INFECTIONS OF THE DIGESTIVE TRACT 17 



of nurslings and of bottle-fed children could not be 

 observed. In the case of a child suffering from a chronic 

 catarrhal condition of the gastro-enteric tract and 

 marasmus, a great diminution in the inhibitory action 

 was observed. It seems possible that this might be inter- 

 preted on the basis of a diminished growth of colon 

 bacilli rather than by the production of inhibitory 

 substances. 



Experiments made with meconium showed that this 

 material held no bactericidal substances. On the 

 contrary, when mixed with agar it became an excellent 

 nutrient medium for bacteria, although by itself it is 

 only a poor medium for most varieties. 



It is interesting to observe that B. bifidus, which forms 

 the chief representative of the nursling's flora, appeared 

 to be unable to make these inhibitory substances. The 

 question arises in the mind of the critic in connection 

 with this experiment, whether in the observations re- 

 ported there was in reality a good growth of B. bifidus, 

 which is an organism not easily cultivated on ordinary 

 media. 



Moro and Murath attribute the inhibitory action of the 

 nursling's fseces entirely to the presence of organisms 

 of the B. coli type. A comparison of typhoid bacillus 

 with the colon bacillus with respect to the ability to 

 inhibit the growth of various microorganisms showed 

 that the typhoid bacillus possesses little or no capacity 

 to effect this inhibition. 



Criticism of Experiments of Conradi and Kurpjuweit. 

 The interpretation to be placed on the phenomenon of 



