440 MICRO-ORGANISMS AND DISEASE [chap. 



cholera bacteria could be demonstrated in the small in- 

 testine. The experiment had thus in so far succeeded that 

 the cholera bacilli had passed uninjured through the 

 stomach, but they had not set up any disease in the 

 animals." Similar experiments were then made on eight 

 other guinea-pigs. These animals also remained quite 

 healthy. Finally four guinea-pigs were similarly experi- 

 mented upon (5 cc. of solution of sodium carbonate, the 

 10 cc. of cultivation of the comma bacilli in meat infusion) ; 

 three remained well, the fourth appeared ill next day, looked 

 shaggy and did not eat ; on the following day it was very 

 ill ; paralytic weakness of the posterior extremities came 

 on, the respiration was weak and slow, the head and ex- 

 tremities were cold, and the animal died in this condition. 

 On post-mor/em examination the small intestine was markedly 

 reddened and full of a flaky, watery, colourless fluid. The 

 stomach and caecum contained a large quantity of fluid. 

 " The examination with the microscope and with gelatine 

 plates,'' says Koch, "showed that the contents of the small 

 intestine contained a pure cultivation of the choleraic 

 comma bacilli." " That this one animal only should have 

 died, out of a series of nineteen, uniformly experimented 

 upon, suggested some peculiar condition that had obtained 

 in this one animal, and as a matter of fact on examination 

 it was ascertained that this animal had aborted immediately 

 before the injection, and on post-mortem examination it was 

 found that the abdominal walls were very flaccid and the 

 uterus still greatly enlarged. This led me to the idea that 

 either the abortion per se, or perhaps its unknown cause, 

 had acted on the other abdominal organs, more especially 

 on the small intestine, in such a way as to produce a 

 temporary relaxation with arrest of peristaltic movement ; 

 and thus had rendered it possible for the comma bacilli to 



