CHARACTERISTICS OF THE COLON-AEROGENES GROUP 1 
a fundamental difference, especially if it ig not correlated 
with other reactions. So far as data are available, the low 
ratio or B. coli group appears to be a very definite and cir- 
cumseribed entity and there is no apparent reason for 
separating it into specics. Varicties on the basis of saccha- 
rose fermentation might be recognized but the need for these 
is not very evident. 
Gelatin— SPt=106 Vand P- . 
Saccharose + Saccharose — 
100_80 60 40 20 +|- 20 40 60 80 1/00 100 80 60 40 20 +|- 20 40 60 80 /00 
Indol, 
Raffinose. 
Starch 
Inulin, 
Mannitol, 
Glycerol. 
Salicin, 
Dulertol. Sole Aa me, he epee es aren) Pee ep Lio Peeoaboass 
Adomtol. L a glace ete) 
Fig. 3 
Subdivisions of the high ratio group—tThe high ratio or 
aerogenes type shows more evidence of being a heterogeneous 
group capable of subdivision into species than the group just 
considered. Johnson and Levine,?* following the earlier ‘sug- 
gestions of Levine,?* have two species, in one of which all 
cultures are motile and nearly all liquefy gelatin while in 
the other all are immotile and nearly all fail to liquefy gelatin. 
They have also a V and P— group which otherwise resembles 
the aerogenes type and which they consider as intermediate 
between coli and aerogenes. Burton and Rettger™ have three 
groups, one of which is a liquefying spore former, one a non- 
spore forming gelatin liquefier of the cloacae type and one a 
non-liqueficr of the aerogenes type. In our collection from 
grains we found evidences of four high ratio groups including 
one of 40 liquefying cultures and one of 90 non-liquefiers with 
4 Loc. cit. 
3 Loc. cit. 
4 Loe. cit. 
