which contains a large amount of what -is known as ureaic acid, and if not taken out of the blood by these -glands, acts as a poison to the system. - -The Ureters are tubes which carry the urine down from the pelvis of -the kidney to the bladder. They are two in number, one situated on the -right side of the pelvic cavity and the other on the left side, close -to the walls--they enter on each side at the upper surface of the -bladder. They are only about one-sixteenth of an inch in diameter. - -The Bladder is situated in the pelvic cavity. When it is full it -sometimes stretches out into the abdominal cavity. It consists of a -body and neck. The body is the large part, and is placed in front; -the neck being at the back part of the bladder. This is where the -urine passes out of the bladder. The bladder is made up of three -coats, somewhat similar to that of the bowels. The serous coat is a -continuation of the serous coat found in the abdominal cavity lining -the bowels. The inside is lined with mucous membrane which is thrown -into folds when the bladder is empty. Another coat is found between -the two membranes above mentioned, called the muscular coat, the -action of which is to contract the bladder when the animal wants to -urinate. The bladder is held in by ligaments. The rectum lies above the -bladder, which in the horse rests on the floor of the pelvic cavity. -Its position in the mare differs from that of the horse. Instead of -the rectum or back bowel being immediately above it, as in the horse, -the womb is just above the bladder or between it and the rectum. The -bladder acts as a reservoir in which to store the urine until it is -full; it then presses on the walls and nerves, giving a peculiar -sensation to these parts, causing the walls to contract, forcing the -urine into a tube which carries it from the body. This is called the -urethra. The neck of the bladder is simply an opening at the back part, -and is guarded by a valve which prevents the urine from dripping out -except when the animal is passing its urine or water. - -The Urethra is the tube which carries the urine from the bladder out -of the body. It is situated much differently in the mare than in the -horse. In the mare it is very short, passing from the neck of the -bladder along below the womb and vagina, which is the passage from the -outside into the neck of the womb. It opens up into the underside of -this passage about four inches in from the outside. This opening is -guarded by a small, thin valve, and can be felt by passing the finger -along the under side of the passage which leads into the womb. In the -horse this tube is a great deal longer than in the mare. It commences -at the bladder, passes along below the rectum or back bowel to just -below the anus. Here this tube bends downward and forward and passes -into the penis, continuing down to the end where it terminates. Its -purpose is to carry the urine from the bladder out of the body and -to perform certain actions in connection with the genital organs. Its -lining is a continuation of the membrane of the bladder. - - -URINARY ORGANS OF THE OX. - -The chief difference in these organs occurs in the kidneys, which in -the ox are larger, and in place of being smooth, like those of the -horse, are rough, resembling a bunch of grapes. The bladder and the -urinary organs resemble those of the horse. - - -GENERATIVE SYSTEM OF THE HORSE. - -Animals possess the faculty of reproducing or propagating their -species, and this function may be non-sexual or sexual, the former -being confined to certain lowly-organized classes of animals. - -In all the higher animals the generation of a new being is dependent -upon two individuals, a male and a female, the female furnishing a -germ, or ovum, the male a fecundating fluid, or sperm, which animates -the germ and renders it fit for development. - -Both the ovum of the female and the sperm of the male are secretions -of glands, which are termed the genital glands, male and female; and -in either sex the generative system may be said to consist of these -glands, with certain accessory organs. The act of coition brings the -two secretions into contact. - -We have two systems of genital organs to consider--the male and the -female. - -MALE.--The genital organs of the horse are as follows: The scrotum or -bag, the testicles, the spermatic cord, the vesiculae seminales or -pouches which hold the semen or sperm, the urethra, the penis and the -sheath. - -The Scrotum is a sac or bag which contains the testicles. It is -situated between the hind legs, and is covered on the outside by a -very fine, soft skin. Passing up in the center under the sheath the -scrotum is a well marked line in the skin called median raphe. This -can be plainly seen when the horse is on his back. It continues up, -gradually getting fainter until it reaches the anus. Under the skin -are layers of white fascia or tissue which can be seen by cutting -through the scrotum. There is a partition in the scrotum separating the -two testicles. The size of the scrotum is affected very much by the -weather. In cold weather its fibres contract, causing it to get very -much smaller, while in warm weather the fibres relax, causing it to -become very much larger. The scrotum contains, supports and protects -the testicles. - -The Testicles are the glands which secrete the semen or sperm. They -are two in number, one situated on the left side and the other on the -right. They are oval in shape, and are attached above to the spermatic -cord. Before the animal is born the testicles are situated in the -abdominal cavity and attached to the serous membrane which has already -been spoken of in connection with that cavity. At or about the time of -birth, there takes place what is known as the descent of the testicles -into the scrotum. In their downward course they pass through a slit or -small opening at the back part of the muscles of the abdomen, where -they are attached to the under part of the hip bone. These slits or -openings are known as the inguinal rings. They can be felt in the horse -by pressing the fingers well up into the groins. The descent of the -testicles is an important point to remember. If the testicle does not -descend into the scrotum the horse is known as a ridgling. In this case -the testicle is not found in the scrotum. At the front part of the -testicle there is a small ridge called the globus major and at the back -of it is another smaller ridge called the globus minor. Passing between -these two ridges is another well marked ridge called the epididymis. -These can be easily seen by examining the testicle after the animal is -altered or castrated. The substance of the testicle is made up of small -glands and fine tubes. - -These tubes, as they pass towards the back of the testicle, form into -larger tubes and finally unite to form one called the vas deferens. - -The Spermatic Cords, or the cords of the testicles, are attached -above to the inguinal rings or openings mentioned before. They are -about five or six inches long and have the testicles attached to them -below. In each cord is found a small muscle which goes by the name -of the spermatic muscle, the rest of the cord being made up of the -spermatic artery, veins and nerves. Running up at the back of these -cords is found a tube called the vas deferens. Around the spermatic -cords and testicles is a serous membrane, one layer being attached to -the testicle and cord, while the other is closely attached around the -inside of the scrotum. In this membrane are small glands which secrete -an oily fluid to lubricate the parts, preventing friction when they -are jolted about in the scrotum. This fluid flies out as soon as the -scrotum is cut. This is important, because sometimes from a slight -injury the glands will secrete a large amount of this fluid, thus -causing the scrotum to look large and swollen. This disease is known as -hydrocele or water in the scrotum. - -VAS DEFERENS.--These tubes are two in number and are situated just -behind the spermatic cords. They are about an eighth of an inch in -diameter and quite hard. They carry the semen up the back part of the -spermatic cord through the inguinal rings, before mentioned. They -pass backward and upwards, one on each side, to the upper part of the -bladder, where they empty into two small pouches or sacs, called the -vesiculae seminales. These store up the semen as it is secreted by the -testicles, and when full present the appearance of a pear. - -VESICULAE SEMINALES.