CHARACTERISTICS OF THE COLON-AEROOENES GROUP 



99 



they show no liquetiers in feces where they no doubt occur 

 in small numbers. Water and milk can hardly be considered 

 as the habitat of bacteria of this kind. They occur and multi- 

 ply there, but these fluids must be looked upon as carriers 

 into which the bacteria have been introduced from some other 

 source. This statement will probably hold also for grains 

 which may be merely carrying soil or fecal organisms 

 mechanically. 



~~ = 



, Saccharose.* 

 /.0, Saccharose.- 

 1.5-30 Adonitol. + 



GfJ. liquff. SrftOO 

 Gel. liquef. ^f" 1.5-3.0 



Fig. 7 



The most striking feature brought out by Fig. 7 is the 

 very great preponderance of the low ratio groups in feces, 

 and especially in bovine feces from which, in spite of the fact 

 that a special effort was made to isolate high ratio cultures, 

 only a single one was obtained in 150 cultures isolated. They 

 were more frequent in the human feces, although B. coll was 

 in great preponderance there also. There was great variation 

 in individuals and it is difficult to say what the proportion of 

 7>. coll to B. aeroyenes would be, but it would probably vary 

 from 10 to 1 to 100 to 1. 



This seems to agree with the earlier work which touches 

 on this point. MacConkey,'- 7 in 241 cultures from human 

 feces, found none that were V and P+. Ferreira, Horta and 

 Parades 28 found 8 V and P-f- cultures in 117 from human 

 feces. Clemesha-'' says that aerogenes (V and P+) cultures 

 occur very rarely in feces. This all confirms our conclusions 



27 Alfred MacConkey, Lactose-fermenting Bacteria in Feces in Jour. 

 Hyg., 5, 3, pp. 333-379, 1905. 



A. Fei-reira, A. Horta and C. Parades, Recherches sur le B. coli com- 

 munis de I'intestin de I'homme in Archiv. du Real Inst. Bact. Camara 

 Pestona, 2, fac. 2, pp. 153-197, 1908. 



2U W. W. Clemesha, The Bacteriology of Surface Waters in the Tropics, 

 J.oiulon, 1912. 



