INFECTIONS OF THE DIGESTIVE TRACT 15 



similar to those of Conradi and Kurpjuweit. 1 In the 

 series of observations made by them the growth of the 

 following organisms was observed on the specially pre- 

 pared plates : B. coli communis, B. lactis aerogenes, 

 B. typhi, B. Shiga-Kruse, B. Flexneri, Staphylococcus 

 pyogenes aureus, Diplococcus intestinalis, Soor, B. 

 prodigiosus, and B. pyocyaneus. The results were by 

 no means uniform, but showed that the normal nursling's 

 stool exerts an intense inhibitory action against various 

 bacteria. For example, B. typhi and B. Kruse failed to 

 grow even in dilutions of 1 : 400. On the other hand, the 

 representatives of the obligate bacteria of the intestine, 



1 One volume of the fresh faeces is diluted with nine volumes 

 of bouillon. In order to measure the fasces one may use a glass 

 capsule of 1 c.c. capacity, which is then emptied by means of a 

 glass rod of suitable size, into the bouillon. Various quantities 

 of the yellowish emulsion are now permitted to flow into test 

 tubes containing agar cooled to 42 C., so that the fluids so obtained 

 represent dilutions of T V, s, -fa, T<T von, an d T&T of the original 

 fsBcal material. After thorough mixing, the agar is plated in 

 Petri dishes. The surface of these plates is then promptly inocu- 

 lated with approximately the same numbers of different kinds 

 of bacteria. 



The material to be inoculated is prepared by inoculating one 

 normal platinum loop of a twenty-four-hour agar culture into 

 10 c.c. of bouillon, and emulsifying it. From this emulsion of 

 bacteria a smaller loopful is smeared upon the surface of the agar 

 plates. It is convenient to divide up the agar into half a dozen 

 regions by means of a platinum needle. The surface of each one 

 of these islands may be smeared with a different culture of bac- 

 teria so that the growth of several different types of organisms 

 may be observed on one plate. The bacteria inoculated on one 

 of these islands does not extend to others. The growth is observed 

 at the end of twenty to twenty-four hours, and controls are made 

 with material of the same origin, diluted to one- tenth, boiled, and 

 then incubated for twenty-four hours. 



