Tuberculosis 119 



mitted. The fresh material has usually proven to be the 

 most virulent. Van Es and Schalk ^ report that of 12 Eng- 

 lish sparrows each fed one meal of chopped tuberculous 

 chicken liver all died in from 73 to 202 days with generalized 

 tuberculosis. It is quite probable that the English sparrow 

 often serves to infect domestic fowls. 



Koch and Rabinowitsch " state that while fowls are easily 

 infected with avian tuberculosis by feeding, it is very difficult 

 to infect them with the mammalian strains in the same way. 

 On the other hand, some birds, especially cage birds, are 

 very readily infected in various ways. Parrots, in particular, 

 are susceptible not only to avian tuberculosis, but also to 

 mammalian and human tuberculosis. Also canary birds, 

 sparrows, and various birds of prey were proven to be sus- 

 ceptible to both avian and mammalian tuberculosis. In these 

 respects such birds differ materially from the domestic fowls. 



On the other hand their later researches have made it 

 apparent that a large number of mammals are susceptible to 

 avian tuberculosis. These include not only the small 

 laboratory animals as rabbits, mice and guinea pigs, but also 

 cattle, hogs, horses, goats, and donkeys. Also avian tubercle 

 bacilli have been found in cases of human tuberculosis. 



Himmelberger ^ reports experiments in which it was 

 possible to infect a calf by feeding it the macerated organs of 

 a tuberculous hen. This result is of considerable interest in 

 view of the question of the relation of the avian tubercle 

 bacillus to the causative factor in Johne's disease of cattle. 

 Johne's disease presents many of the symptoms of tuber- 



1 Van Es, L., and Schalk, A. F., "Avian Tuberculosis." North 

 Dakota Agr. Expt. Stat. Bui. 108, pp. 1-94, 1914. 



2 Koch, R., and Rabinowitsch, L., "Die Tuberculose der Vogel 

 und ihre Beziehungen an Saugetiertuberculose." Arbeiten a. d. 

 Kaiserl. Gesundheitsamte, 1904. 



3 Himmelberger, L. R., Centralb. f. Bakt. etc. Abt. 1, Bd. 73, 

 pp. 1-11, 1914. 



