INFECTIONS OF THE DIGESTIVE TRACT 83 



organisms which were regarded as special forms of B. 

 coli. In the case of the goat the fields contained some 

 Gram-positive bacteria, and of the Gram-negative ones 

 a considerable number were of greater length than the 

 dominant small forms which were regarded as belonging 

 in the class of colon bacilli. In the case of the buffalo, 

 mixed fields were found as regards the Gram-staining 

 and many of the positive organisms were found to be 

 small diplococci and small bacilli. In none of these 

 animals were seen any organisms suggesting B. aerogenes 

 capsulatus, excepting in the case of the buffalo, where 

 the number of bacilli of this type was very small. Spore- 

 holding organisms were not observed, but moderate 

 numbers of free spores were noticed in all the fields except 

 those from the elephant. In the fields showing the 

 largest number of spores their occurrence was far less 

 frequent than in the lion, tiger, wolf, or cat. 



The mixed flora of these different herbivorous animals, 

 grown upon peptone bouillon, failed to show the produc- 

 tion of methyl mercaptan excepting in the case of the 

 horse, where a moderate reaction was obtained. 



Observations were also made upon the effect of sus- 

 pensions of the mixed flora from herbivorous animals 

 when injected subcutaneously. The quantities of 

 suspension employed were usually about twice as great 

 as in the case of the suspensions from the carnivorous 

 animals. With the exception of the suspensions obtained 

 from the horse, the pathogenicity of these suspensions 

 was found to be slight, the guinea-pigs frequently 

 living two or three days or entirely recovering. In the 



