440 DISEASES OF CATTLE. 



bodies of human beings that died of tuberculosis which proved to 

 have about the same vinilence for cattle as had the bacilli from 

 bovine animals alfected by the disease. 



Kossel, in a preliminary report, stated that the German commission 

 had tested 7 cultures of tuberculosis from cattle and hogs — 4 from 

 cattle and 3 from hogs. Two of these cultures proved acutely fatal 

 in cattle after eight to nine weeks; 4 of the cultures likewise pro- 

 duced a generalized tuberculosis, but which certainly had a more 

 chronic course, while 1 of the cultures caused only an infiltration at 

 the point of inoculation, with some caseous foci in the adjoining 

 prescapular gland and in one of the mediastinal glands, and there 

 was lacking the spreading of the tuberculosis over the entire body 

 which they were accustomed to see after the injection of cultures of 

 bovine tuberculosis. " Hence," says Kossel, " among bovine tuber- 

 culosis bacilli there can also occur differences with regard to the 

 virulence." 



The German commission also tested 39 different freshly made cul- 

 tures from tuberculous disease in man. Nineteen of these cultures 

 did not produce the slightest symptoms in cattle ; with 9 others the 

 cattle exhibited after four months very minute foci in the prascapu- 

 lar glands, which were mostly encapsuled and showed no inclination 

 to progi'ess; with 7 other cases there was somewhat more marked 

 disease of the prescapular glands, but it did not go so far as a mate- 

 rial spreading of the process to the glands next adjoining. There 

 were 4 cultures, however, which were more virulent and caused gen- 

 eralized tuberculosis in the cattle inoculated with them. 



It would appear, therefore, that hereafter everyone must admit that 

 it is impossible always to tell the source of a culture of the tubercle 

 bacillus by its effect when it is inoculated upon cattle. One of the 

 bovine cultures failed to produce generalized tuberculosis in cattle, 

 and some of the human cultures did produce this form of the disease 

 in such animals. Moreover, while some of the human cultures caused 

 no disease at all, others led to the development of minute foci in the 

 prescapular glands, and still others to somewhat more marked disease 

 of these glands. There were, consequently, four degrees of virulence 

 noted in these 39 cultures of bacilli from human sources and three 

 degrees of virulence in the 7 cultures from animal sources. 



Now, if we accept the views of Koch as to the specific difference 

 between human and bovine tubercle bacilli, and that the human bacilli 

 produce only localized lesions in cattle, while bovine bacilli produce 

 generalized lesions in these animals, must we not conclude that the 

 one nonvirulent bovine culture was in reality of human origin, and 

 that the animal from which it was obtained had been infected from 

 man? This is a logical deduction, but reverses the dictum laid down 

 at London that hmnan tuberculosis is not transmissible to cattle. 



