BULLETIN No. 81. MAY, MY 1897. 87 ALABAMA agricultura1 -Experiment =Station AND OFTEAGRICULTURAL MECHANICAL COLLEGE,AUBURN. ME AT -INSPECTION. C. A. GARY, Veterinarian. MONTGOMERY, ALA.: THE BROWN PRINTING COMPANY, PRINTERS 1897. COMMITTEE OF TRUSTEES ON EXPERIMENT STATION. I. F. CULVER ............................... J. G. GILCHRIST .................................... H. Union Springs. Hope Hull. CLAY ARMSTRONG................................Auburn. STATION COUNCIL. WM. P. H. B. B. J. F. LEROY BROUN.......................................President. MELL...............................................Botanist. Ross................................. ..... Chemist C. A. CARY, D. V. M. .......................... Veterinarian DUGGAR........................................Agriculturist. and Horticulturist. F. S. EARLE...........................Biologist C. F. BAKER........................................Entomologist. ASSISTANTS. J. T. ANDERSON............................. First Assistant Chemist. C. L. HARE ............................... R. G. WILLIAMS .......................... T. U. CULVER............................. Second Assistant Chemist. Third Assistant Chemist. Superintendent of Farm. "The Bulletins of this Station be sent free to any citizen of the State on application to. the Agricultural Experiment Station, Auburn, Alabama. will CO NTENTS, PAGE. Introduction.............................................. Hog Cholera........ ................. ...... ........... Swine Plague ............................................. Tuberculosis of Cattle... ................................... Tuberculosis of Pigs ....................................... Tuberculosis of Birds .......... . .......................... Post-Mortem Appearances of Tuberculosis of Cattle ............ it ." it it t i it " 289 291 298 299 303 304 304 312 314 "Pigs " ............. < Birds ............ Staining Tubercie Bacilli................... ................ Histology of Tuberculous Lesions ........................... Actinomycosis ................... ........ ................ Anthrax.................. ....... .. ............ ....... Texas Fever .............................................. Catarrh of Cattle................................ 315 318 321 320 328 Malignant Miscellaneous Suggestions .................................. 330 332 Putrifying or Decaying Meat................................33 Course or Order of Post-Mortem Examinations................ 334 Animal Parasites of Domestic Animals....................... 337 Cysticercus bovis................................... Cellulosac it it ............................. 337 337 Caenurus cerebralis ................................ Cysticercus tenuicollis .............................. pisiformis............................... 339 340 340 Echinococcus veterinorum "denticulata .......................... .... .... ....... .. 340 Teenia expansa ..................................... .................................. 341 342 Distoma hepaticum ............. Stron gyl us micrurus "imbriata ..................................... Trichina spiralis .......... ........................ Stephanurus dentatus............................... Strongylus commutatis............................. .347 Esophagostoma Columbianum........................ 348 it . ............. 342' 34 .343 346 346 ................ filaria .................................. ovis-pulmonalis ......................... 347 347 paradoxus... .. .. .. .. ... .. .. .. .. .. .. ..... 347 348: 349 350 350 354 Echinorhynchus gigas ....................... ....... Ascaris lumbricoides ................................ Lingulata teenoides................................. Montgomery Meat Inspection Law ............ ............. References............. ..... .............................. MEAT INSPECTION. BY C. A. CARY. INTRODUCTION. Sanitary science has been greatly extended since the advent of the bacterial origin of many diseases. It is now a well established fact that some parasitic diseases are common to man and many of the domestic animals. In some instances a disease may not always manifest the same symptoms or pathological lesions in a man that it does in animals, and the disease, wherever found, may be caused by the same micro-organism. Yet, such a disease is transmissible from animals to man or from man to animals. The common illustrations of such diseases are found in tuberculosis and anthrax. It is now a positive fact that during the past five or six years a sufficient number of cases of anthrax, tuberculosis, swine plague, hog cholera, etc., have been observed in this State to justify a system of thorough and efficient meat inspection in the larger cities and, if practicable, in the smaller cities and towns of the State. There is no occasion for alarming statements; meat inspection only means that one of the numerous ways of transmitting or spreading the cause of disease can and should be checked. It is not only the aim of the meat inspector to cut off one of the ways of transmitting the germs of disease to man' but also to eliminate from the food of man the poisonous chemical compounds, known as ptomaines, leucomaines and organicferments that may be developed in the body of an animal during disease or may be developed in decomposing 290 meat. Many of these chemical compounds are very poisonous and they can not always be destroyed by cooking the. meat as can the germs of disease. For instance, in the disease known as tetanus (lock-jaw) the tetanus bacillus develops, or in some way produces, a chemical substance called tetanin which is a very powerful poison; in fact, it will kill a healthy man or horse in a short time if a comparatively small quantity of it is injected into the circulation. It is in the same way that many other poisonous. chemical compounds are developed in the body of animals during disease. All of these chemical substances do not possess the same degree of poisonous potency; but the power of the poison will vary in almost every case or kind of germ, by which it is produced or with which it is associated. Many animal parasites are common to man and the domestic animals. Trichina spiralis has been found in this State; also the cystic stage of many of the tapeworms, especially of tcenia solium, have been observed in Alabama. It is obvious to any well informed medical man that thorough and efficient meat inspection is a practical means of preventing many diseases in the human family. The writer uses the words "thorough" and "efficient" because there is a tendency on the part of the powers, who appoint inspectors, to appoint political favorites, regardless of their qualifications. That day is passed when a man can be an expert in more than one thing. It is a great mistake to think that a druggist, a carpenter, a horse-trader, a liveryman or a butcher can make an efficient meat inspector without two or more years of specific preparation. A man, through ignorance or a desire for gain, can deceive himself. For example, I have seen butchers, let us hope through ignorance, pass carcasses to the market that were absolutely unfit for human food and in many instances dangerous; and no doubt in some cases produced sickness in the consumers that could not be accounted for by the family physicians;. 291 because they knew not the condition of the meat their patients had eaten. In a prominent city of the United States, the writer found the inspector sitting in a chair watching the animals pass by him. No inspection of the carcass was made at the slaughter. A glance at the animals as they passed to the slaughter is almost equivalent to no inspection. A practical inspection law and honest, competent inspectors always mean thorough and efficient meat inspection. HOG CHOLERA. Synonyms. -Swine Fever (England), Swine Pest(Germany). Sympioms.