--These sacs or pouches are situated at the upper -side, over the neck of the bladder, one on each side. They have the -vas deferens emptying into them at the front end, while at the back -end of each is a small opening that leads out into another small tube -which passes backward and empties into the urethra, mentioned before as -carrying the urine out from the bladder. These sacs or pouches store -up the semen or sperm of the horse. During sexual intercourse, these -pouches contract and force the semen through the little tubes mentioned -out into the urethra, leading down through the penis. - -The Penis is the main organ of sexual intercourse. Its substance -is formed of what is known as erectile tissue, which under certain -circumstances becomes enormously distended with blood. Passing up the -under side there is, what has already been mentioned, the urethra, or -the tube, which carries the urine out of the body, and also in the act -of intercourse carries the semen. This is used for two purposes, as we -have already mentioned. - -The Sheath is a loose process of skin which passes downward from the -scrotum, generally from about five to six inches, according to the -size of the animal. It is attached to each side, leaving a hole or -opening in the center through which the penis passes. The outside of -the sheath is covered by a thin, delicate skin similar to that of the -scrotum. It is lined inside by a membrane containing many small glands, -which secrete a thick, dark fluid to lubricate this passage. Sometimes -this fluid collects in here and has the appearance of tar. This is -important, for when it collects to a large extent the sheath should be -washed. - -The Semen or sperm of the horse is a light fluid, which, when -examined under a microscope is found to contain small objects called -spermatozoa. These move about, and when in the womb meet the ovum of -the female, which is secreted by a gland called the ovary. When these -two small objects unite, they form the foetus, or what may be called -the animal in its first stage of development. - - -FEMALE GENITAL ORGANS. - -The female genital organs, or the organs of the mare, are very much -different from those of the horse. They are known as follows: The -ovaries, the fallopian tubes, or tubes which carry the ovum from the -ovaries to the uterus or womb, the uterus or womb, the vagina, and the -vulva. - -The Ovaries in the mare correspond to the testicles in the horse. Each -is about the size of a pigeon’s egg, and resembles it much in shape. -They are held in place by ligaments, and at the back part are provided -with tubes leading from them called the fallopian tubes. The ovaries -secrete the ovum or germ. This is a very minute body, which, when -examined under the microscope, is found to be only 1-150 of an inch in -diameter. - -The Fallopian Tubes are two canals, one on each side. They pass -backward and upward, and enter the front part of the uterus or womb. -These small tubes are simply used to carry the germ or ovum up from the -ovaries and empty into the uterus or womb. - -The Uterus or Womb is a muscular sac situated in the pelvic cavity, -bounded above by the rectum, below by the bladder, and on either side -by the walls of the pelvic cavity. It is divided into what is known -as a body and a neck. The body of the womb is very small, being only -about four to six inches in length and a couple of inches in diameter -when the animal is not pregnant. Near the front end, at the upper side -there are openings by which the ovum enters. When the animal becomes -pregnant, the body of the womb becomes enlarged and passes forward -and to the left side of the abdominal cavity. It continues to enlarge -as the time of pregnancy passes on, until the foetus, or young, has -attained its full size. After the mare has had her young, the womb -begins to get smaller until it attains its natural size again. The -womb is very largely supplied with blood vessels and nerves. This is -especially so when the animal is pregnant, as it takes a large amount -of blood to nourish the foetus, or the young animal, before birth. It -is made up of three coats. The inner is called mucous membrane, and -in the mare, while pregnant, is covered with numerous processes about -the size of peas to which the placenta or after-birth of the foal is -attached. The muscular coat is next to that of the mucous coat, and -lies between the outer and inner coats of the womb. It is made up of -muscular fibres, and is strong and thick in the womb, much thicker -than it is in the bowels or other organs, already mentioned. This coat -supports and protects the foetus, or young, while being carried in -the womb, and at the time of parturition, or what is commonly known -as foaling, this coat also comes in use. It contracts the womb very -forcibly on the foal, while the neck of the womb lies open, thus -helping to force the foal out of the womb. This is important as the -contraction of this coat produces what is known as labor pains. Lying -outside, and covering around the womb, is a serous coat, a continuation -of the serous coat of the bowels. The womb is held in place by strong -ligaments attached to the sides, and from there to the hip bones. These -are called broad ligaments. At the back part of the womb is the neck. -It consists of an opening, formed by a projection about the size of an -egg. This has a hard, gritty feeling when the animal is not in season. -The neck at this time is closed. The neck of the womb is under control -of the muscle around it, and this muscle is under control of the nerves -of the womb. When a mare comes in season this muscle is relaxed to a -certain extent, thus allowing the neck to open wide enough for the -passage of a couple of fingers. By working around it with the fingers -at this period it can be forced wide enough to admit a man’s hand. If -the mare is put to the horse at this time and becomes pregnant or with -foal, the muscles in the neck of the womb contract, firmly closing -it. It remains closed until the time of foaling. When, at the time -of foaling, the labor pains come on, the muscle in the neck dilates, -allowing the neck of the womb to open large enough for the foal to -pass out. The neck of the womb can be felt easily by oiling the hand -and passing it into the passage of the womb. It will be noticed, too, -that the neck spoken of projects into the passage. - -THE VAGINA AND THE VULVA.--These two organs together make up the -passage which leads into the womb from the outside. In the young mare -they are separated by a thin curtain, or partition, made up of mucous -membrane. This curtain is found about four inches from the outside, -and is known as the hymen. It is destroyed, or should be, when the -mare is first put to the horse, although it is broken down other ways, -and in some cases it will disappear of its own accord. The part of -the passage in front of the hymen is called the vagina. This passage, -in structures, resembles the womb, but is not so strong. There are -numerous glands situated along the inner lining which secretes a fluid -to lubricate it. The principle use of this organ is to guide the penis -during sexual intercourse, and at the time of foaling serves as a -passage for the foal. That part of the passage behind the hymen is -known as the vulva. It is about four inches long and about two or three -inches high, varying according to the size of the mare. In front, it -is separated from the vagina by the hymen membrane. It resembles the -vagina in structure and is also provided with little glands in its -inner membrane to secrete fluid to lubricate the passage. At the back -part of the vulva or around the outside is what is known as the lips -of the vulva, one on each side of the opening. The outside of the lips -is covered by a very fine skin. Just below the skin, they consist of -erectile tissue, which is the same kind of tissue as that of the penis -of the horse. This tissue is found more abundantly in the lips of the -vulva of the young mare than in those of an old mare. The opening -between these lips is situated just below the anus, or the opening -where the back bowel ends. At the back part of the vulva, on the under -side, is an opening, or hole, about large enough for the passage of -a man’s finger. Through this hole the tube leading from the bladder -enters into the passage and allows the urine to pass into the vulva, -through which it runs out of the body. The clitoris is situated on the -upper side of this passage, just inside the lips. It can be seen in -the mare when she works the vulva after passing urine. Just below the -clitoris are found two or three small glands which secrete the fluid -that passes away when the mare is horsing. - -Mammary Glands, or what is known as the mare’s udder or bag, are two -in number, situated between the thighs. In the young mare they are -very small, but after the mare is pregnant a few months these glands -enlarge, until at foaling time they attain their largest size. They are -covered outside by a thin, smooth skin. The substance of them consists -of small glands and tubes retain or hold milk until it is drawn away -from the bag either by milking or by the young animals sucking. During -the time of suckling the young, the glands are largely supplied with -blood, from which the milk is secreted. On the under side of each -gland is found the teat, or that part taken hold of by the young when -sucking. The end of the teat is pierced by several small holes, through -which the milk passes. - - -GENITAL ORGANS OF THE BULL. - -The testicles are ovoid in shape and well developed, its long axis -being nearly vertical; the membrane which separate the two testicles is -very strong. - -The spermatic cord and artery are small compared with those of the -horse. - -The penis is long and pointed, and has an S-shaped curve in it just -below the pelvic bones; this curve can be felt by feeling just behind -the bag. - -The sheath is long and runs further forward on the belly. It has a tuft -of hair on the point of it. During the time the bull is serving the -S-shaped