TUBERCUL OSIS. 33 1 



b. Rabbits. — All of the rabbits which were inoculated 

 into the ear vein with the bovine bacillus died in from 

 seventeen to twenty-one days. Those receiving human 

 bacilli sometimes lived several months. 



c. Cattle. — Cows and heifers receiving intrapleural and 

 intra-abdominal injections of the human bacilli usually 

 gained in weight and showed no symptoms. When ex- 

 amined post mortem, circumscribed chronic lesions were 

 found. Those inoculated with the bovine bacillus lost 

 weight, suffered from constitutional symptoms, and 

 showed at the necropsy extensive lesions. Two-thirds 

 of the cattle inoculated experimentally with the bovine 

 bacillus died. 



5. Lesions. — In general the lesions produced by the 

 bovine bacillus were rapid, extensive, and necrotic. Many 

 bacilli were present. Those produced by the human 

 bacillus were more apt to be productive, chronic, and un- 

 accompanied by large numbers of bacilli. The bacilli of 

 human tuberculosis produced lesions with many giant 

 cells; those of bovine tuberculosis, lesions with rapid 

 coagulation-necrosis. The lesions resulting from the 

 intravenous injection of human bacilli into rabbits re- 

 sembled those observed by Prudden and Hodenphyle 1 

 after the intravenous injection of boiled, washed tubercle 

 bacilli. 



From these data it is evident that the bovine bacillus 

 is by far the more virulent and dangerous organism. 

 While the human bacillus infects cattle with difficulty, 

 the bovine bacillus infects animals, and probably man, 

 with great readiness. The urgent need of securing milk 

 free from all possible tuberculous infection will be evi- 

 dent to all who reflect upon the subject. 



Upon culture-media a distinct rapidity of growth is 

 observable, and we find that, instead of growing only 

 when glycerin is present, the Bacillus tuberculosis galli- 

 narum will grow upon blood-serum, agar-agar, and bouil- 

 lon as ordinarily prepared. It will not grow upon potato. 



1 N. Y, Med. Jour., June 6-20, 1891. 