-In hog cholera, the skin is usually red on the nose, the ears, the abdomen, on the inside of the front limbs, on the inside of the thighs, on the skin of the groins and around the anus. Sometimes red spots may appear on the skin of any region of the body. This redness of the skin varies from a light red tint to a deep bluish red or purple. It may be confined to spots or it may become diffuse and extend over considerable skin surface. It is well to note here that the skin may be covered with red spots or diffuse red patches in some cases of American swine plague (Salmon and Smith), in infectious pneumonia (Schiitz) and in the European swine plague (Laffler, Schitz). In some chronic cases of hog cholera skin eruptions may appear over the head, neck, body and limbs. In such cases the redness of the skin may ba very slightly marked. Diphtheritic ulcers may appear on the tongue, on the inside of the cheeks, on the palate, the gums and the tonsils. These ulcers are covered with grayish-white or yellowishgray scab-like material; in some cases they have a greenish tint. The chronic case may cough from time to time; the respirations may be normal, but they are accelerated and 292 labored in acute cases. The conjunctiva of the eye is red and the eye lids may be stuck together with dried mucus. The temperature in chronic cases may be normal (101' to 1010 Fah. according to Kilborne), but in acute attacks it may be 3 to 5 degrees above the normal. In acute cases the appetite is entirely or partially lost, and the bowels are constipated; in a short time diarrhoea appears and the excrements are liquid and fetid, occasionally mixed with blood. In chronic cases the appetite may remain good; yet the animal may have diarrhoea. The color of the excrement always depends upon the character of the food eaten. In hogs fed corn it is yellow; in those which are fed slops and mixed foods, the excrement is grayish or black. Vomiting is rare in hog cholera; but more common in swine plague. In acute cases some animals become weak, greatly depressed in vigor; lie quietly, huddled together, hide under litter, and toward the end of the disease lose control of the hind limbs. Friedberger and Frohner state that death is preceded by convulsions and Kilborne states that "death ensues quietly. Rarely convulsive kicking is observed." It is well to note that all of the foregoing symptoms are not distinctly marked in each hog but that the symptoms will vary in intensity and some of them may not appear or be overlooked on account of their being slightly marked and of short duration. It is difficult, many times impossible, to make a positive diagnosis with only an ante-mortem examination. The mortality, in hog cholera, is very high; 80 to 90 per cent., of those attacked die (Salmon and Smith). PosT-MORTEM APPEARANCES: In acute cases.-Salmon and Smith suggest that acute cases might be embraced under the general head hemorrhagic type; because the chief morbid changes that occur are hemorrhagic in character. (The hemorrhagic spots or patches that are so common in these cases result from the .93 escape of blood from small blood vessels or capillaries; they vary from a scarlet red to a black red in color. They also vary in size and are spoken of as "blood extravasations," "ecchymoses," "petechiee," "hemorrhagic spots or patches." These changes are most distinct immediately after the death of the animal.) The spleen is usually enlarged, engorged with blood; it may be twice as large and long as the normal spleen. The mucous membrane lining the stomach is very red and sometimes there may be blood on its surface. This red or bloody portion of the mucous lining is usually confined to a large patch in the base or fundus of the stomach. There may be numerous hemorrhagic (bloody) spots or large patches in or beneath the mucous membrane lining the small and large intestines; these spots may be so numerous as to give the lining membrane a dark red color. Occasionally food in the intestines is found encased in sheets of blood clots, a result of hemorrhage on the surface of mucous membrane. Hemorrhagic spots are quite frequently found beneath the external covering or serous coat of the intestines. These blood spots are occasionally found beneath the serous lining of the thorax and abdomen; under the serous membrane (peritoneum) near the kidneys, over the diaphragm (midrif) under the serous membrane (pleura) that lines the walls of the thorax, blood extravasations may occasionally appear, that are nearly one inch in diameter. Sometimes in the kidneys there are extensive hemorrhagic changes. When a kidney is cut into halves, large blood extravasations will appear in the central or medullary portions and small red spots (engorged glomeruli) will be observed in the cortical or outer part of the kidney. In some cases numerous blood spots will be observed under the serous (pleura) coverings of the lungs, and on cutting into the lung tissue small hemorrhagic spots may be seen in all parts of the lungs. In rare cases hemorrhagic changes may involve one or more 394 lobes of the lungs. The subcutaneous connective tissue may be filled with small hemorrhages. These are found mostly in the subcutis over the abdomen but may appear in any part of the surface of the body. Occasionally in the subcutis, around the mammary glands of sows that have suckled pigs, may be seen more or less large, bluish black patches of pigment, a result of the irritation and inflammation induced by the "rooting" of the pigs when sucking. Occasionally small blood collections may be found in the surface muscles and in various tissues of the body. Some authorities suggest that hemorrhages may be found in the brain and spinal cord. However, few records have been made upon the frequency of these lesions in the brain and spinal cord. As a rule the lymphatic glands of the large intestines, of the stomach, of the peritoneum, those in the pelvis, at the root of the lungs and along the posterior part of the aorta in the thorax, and sometimes lymphatic glands in other parts of the body, are more or less filled with extravasated blood. Sometimes the extravasations may be confined to the outer cortex or be infiltrated throughout the entire gland. These glands may have a light red color or be almost black. In chronic cases.-These cases are the ones that are most commonly observed in the slaughter houses and are always more fully described in the literature on hog cholera than acute cases. As a rule, the past-mortem appearances are more definite and distinct in chronic than in acute cases. However, chronic and acute cases may be found in the same herd; and both chronic and acute post-mortem appearances may be found, in some instances, in the same hog. In some chronic cases ulcers may appear in the mouth. They are usually found on the sides of the tongue along about its upper third, in the corners (commissures) of the mouth, on the tonsils and on the inside of the cheeks. These ulcers are usually circular or oval in outline and have 395 a grey, dtr. dead appearance, resembling very closely the diplhtheritic ulcers that are so constant and promilnent in the intestines. In rare cases there are a few (two or three) ulcers found in the stomach. LI the lower or terminal part of the small intestine, its lining mucous membrane presents small circular ulcers, which are produced by a diphtheritic inlanit at ion that destroys the mucous melnlbrane in spots amI the dead ( necrotic 1 parts of the membrane become detached leaving the tepressed reti ulcers. Occasionally, these ulcers mnaY be, more extensive or larger, especially near the end of the ileum. As a rule, these ulcers are formed earlier ani heal more rapitdly than t hose of the large [utestines. The diphitheritic AA j/ $Z; t1~ it ~ I ~ - : kA.A. I 'Mc, A __ ig.. 1. IipIhtIIriti( lcet in large inutestin of hog cholera (after DeItmers). 