382 A MANUAL OF BACTERIOLOGY 



on the dose, i.e. the number of bacilli, administered. 

 Thus, whereas 50 mgrm. of culture always induced a fatal 

 generalised progressive tuberculosis, in two instances 

 much smaller doses 0-01-0-02 mgrm. produced only 

 limited retrogressive tuberculosis. Feeding, on the other 

 hand, usually produced lesions limited to the neighbour- 

 hood of the digestive tract, which generally retrogress 

 and become calcareous. The bovine bacillus, when intro- 

 duced into rhesus monkeys or chimpanzees, either by 

 inoculation (even in so small a dose as 0-001 mgrm.) or by 

 feeding, induces rapid generalised tuberculosis, and, 

 considering the close relation that exists between the 

 anthropoid apes and man, these results are of the highest 

 importance. In pigs, generalised progressive tuberculosis 

 is readily set up both by feeding with, and by the inocula- 

 tion of, bovine bacilli. Goats, dogs, and cats are relatively 

 less susceptible, but more or less tuberculous infection 

 can similarly be produced in them. On this part of the 

 investigation the Commissioners remark that the bacillus 

 of bovine tuberculosis is not so constituted as to act on 

 bovine tissues only, and the fact that it can readily infect 

 the anthropoid apes, and, indeed, seems to produce this 

 result more readily than in the bovine body itself, has an 

 importance so obvious that it need not be dwelt on. The 

 viruses isolated from sixty cases of the disease in man 

 were also studied, and the results obtained show that 

 they may be divided into two groups, subsequently 

 referred to as Group I and Group II. The bacilli of 

 Group I comprised fourteen viruses, one obtained from 

 sputum, three from tuberculous cervical glands, and ten 

 from mesenteric glands of primary abdominal tuber- 

 culosis in children. The results produced by introducing 

 these viruses into animals are identical with those pro- 

 duced by the bovine bacillus. The bacilli of Group II. 

 comprising forty viruses obtained from various forms of 