part of the penis is straightened out by the action of the -protracter muscles, and drawn back into the S-shaped curve by retractor -muscles. - -The urethra is completely enveloped by the fibrous sheath. - - -GENITAL ORGANS OF THE COW. - -The ovaries of the cow are comparatively smaller than those of the -mare, but resemble them in structure. - -The uterus or womb of the cow somewhat resembles that of the mare, but -the inner membrane is different, being covered with sixty or eighty -mushroom-like bodies about the size of a pigeon’s egg, more flattened -out. These bodies receive the name of cotyledons; to these the placenta -or afterbirth is attached--a very important point with which every -person interested should be familiar. These may be felt by examining a -cow soon after calving. The passage from the womb of the cow is shorter -than that of the mare, but is formed on the same principles. - -The mammary glands constitute an organ termed the _udder_, which is -composed of two symmetrical halves, placed one against the other. Each -half is again divided into two distinct glands, each with its own -teat, so that the udder consists of four mammae and four teats; behind -this there may be two small rudimentary teats. In the center of each -quarter, just at the base of the teat, is a large cavity, the general -receptacle of all the milk ducts. From this cavity, which is sometimes -large enough to contain a quart, proceeds down the center of the teat -one defined canal from which the milk is drawn. - -In the small ruminants as the sheep and goat there are two mammae and -two teats, constructed like those of the cow. - - - - -CHAPTER V. - -ANGIOLOGY. - - -Blood-Vascular System of the Horse. - -Under this heading we describe the organs of circulation, by the action -of which certain fluids are propelled through the body. It is customary -to divide this branch of the subject into two sections, considering -respectively the blood-vascular and lymphatic systems. - -BLOOD-VASCULAR SYSTEM.--This involves the consideration of the -blood, a fluid which supplies nutriment to the tissues and receives -effete material from them; the heart, a muscular organ which, by its -contraction, initiates the motion of the blood; the arteries, a series -of tubes which convey the blood from the heart to all parts of the -body; the veins, tubes which return that fluid to the heart; and the -capillaries, minute tubes joining the small arteries and veins. - -BLOOD.--Blood is a fluid tissue, which nourishes all living structures, -being the medium by which nutritive material is conveyed to, and effete -or waste material conveyed away from the solid tissues. It is an -opaque, thickish, clammy liquid, with a peculiar odor, sickly saline -taste, and alkaline reaction. Its color varies in different parts of -the same animal, that in the arteries being bright red or scarlet, -while the blood in the veins is of a dark purplish hue. - -When examined microscopically, the blood is found to consist of -minute corpuscles, and a clear, transparent, yellow fluid, the liquor -sanguinis, or plasma, in which the corpuscles float. The corpuscles are -of two kinds, the red and the white or colorless; the former, by far -more numerous, vary in proportion. Red corpuscles vary in shape, but in -all mammals (animals that suckle their young) are more or less flat, -the families excepted where they are oval, as in birds, reptiles, and -fish, which are also nucleated. Their average diameter in the horse, -ox or sheep is about 1/4000th part of an inch, their average thickness -being about one-fourth of this. Each surface is depressed towards its -center, hence the corpuscle is appropriately described as a bi-concaved -disc. - -The white corpuscles are larger than the red, round in shape, and -nucleated. - -The liquor sanguinis is pale and clear, and consists of water, fibrin, -albumen, fatty compounds, extracts, odoriferous and saline matters. -The serum is a thin, transparent liquid, of a pale-straw or yellow -color, consisting of the liquor sanguinis deprived of fibrin. It -contains nearly 90 per cent of water, is always slightly alkaline, -and coagulates when heated, owing to the large quantity of albumen it -contains. Fibrin is a white, stringy elastic substance, which, when the -blood is in circulation, is in solution, and cannot be distinguished -from the other constituents of the plasma. - -HEART.--The heart is the principal organ of circulation; it weighs -about six and one-half pounds in the average horse and acts as a force -pump to force the blood through the arteries. It is composed of strong -muscular tissue, which acts involuntarily, and is situated between the -lungs, which are divided by what is known as the mediastinum. This is -a division between the lungs made up of two folds, the heart being -between them. The bottom or apex, of the heart is downward and rests -just above the breast-bone; the upper part, or base is directed upward -and to the left side, the left lung having a depression on its inner -surface for the heart to work in. There is a covering or sack around -the heart which helps to protect and support it in its place. It is -attached above to the back-bone, and below to the bones of the breast. -This sack is made up of fibrous tissue and is of a whitish appearance; -inner surface is smooth, and supplied with numerous small glands which -secrete an oily substance called serous fluid. This lubricates the -outer surface of the heart and the inner surface of the sack so that -in action it does not irritate the walls or surfaces. The cavity of -the heart is divided into two parts, the right and left sides; each of -these parts is again subdivided. The upper cavity is called auricle and -the lower cavity ventricle; thus there are the right and left ventricle -and right and left auricle. The right auricle communicates with the -right ventricle by an opening in the septum or partition on the right -side of the heart. This opening is guarded by a valve to keep the blood -from flowing back into the auricle. The left auricle communicates with -the left ventricle, same as on the right side. The right side of the -heart is sometimes called the venous side and contains only venous or -impure blood. The left side is sometimes called the arterial side. It -contains pure blood only. This side of the heart is very much stronger -and thicker than the right side. - -[Illustration: PLATE V. - -THE HEART AND THE CHIEF BLOOD VESSELS OF THE HORSE--AFTER MEGNIN.] - - -EXPLANATION OF PLATE V - -BLOOD-VASCULAR SYSTEM OF THE HORSE - - 1. Heart, right ventricle. - 2. Heart, left ventricle. - 3. Heart, left auricle. - 4. Pulmonary artery. - 5. Pulmonary veins. - 6. Anterior aorta. - 7. Carotid artery. - 8. Glosso-facial artery. - 9. Left brachial artery. - 10. Dorsal artery. - 11. Superior cervical artery. - 12. Vertebral artery. - 12´. Internal thoracic artery. - 13. Humeral artery. - 14. Radial artery. - 14´. Cubital artery. - 15. Great metacarpal artery. - 16. Ungual branches. - 17. Posterior aorta. - 18. Coeliac axis. - 19. Mesenteric arteries. - 20. Renal artery (left). - 21. Small testicular artery. - 22. Posterior vena cava. - 23. Portal vein. - 23´. Hepatic circulation. - 24. External iliac artery. - 25. Internal iliac artery. - 26. Lateral sacral artery. - 27. Femoral artery. - 28. Posterior tibial artery. - 28´. Anterior tibial artery. - 28´´. Femoro-popliteal artery. - 29. Metatarsal vessels. - 30. Venous plexus of the foot. - 31. Internal saphenic vein. - 32. Cephalic vein. - 33. Jugular vein. - -ARTERIES.--Arteries are tubes the purpose of which is to convey the -blood from the heart. For this reason it is apparent that all arteries -carry pure arterial blood with but one exception. The pulmonary -artery carries the blood from the right ventricle to the lungs, and -consequently carries impure or venous blood. Each time the left -ventricle contracts it causes a wave, as it were, to pass all through -the arteries. This contraction takes place when in a healthy condition -about 36 to 42 times every minute and gives rise to what is known as -the pulse. This wave, or beating, may be detected at any point where -the artery is situated so closely to the surface as to affect the -outside of the body sufficient to be felt by placing the finger on the -point; consequently the pulse may be counted at any of these points. -Place your forefinger on the lower edge of your own lower jaw directly -under the corner of your mouth. At this point an artery passes out over -the jaw bone and therefore runs very close to the surface, making it -quite possible to feel the wave caused by the contraction of your own -heart, quite distinctly. Near this point on the jaw of the horse the -pulse is most conveniently felt and counted. - -The walls of the arteries are composed of elastic tissue and after -death are always lying open. Blood is never found in them after death -because they continue to contract sufficiently long enough to force all -the blood through them. - -VEINS.--Veins are tubes in construction not so strong as the -arteries--the purpose of which is to convey the blood from all parts -of the body to the heart. The heart wave does not affect the veins, -and consequently the pulse cannot be detected by placing the finger -on an exposed portion of one of them. It is also apparent that all -veins carry impure or venous blood with but one exception, viz., the -pulmonary vein, the purpose of which is to conduct the purified blood -from the lungs to the heart. - -CAPILLARIES.