293 inflammation that produces the death of the mucous membrane is said to be "a diffuse superficial necrosis (death) of the mucous membrane, accompanied by the coagulation of a thin layer of croupous or fibrinous exudate. Sometimes only the superficial parts (the villi propria mucosa, and crypts of 'Lieberkiihn) are destroyed, but in other cases the entire thickness of the mucous membrane is destroyed, and included in the slough." In four days or more after the manifestation of the disease, diphtheritic ulcers appear in the mucous membrane of the large intestine. They are found most commonly in the cecum (blind pouch) the first part of the colon and in the rectum. They vary in size and outline; may be small (onefourth to one-half inch in diameter) or involve large patches; may be circular, oval or irregular in outline. The greater the number and more extensive the outline, the greater the degree of infection and more severe the disease. It seems that the development of these ulcers have never been observed in their early stage. It is propable that they appear as a result of a diffuse diphtheritic inflammation involving spots or patches of the superficial parts, or the entire thickness of the mucous membrane. The death or necrosis of the mucous membrane usually begins in small spots and involves the surface; it extends in depth until the entire thickness of the mucous membrane is involved, and, in rare instances, it may involve the middle (muscular) and outer (serous) coats of the intestine, leading to perforation of the bowel and thus producing peritonitis and death. The necrosis also extends regularly in all directions around the beginning spot; this increases the size of the ulcer, maintains its circular outline and accounts for the alternate black and white concentric rings of old ulcers. The diphtheritic or fibrinous exudate, first thrown out on the surfrce, is probably soon detached, but the fibrious exudate in the dead parts of the mucous membrane remains until the death of the animal 297' ,or the entire dead part of the ulcer is detached and the healthy healing (cicatrization) process begins. The diphtheritic, ulcers are greyish, yellowish, greenish or black in 'color Sometimes, in tenor twenty days after the beginning of the disease, the dead parts of someof the ulcers are cast off and the healing begins. The epithelium grows gradually; from the margin of the ulcer; but if the glands (Lieberkilhr's, solitary glands or Peyer's patches) have been destroyed they are never restored. After healing is completed (in recovered cases) "a smooth shining depressed scar marks the seat of the original ulcer." These scars are somewhat difficult to find and thorough search must be made after the intestines have been carefully washed. Some authorities (Salmon and Smith) assert that the ulcers(?) immediately around the opening of the small intestine into the cmcum are very constant and characteristic. McFadyean says: "Not infrequently, especially in old pigs, these crypts (Lieberkilhn's glands) in the mucous membrane around the ileo-cecal opening contain masses of what appears to be inspissated (dried) secretion, which may be squeezed out of them under slight pressure between the finger and thumb; indeed this condition is so common that it can hardly be considered an abnormality, and in many cases it has nothing to do with swine fever." In some instances, the liver is involved. Near the center of each lobule begins a necrosis which extends to its border. These dead specks in many of the lobules may be mistaken for miliary tubercles and to the naked eye appear as "greyish opaque specks about the size of a mustard seed." "These necrotic areas contain large numbers of the swine fever (hog cholera) bacillus in pure culture" (MhcFadyean). The lymphatic glands of the mesentery are usually swollen and frequently exhibit morbid changes that are similar to those that take place in lymphatic glands when effected with 398 tuberculosis. In these cases, the caseous centres in the lymphatic glands are surrounded by a connective tissue envelope. Friedberger and Frohner state that caseous centres may occasionally appear in the lungs; these centres are located in or near the surface of the lungs and produce an exudative pleurisy which results in adhesions of the lungs to the walls of the thorax, the diaphragm and the pericardium. The spleen, in chronic cases, is usually not involved but may sometimes be swollen or enlarged. The liver, kidneys, heart and muscles may show degenerative changes. AMERICAN SWINE PLAGUE. Symptoms:--Inasmuch as the lungs are most frequently involved, the breathing is more labored and oppressive, and the cough is more aggravated and painful than in hog cholera. In other respects the symptoms are not noticeably different from those manifested in hog cholera. In fact, Dr. Salmon states that in some instances, both hog cholera and swine plague may be present in the same hog. Post-Mortem Appearances:-Since the germs are distributed evenly throughout the blood in swine plague and rarely plug up capillaries and cause them to burst or rupture as in hog cholera, hemorrhagic spots or patches are seldom observed in swine plague. However, hemorrhagic inflammatory changes may be seen in the mucous membrane of the stomach and intestines, especially the large intestines. This may lead to fibrinous exudative deposits on the surface of the large intestines. According to Dr. Salmon, there is no. distinct hemorrhagic changes in the skin; and in only a few cases, have swellings (under the skin along the neck), been observed. These swellings are very common in the German swine plague and are due to an infiltration of yellow lymph in the subcutaneous connective tissue. In American swine plague, the chief or characteristic lesions are found in the lungs. They may be inflamed and 399 exhibit large numbers of small, pale, points or dots where the tissue is dead. Cheese-like masses from one to one-half to two inches in diameter may also be found in the lungs. The serous membranes, which line the abdomen and thorax, and are reflected over the organs in these cavities, are usually inflamed. As a result of the inflammation in these serous membranes, fibrinous inflammatory deposits are found on their surfaces. Dr. Salmon briefly states the difference between hog cholera and the American swine plague as follows: "We find the most characteristic lesions of hog cholera to consist of (1) Hemmorrhages, particularly in the subcutaneous, sub-mucous and subserous connective tissue; in the lymphatic glands and in the various organs of the body. (2) Ulcerations of the large intestines. (3) Callapse of lung tissue, and, less frequently, broncho-pneumonia." "The most characteristic lesions of swine plague are: (1) Inflammation of the lungs; numerous small necrotic points in these organs, or a few larger cheesy masses. (2) Inflammation of serous membranes with fibrinous deposits. Congestion of mucous membrane of intestine, or in(3) flammation of the same with fibrinous deposits." All cases of hog cholera or American swine plague should be rejected at the ante-mortem inspection or condemned and tanked at the post-mortem examination. TUBERCULOSIS OF CATTLE. Symptoms.