VII TUBERCULOSIS OF THE COW 141 



in 1908, examined 150 samples of Leipzig butter, and in 18 

 found tubercle bacilli (12 per cent). 



Cheese. — Hormann and Morgenroth found tubercle bacilli 

 in 3 out of 15 samples, Eabinowitsch in 3 out of 5 samples, 

 Harrison in 3 out of 5 samples, and Eber in 2 out of 50 

 samples. 



BoYiNE Tuberculosis as a Cause of Human Disease 



The relationship of human to bovine tuberculosis is a 

 subject which has been much discussed, but which may now 

 be said to rest on a fairly sure basis. The earlier conception 

 assumed a nearly complete unity between the tuberculosis of 

 man and of cattle, based upon the histological identity of 

 the lesions and the close similarity of the bacilli obtained 

 from the two sources. This view was very clearly expressed 

 and emphasised by the Eoyal Commission on Tuberculosis, 

 who, in their Report (1895, Part i.), stated: 



We find the present to be a convenient occasion for stating 

 explicitly that we regard the disease as being the same disease in 

 man and in the food animals, no matter though there are differences 

 in the one and the other in their manifestations of the disease ; and 

 that we consider the bacilli of tubercle to form an integral part of 

 the disease in each, and (whatever be its origin) to be transmissible 

 from man to animals, and from animals to animals. 



Investigators had pointed out from time to time certain 

 differences of virulence, morphology, etc., while in particular, 

 in 1896, Theobald Smith drew attention to differences of 

 morphology, cultural characters, and virulence between the 

 bacilli derived from human and bovine sources. In particular 

 he showed that human tubercle bacilli inoculated into cattle 

 produced either no tuberculosis or only local non-generalised 

 lesions. The view of the inherent identity of the bacilli from 

 animal sources was, however, generally accepted until 1901, 

 when Koch, at the British Congress on Tuberculosis, lent the 

 weight of his unique authority to the conception that human 

 and bovine tuberculosis are, for practical purposes, distinct 

 diseases, and that the cases in which human infection results 

 from bovine tuberculosis are so rare that special methods 

 against bovine tuberculosis are not required. 



The immense practical importance of the subject led to the 