--The small arteries terminate in a system of minute -vessels--the capillaries--which are interposed between the termination -of the arteries and the commencement of the veins, forming plexuses -(network) which vary much in arrangement. Their average diameter is -about 2/1000ths of an inch, varying in different construction of the -organs, smallest in the brain and mucous membrane of the intestines, -larger in the skin, in glands, and the interior of bones. All arteries -do not terminate in capillaries, an exception being in erectile -tissue of the penis, where arteries end in cells or cavities placed -at the origin of the veins. As the blood passes slowly through these -capillaries, the nourishment is absorbed from it through their very -thin walls to supply the tissues of the body. When the blood passes -through this capillary network it again enters into large vessels -called the veins, which carry it on its way back to the heart. - -COURSE OF THE BLOOD.--We have seen that the heart is divided into a -right or venous, and a left or arterial portion. The blood is pumped -by the heart to all parts of the body, through the arteries, passing -through the capillary system, where it parts with its nourishment, is -collected and returned to the heart by the veins, is again pumped by -the heart to the lungs, where it is purified and returned to the heart -to again commence the circuit as before. - -LYMPHATIC SYSTEM.--The lymphatic or absorbent system is closely -connected with the blood-vascular system, and is made up of very fine -minute tubes and glands. These convey from the tissues of the body a -clear fluid known as lymph, and pours it into the blood of the veins as -it is on its way back to the heart. These glands are found all through -the body; for instance, there is a large group inside the thigh or -stifle joint of the horse, and another large group inside the shoulder. -It is important to note these, as they sometimes become inflamed and -the leg is swollen. They are then the seat of the disease called weed -in the leg, or lymphangitis. - -[Illustration: PLATE VI. - - _1. Brain._ - _2. Spinal cord._ - _3. Brachial plexus._ - _4. Sacrolumbar plexus._ - _5. Pneumogastric._ - _6. Sciatic._ - _7. Sympathetic System._ - _8. Solar plexus._ - -NERVOUS SYSTEM OF A HORSE--AFTER MEGNIN.] - - - - -CHAPTER VI. - -NEUROLOGY. - - -This illustration shows where the brain, spinal canal and the principal -nerves of the horse are located. - -STUDY OF THE NERVES.--The nervous system is a very important set of -organs controlling the motion of the various members of the body and -supplying the different senses of feeling, seeing, hearing, smelling -and tasting. The two principal organs of the nervous system are the -brain and spinal cord. - -The brain is the center of the whole nervous system, and is situated in -the cranial cavity, surrounded by three delicate membranes, the outer -one being attached to the inner wall of the bones forming the brain -cavity. The brain contains several important nerves called cranial -nerves, which are given off from the brain and pass down through the -various foramen or openings in the head to supply the different organs -situated there. The optic nerve passes down to the eye, giving the -sense of sight. The auditory nerve passes down to the drum of the ear -to give the sense of hearing. The olfactory nerves, which give the -sense of smell, are situated in the mucous membrane lining the nose. -The nerves passing down to the tongue give the sense of taste. Other -nerves pass down to the lips, teeth, mouth and face, giving motion and -feeling to the parts mentioned. Others pass down to the pharynx or -gullet, giving it the power of swallowing. - -The spinal cord passes from the brain through the openings in the -bones of the back, which gives off numerous small nerves that supply -the muscles of the back with motion and feeling. Nearly opposite the -shoulder blade the spinal cord gives off a large trunk of nerves, -portion of which supplies the heart and lungs with nervous power. -This is a point of importance, for if the spinal cord becomes injured -in front of these nerves immediate death is the result. The other -portions of this trunk of nerves supply the shoulder, chest and muscles -of the front legs. Passing backward along the spinal cord is found the -sympathetic system of nerves, which go to supply the bowels, stomach, -liver, kidneys, and other organs situated in the abdominal cavity. -Coming backwards along the spinal cord to about opposite the hip bones, -is another set of nerves, one of which goes to supply the rectum, or -back bowels. Others go to the generative and urinary organs where they -assist in performing their functions. Other nerves pass to the small -organs situated in the pelvic cavity; some of these nerves pass down to -the hind legs, supplying them with nervous power. The remainder of the -nerves go to supply the tail. - -The difference between the nervous system of a horse and other animals -is not worth mentioning. - - - - -CHAPTER VII. - -AESTHESIOLOGY. - - -The study of organs of special sense, the ear, eye and organs of -special sensation, skin, hair, foot, etc. - - -THE EAR. - -The apparatus of hearing is composed of three parts the outer, middle, -and inner ear; the two first being accessory for the collection and -transmission of sounds, and the latter the essential organ which -receives the impressions thus conveyed. - -The inner part, or drum, of the ear, is situated in the hardest bone -of the body, called the petrosal. The nerve which passes into the drum -of the ear and gives the sense of hearing, is called the auditory -nerve. From the drum a small opening passes out into the outer part of -the ear; this is the portion which is seen on top of the head. It is -made up of a membrane known as the cartilage, which gives the ear its -stiffness. This cartilage is covered by a fine, delicate skin, covered -on the outside by fine, short hair. Situated on the inner side of the -outer ear are numerous long hairs projecting outward, the use of which -is to keep foreign bodies from dropping into the ear. The ear is moved -backward and forward by small muscles which are attached around it. - - -THE EYE. - -The apparatus of vision comprises the essential organ, the globe of -the eye or eyeball, and its accessory parts or appendages. The eyeball -is situated in the orbital fossa, mentioned in chapter on the bones of -the head. It is chiefly made up of several coats around the outside, -and in the center by the humours of the eye. On the inner side of these -coats is a thin membrane called the retina, which contains the branches -of the optic nerve. This receives the reflections of objects as they -pass through the humours of the eye and from which the sensation -passes along the optic nerve to the brain. The oblong opening seen -in the middle of the eye is known as the pupil. If a horse be led -from a dark stall into the light and the pupils of the eyes watched -closely, it will be noticed that they get smaller, but on returning -it to the stall the pupils will be noticed to dilate or get larger; -thus it is seen that the pupils do not always remain the same size. -The chief use of the pupil is to gauge the sight. At the back part of -the eye are several muscles attached from around the eye to the bones -in the fossa. These muscles move the eye and assist in holding it to -its place. Around the front part are two movable curtains, one above -and the other below, called eyelids, the use of which is to open and -close the eye, and also to protect it from injuries. Around the free -border of the eyelids are what is known as the eyelashes, which keep -foreign substances from falling into the eye. Situated in the inner -angle is what is known as the haw of the eye; this membrane also helps -to protect it. In the corner of this angle is a small duct or opening, -through which a fluid called the tears passes down into the nasal -tubes, from whence it is carried down through the bones of the head and -emptied into the under part of the nostril or nose. A small gland is -situated on the upper part of the eye. This gland secretes the tears -which lubricates the eyes. The color of the eye is generally brown, but -in some cases it is white. It is then called a moon eye. - - -THE SKIN. - -The skin is a membrane or external casing of the body. The skin itself -consists of two layers covered with hair, fine or coarse, long or -short, according to its position or purpose which nature intended it to -serve. The outer layer is called the epidermis, the inner the dermis. - -THE EPIDERMIS.--The epidermis is the outer layer. It is not supplied -with nerves and blood vessels, its purpose being to protect the inner -layer. This layer undergoes a continual process of being made up and -passing away in dandruff. - -THE DERMIS.