-Inasmuch as this disease in cattle develops very slowly and may exist for months without presenting any marked changes in the apparent health of the animal, it becomes extremely difficult for an expert to make a clinical diagnosis in all cases, except those in the advanced stages. 300 1., Pulmonary Tuberculosis.-This form involves chiefly the lungs; it is the most common form of tuberculosis and is sometimes designated consumption. It is also the most serious and dangerous to the health of the diseased animal and as a means of spreading the tubercle bacilli to other animals. The broken down nodules or tuberculous abscesses in the lungs, in many cases, empty virulent masses into the bronchi and this germ ladened material is scattered here and there by coughing. It dries and floats about into the air; is carried into the air passages where the bacilli may begin to multiply or it may become mixed with the food and infect another animal by way of the digestive tract. In the early stages there may be a slight cough; it is dry and short; occurs in the morning at time of eating or drinking or when turned from a warm stall out in the cold air. If, in the early stages, the temperature is taken regularly, one may find sudden and temporary rises in temperature of . to 3 degrees Fah. With exercise the animal may exhibit shallow breathing which is slightly increased in rapidity. If it is a cow, she may have frequent and long periods of heat and be very difficult to get with calf. In the second stage the animal may become sensitive to pressure over the region of the kidneys; pressure on the ribs or over the kidneys may cause groaning and coughing. The cough is dry, hoarse, wheezy, frequent and painful. Sometimes the cough is moist, and yellow purulent material (sputa) may be thrown out of the mouth and nostrils during paroxyisms of coughing. That part of the sputa which drops into or remains in the throat (pharynx) after coughing may be swallowed. The hair is rough, dull and stands more erect than usual; the skin is dry and closely adheres to the tissue beneath it. During exercise the breathing becomes irregular, hurried, short, interrupted and difficult or labored. If the changes in the lungs are extensive or if tubercles develop over considerable pleural surface, striking over these places in the rib region may give a dull sound. If the 301 muscles-are not too thick over the thorax, by placing the ear in contact with the rib region, one may detect the bubbling of air through purulent matter in the. small bronchi. As a rule, percussion (striking) and auscultation (listening) are very indefinite and in the majority of cases the expert is baffled. The appetite may be poor and variable. Rumination is irregular and slow and gaseous distention of the abdomen may appear. The secretion of milk may become diminished; the milk may be "watery" and have a faint bluish tint; yet these changes are not always distinct. In the last stage the development of the disease becomes rapid. The animal becomes emaciated; the skin very dry and "bound down to the bones;" the hair is dull and bristling. The eyes sink back into their sockets; they are watery and the lids are covered with scaly matter. A yellow bad smelling discharge may trickle from the nostrils. The breathing is short, irregular and quick; the elbows may be thrown outward in order to aid expansion of the thorax and the animal remains standing most of the time. The cough is weak, frequent and painful. The stethoscope and other instruments will now reveal, to a greater or less degree, the location of large pleural or lung lesions. Percussion may locate extensive dull areas. Sometimes an extra resonance may be manifested in some places; this is due to the pus cavities which have empted their pus into the bronchi. Rattling cavernous sounds, irregular murmurs and splashing sounds may be heard without great difficulty by applying 'the ear to the thorax. As a rule, during this stage the disease becomes more and more general, extending to various organs of the body. Consequently, numerous symptoms may appear. As a rule, the animal dies from asphyxia (suffocation) and exhaustion. Abdominal Tuberculosis:-When the intestines and mesentery are involved the animal may have repeated attacks of colic and of diarrhoea alternating with obstinate constipation. If the peritoneum is involved, the genital organs become tuberculous; this leads to frequent and long periods of heat; 402 such a cow rarely becomes pregnant, and, when she does, the full term of pregnancy will 'rarely beeompleted. Uierine tubeiculosis may be manifest by a purulent discharge; this may be injected into some small susceptible animal or examined under the microscope for the bacilli. From a clinical standpoint it is impossible in a majority of cases to make a clinical diagnosis of abdominal tuberculosis. Tuberculosis of the Udder:-A slightly hard diffuse swelling, without heat or tenderness of the udder indicates a tubercular change in that organ. As a rule, only onequarter of the udder is involved. In the early stages the milk is normal, but it gradually becomes more and more watery and yellowish in color; then it may contain small coagulated clots which contain tubercle bacilli. Later the milk becomes more and more purulent and then the cow may cease to give milk. The toughness and hardness of the udder may increase until it becomes almost as hard as wood. At the same time the mammary lymphatic glands become enlarged, hard and nodular. The lymphatic glands in any part of the body may be involved. The superficial ones may be detected, if involved in tuberculous changes. The glands below the ear, back of the lower jaw, back of the throat (pharynx), along the neck, in front of the shoulder, in front of the stifle, etc., may become enlarged and hard in tuberculosis. When time is not an important item, the discharge from the nostril, purulent sputa, the purulent or yellowish milk, or the discharge from an open gland or joint may be injected into the peritoneal cavity of a guinea pig and in from one to three weeks typical lesions of tuberculosis will have developed. Or these materials may be examined microscopally to determine whether the germs are present or absent in the discharge. Also the tuberculin test may be,.employed; this is the most accurate means of determining the presence or absence of tuberculosis in all kinds of cases. 403 Symptoms of Tuberculpsis of the Pig :-Sometimes local or general tuberculosis in the hog is indicated by changes in the condition of the animal, which vary according to the part involved. Primary pulmonary tuberculosis is very rarely found in the hog. It is usually preceded by abdominal tuberculosis. In the first stage the cough is dry and short, and later it becomes painful and is frequently followed by vomiting. Respirations are, at first, slightly difficult and accelerated and gradually become, more difficult and hurried, and finally become painful. The abdominal organs are usually the primary seat of tuberculosis. The fattening of the hog is first checked; then it gradually becomes more and more emaciated; the skin becomes dirty; the visible mucous membranes become pale; constipation may alternate with diarrhoea. The animal becomes weak and shy, hides in the litter. The abdomen becomes pendulous and sensitive to pressure. Sometimes a glandular tumor may be found in the space between the branches of the lower jaw, under the throat or along the under surface of the neck. The lymphatic glands, which lie beneath the parotid glands, that are located below the base of the ears, may become swollen and lift up the parotid gland. Hence, a distinct, but not painful, swelling