158 WOOLFOLK : 



by other investigators, and were, but the demands of Koch 

 are only practicable in so far as they relate to the inoculation 

 of cattle with tubercle bacilli of human origin, since direct 

 proof that would be forthcoming by inoculating man with 

 bovine bacilli cannot be obtained. 



The practical importance of having exact knowledge of 

 the intertransmissibility of human and bovine tuberculosis 

 has long been realized by the sanitarian, and was immediately 

 recognized by the public when it became acquainted with the 

 statements made by Koch. As a result of Koch's opinions, 

 health officers in the enforcement of their regulations at once 

 met with opposition from the people who are always willing 

 to grasp at a new thought or idea. But the results obtained 

 by a majority of those who immediately undertook to solve 

 this problem were in opposition to Koch, and they almost 

 unanimously recommended that it would be unsafe to relin- 

 quish or modify the present sanitary police regulations with 

 reference to bovine tuberculosis. 



Since human and bovine bacilli comprise the most import- 

 ant type known, much of the comparative work has been 

 centred around them. 



In the intervening years many instances have been cited 

 of the infection of man through cuts and injuries received 

 while slaughtering tubercular cattle. Numerous attempts 

 have been made to infect cattle through various methods of 

 inoculation with human sputum or with cultures derived from 

 human cadavers. The results have been varied, but the con- 

 clusion of the majority of investigators is strikingly uniform, 

 and proof conclusive that the two forms of bacilli are inter- 

 changeable. 



While it has been shown conclusively that a greater path- 

 ogenic power is the most distinguishing character between 

 bovine and human tubercule bacilli, even this is not constant. 

 The pathogenic action of the bovine bacillus for man is seen 

 where a careful study of wound infection is made. A com- 

 parison with similar infections with human tuberculous mate- 



