586 REPORT OF COMMISSIONER OF FISE AND FISHERIES. [84] 
FOOD OF THE YOUNG FISHES. 
On December 31, a few hundred whitefish eggs taken November 1 
were arranged in a perforated tin box, and placed in the spring pond in 
a temperature ranging from 43° to 45°. These began hatching January 
15, and were all hatched out by January 24. The fry were then divided 
into two lots, one of which was removed to the lower spring near its 
source, where the water ranges from 45° to 47°. The others were set 
free in a tank in the hatchery, the water being quite variable, but 
averaging much colder than the spring. Those in the spring were offered 
no food, but those in the tank were given the privilege of partaking 
of shrimp (Gammarus) pounded to a pulp and diffused into the water 
two or three times daily. Specimens from both lots were, from time to 
time, sent to Prof. S. A. Forbes, Normal, IL., who made a thorough mi- 
croscopical examination of their stomach contents, and reported the 
results of his investigations as follows: 
NORMAL, ILu., March 29, 1881. 
F. N. CLARK, Esq., 
Northville, Mich.: 
DEAR Sir: Having now finished work on the young whitefish sent 
me since February 1, I wish to make a connected statement of my ob- 
servations and conclusions, to take the place of the rather confused 
memoranda I have sent you heretofore. 
Ihave been carefully over the slides a second time, and think that 
there is little, if anything, more to be learned from them. 
1. FRY FROM THE SPRING. 
a. Received February 9. 
One hundred specimens were examined from this lot. Only one had 
lately taken food, and this had eaten some filamentous alga and a 
minute fragment of the parmchyma of some higher plant, with a few 
scattered diatoms. 
b. Received February 17. 
There were also one hundred in this lot of the fry. All were passed 
under the microscope, and food was found in but one. This consisted 
of a few particles of vegetable parmchyma, doubtless derived from the 
decaying plant structures in or about the water. 
c. Received February 25. 
In this lot there were but forty-two specimens. Six of these showed 
traces of food in the intestines, consisting almost entirely of filamentous 
alg and a little vegetable parmchyma. Desmids and diatoms were 
observed in trivial number, associated with oscillatoria, &c., in a single 
specimen. Total from the spring, 242; containing vegetable food, 8; 
containing animal food, none, 