is observed in the parotid region. The sublingual, posterior pharyngeal (throat) and superior neck lymphatic glands are usually involved in connection with the lymphatic glands under the parotids. When all are involved a chain of swellings or knots are found extending from one ear around to the other. Sometimes these hard knotty enlargements may appear at the base of the neck, behind the shoulder or in the groins. These hard tumors may adhere to surrounding tissues and occasionally become soft, and form abscesses which erupt and dischage a small amount of thick, grumous pus. The bones are frequently involved; enlargement in the bones near the joints may lead to constant lameness, and finally to a fistulous opening which discharges a bad .smelling pus indicative of 304 destruction of bone. The foregoing changes usually appear very slowly and are not always distinct. The tuberculin test may be applied to the hog; but remember that the normal temperature of the hog may vary from 101 to 104 degrees Fah. Symptoms of Tuberculosis in Birds :-The most prominent symptom is the progressive wasting of the bird. The breast bone is very sharp,. a result of the wasting of the breast muscles. The diseased bird (chicken, turkey, etc.,) are listless and dumpish; the comb is soft and pale. Sometimes the infected bird becomes lame and this lameness may be due to a swelling about some joint, or to an open joint which discharges pus that contains numerous tubercle bacilli that may be examined microscopically. Dogs and cats may have tuberculosis. They obtain it by eating tuberculous meat or milk or other food contaminated with tuberculous sputa or dust. Or, they may contract it by living in close contact with tuberculous persons. The sheep and the goat rarely have tuberculosis. POST-MORTEM APPEARANCES-MORBID OR PATHOLOGICAL ANATOMY OF TUBERCULOUS CATTLE. According to Nocard tuberculosis may attack any of the organs of the body but appears more frequently in some tissues or organs than in others. The following organs or tissues are most frequently involved in the order in which they are named: The lungs, the lymphatic glands, serous membranes (pleure, peritoneum, etc.), the liver, the intestine, the uterus, the spleen, the marrow of the bones, the joints, the udder, the skin. CharacteristicAppearances of Taberculous Lungs :-- Usually the diseased lungs are bulky and heavy, and only partially collapse. They may weigh from 40 to 70 lbs. The surface of the lungs may be covered with nodules that vary in size and outline and are composed of collections of tuberculous lesions. Sometimes these nodules are hard and tough, and creak when cut with a knife; the freshly cut surface is in- V vell )W. with softenied places between the rough and SolovN-x hi Bard grains are felt when tha tough parts. cheesy hatter, from thesft places, is rubbed sf-ened between the fingers. The larger / 1ldlles~u:1V, w hell cut open, tensel - ! ths w~ould indicate that the tuerculous nodule had par'- t al nidergone Gaseousad tissue; the tubercle nmav he Seci~ -' from lilule e inlamiatissuzoe orthe a narro n tiualmis s P~ll ei wn usua urcleofgmaliiltler10i the .. Vieitop1ntcw rbwsler ii(' grdule-lec inree in o te sz soltde isthe and cot.e mored enseo tihoons titoerioruroid tueriee tof cma mortnorulesor tubeicle, tho ec tuhre. Th yelowith, 1l r oea fldpat ondthstuerenos apatily intancesor toe heserle rl ata is ntcent ceesy inorted baylie salts. nrre butsarl remain isowlaer. oter tartercfiesdeberlp near 406 the primary one and all may be enclosed in the same fibrous sheath. When the disease has existed for some time, these accumulated tubercles may be softened and changed into large, tuberculous abscesses, having thick fibrous walls and containing yellowish or greenish thick, grumous pus. This pus will not smell badly until the walls of the abscess are broken and the pus partly escapes into a bronchus and decomposition begins. The walls of a tuberculous abscess or cavity are always irregular and tortuous in outline. Sometimes the abscess cavity is crossed by thick, tough bands, covered by fleshy buds. These are arteries or nerves or bronchi that are involved in the tubercles. Sometimes numerous round tubercles, as large as a hazel-nut orwalnut, may be found in the lungs; they have a firm consistency, are dirty white in color and are free from central softening. Local centres of caseous pneumonia may develop by preference in the anterior lobe of the lung; they are slate colored or yellowish in color and quickly undergo caseous or purulent softening. Sometimes an entire lung is solidified and a freshly cut surface resembles a moderately firm, cheesy mass. This gray mass contains irregular cavities, filled with bad smelling pus and mucus; these cavities appear to follow the bronchi and are very propably dilatations of the smaller bronchi. Sometimes the bronchus that runs to the anterior lobe becomes obstructed; this cuts off the inspired air from that lobe; it collapses and becomes engorged with impure blood which gives it a purple red tint. The small bronchi may be slightly dilated and filled with a thick mixture of mucus and pus. The smaller bronchi are often surrounded by collections of miliary tubercles; they at first compress the bronchi and finally obstruct them. The bronchi beyond the obstruction dilate and become filled with mucus and pus. Sometimes the bronchi be'come involved in chronic inflammation; their lining mucus membrane becomes thickened and folded and contain yellow muco-pus. Occasionally yellowish gray granulations are found in the lining mucous membrane of 407 the bronchi; and sometimes the mucous membrane of the bronchi may be covered with deep, irregular ulcers. Similar nodules and ulcers may appear in the trachea and larynx. The nodules may be isolated, close together or arranged in lines; they quickly soften in their centres, erupt and form irregularly bordered ulcers which have hard margins; branches from these ulcers may contain specks of bright yellow tuberculous material. The bronchial and posterior mediastinal lymphatic glands (see plates) which collect lymph from tuberculous lungs may become infected. When tuberculous these glands may be enlarged, hard and knotty; a freshly cut surface will exhibit a number of yellow, hard, calcified miliary tubercles. These tubercles or nodules increase in number and unite into one dry fibrous mass which becomes infiltrated with lime salts; this dry mass may occupy from one-third to three-fourths of the gland. Finally all this mass softens and the gland becomes a fibrous sack filled with thick grumous, yellow, cheesy material. FIG. 3. A portion of a tuberculous lung (bovine) (Borrowed from Vermont Station.) [After Virchow.] Tuberculosis of the Serous IMemtbranes :-In some cases the pleura the peritoneum, the synovial membranes and the meninges of the brain and spinal cord may become tubercu- lous ; while the organs may remlain free from tublerculous lt 1In the serouis membrane very small, tranlsparen invaslioni. Around pinukislh gray and round granulations develop. each granule is an abnIormlallyv ascular zone and a growth of n10w co nnective tissue progresses until small, ri und, flat tumo~rs are dev eloped ;they projec(t more or less from the serous stHrfnl( and are united to it onlyv by at small pedlicle or tough. ialstrong that is usually qIuite long and vr 'Fliese tiiler~sulons tumors or nodules have a sliiniing surface lik.e mnothler-(J- pearl ; they are hard anid whitish and are sometimes scattered over the surface of the serous memI ianOe or mal~y he ci llected inl masses Ilike 11unilcs of grapes; ir they may- grow to considerable size. At first these nodules are soft but soon undiergoi calcareoins inftiltration. Their contents are theni hard, firm, (liv a d t hey are enclosed in a thick, to ugii, fibrous case. 