-~ 
organism in Calcutta drinking water, yet there was no increase 
in the number of the species in feces. Consequently, one 
is forced to the conclusion that the presence contempora- 
neously of bacillus cloace in both feces and water-supplies 
is not yet satisfactorily explained. It will be noticed that 
we are still without any trace of explanation of the conditions 
which bring about these changes in the bacteriological contents 
of the intestinal canal of man and animals, and after four years’ 
work we are not prepared to make any suggestions. That 
such influences exist, and'that they are active over a very 
wide area, is certain. 
In the light of these remarks nothing more need be said 
on the utility of attempting to establish an approximate 
percentage composition of the intestinal bacilli in the dejecta 
of different animals. Even the percentages in the four large 
groups, described by MacConkey, are of so little value that 
only the vaguest generalizations are possible. 
We have never found any fecal organism special to the 
intestinal tract of either man, cows or goats. It is true that 
a very few rare organisms found in cowdung have not yet 
been isolated from human feces, but it is probably only a 
question of time until they are found to be present there also. 
On the other hand, we have not isolated a single organism 
from human feces, that has not been found in cowdung at 
one time or another. For some time we thought organism 
No. 33 was confined to the intestinal tract of man, but it was 
eventually obtained from cowdung. Not only is it true that 
““at present there is no means of differentiating the lactose 
fermenting organisms of human from those of animal origin ’’ 
(MacConkey 1905) ; but there is probably not a single lactose 
fermenting organism that is peculiar to any given animal. 
More work is required on this very interesting subject 
of bacteria in feces ; at present we can only be said to have 
pointed out a few leading lines, and to have discovered certain 
problems, of the explanation of which we are at this stage 
entirely ignorant. We consider the following wide conclu- 
sions are justifiable :— 
(1) That the flora of the intestinal tracts of men and 
animals are subject to very considerable changes, due to influ- 
