462 THE TUBERCLE BACILLUS GROUP 



for several months both in cultures and in uncontaminated material 

 from infected birds. Unlike the human or the bovine disease, avian 

 tuberculosis is transmitted ordinarily as a congenital infection. Birds 

 are comparatively readily infected artificially, however, by injection 

 of the organisms. Edwards 1 has infected hens with the excrement of 

 infected birds. The liver and the spleen are the organs more commonly 

 involved. 2 



Among laboratory animals rabbits appear to be more susceptible 

 than guinea-pigs, although Edwards 3 appears to have successfully 

 infected several guinea-pigs with pure cultures of the organism. 

 Moore 4 was unsuccessful in causing the bacilli to multiply in guinea- 

 pigs but observed that the animals frequently died of marasmus, 

 apparently from the absorption of toxins from the bacilli; Mohler 5 

 has induced infection in swine by feeding them the carcasses of tuber- 

 culous hens. Himmelberger 6 has made the important observation 

 that calves may be susceptible to infection with the avian tubercle 

 bacillus. 



1 Ont. Agricult. College Bull., No. 193. 



2 De Jong, Ann. Inst. Past., 1910, xxiv. 



3 Loc. cit. 



4 Jour. Med. Research, xi, 521. 



5 Twenty-fourth Annual Report, Bureau of Animal Industry. 



6 Centralbl. f. Bakt., Orig., 1914, Ixxiii, 1. 