'These pearly masses are found they are not so dischielly on th lheura andi per itonleu ,111 tinict onl the synovial memhranes of the joinits and tendons; and inl the coverings oif the brain and spinaLl cord they rarely dev elop beyond the earliest stage or thce gray miliary tubercde. JMiliary tubercle s miay also appiear in the pericardiumn. Sonetimies the serous surfaces of tihe epiicardium and pericardium may be changed into a thick layer of tuberculous material ; this mass is firm, yellowish 'white and rarely does it become caseous. coi\ "Floss." r*utio ii Ft(; A. 1Ilpend g ad from Hxjiirii The cascous- degenration is showni by the roughiened surfaes. These glands~ arc several times normal size. ( Borrowed from Vermont S tat ion.) 309 Tuberculosis of the Lymphatic Glands.-It is not uncommon to find the tuberculous changes in the body limited to one or more lymphatic glands. Occasionally the posterior pharyngeal gland is the only one in which tuberculous lesions may be found (Smith). As a rule, more than one gland is involved. Usually certain groups are involved: 'for example, the lymphatic glands beneath the parotid gland and alo the superor posterior border of the lower jaw, the posterior, pharyngeal, the superior and inferior cervical (neck) :lymphatic glands may be involved entirely or partially (see plate); the bronchial and mediastinal may be alone tuberculous, and the abdominal lymphatic glands (sublumbar, mesentiric, hepatic, intestinal, etc.,) may alone be tuberculous. These glands may be tuberculous when the organ with which they are attached and connected by lymphatic vessels are almost or entirely free from tuberculous lesions. The reasons why the lymphatic glands are tuberculous without the organs being involved is not readily explained. However, it is very probable, that the tubercle bacilli get into the lymphatic vessels and are carried to the lymphatic glands; when one gland is destroyed, the bacilli invade another and thus a closely connected group of glands becomes tuberculous. At first the lymphatic gland is enlarged, indurated (hardened) and filled with sm.ll knotty tubercles that are yellow and calcified; the regular tuberculous changes may proceed until the "dry fibrous mass' is formed and later central caseous softening appears, forming an abscess, a fibrous sack of grumous, yellow, mortar-like, semi-liquid material. Tuberculosis of the Organs and Glands of the Abdomen.-The peritoneum and the lymphatic glands are most frequently tuberculosis. The liver, the uterus and its appendages and the spleen are next involved in frequency in the order named. Miliary tubercles are sometimes found in the mucous or submucous tissue of the small intestine and the cecum. These tubercles are occasionally found in the mucous or sumbnu Icous tissue of the small intestine andl the ca cum. These tubercles may be isolated or in groups ;they very t. f '4 : i.d . :in nggr a c~ed c~asto wi-iculois of tilt ollieitl ering of the abdoial x isceral; also a tuberculous gland. rowed from Vermonalt Station.) (c ov (Bor- quickly undergo softening and1 emplty their p)urulent contents into the alimentary canal ; small ulcers, wxhich have little or no incilination to heal, mark the p~lace of the tub~ercles. These ulcers appear as if they were punched out with uirregular p~unch1 ; their margins are always thick and hard. The isolated ulcers are at first very small but gradunally increase in size. They are usually found involving tihe solitary glands and Peyer's patches ; yet they are ntot limited to thlese lymph~l glands. Frequently tho nmesenteric lymphatic glands may he tuberculons lheu. there are no v isible tuberculous lesions in the intestine. 311 Tuberculous lesions in the liver usually appear as more or less large masses scattered through its substance. These masses may be numerous and greatly increase the weight of the liver. The tubercles in the liver, as a rule, undergo central softening more rapidly and completely than in other organs. Tuberculous lesions of the uterus may be found in the mucous or submucous tissue. Sometimes one horn may be involved. The tuberculous uterus may become so large as to suggest the presence of a foetus. The mucous membrane may be crowded with miliary tubercles that usually undergo caseous and muco-purulent softening, an d finally erupt then the cavity of the uterus becomes filled with yellow grumous muco-pus and the surface of the mucous membrane is covered with ulcers. Sometimes the tubercles do not undergo caseation; the mucous membrane becomes thick, hard and white; these infiltrated tubercles have numerous giant cells, and very few tubercle bacilli. In the kidney the tubercles develop in the fibrous capsule or in the subcapsular layer of connective tissue. The spleen is very rarely tuberculous. It may be filled with a great number of minute gray granulations (miliary tubercles); but usually the tuberculous changes in the spleen are few, comparatively large, hard, calcified and are surrounded with a tough fibrous capsule. The marrow of the bones may contain numerous gray granulations. Sometimes the yellowish white, somewhat firm, round nodules, as large as a pea or a walnut, may be found in the breast bone, the bodies of the vertebrae, or in the articular ends of the long bones. These lesions are usually developed in the cancellated or spongy bone tissue, but the neighboring compact bone tissue may be irritated, thickened and a layer of subperiosteal bone developed. Occasionally these tuberculous lesions may soften and form fistulous openings into the articulation or discharge their contents externally. . In the udder, the tuberculous change usually begins by 312 an increase in the growth of the interlobular connective tissue. This tissue is"filled withlminute miliary tubercles which are at first gray but may becone yellow and caseous. and scattered here and there in various numbers. Later these tubercles may become softened or infiltrated with lime salts. The mammary glandular tissue is gradually destroyed by the pressure of the greatly developed interlobular connective tissue. The excretory milk ducts are dilated in places by masses of yellow caseous material which is very rich in'tubercle bacilli; the walls of the ducts may be filled with minute yellow granulations. Tuberculosis .of the testicles, vagina, spermatic cord, prostrate gland, thetongue, the subcutaneous connective tissue, and intra-muscular connective tissue, may occasionally occur. However, tuberculosis does not appear in all of the foregoing locations in any one animal. It is very rarely that any one of Lthese places are involved. In generalized tuberculosis or acute miliary tuberculosis, many of the abdominal organs (liver, spleen, kidneys, etc.), the lungs and the pleura maybe [filled with an infinite number of very small (as large'as a millet seed) transparent gray granulations (miliary :tubercles). If all of these tubercles have reached the same stage in their development, it signifies that the generalization occurred through the blood vessels, thus infecting :mnanygof thelorgans at about the same time. Post-mortem Appearances of Tuberculosis in the Hog.Miliary tuberculosis is the most common form in the pig; these gray granulations quickly become yellow and caseous. If generalization occurs the lungs and abdominal organs are filled with miliary tubercles; these are translucid, or have opaque centres, and are very like the gray granulations in cattle. Inasmuch;as