NON-SPORING BACILLI 301 



wholly free from risk of infection, through animal food, 

 with that type of bacillus to which he is most prone, 

 namely the human type ; though the degree of danger to 

 him in this sense must for the present remain undetermined. 

 The pig, though experimentally it fostered human bacilli 

 in a minor degree only, may have to be regarded as a 

 possible source of this kind of infection, since particular 

 glands of the pig's body, in which human tubercle bacilli 

 have occasionally been found, are likely to enter into 

 certain prepared foods. 



(iii.) (a) The pig is a potential source of infection of man 

 with bovine tubercle bacilli. This bacillus was present in 

 50 -f- 1 cases of tuberculosis in pigs, out of 59 cases of 

 tuberculosis investigated. In 32 + 1 of these cases, it 

 caused generalized tuberculosis, and in 18 cases, local 

 tuberculosis. (The -f 1 case was one of mixed bovine and 

 avian infection.) There is no reason to suppose that the 

 bovine tubercle bacilli are rendered less infective to human 

 beings by previous residence in the tissues of the pig. 



(b) The actual number of cases representing the various 

 clinical manifestations of tuberculosis commonly found in 

 man, on which the conclusions are based, is. 128. So far 

 as these have been examples of tuberculosis in adults, 

 and especially when they have been cases of pulmonary 

 tuberculosis, the lesions of the disease, when fatal, have 

 been referable to the human tubercle bacillus, with but 

 few exceptions. 



In human abdominal tuberculosis, the experience has 

 been very different, especially as regards children. Of 

 young children, dying of primary abdominal tuberculosis, 

 the fatal lesions could be referred to the bovine tubercle 

 bacillus, and it alone, in nearly one-half of the cases. 



In cervical-gland tuberculosis, in children, and often 

 also in adolescents, a large proportion of the cases examined 

 could be referred to the bovine tubercle bacillus. 



In lupus, too, in the cases examined occurring in 

 adolescents and children, the amount of infection with 

 the bovine type was marked. 



Whatever therefore may be the animal source of 

 infection with the bovine type of bacillus in adult and 

 adolescent mankind, there can be no doubt that a consider- 



