CHARACTERISTICS OF THE COLON-AEROGENES GROUP 99 
they show no liquefiers in feces where they no doubt oveur 
in small numbers. Water aud milk can hardly be considered 
as the habitat of bacteria of this kind. They occur and multi- 
ply there, but these fluids ust be looked upon as carriers 
into which the bacteria have been intrcduced from some other 
source. This statement will probably hold also for erains 
which may be merely carrying soil or fecal organisms 
mechanically. 
Grains 
coz 
“aa 7106, Saccharose,+ 
Soa =106, Saccharose.— 
$92 =15-30 Adonitol. + 
$04 =/5-30 Adonitol— 
Gel. liquel $Pz=00 
Gel. iquef $92=15-30 
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 fatt 
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. coli was 
in great preponderance there also. There was great variation 
in individuals and it is difficult to say what the proportion of 
LB. coli to B. aerogenes 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,?’ in 241 cultures from human 
feces, found none that were V and P+. Ferreira, Horta and 
Parades?* found 8 V and P+ cultures in 117 from human 
feces. Clemesha”® says that aerogenes (V and P-++) cultures 
oceur very rarely in feces. This all confirms our conclusions 
2 Alfred MacConkey, Lactose-fermenting Bacteria in Feces in Jour. 
Hyg., 5 3) pe. 333-379, 1905, 
2A. Ferreira, A. Horta and C. Parades, Recherches sur le B. coli com- 
munis de Vintestin de Vhomme in Archiv. du Real Inst. Bact. Camara 
Pestana, 2, fac. 2, pp. 153-197, 1908. 
22°W. W. Clemesha, The Bacteriology of Surface Waters in the Tropics, 
London, 1912. 