the pig is usually infected by eating infectious material, the digestive apparatus and the lymphatic glands along the digestive tract are usually first and most frequently involved. The tonsils and the submaxillary, the parotid, the post-pharyngeal, the superior cervical, the mesenteric, the sublumbar and the intestinal lymphatic 313 eglands may become distinctly tuberculous before the organs manifest any distinct signs of the disease. Ulcers and miliary tubercles of the mucous membrane are occasionally found in the small intestine and the cecum; sometimes tuberculous infiltrations may involve the mucous membrane, the muscular and serous coats of the intestine. The liver is usually involved; yellow, caseous miliary tuberculous centres may be scattered through the s ubstance of the liver, or there may be round, yellowish white, tough tubercles, as large as a pea or hazel-nut; these tubercles may, upon in-spection, appear as if they were composed of fibrous material, with a small, soft centre. The peritoneum and the pleura .are occasionally filled or covered by numerous fine miliary tubercles which have no tendency to undergo other changes. The lungs may be involved similar to the tuberculous lesions in the liver, but as a rule the lungs contain numerous miliary tubercles only in acute generalized t uberculosis. In .acute generalized tuberculosis, the liver, the spleen, the kidneys, the marrow of the bones, and the mammary glands, are filled with miliary tubercles. In some cases the disease may be localized in one or more of the ly mphatic glands. The post-pharyngeal or the submaxillary lymph atic glands and hetonsils are most frequently tuberculous; they bee come enlarged, hard and knotty; they undergo a true fibrous change; are hard to cut out, and when cut with a knife .he tissue creaks and the section appears very like old fibrous tissue. In these tuberculous glands there may be small soft spots or somewhat large pus collections. Nocard says bacilli may not be found in these soft materials by microscopic examinations; yet they are p resent ; because, when a guinea pig or rabbit is inoculated into the peritonial cavity with this material, tuberculosis develops. The slow growing glandular changes have been considered as scrofula of the pig and sometimes the tuberculous -changes in the bones are called scrofula. As a rule, most of the so-called cases of scrofula in the pig are true cases of tuberculosis. 314 Post-mortem Appearances qf Tuberculosis of Birds.-The tuberculods changes are found almost entirely limited to the digestive apparatus; and the liver is the organ that is most frequently involved. It is greatly enlarged and filled with tubercles, varying in size. In some cases the tubercles appear small hard, white or yellow nodules, varying in a millet seed to a pea; in other cases the tubersize from culous lesions in the liver may be as large as a hazel-nut or walnut, white and fibrous, hard or softened in the centre. The liver tissue between the tubercles may appear normal, yet is more friable and liable to rupture. The spleen is involved in the order of frequency next to the liver. It may be filled with very small white granulations (tubercles) or it may contain hard calcareous nodular masses which are sometimes very large. Sometimes granular or nodular masses may become so large in the intestine as to obstruct the canal. Occasionally the tuberculous lesion in the intestine may be in the form of an infiltration of all three coats of the intestinal wall; ulcers may appear on the mucous surface that are more or less deep. The peritoneum is occasionally the location of white and hard miliary tubercles. The lungs are rarely tuberculous in birds. In the lungs of birds masses of miliary tubercles will at first develop and these will develop into small white caseous masses. The joints and their surrounding tissue may become tuberculous; these may be hard or soft; the joints may be ulcerated and have an opening discharging infected and broken down tissue material. According to some authorities many of the diphthoriti membranes that develop in the mouth. pharynx, nose and eyes are tuberculous lesions and always contain tubercle bacilli. Also, certain horny, warty tumors that develop in the skin of the face, head, neck or feet are tuberculous because they contain numerous tubercle bacilli. In all tuberculous lesions of birds, the tubercule bacilli are numerous; they collect in tufts or clusters. According to Nocard the tubercle bacilli in birds is a little longer 7as 315 than those in tuberculous mammals. The bacillus from birds is more vigorous; grows more rapidly and will withstand a higher temperature than the bacilli from mammals. However, the bacilli have the same peculiarities in reference to the culture media upon which they grow, and also in regard to their staining. Yet avian tuberculosis cannot be transmitted by inoculation to mammals and the ma-ammalian form cannot be transmitted to birds. Some authorities. believe that tuberculosis of birds is entirely distinct from tuberculosis in mammals. Nocard, however, believes that the bacillus of avian tuberculosis is a variety of the bacillus of mammalian tuberculosis. STAINING THE TUBERCLE BACILLI. Many times a microscopic examination will confirm the presence of the exciting cause (bacillus tuberculosis) in the muco-pus products of a tuberculous lesion. However, there are cases where no bacilli can be detected by the microscope, and yet when some of the tuberculous material is injected into the guinea pig or rabbit, the disease is produced and the bacilli may be discovered by microscopic examination. Hence, if the microscopic examination fails to find the bacillus, the proof is not absolutely positive that the disease is not tuberculosis. Ziehl's method is one of the very best and the simplest for staining tubercle bacilli, especially cover glass smears. His staining solution is made as follows: Carbolic Acid (5 per cent. solution). .90 parts. Alcohol (90 per cent.).............10 parts. Fuchsin..... ..................... 1 part. Mix thoroughly and filter before using. A very small quantity of the suspected tuberculous material (sputa, purulent nasal discharge, pus from a tuberculous articulation, pus from any tuberculous abscess, etc., etc.) is spread over an absolutely clean cover glass (No. 0 or No. 1) and slowly dried over an alcohol lamp or a Bunsen burner; when dry it is passed two or three times 3!6 through the flame to fix it on the cover glass. The cover glass is plunged into alcohol and then into the staining solution, or the staining solution is placed on the cover glass with a dropper. The cover glass is now held over a flame until the vapor begins to rise; this heating may be repeated as often as the stain on the cover glass cools, and the staining contiiiued from four to ten minutes. Or the cover glass may be floated (smear side down) on the surface of the staining solution in a watch glass, and the solution may be kept warm in the incubator or on a paraffine water bath for thirty to sixty minutes. The cover glass is next washed in distilled water and decolorized, in a 33 per cent. nitric acid or a 20 per cent. sulphuric acid solution. The decolorization (usually takes five or ten seconds) should be continued until all or nearly all of the visible color is removed from the cover glass. Next it is washed in distilled water; dried over the flame and mounted in balsam. A 1-12 in. oil-immersion objective and a substage condenser are necessary to make an accurate examination of the prepared slide. Some prefer to make a double stain by using gentian violet or Bismarck brown just after