292 PUBLIC HEALTH BACTERIOLOGY 



glands, muscles, and bones. After the feeding method, 

 there are similar lesions, with, in addition, characteristic 

 tuberculous lesions in the mucous membrane of the 

 intestines. 



Parrots show similar results, but by feeding method 

 do not so regularly show intestinal lesions. Parrots are 

 susceptible to both the bovine and human tubercle bacilli, 

 by inoculation and feeding ; the effects are similar to those 

 produced by the avian type, except that the bovine type 

 is apparently the most virulent for parrots. 



The rabbit and the mouse are the only two mammals 

 in which the avian tubercle bacillus causes progressive 

 tuberculosis. 



Rabbits : moderately large doses, by inoculation, 

 produce a fatal issue ; the bacillus is less virulent than 

 bovine tubercle bacillus, but more virulent than human 

 tubercle bacillus. The distribution of the lesions differs 

 most markedly from that set up by the bovine and human 

 types. Intravenously, I to 10 mgr. lead to speedy death, 

 with great multiplication of the bacilli in the organs, which 

 show general pallor ; slight oedema of the lungs, slight 

 enlargement (with tubercles) of the spleen. If the animal 

 lives four to five weeks, the spleen is greatly enlarged owing 

 to formation of tubercles, and tubercles are found in the 

 liver ^nd to a less extent in the lungs. In o-ooi mgr. dose, 

 the disease is very chronic, and resembles that produced 

 by subcutaneous injection, the joints being affected. Sub- 

 cutaneous injection of doses of 50 mgr. down to a fraction 

 of i mgr. causes very chronic disease, and the lesions have 

 the same distribution, irrespective of size of dose : local 

 lesion and nearest lymphatic glands ; liver and spleen 

 rarely affected ; kidneys vary ; but most commonly and 

 characteristically there is a tuberculosis of the joints of 

 the limbs, which runs a chronic course. Joint tuberculosis 

 occasionally follows intravenous injection of human 

 tubercle bacillus, but has not been observed after sub- 

 cutaneous injection of the rabbit with the human virus. 

 It has however been noted after subcutaneous injection 

 of the bovine type, when the animal survives for a long 

 period, i.e., the disease is chronic. By feeding, similar 

 lesions are produced, with local intestinal ones. 



