Fs 
the more remarkable that the prevailing bacteria present in 
water and faces should be identical, and it suggests that a 
reverse action is taking place, namely, that the organisms 
prevalent in the water-supplies are influencing the bacterio- 
logical contents of the intestines. At one time in the course 
of our investigations we were somewhat inclined to this view. 
The experiment given by MacConkey (Journal of Hygiene, 
1905), where he inoculated the food of a cat with an outside 
organism, and recovered it in the feces 24 hours afterwards, 
seemed to support this theory. In order to test the truth of 
this surmise, certain experiments were made in the King 
Institute, to see if it were possible to demonstrate any rela- 
tion between the organisms present in an artificially con- 
taminated drinking-water supply, and the faces of animals 
drinking such water. Altogether about eight calves were 
selected. They were given King Institute well water morning 
and evening ; but to each bucket a large number of one of the 
following organisms were added—oxytocus perniciosus, organ- 
ism No. 97, cloace, lactis erogenes and coli communis. At 
periods varying from one day to a week (the feeding experi- 
ments being kept on all this time), the faces were examined ; 
in no case were we ever able to recover in the feces of the 
calves the organism that was present in the drinking-water. 
Great care was taken not to alter the daily routine of the © 
animal’s life; no drinking-supply, other than the artificially con- 
taminated water, was allowed. Very large quantities of the 
organisms were given. It is true the bacilli used were derived 
from laboratory cultures, but this would not be likely to 
vitiate the results. The negative results obtained in these 
experiments would appear to show that the organisms taken 
in drinking-water produce no alteration in the intestinal 
flora. 
There is also a further point which may be mentioned. 
Throughout the months of October, November and December, 
lactis erogenes was an extraordinarily common organism in 
all the water-supplies. Yet there was no correspondingly 
increased prevalence of this organism in the samples of feces | 
examined at that time of year. Similarly in March and April 
Ig10, a glucose fermenting organism was by far the commonest 
