Bovine Tuberculosis 687 



little. The most important is that of the Royal Commission on 

 Tuberculosis of Great Britain.* The general tenor of this report 

 is contrary to Koch's views, and many believed it settled the ques- 

 tion. At the International Congress on Tuberculosis in Washington, 

 1908, Koch reviewed the subject and stated his continued belief 

 in the principle he had enunciated 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,t 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 dis- 



eases 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 collected dur- 

 ing seven years, showed how errors had crept into the investi- 

 gations, 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 supposed 

 modifiability of the tubercle bacillus in different environments. 

 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, 

 Moriyat seems to have shown that such changes are either purely 

 hypothetic or come about with great difiSculty. 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. Unfortunately he died 

 before the results could be compiled, but much work had been done 

 and much support thereby given his views. A most fertile research, 

 the results of which form a valuable addition to our knowledge of 

 the problem has been published by Park and Krumwiede,§ who, 

 basing their opinions upon the following tabulation of 1224 cases, 

 come to the following conclusions: 



* See the "British Medical Journal," 1907 and igo8. 

 t "Jour. Amer. Med. Assoc," Oct. lo, 1908, 11, No. 15, p. 1256. 

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

 § "Journal of Medical Research," 1910, xxui, No. 2, p. 205; 1911, xxv, No. 2, 

 P- 313- 



