Bovine Tuberculosis 751 



The general tenor of this report is contrary to Koch's views, 

 and many believed it settled the subject. At the Inter- 

 national Congress on Tuberculosis in Washington, 1908, 

 Koch reviewed the subject and stated his continued belief 

 in the principle he had enumerated seven years before. 

 Practically the same contentions were raised against him 

 by much the same group of men, but the controversy was 

 more bitter than before. Koch,* however, leaves us in no 

 doubt upon the subject, summarizing his views in these 

 words : 



1. The tubercle bacilli of bovine tuberculosis are different from 



those of human tuberculosis. 



2. Human beings may be infected by bovine tubercle bacilli, but 



serious diseases from this cause occur very rarely. 



3. Preventive measures against tuberculosis should, therefore, 



be directed primarily against the propagation of human 

 tubercle bacilli. 



He weighed the contrary evidence that had been col- 

 lected during seven years, showed how errors had crept 

 into the investigations, and laid down certain rules to be 

 observed before the experiments could be accepted. At the 

 close of the congress the matter remained unsettled, Koch 

 appearing to have the best of the argument. 



The opponents of Koch based their opinions upon the sup- 

 posed modifiability of the tubercle bacillus in different en- 

 vironments. When it lived in man, it was by virtue of the 

 contact with the human juices and their chemical peculiarities 

 compelled to assume the human form ; in the cow, by virtue of 

 the different chemical conditions, the bovine form, etc. 

 Proofs of this were, however, wanting, and have not yet been 

 published. On the other hand, Moriyaf seems to have shown 

 that such changes are either purely hypothetic or come 

 about with great difficulty. He succeeded in keeping human 

 and also bovine types of tubercle bacilli alive in tortoises 

 for twelve months, at the end of which period each was found 

 unmodified and possessed of its original characteristics. 



It was Koch's hope to be able to finally settle the whole 

 matter, and to this end he asked the cooperation of many 

 laboratories throughout different parts of the world. Un- 

 fortunately he died before the results could be compiled, but 

 much work had been done and much support thereby given 



* "Jour. Amer. Med. Assoc.," Oct. 10, 1908, u, No. 15, p. 1256. 

 t "Centralbl. f. Bakt. u. Parasitenk.," i. Abt. Orig., u, 1909, 460. 



