INFECTIONS OF THE DIGESTIVE TRACT 53 



the diminution of food and the lack of moisture prob- 

 ably are among the most effective. 



A satisfactory study of the products of the mixed fsecal 

 flora from normal nurslings has not yet been made. One 

 fact nevertheless stands out, namely, that on sugar 

 bouillon containing blood the volatile acid or acids pro- 

 duced give a molecular weight corresponding closely to 

 that for acetic acid. The presence of only insignificant 

 amounts of higher volatile fatty acids points to the 

 absence of considerable numbers of anaerobic putrefac- 

 tive bacteria, since these form the higher acids, pro- 

 vided anaerobic conditions be secured. 



In harmony with this is our observation that ten or 

 twenty cubic centimeters of a ten per cent, suspension 

 of fsecal bacteria from a normal nursling may be in- 

 jected into a rabbit, which is then incubated, without 

 inducing a gas-liver from putrefactive anaerobes (B. 

 aerogenes capsulatus). 



The mixed fsecal flora when grown on plain bouillon 

 makes indol, doubtless owing to the multiplication of 

 colon bacilli. 



The Infection of the Nursling's Digestive Tract and the 

 Relation of the Microorganisms to the Permanent Bac- 

 terial Flora. One naturally asks the question : What is 

 the origin of the normal intestinal flora of the nursling 

 child? How does it happen that the meconium, which 

 is a sterile medium derived from the intestinal juices 

 and epithelial cells, becomes the seat of bacterial life? 

 As the mother's milk is normally free from bacteria 

 when it issues from the breast, one cannot attribute the 