--The dermis or true skin lies under the epidermis. It is -well supplied with nerves and blood vessels, part of the nerves being -the nerves of touch. This fact accounts for its becoming so very -sensitive and painful when through injury of any kind the outer layer -is scraped off. It is attached to the body by a layer of white tissue -known as the areolor tissue, this being that which is cut through -when the animal is being skinned. The thickness of the skin varies in -different parts of the body, being thinnest in the under parts. The -sweat glands are situated in the dermis. - - -THE HAIR. - -There are three kinds of hair on the horse--the common, the finest of -the three, covers most of the body; that of the mane and tail, coarse -and long; and that growing on the muzzle or nose and lips, long and -usually black, known as tactile or cat hairs. - -On the inside of the front legs, just above the knee, and on the inside -of the hind legs, above the hock, are rough, horny spots. These are -called chestnuts. - - -EXPLANATION OF PLATE VII - -ANATOMY OF THE FOOT.--This illustration represents the foot of a horse -sawed from above the fetlock down through the center of the foot. It -shows the structure of the foot, the name of each part being given -according to number. - - 1. Lower end of large metacarpal, or cannon bone. - - 2. Bursa, which secretes the joint oil that lubricates the place where -the tendon, or cord, on the front of the leg passes down over the front -of the fetlock joint. This is important as it sometimes gets injured -and becomes enlarged. It is then called a bursal enlargement, and is of -the same nature as a wind gall. - - 3. Fetlock joint. - - 4. Os suffraginis, or large pastern bone. - - 5. Pastern joint. This joint is important; when diseased it is the seat -of a high ringbone. - - 6. Os coronae or small pastern bone. - - 7. Coffin joint. This joint is important, for when it is diseased it is -known as a low ringbone. - - 8. Wall of the hoof. - - 9. Os pedis, or coffin bone. - -10. Sensitive wall, or quick of the foot. - -11. Sensitive sole, or quick of the foot. - -12. Frog of the foot, or horney frog. - -13. Plantar cushion, or fatty frog. - -14. Navicular bone. This is also important, for when diseased it is the -seat of navicular, or coffin joint lameness. - -15. Back tendons below the fetlock. - -16. Sesamoid, or fetlock bones. - -17. Skin. - -18. Back tendons above the fetlock. - -[Illustration: PLATE VII. - -CROSS SECTION OF THE FOOT OF THE HORSE.] - -FOOT.--In equine anatomy the word “foot” implies the hoof, together -with the bones and soft structures contained therein. Many of these -objects have already been described, so that our description here will -be confined almost to the hoof and the structures with which it comes -into immediate contact internally. - -WALL OF THE FOOT.--The wall is that part of the hoof seen when the -foot is resting flat on the ground. It is divided into the toe, the -quarters, the heels and the bars. The toe forms the front, and is the -thickest and strongest part of the wall. The quarters are situated at -the side. The walls are not nearly so thick here as at the toe, but are -almost straight up and down. The heels are situated at the back part -of the foot. From the heel is a process of hoof, which looks like a -bar, passing forward between the frog and the sole of the foot; this -can be seen plainly by raising up the foot. There is one of these at -each side of the frog. They act as braces to the heel and the quarters -of the wall; these are called the bars. Covering the outside of the -wall is a fine membrane called the periople, which gives the hoof its -polished appearance. This can be seen best when the hoof is well washed -off, as it is after traveling through wet grass. This membrane keeps -the moisture in the hoof and protects it from water. This is a point -of importance in shoeing horses, as it is very injurious to file the -wall too much. Around the top part of the wall, where it unites with -the skin, is a groove which contains a white band, called the coronary -substance, or band. This nourishes the wall of the hoof, or, in other -words, it is from this that the wall of the hoof grows. The under part -of the wall, or that which rests on the ground in the unshod animal, -is called the spread of the foot. On the inside of the wall, attaching -it to the bone of the foot called the os pedis, is the part called the -quick, or sensitive laminae. It is important to note this when driving -nails in shoeing. The nail should not be driven into this membrane, nor -should it be even pressed upon, for it is very sensitive. When a nail -has been driven so as to injure the membrane it is a common expression -to say, “You have pricked that horse’s foot.” - -SOLE OF THE FOOT.--The sole is a thick plate of horn which helps to -form the under part of the hoof. It is situated between the inner -border of the under part of the wall already mentioned and the front of -the frog. The under part of the sole is concave, or hollowed out. The -upper part of the sole is attached to the under surface of the os pedis -bone, or bone of the foot, by a membrane called the quick, or sensitive -sole--this membrane is merely a continuation of the sensitive laminae. -The outer part of the sole is attached to the inner part of the wall. -When pared down a white ring is seen where the sole and the wall unite. -At the back part of the sole there is a notch the shape of the letter -V; in this notch the frog is situated. It is important to remember when -shoeing never to let the shoe rest on any part of the sole; neither -is it well to pare off too much of the barky-looking substance of the -sole, as this helps to keep the moisture in the foot. When this is -taken off it allows the moisture to escape and the hoof becomes dry and -contracted. - -FROG OF THE FOOT.--The frog is the important spongy horn found in -the V-shaped notch in the back of the sole. It is wide at the back -and helps to form the heel of the foot; the pointed part in front is -called the apex of the frog. The under part of the frog is triangular -in shape and has a hollow in it called the cleft of the frog. There is -a hollow at each side of the frog, between it and the bars, called the -commissures of the frog. On the upper part is a membrane, known as the -sensitive frog, which attaches it to the under part of the os pedis, or -foot bone. This membrane is simply a continuation of the sensitive sole -spoken of in connection with the sole. The back part of the frog is the -widest part and spreads out to form the heel. - -The study of the foot of the horse is of the greatest practical -importance, owing to the many diseases and injuries to which it is -liable. It resolves itself here into the consideration of the hoof or -horny case, and the parts contained within it. - - - - -CHAPTER VIII. - -EMBRYOLOGY. - - -THE DEVELOPMENT OF THE YOUNG.--We must here first speak of the ovum or -germ, which is secreted by the ovary of the mare. Every time she comes -in season (which occurs every three weeks during the hot weather) this -ovum passes down the tubes before the womb as before mentioned, where -it remains a few days and then dies if she is not put to the horse; but -if, during the time this ovum is in the womb she is put to the horse -and one of the spermatozoa from the semen of the horse comes in contact -with it (the ovum) and a union of these takes place, then the rest of -the semen dies and passes away, and the neck of the womb contracts -gradually until it is perfectly tight. These two little bodies begin -to grow when united and form the foetus, or foal. The foetus may be -for convenience divided into three parts, viz.: the foetus proper, the -navel string, and the placenta. The placenta is the part which is found -covering the foal and is attached to the little pea-like elevations -on the inside of the womb. This covering is found to be full of small -blood vessels which finally unite to form two larger vessels, known as -the navel veins. These carry the blood up through the navel opening of -the foal and then to its heart. By the action of the heart it is forced -all through the body of the foal and returned again to the heart. It is -then forced down another artery to the navel opening, along the navel -cord, into the placenta again, where it is distributed through the -small blood vessels. When the blood comes down this cord from the foal -it is in its impure state, and while it is passing through these small -vessels in the placenta it comes very close to the small blood vessels -in the womb. The blood is cleansed and nourished from the blood of its -mother by a process similar to that which was spoken of when describing -the lungs. The foetus, or foal, does not grow so fast the first month -as it does later on. At the age of seventeen weeks the first hair -appears on the lips and the tip of the tail. Between the thirty-fifth -and the fortieth week the foal begins to show signs of life, and is -completely covered with hair. After this time it grows very rapidly -and may be seen moving around by watching the flank closely. The mare -carries her foal eleven months, but in some cases an aged mare has been -known to carry her foal over twelve months. In rare cases young mares -may lack a few days of eleven months. - - -The Average Periods of Gestation of Domestic Animals. - - Mare 11 months - Ass 12 months - Cow 9 months - Sheep 5 months - Goat 5 months - Sow 3-1/2 months - Bitch 9 weeks - Cat 8 weeks - -Note--A mare having been served by a stallion may occasionally in the -course of four or five weeks, manifest a desire for a second visit from -the male; is again served and conceives both times. This is known as -superfoetation. Such a case has been recorded by a veterinarian; the -animal in question, a mare, giving birth to a horse colt and a mule -colt, both dead. The mare had been covered by a jack and subsequently -by a horse. - -SIGNS OF PREGNANCY.