25 
The importance of this fact will be seen later on when we 
come to deal with the presence of these organisms in water. 
This concludes what we have to say on this particular 
group of organisms. The points which we wish to lay particular 
stress on, and which will be of considerable importance later 
on are :— 
(1) That, from investigations carried out at different 
times during four years, we find that the particular group of 
organism whose fermentative reactions are glucose + lactose —, 
are rare in the feces of human beings and animals as a 
whole, 5 per cent. or under representing their numerical 
value in a mixture. The common fecal organism ferments 
both lactose and glucose. 
(2) As far as can be ascertained at present ‘“ epidemics ’”’ 
of these organisms have not been met with, during the three 
or four years that the study of feces has been going on. 
(3) Separating the organisms out with sugar reactions 
does not show that any member of the group is particularly 
common ; it is to be observed that organism P. is rare rather 
than otherwise. 
