IOWA ACADEMY OF SCIENCE 
135 
Stream 
Date of col- 
lection oi 
water 
Number of 
bacteria 
per c. c. 
Bacillus 
fluores. 
cens 
02 
03 
0 
Remarks 
Yellowstone, Livingston, Mont 
Aug. 17 
500 
0 
Slightly turbid 
350 
0 
Average 
425 
Yellowstone river, Billings, Mont 
July 14 
4200 
0 
Water cloudy 
2800 
0 
2400 
0 
2000 
0 
60 
0 
250 
0 
Average 
1951 
Glendive, Yellowstone River 
14000 
0 
Water muddy 
40 
0 
3200 
0 
1050 
0 
Average 
4572 
The above table shows the number of organisms found in the 
different streams. I may say that in connection with the test for 
colon bacillus, the writer used from one to ten cubic centimeters of 
water. It may be said in this connection, however, that the quantity 
of water used was perhaps too small. It may be added further in 
this connection, with reference to the Cedar River water, that a 
large amount of debris, such as logs, shingles and lumber, in the 
water will somewhat help to remove the organisms that are found 
in the stream. 
The cases cited above indicate that railroads paralleling streams 
do not . contaminate the same from the dejecta or the passage of 
tramps up and down the right of way of the railroad. The presence 
or absence of B. coli-communis is given, because this organism indi- 
cates fecal contamination. 
There was no doubt in my mind through the entire region of the 
Cedar River to be traversed by the railroad, that there will not be 
any danger from sewage pollution, or contamination, provided 
proper precautions will be observed. The opinions expressed by dif- 
ferent investigators concerning this problem, are best stated in their 
own words. 
Professors Abbott, Sedgwick, and Harrington state: 
“It appears that along much of the proposed location, gravel 
and sand are not to be found. The forest floor appears to be 
