46 INFECTIONS OF THE DIGESTIVE TRACT 



of inducing decomposition with the production of 

 butyric acid. Of these the granulo-baciUus immobilis 

 liquefaciens is probably identical with B. aerogenes 

 capsulatus (but not pathogenic), and was described by 

 Passini in 1902 as occurring in the faeces of normal nurs- 

 lings. This is undoubtedly true, but I wish to empha- 

 size the fact that the organism normally occurs under 

 these conditions in only very small numbers as com- 

 pared with bacteria of the bifidus type. One may look 

 through many Gram-stained fa3cal fields without find- 

 ing any evidence of its presence. The physiological 

 significance of this fact will later be pointed out. The 

 other organism which appears to have been included 

 in Botkin's description of his B. butyricus, is one closely 

 related to B. aerogenes capsulatus in morphology. It is, 

 however, motile, does not liquefy gelatin, and readily 

 forms spores features which distinguish it sufficiently 

 for the present enumeration * of the anaerobic flora. 

 This organism has been found in the faeces of nurslings, 

 but is of much less importance than B. aerogenes capsu- 

 latus. Occasionally, too, the nursling's fa3ces have been 

 found to contain the bacillus of malignant oedema 

 (Passini) and a very closely related microorganism which 

 differs from the bacillus of malignant cedema in being 

 Gram-positive and in making skatol. 



One may summarize the results of cultural studies of 

 the bacterial flora of normal human nurslings as follows. 

 The stools and the contents of the large intestine from 



1 It is known as the granulo-bacillus mobilis nons-liquefadens 

 of Grassberger and Schottenfroh. 



