ACID-FAST GROUP 325 



tuberculosis and of infection of the other abdominal organs, the 

 mesentery, and the peritoneum. The tonsils are believed with 

 good reason to permit the infection of the neighboring lymph- 

 glands and the consequent production of scrofula. Cutaneous 

 lesions following abrasions or cuts of the skin have been observed, 

 particularly in butchers, and in a few instances in veterinarians. 



Intertransmissibility of Human, Bovine, and Avian Tuberculosis. 

 Human tubercle bacilli do not readily infect cattle. When 

 injected, they may cause local, but rarely general, infection. The 

 fact that the human and bovine types of bacilli may be differen- 

 tiated has already been emphasized. Both types of bacilli produce 

 fatal infection in the monkey. Instances of probable cutaneous 

 infections of man from cattle are on record. 



Park and Krumweide have outlined the factors which must 

 be taken into consideration for differentiation of the bovine and 

 human type of tubercle bacilli. In their own isolations of the 

 tubercle bacilli from the human they have used the following 

 criteria: " All cultures showing maximum luxuriance on glycerin 

 egg in primary cultures are certainly human. All cultures not 

 showing maximum luxuriance should then be transferred to 

 glycerin egg, potato, and glycerin egg with bouillon added. Cul- 

 tures which have failed on glycerin egg should also be transferred 

 on plain egg, as glycerin egg may again fail. All cultures showing 

 maximum luxuriance are quite certainly human." The forms 

 which show a very sparse growth are as quite certainly bovine. 

 Intermediate forms are tested upon rabbits, and, if necessary, upon 

 calves. 



Swine readily contract bovine tuberculosis. They have also 

 been known to become infected with avian tuberculosis through 

 the consumption of birds dead from the disease. 



Birds contract the disease from each other by ingestion of 

 excreted bacteria. Whether or not the disease may start from 

 ingestion of bovine or human tubercle bacilli is not certainly 

 known. 



It is evident that while each of the types of tubercle bacilli are 

 generally associated with a specific host, on the other hand, 

 each may, under appropriate conditions of infection and suscep- 

 tibility, produce infection in other hosts. 



