232 THE DISEASES AND DISORDERS 01' THE OX. 



ingested by animals for any length of time, tuberculosis -will be developed. 

 Bang has recorded the results of an examination of twenty-seven cases of tuber- 

 cular mammitis, and he was able to prove the presence of tubercle-bacilli in 

 the milk or in the sediment, and with this milk or sediment he produced tuber- 

 culosis both by means of inoculation and by ingestion. 



Dr. Woodhead, together with Professor McFadyean, found 37 cows out of 

 600 affected with mammitis. In six cases they made sure of the existence of 

 enormous numbers of bacilli in the udder by means of microscopical examina- 

 tion. They found new tubercular tissue distributed in patches of various size 

 throughout a portion of the gland, and small round cells provided with large 

 nuclei and epithelioid cells between or amongst which a fairly well developed 

 reticulum was seen. The giant-cells were very numerous, and scattered 

 throughout the new tissue ; but they were not so well defined as in the case of 

 human tuberculosis. Caseation may occur at certain points. The new growth 

 of tuberculous tissue gradually invades the lobules of the gland, passing in along 

 the lymphatics of the interlobular septa. Innumerable bacilli are present in 

 the parts which are tuberculous. They are first seen as small stained rings 

 (masses of bacilli) around a slightly granular or homogeneous mass — in fact, the 

 giant cells seem to consist of the debris of cells, the result of the growth and 

 processes of the bacilli. These tubercle-bacilli may also be seen in the smaller 

 cells, and also in the spaces between the cells. At the margin of the new growth, 

 ulceration into the ducts may be made out. The basement membrane of the 

 ducts may give way, and a small mass of tubercular granulation may be seen 

 projecting into the lumen. In the granulation-tissue, the epithelial cells, and 

 in the lumen of the tubes numerous bacilli may be seen lying free, and hence 

 they gain entrance into the milk. Giant cells may perhaps be acini or ducts, in 

 which the bacilli have attacked and destroyed the epithelium. 



It seems to be the case that it is only when the functions of the intestine are 

 interfered with, and when there consequently are temporary or permanent 

 alterations in structure and also in the chemical constituents of the fluids and gas 

 in the alimentary canal, that tubercle-bacilli can make their way through the 

 epithelial barrier. 



There are numerous cases in which tubercular disease of bone, of synovial 

 membranes, &c., has followed on measles, scarlatina, small-pox, and similar 

 conditions, and when an attack of typhoid fever or other intestinal mischief has 

 been considered as marking the date at which serious tubercular mischief first 

 commenced. In the first instance the glands act as vital filters ; but if they 

 degenerate and become encapsuled in fibrous tissue, they may suppurate, and 

 so become centres from which other areas are affected. 



Dr. Woodhead, in common with Koch, Bland Sutton, Watson Chejme, and 

 numerous other workers, holds that any differences which may be discerned 

 between the size, mode of growth, and position of human and bovine tubercle- 

 bacilli are not sufficient to constitute a specific or even a varietal difference. 

 Some bacilli found present in human sputum were at least one-third or even one- 

 half larger than others. Again, he showed a specimen of tuberculous udder in 

 which were tubercle-bacilli, some of which were embedded in epithelial cells, whilst 

 others were lying singly in the spaces between the cells. Klein has shown that 

 fowls may be successfully inoculated with tubercle taken from a human being, 

 that with tubercle from a guinea-pig we can inoculate an ox, but that we cannot 

 readily succeed in inoculating fowls with tubercular matter taken from an ox. 

 Koch states that tubercle-bacilli grow at temperatures varying from 80° to 

 105° F. Outside these limits it is extremely difficult to obtain a luxuriant 

 growth. In the case of children, especially those who are subject to the 



