THE PRESENCE IN MILK OF CERTAIN ORGANISMS 253 



The Royal Commission on Tuberculosis, as a result of the 

 evidence obtained by them, state : ' Bovine tubercle bacilli are 

 apt to be abundantly present in milk as sold to the public when 

 there is tuberculous disease of the udder of the cow from which 

 it was obtained . . . but these bacilli may also be present in the 

 milk of tuberculous cows presenting no evidence whatever of 

 disease of the udder, even when examined post-mortem. Further, 

 the milk of tuberculous cows not containing bacilli as it leaves 

 the udder may, and frequently does, become contaminated with 

 the faeces or uterine discharges of such diseased animals/ 



2. On the Infectivity of Tuberculous Milk The importance 

 of ascertaining the presence of tubercle bacilli in milk is essentially 

 bound up with the question of whether such bacilli can produce 

 tuberculous lesions in the human species. Here again the literature 

 is voluminous and highly controversial, and it is not proposed to 

 deal with it in this work. It will suffice to quote some of the 

 results obtained by the extended investigations which have been 

 carried out by competent authorities. 



It has been known for a number of years that certain differences 

 exist between the tubercle bacilli found in cattle and those found 

 in the human species. These have been fully investigated, and 

 for further details any one interested is referred to the report of 

 the Royal Commission on Tuberculosis. The essential point 

 is the presence of bovine tubercle bacilli in lesions in the human 

 subject. The most extensive observations have been carried out 

 by the workers for the Royal Commission, and it will be of interest 

 to quote sentences from the report made by the Commissioners. 

 After dealing with the investigations which were conducted upon 

 108 cases of human tuberculosis in persons of various ages, the 

 Commissioners say : ' Of the total 108 cases of human tuberculosis 

 investigated, 84 yielded human tubercle bacilli, only 19 yielded 

 bovine tubercle bacilli, and 5 both bovine and human tubercle 

 bacilli. Although the bovine tubercle bacilli may, as it appears, 

 be solely responsible for certain cases of pulmonary tuberculosis 

 (consumption), and though it may be present with the human 

 tubercle bacillus in the bronchial glands, it is evident from the 

 data recorded that the majority of cases in which the bovine tubercle 

 bacillus is the infective agent in the human being are cases of 

 alimentary tuberculosis. Such are cases of cervical gland and 

 primary abdominal tuberculosis. In the latter class of cases at 

 least the tubercle bacillus has unquestionably been swallowed. . . . 

 The percentage of these cases of alimentary tuberculosis due to the 

 bovine tubercle bacillus is very large/ (The percentage appears 

 to be about 50 per cent.) 



It is not necessary to bring forward evidence to show that 

 bovine tubercle bacilli affect young children rather than adults. 

 The prevalence of gland infection in children and of pulmonary 

 infection in adults is a matter of common medical knowledge. 