--The veterinarian is occasionally called upon to -give an opinion as to the pregnancy or non-pregnancy, of an animal and -consequently should familiarize himself with the various indications -which tend to prove the absence, or presence, of this condition. As a -rule, when the mare conceives, heat, or the desire for the male, is -no longer observable, and, on being led to the horse, she not only -refuses to receive his caresses, but assumes the offensive, viciously -striking and biting at him until led away. Soon the hair becomes more -glossy, and the mare becomes quieter in disposition. This change is -usually well marked in mares that are of a vicious disposition. The -abdomen gradually enlarges as pregnancy advances, the right side being -a little larger than the left. This enlargement is especially well -marked in the cow. In some cases the beating of the foetal heart may -be heard with the assistance of the stethoscope. Such an examination -is, however, very likely to give rise to mistakes. After the eighth -month well-marked symptoms of pregnancy are manifested, the belly at -this time being considerably distended, the back sinking, etc. Before -this time it is, however, impossible to make a positive statement as to -the condition of the animal except by making a very close and thorough -examination per rectum. The rectum should be cleared out by means of an -enema (injection) of tepid water; the hand and arm should be well oiled -and passed into the rectum. The region of the uterus being reached, an -examination may be made of its condition. As the time for parturition -approaches, the ligaments relax to a greater or less degree, and -a well-marked depression or sinking in the lumbosacral region may -be observed, the udder or bag enlarges, and milk is secreted. -The secretion of milk sometimes appears long before the time of -parturition, and has frequently been noticed to take place in animals -that have never been bred. As a rule the animal shows slight uneasiness -for a day or two before parturition, slight abdominal pain, etc., being -manifested. About this time the vulva becomes larger, and presents more -or less tumefaction. There may also be observed a flow of mucous taking -place from the vulva for a day or two before parturition. - - - - -INDEX - - - HORSE - - Descriptive Anatomy, 5 - Dissection, 6 - - - BONES - - Osteology - Back Bones, 11 - Breast Bone, 12 - Cannon Bone, 13 - Carpus, 13 - Cervical Vertebrae, 11 - Classes of Bones, 9 - Coccygeal Vertebrae, 12 - Coffin Bone, 14 - Contents of Bones, 9 - Distal Phalanx, 14 - Dorsal Vertebrae, 11 - Femur, 15 - Fibula, 16 - Fore-arm Bone (large), 13 - Fore-arm Bone (small), 13 - Hip Bones, 12 - Hock Bones, 16 - Humerus, 12 - Knee, 13 - Loin Bones, 11 - Lumbar Vertebrae, 11 - Median Phalanx, 14 - Metacarpal, 13 - Metatarsus, 17 - Neck Bones, 11 - Os Coronae, 14 - Os Metacarpi Magnus, 13 - Os Metatarsi Magnum, 17 - Os Naviculare, 15 - Os Pedis, 14 - Os Suffraginis, 14 - Ossa Metatarsi Parva, 17 - Ossa Metacarpi Parva, 14 - Pastern Bone (large), 14 - Pastern Bone (small), 14 - Patella, 15 - Pelvic Bones, 12 - Proximal Phalanx, 14 - Radius, 13 - Ribs, 12 - Rump Bones, 12 - Sacral Vertebrae, 12 - Scapula, 13 - Sesamoid Bones, 14 - Shoulder Blade, 13 - Shoulder Bone, 12 - Shuttle Bone, 15 - Skeleton, 7 - Skull, 10 - Splint Bones (fore limb), 14 - Splint Bones (hind limb), 17 - Sternum, 12 - Stifle Bone, 15 - Structure of Bones, 8 - Tail Bones 12 - Tarsus, 16 - Thigh Bone, 15 - Tibia, 16 - Ulna, 13 - - - JOINTS - - ARTHROLOGY - Adipose Tissue, 22 - Cartilage, 21 - Connective Tissue, 21 - Elastic Tissue (Yellow), 22 - Fat, 22 - Ligaments, 22 - Synovial Membranes, 23 - Synovia, 23 - - Joints - Carpus, 25 - Classes of Joints, 24 - Coffin Joint, 26 - Elbow Joint, 24 - Fetlock Joint, 25 - Hip Joint, 26 - Hock Joint, 26 - Joints of the Front Leg, 24 - Joints of the Hind Leg, 26 - Knee Joint, 25 - Motion in Joints, 24 - Pastern Joint, 25 - Shoulder Joint, 24 - Stifle Joint, 26 - Tarsus, 26 - - - MYOLOGY - Abdominal Muscles, 32 - Back Muscles, 30 - Coccygeal Muscles, 30 - Deep Layer of Muscles, 31 - Gluteal Muscles, 30 - Gullet Muscles, 30 - Head Muscles, 30 - Hip Muscles, 30 - Involuntary Muscles, 35 - Leg Muscles (front), 33 - Leg Muscles (hind), 34 - Muscles, 28 - Neck Muscles, 30 - Pharynx Muscles, 30 - Shoulder Muscles, 32 - Superficial Layer of Muscles, 29 - Tail Muscles, 30 - Voluntary Muscles, 30 - - - SPLANCHNOLOGY - Air Cells, 53 - Bladder, 56 - Bowels, 41 - Breathing, Normal, 55 - Bronchial Tubes, 53 - Canine Teeth, 49 - Cementum (or crusta petrosa), 48 - Dentine (or ivory), 48 - Digestive Apparatus, 37 - Enamel, 48 - Fallopian Tubes, 62 - Female Genital Organs, 62 - Generative, 58 - Incisor Teeth, 49 - Kidneys, 56 - Larynx, 53 - Liver, 43 - Lungs, 54 - Male, 58 - Mammary Glands, 65 - Molar Teeth, 49 - Nasal Chambers, 52 - Nostrils, 52 - Organs of Respiration, 52 - Ovaries, 62 - Pancreas, 43 - Penis, 61 - Permanent Teeth, 49 - Rectum, 42 - Respiration, 54–55 - Respiratory System of the Horse, 52 - Salivary Glands, 39 - Scrotum, 58 - Semen, 61 - Sheath, 61 - Spleen, 43 - Sperm, 61 - Spermatic Cords, 60 - Stomach, 40 - Teeth, 48 - Teeth Tables (comparative), 51 - Temporary Teeth, 49 - Testicles, 59 - Ureters, 56 - Urethra, 57 - Urinary System, 56 - Uterus, 62 - Vagina, 64 - Vas Deferens, 60 - Vesiculae Seminales, 60 - Vulva, 64 - Windpipe or Trachea, 53 - Wolf Teeth, 49 - Womb, 62 - - - ANGIOLOGY - Arteries, 70 - Blood, 67 - Blood-vascular System, 67 - Capillaries, 71 - Circulation, 69 - Corpuscles, 67 - Course of Blood, 71 - Heart, 68 - Liquor Sanguinis, 68 - Lymphatic System, 72 - Veins, 71 - - - NEUROLOGY - Brain, 73 - Spinal Cord, 73 - - - AESTHESIOLOGY - Anatomy of the Foot, 78 - Dermis, 77 - Ear, 75 - Epidermis, 77 - Eye, 75 - Foot Sole, 80 - Foot Frog, 80 - Foot Wall, 79 - Frog of Foot, 80 - Hair, 77 - Skin, 76 - Sole of Foot, 80 - Wall of Foot, 79 - - - EMBRYOLOGY - Development of Young, 81 - Gestation of Domestic Animals, 82 - Pregnancy, 82 - - - COMPARATIVE ANATOMY - Abomasum, 46 - Air Cells, 53 - Aves, 20 - Back Bones, 18 - Bowels, 46 - Bronchial Tubes, 53 - Carnivora, 19 - Cervical, 18 - Chewing Cud, 46 - Coccygeal, 18 - Comparative Osteology, 17 - Cud Chewing, 46 - Digestive System, 44 - Dorsal, 18 - Fourth Stomach, 46 - Genital Organs of the Bull, 65 - Genital Organs of the Cow, 66 - Gullet, 44 - Hip Bones, 19 - Honey Comb, 45 - Larynx, 53 - Liver, 46 - Loin Bones, 18 - Lumbar, 18 - Lungs, 54 - Mammary Glands, 66 - Many-plies, 45 - Neck Bones, 18 - Normal Breathing, 55 - Nostrils, 55 - Oesophagus, 44 - Omasum, 45 - Omnivora, 19 - Paunch, 45 - Pelvis Bones, 19 - Penis, 65 - Process of Digestion, 47 - Respirations per Minute of Different Animals, 54 - Respiratory System of the Ox, 55 - Reticulum, 45 - Rumen, 45 - Ruminantia, 44 - Ruminantia (cud chewing animals), 18 - Rumination, 47 - Rump Bones, 18 - Sacrum, 18 - Salivary, 44 - Sheath, 65 - Skull, 18 - Spermatic Cord, 65 - Stomach, 45 - Tail Bones, 18 - Teeth, 44 - Teeth, Front, 44 - Teeth, Molars, 44 - Testicles, 65 - Thoracic Cavity (lung cavity), 55 - Tongue, 44 - Trachea, 53 - Urethra, 66 - Uterus, 66 - Urinary System of the Ox, 58 - Vertebrae, 18 - Windpipe, 53 - Womb, 66 - - - - - PRESS OF - SWEENEY, VARNEY & STRAUB - PORTLAND, OREGON - - - - -Spelling_inconsistencies: - - after-birth/afterbirth - anus/annus - areolor/areolar - blood vessels/blood-vessels/bloodvessels - Œsophagus/oesophagus - pully/pulley - sweeney/sweeny - tendinous/tendonous - vertebræ/vertebrae/vertebraes - principle/principal not used strictly in accordance with present day usage - - -Spelling corrections: - - angilogy → angiology - Corpulscles → Corpuscles - cusion → cushion - Dessection → Dissection - discribing → describing - feltock → fetlock - femer → femur - Fermoro-popliteal → Femoro-popliteal - form → from - Forth → Fourth - heapitic → hepatic - lumlosacral → lumbosacral - mammelia → mammalia - Many Plies → Many-plies - mostened → moistened - muscles plays → muscles play - oposite → opposite - pannisulus → panniculus - planter → plantar - prefrom → perform - protracters → protracter - skining → skinning - thench → thence - through → though - vasiculae → vesiculae - Voscular → Vascular - - - - - -End of Project Gutenberg's Notes on Veterinary Anatomy, by Charles J. Korinek - -*** END OF THIS PROJECT GUTENBERG EBOOK NOTES ON VETERINARY ANATOMY *** - -***** This file should be named 60949-0.txt or 60949-0.zip ***** -This and all associated files of various formats will be found in: - http://www.gutenberg.org/6/0/9/4/60949/ - -Produced by The Online Distributed Proofreading Team at -http://www.pgdp.net (This file was produced from images -generously made available by The Internet Archive) - -Updated editions will replace the previous one--the old editions will -be renamed. - -Creating the works from print editions not protected by U.S. copyright -law means