CHAP PEAY EDT. ikea aka 
BACTERIOLOGY OF FACES (continued). 
STUDY OF A GROUP OF BACILLI THAT FERMENT GLUCOSE BUT 
NOT LACTOSE. 
IN our researches into the bacteriology of water it 
has been discovered, as will be shewn later, that a class of 
organisms which ferment glucose but do not ferment lactose 
is not only exceedingly common in water, under certain cli- 
matic conditions, but the significance of these bacteria is of 
great importance to the water analyst ; hence it has become 
necessary to study them in fresh feces. In order to do this 
a careful research was carried out on exactly the same lines 
as that already described in Chapter II. The experiments 
will be divided into the following series :— 
Series I.—8 samples of cowdung were taken and an 
emulsion of each was made. A small quantity of each was 
placed in the centre of a bile salt neutral red glucose agar plate. 
From 7 plates 20 colonies were picked off and from 1 plate 
12 colonies (making a total of 152 in all) ; these were inocu- 
lated into the usual glucose and lactose fermentation tubes. 
Out of these 152 colonies 150 fermented lactose and glucose ; 
2 fermented glucose only, none fermented neither lactose nor 
glucose ; in other words 98°6% of all the colonies fermented 
both lactose and glucose and 1°4°% fermented glucose but 
not lactose. 
Series II.—A precisely similar experiment was carried 
out with 14 samples of human feces, 272 colonies from 
these samples being tested with glucose and lactose tubes. 
Out of these 272 colonies, 255 or 93°7°% fermented both lactose 
and glucose ; 17 or 6°3°% fermented glucose but not lactose. 
Only 5 out of the 14 samples contained any of this latter 
class. 
Series III.—A small portion of 12 separate samples of 
human feces were inoculated into separate tubes of bile salt 