the decolorizing acid is washed from the cover glass smear. This gives the pus cells and other bacteria a brown or a blue color, while tubercle bacilli stand out in contrast, a distinct red color. Tubercle bacilli are in length from I to 2 the diameter of a red blood corpuscle, and their breadth is about 1-15 of their length. They are very slender and usually straight, but may be curved. In recent or new tubercles they appear as solid rods, but in old lesions, sputum and muco-pus they appear to be made up of ovoid grains, closely adhering to one another. It is very probable that short or broken chains of micrococci (streptococci) are sometimes mistaken for tubercle bacilli. In cases where it is impossible to detect the tubercle bacilli by microscopic examination, a smal quantity of the muco-pus or tuberculous material may be injected into the peritoneal cavity of a guinea pig. In a short 317 time the inoculated guinea pig will begin to grow thin, and if killed in fifteen or twenty days after the inoculation, tuberculous lesions will be found in the spleen, liver, etc. Villemin and others claim that the lesions will always be the same in the spleen, no matter what is the origin of the tuberculous material (from animal or man) with which the guinea pig is inoculated. The spleen is always greatly enlarged in all directions; in the early stages it is always filled with a great number of minute tuberculous granules; later its surface will appear "marbled;" surface lines are formed where the spleen substance has undergone caseous degeneration. These lines are said to "design variable arabesques of curious and asymmetrical shape." In old cases, the liver will exhibit similar changes, except that they are less distinct than those in the spleen. If the tuberculous material be injected into the subcutaneous connective tissue of a guinea pig, it will become tuberculous; but the disease will develop more slowly When the than by the peritoneal method of injection. material is injected into a vein general tubercutuberculous The lungs, liver, spleen, los;s very quickly appears. marrow of the bones and all other vascular organs very quickly become filled with a great number of miliary tubercles; the tubercles in the liver, spleen and marrow of the bones contain numerous tubercle bacilli. To the naked eye these organs appear enlarged, engorged with blood, and very friable. In fifteen or twenty: days the intravenously inoculated guinea pig will die from a veritable tuberculous septicaemia; during this time it will lose from one-third to one-half of its weight. In all cases, no matter what is the source of the tuberculous material (from man or other mammals) and no matte r if the microscopic examination of the tuberculous material fails to discover tubercle bacilli, a microscopic exa.xination of the tuberculous material from the inoculated guinea pig, always discovers the bacillus. 318 HISTOLOGY OF TUBERCULOUS LEGIONS. There are three kinds or forms of tuberculous lesions: (1) Miliary tubercles, or small gray granulations, which vary from one-two hundred and fiftieth to one-twenty fifth of an inch in diameter, are gray, translucid, and occasionally have a light tinted centre. (2) The yellow, . hard,. calcified mass, varying from the size of a pea to that of a walnut or apple. (3) A yellowish opaque infiltration of the tissues. Nocard sums up the anatomical characteristics of the tuberculous granulation, as follows : (1) "The nodular, form of the mass." (2) "The tendancy of the central portion to become caseous." (3) "The frequent occurrence of giant cells in the centre." (4) "The concentric arrangement of the peripheral cellular elements." (5) "The complete absence of vessels." "The miliary tubercle" consists of the aggregation of a certain number of elementary granulations in a single fibrocellular envelope, the toughness of which gradually increases. 'Tubercular masses,' whether small or great, are collections of a variable number of caseous, calcareous or softened miliary tubercles surrounded by a more or less thick and tough fibrous shell." "The 'caseous infiltration' of the tissues is the result of the development of a considerable number of tuberculous follicles, whose peripheral elements, having no tendency to undergo fibrous transformation, remain in a cellular state and retain their concentric arrangement, until they are attacked, like the centre of the follicle, by caseous degeneration. This latter form of lesion rarely undergoes calcification." CONDEMN TUBERCULOUS AN[MALS OR CAROASSES. The German inspectors condemn the carcass of an animal when tuberculous lesions are found in the thorax and in 319 the abdomen, or when there is generalized tuberculosis. By a direct vote of the Inter-National Yeterinary Congress of 1896, it'was decided that it was safest and best to condemn the entire carcass of a tuberculous animal no matter how much localized or generalized the lesions may be. Since it is very difficult to fully determine the extent of the tuberculous lesions without great expense and considerable time and, in many cases, without almost entirely ruining the carcass for beef, the only practicable and safe method is to condemn the entire carcass when it is tuberculous in any degree. The following cuts were taken from Bulletin No. 7, of the Bureau of Animal Industry, Dep't of Agriculture, Washington. Prepared by Theobold Smith. FIG. 6.--Dorsal aspect of the bovine lungs. The lungs are laid so that the dorsal (or upper) surface is shown. The various lobes are drawn apart so that their outlines may be distinctly seen. The lobes are named in the text as follows: a, ca, right and-left caudal lobes, b, b,, right and left ventral lobes. c, c, the two portions ,of the' right=cephalic lobes, denominated first and second cephalic lobes. c2, left cephalic lobe. e, trachea. x, region most frequently involved in the earliest stages of pulmonary tuberculosis. The lesions in this stage are, as a rule, embedded in the lung tissue so as to remain invisible from the surface. .respectively. FIG. 7.--Ventral aspect of the bovine lungs. The letters correspond to those on Fig. 6. a, a,, right and left caudal lobes. b, b,, right and left ventral lobes. c, c, first and second right cephalic lobes. c2, left cephalic lobe. d, azygos or median lobe (belonging to the right lung). lobe is involved in the most advanced cases only. e, trachea. x, usual location of the earliest lesions of tuberculosis. This 320 SFIG,. -.-Trachea and bronchial tubes of the bovine lungs showing attached bronchial glands. a, a, air tubes supplying the right and left caudal lobes. b, b,, air tubes supplying the right and left ventral lobes. c, c,, branches of the right supernumerary bronchus supplying the first and second cephalic lobes of the right lung. c2, air tube supplying the left cephalic lobe. Sd,branch to azygos lobe. e, trachea. A. left bronchial lymph gland. B, right tracheal lymph gland. C, lymph gland at root of right supernumerary bronchus. D, gland in the angle between bronchi; not always present. The minute intra-pulmonary glands, situated along the main bronchi, are not shown. FIG. 9.--Dorsal aspect of the bovine lungs showiny the position of the posteriormediastinal glands. a, a', caudal lobes. b, b, ventral lobes. c, ci, c2, cephalic lobes. e, trachea. f, oesophagus. g, muscular pillars of the diaphragm. h, posterior aorta cut through just beyond the arch and reflected so as to uncover the left bronchial gland A, resting against the root of the left bronchus. i, caudal margin of the ligament of the lungs (ligamentum latum.) The mediastinal glands are shown, most of them resting on the n