that no one owns a United States copyright in these works, -so the Foundation (and you!) can copy and distribute it in the United -States without permission and without paying copyright -royalties. Special rules, set forth in the General Terms of Use part -of this license, apply to copying and distributing Project -Gutenberg-tm electronic works to protect the PROJECT GUTENBERG-tm -concept and trademark. Project Gutenberg is a registered trademark, -and may not be used if you charge for the eBooks, unless you receive -specific permission. If you do not charge anything for copies of this -eBook, complying with the rules is very easy. You may use this eBook -for nearly any purpose such as creation of derivative works, reports, -performances and research. They may be modified and printed and given -away--you may do practically ANYTHING in the United States with eBooks -not protected by U.S. copyright law. Redistribution is subject to the -trademark license, especially commercial redistribution. - -START: FULL LICENSE - -THE FULL PROJECT GUTENBERG LICENSE -PLEASE READ THIS BEFORE YOU DISTRIBUTE OR USE THIS WORK - -To protect the Project Gutenberg-tm mission of promoting the free -distribution of electronic works, by using or distributing this work -(or any other work associated in any way with the phrase "Project -Gutenberg"), you agree to comply with all the terms of the Full -Project Gutenberg-tm License available with this file or online at -www.gutenberg.org/license. - -Section 1. General Terms of Use and Redistributing Project -Gutenberg-tm electronic works - -1.A. By reading or using any part of this Project Gutenberg-tm -electronic work, you indicate that you have read, understand, agree to -and accept all the terms of this license and intellectual property -(trademark/copyright) agreement. If you do not agree to abide by all -the terms of this agreement, you must cease using and return or -destroy all copies of Project Gutenberg-tm electronic works in your -possession. If you paid a fee for obtaining a copy of or access to a -Project Gutenberg-tm electronic work and you do not agree to be bound -by the terms of this agreement, you may obtain a refund from the -person or entity to whom you paid the fee as set forth in paragraph -1.E.8. - -1.B. "Project Gutenberg" is a registered trademark. It may only be -used on or associated in any way with an electronic work by people who -agree to be bound by the terms of this agreement. There are a few -things that you can do with most Project Gutenberg-tm electronic works -even without complying with the full terms of this agreement. See -paragraph 1.C below. There are a lot of things you can do with Project -Gutenberg-tm electronic works if you follow the terms of this -agreement and help preserve free future access to Project Gutenberg-tm -electronic works. See paragraph 1.E below. - -1.C. The Project Gutenberg Literary Archive Foundation ("the -Foundation" or PGLAF), owns a compilation copyright in the collection -of Project Gutenberg-tm electronic works. Nearly all the individual -works in the collection are in the public domain in the United -States. If an individual work is unprotected by copyright law in the -United States and you are located in the United States, we do not -claim a right to prevent you from copying, distributing, performing, -displaying or creating derivative works based on the work as long as -all references to Project Gutenberg are removed. Of course, we hope -that you will support the Project Gutenberg-tm mission of promoting -free access to electronic works by freely sharing Project Gutenberg-tm -works in compliance with the terms of this agreement for keeping the -Project Gutenberg-tm name associated with the work. You can easily -comply with the terms of this agreement by keeping this work in the -same format with its attached full Project Gutenberg-tm License when -you share it without charge with others. - -1.D. The copyright laws of the place where you are located also govern -what you can do with this work. Copyright laws in most countries are -in a constant state of change. If you are outside the United States, -check the laws of your country in addition to the terms of this -agreement before downloading, copying, displaying, performing, -distributing or creating derivative works based on this work or any -other Project Gutenberg-tm work. The Foundation makes no -representations concerning the copyright status of any work in any -country outside the United States. - -1.E. Unless you have removed all references to Project Gutenberg: - -1.E.1. The following sentence, with active links to, or other -immediate access to, the full Project Gutenberg-tm License must appear -prominently whenever any copy of a Project Gutenberg-tm work (any work -on which the phrase "Project Gutenberg" appears, or with which the -phrase "Project Gutenberg" is associated) is accessed, displayed, -performed, viewed, copied or distributed: - - This eBook is for the use of anyone anywhere in the United States and - most other parts of the world at no cost and with almost no - restrictions whatsoever. You may copy it, give it away or re-use it - under the terms of the Project Gutenberg License included with this - eBook or online at www.gutenberg.org. If you are not located in the - United States, you'll have to check the laws of the country where you - are located before using this ebook. - -1.E.2. If an individual Project Gutenberg-tm electronic work is -derived from texts not protected by U.S. copyright law (does not -contain a notice indicating that it is posted with permission of the -copyright holder), the work can be copied and distributed to anyone in -the United States without paying any fees or charges. If you are -redistributing or providing access to a work with the phrase "Project -Gutenberg" associated with or appearing on the work, you must comply -either with the requirements of paragraphs 1.E.1 through 1.E.7 or -obtain permission for the use of the work and the Project Gutenberg-tm -trademark as set forth in paragraphs 1.E.8 or 1.E.9. - -1.E.3. If an individual Project Gutenberg-tm electronic work is posted -with the permission of the copyright holder, your use and distribution -must comply with both paragraphs 1.E.1 through 1.E.7 and any -additional terms imposed by the copyright holder. Additional terms -will be linked to the Project Gutenberg-tm License for all works -posted with the permission of the copyright holder found at the -beginning of this work. - -1.E.4. Do not unlink or detach or remove the full Project Gutenberg-tm -License terms from this work, or any files containing a part of this -work or any other work associated with Project Gutenberg-tm. - -1.E.5. Do not copy, display, perform, distribute or redistribute this -electronic work, or any part of this electronic work, without -prominently displaying the sentence set forth in paragraph 1.E.1 with -active links or immediate access to the full terms of the Project -Gutenberg-tm License. - -1.E.6. You may convert to and distribute this work in any binary, -compressed, marked up, nonproprietary or proprietary form, including -any word processing or hypertext form. However, if you provide access -to or distribute copies of a Project Gutenberg-tm work in a format -other than "Plain Vanilla ASCII" or other format used in the official -version posted on the official Project Gutenberg-tm web site -(www.gutenberg.org), you must, at no additional cost, fee or expense -to the user, provide a copy, a means of exporting a copy, or a means -of obtaining a copy upon request, of the work in its original "Plain -Vanilla ASCII" or other form. Any alternate format must include the -full Project Gutenberg-tm License as specified in paragraph 1.E.1. - -1.E.7. Do not charge a fee for access to, viewing, displaying, -performing, copying or distributing any Project Gutenberg-tm works -unless you comply with paragraph 1.E.8 or 1.E.9. - -1.E.8. You may charge a reasonable fee for copies of or providing -access to or distributing Project Gutenberg-tm electronic works -provided that - -* You pay a royalty fee of 20% of the gross profits you derive from - the use of Project Gutenberg-tm works calculated using the method - you already use to calculate your applicable taxes. The fee is owed - to the owner of the Project Gutenberg-tm trademark, but he has - agreed to donate royalties under this paragraph to the Project - Gutenberg Literary Archive Foundation. Royalty payments must be paid - within 60 days following each date on which you prepare (or are - legally required to prepare) your periodic tax returns. Royalty - payments should be clearly marked as such and sent to the Project - Gutenberg Literary Archive Foundation at the address specified in - Section 4, "Information about donations to the Project Gutenberg - Literary Archive Foundation." - -* You provide a full refund of any money paid by a user who notifies - you in writing (or by e-mail) within 30 days of receipt that s/he - does not agree to the terms of the full Project Gutenberg-tm - License. You must require such a user to return or destroy all - copies of the works possessed in a physical medium and discontinue - all use of and all access to other copies of Project Gutenberg-tm - works. - -* You provide, in accordance with