568 



CLINICAL VETERINARY MEDICINE AND SURGERY. 



though exceptional in GalHnacese, is fairly frequent in parrots ; this 

 constitutes a further analogy with human tuberculosis. Sometimes, 

 however, infection occurs through the skin ; sometimes through the 

 digestive tract. But while the Gallinaceas are almost always infected 

 by means of the food, and frequently show tuberculous enteritis, 

 parrots, although they sometimes swallow food soiled with bacilli, are 

 most commonly inoculated by contact with tuberculous persons, or by 

 rubbing the head against' the bars of their cage. This explains the 

 frequency in them of lesions about the head, beak, tongue, palate, or 

 pharynx. 



Although the cases we have recorded appear to suggest that tuber- 



FiG. 8i. 



culosis in the parrot is of human origin, the question could only be 

 finally decided by experiment, and by directly transmitting mammalian 

 tuberculosis to birds. We made three attempts of this character. 

 The results were so clear and concordant that it appeared unnecessary 

 to multiply experiments. 



Experiment i. On the 20th June, 1894, ^ green parrot was inocu- 

 lated on the head with tuberculous material obtained from a guinea- 

 pig, which had died from tuberculosis of canine origin. 



On the 5th July two small nodules appeared, and became covered 

 with thick blackish crusts. On the 15th August the crusts fell, leaving 

 exposed a roughened, irritable, verrucous surface. Most of the nodules 



