IOWA ACADEMY OF SCIENCES. 
275 
number of species that it would be a mere accident to dis- 
cover the organism. As said heretofore it seems to me to 
be reasonable that the milk formed a favorable medium 
for the growth of the organism, and be it specially remem- 
bered that Mr. Briley, from his own testimony, failed to 
wash the cans with boiling water as should have been done. 
The milk cans could easily have been contaminated, and 
the failure on his part to wash the cans, it seems to me, 
made it not only possible but probable that these germs 
propagated in the milk. 
A comparison of the water of the Briley well and the 
college effluent shows that the Briley well had a greater 
amount of contamination than the college effluent from the 
sewage filter beds. 
DRIFT EXPOSURE IN TAMA COUNTY. 
BY T. E. SAVAGE. 
A few months ago, in making some improvements in 
the roadbed of the Chicago & Northwestern Railroad, a 
deep cut was made in a hill about three miles west of the 
city of Toledo, in Tama county, Iowa, where the following 
section was exposed: 
5. Fine grained, yellowish colored loess clay without gravel or 
bowlders 4 £ 
4. Bed of sand in alternating bauds of finer and coarser grained 
material 8 
3. Bed of clay, containing numerous pebbles and bowlders 24 
2. Band of brown colored, somewhat sandy soil, containing 
impressions of vegetable remains and a few bits of wood, 
1. Bed of bluish colored clay, with numerous pebbles and 
bowlders down to the base of the exposure 16 
In the section given above, Number 5 is the common 
fine grained loess that forms the surface soil over most of 
the neighboring region. It contains no pebbles nor bowl- 
ders, nor any calcareous matter, as shown by the want of 
action when treated with hydrochloric acid. It is of a 
yellowish color in the upper part, becoming tinged with 
brown in the central and lower portions. 