paragraph 1.F.3, a full refund of - any money paid for a work or a replacement copy, if a defect in the - electronic work is discovered and reported to you within 90 days of - receipt of the work. - -* You comply with all other terms of this agreement for free - distribution of Project Gutenberg-tm works. - -1.E.9. If you wish to charge a fee or distribute a Project -Gutenberg-tm electronic work or group of works on different terms than -are set forth in this agreement, you must obtain permission in writing -from both the Project Gutenberg Literary Archive Foundation and The -Project Gutenberg Trademark LLC, the owner of the Project Gutenberg-tm -trademark. Contact the Foundation as set forth in Section 3 below. - -1.F. - -1.F.1. Project Gutenberg volunteers and employees expend considerable -effort to identify, do copyright research on, transcribe and proofread -works not protected by U.S. copyright law in creating the Project -Gutenberg-tm collection. Despite these efforts, Project Gutenberg-tm -electronic works, and the medium on which they may be stored, may -contain "Defects," such as, but not limited to, incomplete, inaccurate -or corrupt data, transcription errors, a copyright or other -intellectual property infringement, a defective or damaged disk or -other medium, a computer virus, or computer codes that damage or -cannot be read by your equipment. - -1.F.2. LIMITED WARRANTY, DISCLAIMER OF DAMAGES - Except for the "Right -of Replacement or Refund" described in paragraph 1.F.3, the Project -Gutenberg Literary Archive Foundation, the owner of the Project -Gutenberg-tm trademark, and any other party distributing a Project -Gutenberg-tm electronic work under this agreement, disclaim all -liability to you for damages, costs and expenses, including legal -fees. YOU AGREE THAT YOU HAVE NO REMEDIES FOR NEGLIGENCE, STRICT -LIABILITY, BREACH OF WARRANTY OR BREACH OF CONTRACT EXCEPT THOSE -PROVIDED IN PARAGRAPH 1.F.3. YOU AGREE THAT THE FOUNDATION, THE -TRADEMARK OWNER, AND ANY DISTRIBUTOR UNDER THIS AGREEMENT WILL NOT BE -LIABLE TO YOU FOR ACTUAL, DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE OR -INCIDENTAL DAMAGES EVEN IF YOU GIVE NOTICE OF THE POSSIBILITY OF SUCH -DAMAGE. - -1.F.3. LIMITED RIGHT OF REPLACEMENT OR REFUND - If you discover a -defect in this electronic work within 90 days of receiving it, you can -receive a refund of the money (if any) you paid for it by sending a -written explanation to the person you received the work from. If you -received the work on a physical medium, you must return the medium -with your written explanation. The person or entity that provided you -with the defective work may elect to provide a replacement copy in -lieu of a refund. If you received the work electronically, the person -or entity providing it to you may choose to give you a second -opportunity to receive the work electronically in lieu of a refund. If -the second copy is also defective, you may demand a refund in writing -without further opportunities to fix the problem. - -1.F.4. Except for the limited right of replacement or refund set forth -in paragraph 1.F.3, this work is provided to you 'AS-IS', WITH NO -OTHER WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT -LIMITED TO WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY PURPOSE. - -1.F.5. Some states do not allow disclaimers of certain implied -warranties or the exclusion or limitation of certain types of -damages. If any disclaimer or limitation set forth in this agreement -violates the law of the state applicable to this agreement, the -agreement shall be interpreted to make the maximum disclaimer or -limitation permitted by the applicable state law. The invalidity or -unenforceability of any provision of this agreement shall not void the -remaining provisions. - -1.F.6. INDEMNITY - You agree to indemnify and hold the Foundation, the -trademark owner, any agent or employee of the Foundation, anyone -providing copies of Project Gutenberg-tm electronic works in -accordance with this agreement, and any volunteers associated with the -production, promotion and distribution of Project Gutenberg-tm -electronic works, harmless from all liability, costs and expenses, -including legal fees, that arise directly or indirectly from any of -the following which you do or cause to occur: (a) distribution of this -or any Project Gutenberg-tm work, (b) alteration, modification, or -additions or deletions to any Project Gutenberg-tm work, and (c) any -Defect you cause. - -Section 2. Information about the Mission of Project Gutenberg-tm - -Project Gutenberg-tm is synonymous with the free distribution of -electronic works in formats readable by the widest variety of -computers including obsolete, old, middle-aged and new computers. It -exists because of the efforts of hundreds of volunteers and donations -from people in all walks of life. - -Volunteers and financial support to provide volunteers with the -assistance they need are critical to reaching Project Gutenberg-tm's -goals and ensuring that the Project Gutenberg-tm collection will -remain freely available for generations to come. In 2001, the Project -Gutenberg Literary Archive Foundation was created to provide a secure -and permanent future for Project Gutenberg-tm and future -generations. To learn more about the Project Gutenberg Literary -Archive Foundation and how your efforts and donations can help, see -Sections 3 and 4 and the Foundation information page at -www.gutenberg.org - - - -Section 3. Information about the Project Gutenberg Literary Archive Foundation - -The Project Gutenberg Literary Archive Foundation is a non profit -501(c)(3) educational corporation organized under the laws of the -state of Mississippi and granted tax exempt status by the Internal -Revenue Service. The Foundation's EIN or federal tax identification -number is 64-6221541. Contributions to the Project Gutenberg Literary -Archive Foundation are tax deductible to the full extent permitted by -U.S. federal laws and your state's laws. - -The Foundation's principal office is in Fairbanks, Alaska, with the -mailing address: PO Box 750175, Fairbanks, AK 99775, but its -volunteers and employees are scattered throughout numerous -locations. Its business office is located at 809 North 1500 West, Salt -Lake City, UT 84116, (801) 596-1887. Email contact links and up to -date contact information can be found at the Foundation's web site and -official page at www.gutenberg.org/contact - -For additional contact information: - - Dr. Gregory B. Newby - Chief Executive and Director - gbnewby@pglaf.org - -Section 4. Information about Donations to the Project Gutenberg -Literary Archive Foundation - -Project Gutenberg-tm depends upon and cannot survive without wide -spread public support and donations to carry out its mission of -increasing the number of public domain and licensed works that can be -freely distributed in machine readable form accessible by the widest -array of equipment including outdated equipment. Many small donations -($1 to $5,000) are particularly important to maintaining tax exempt -status with the IRS. - -The Foundation is committed to complying with the laws regulating -charities and charitable donations in all 50 states of the United -States. Compliance requirements are not uniform and it takes a -considerable effort, much paperwork and many fees to meet and keep up -with these requirements. We do not solicit donations in locations -where we have not received written confirmation of compliance. To SEND -DONATIONS or determine the status of compliance for any particular -state visit www.gutenberg.org/donate - -While we cannot and do not solicit contributions from states where we -have not met the solicitation requirements, we know of no prohibition -against accepting unsolicited donations from donors in such states who -approach us with offers to donate. - -International donations are gratefully accepted, but we cannot make -any statements concerning tax treatment of donations received from -outside the United States. U.S. laws alone swamp our small staff. - -Please check the Project Gutenberg Web pages for current donation -methods and addresses. Donations are accepted in a number of other -ways including checks, online payments and credit card donations. To -donate, please visit: www.gutenberg.org/donate - -Section 5. General Information About Project Gutenberg-tm electronic works. - -Professor Michael S. Hart was the originator of the Project -Gutenberg-tm concept of a library of electronic works that could be -freely shared with anyone. For forty years, he produced and -distributed Project Gutenberg-tm eBooks with only a loose network of -volunteer support. - -Project Gutenberg-tm eBooks are often created from several printed -editions, all of which are confirmed as not protected by copyright in -the U.S. unless a copyright notice is included. Thus, we do not -necessarily keep eBooks in compliance with any particular paper -edition. - -Most people start at our Web site which has the main PG search -facility: www.gutenberg.org - -This Web site includes information about Project Gutenberg-tm, -including how to make donations to the Project Gutenberg Literary -Archive Foundation, how to help produce our new eBooks, and how to -subscribe to our email newsletter to hear about new eBooks. - |