278 PUBLIC HEALTH BACTERIOLOGY 



Their results may be summarized thus : 



The results in 606 cases of various kinds of tuberculosis, 

 investigated by different workers, are tabulated thus 

 (three cases showed both types) : 



The bacillus of avian tuberculosis shows a more 

 luxuriant and moister growth than the human type, and 

 grows at 43-5 C., is very pathogenic to rabbits, scarcely 

 pathogenic to guinea-pigs, and not at all to dogs, even 

 intravenously, whereas the human type produces an 

 acute infection. Morphologically it is almost identical 

 with the human type, and stains similarly. It is found 

 in lesions in fowls and pigeons and some other bird 

 species. Fowls fed on human tubercle bacilli are not 

 found to become tuberculous. The identity of the two 

 types is said to be established by the experiments of 

 Nocard, who rendered mammalian tubercle bacilli 

 pathogenic for fowls by keeping them in the peritoneal 

 cavities of hens in collodion sacs for six months. Con- 

 versely, prolonged cultivation and passage of the avian 

 type through the mammalian body are said to cause them 

 to approach closely to the mammalian type. 



The bacillus of a tubercle - like disease in a carp has 



