538 CLINICAL VETERINARY MEDICINE AND SURGERY. 



in perfect health ; when killed at the end of 141 days its condition 

 appeared perfectly normal ; post-mortem examination revealed the 

 existence of five or six scattered tubercles in the liver and lungs ; the 

 spleen was healthy. The virus, instead of increasing in virulence, 

 seemed therefore to have become attenuated by passage through two 

 guinea-pigs. 



To continue the series we inoculated another guinea-pig and a 

 rabbit from the liver of this animal. The guinea-pig died on the logth 

 day, a dozen granulations being found in its liver. The rabbit remained 

 in good health and was killed at the end of 139 days. The cadaver 

 showed numerous granulations remarkable for their localisation ; 

 instead of having invaded the liver and spleen they occupied the lungs, 

 mediastinal lymphatic glands, and kidneys. To test the results of 

 inoculation with this virus, which had behaved in such a peculiar 

 manner, we utilised it to inject a guinea-pig and two fowls. The 

 guinea-pig remained in apparently good health, but on killing it at the 

 end of 169 days we were not a little surprised to find it suffering from 

 generalised tuberculosis ; the lungs, peritoneum, spleen, and liver were 

 filled with granulations ; the liver was the seat of very marked cirrhosis, 

 which rendered its surface bosselated and deeply channelled. The 

 fowls were killed at the end of 169 and 176 days respectively, but the 

 autopsy revealed no appreciable lesion. 



Thus after passing three times through mammals the avian virus 

 behaved very much like that of human tuberculosis ; it produced 

 tubercle in the guinea-pig but failed to affect the fowl. It might, 

 therefore, be suggested that in this second series accidental inoculation 

 with mammalian tuberculosis had occurred, but such a supposition 

 appears to us inadmissible. Along with the first guinea-pig, which 

 showed generalised tuberculosis, a second had been inoculated ; the 

 same syringe had been employed, and the two guinea-pigs had been 

 placed in the same cage ; now one of these behaved as usual, the 

 other died from generalised tuberculosis. Accidental contamination, 

 moreover, seems to us less probable, as at this time the laboratory con- 

 tained animals inoculated only with avian tuberculosis. 



The above experiments show that in some cases intra-peritoneal 

 inoculation with avian tuberculosis may produce in the guinea-pig a 

 generalised crop of tubercles ; such a result is somewhat rare, but is 

 indisputable, and has, moreover, been confirmed by MM. Courmont 

 and Dor, who have also obtained generalised tuberculosis by ino- 

 culating with avian cultures. To enable the reader to more readily 

 follow our experiments, we give the results below in tabular form. 



