_ [85] PROPAGATION OF WHITEFISH AT NORTHVILLE, MICH. 587 
2. FRY FROM THE HATCHERY. 
a. Received February 9. 
Ninety fishes were examined—all but four without result. In three, 
mere traces of dirt were seen in the intestine, and these were not dis- 
sected. In the fourth was a fragment of Gammarus. 
b. Received February 17. 
One hundred and eleven fry, of which seventeen had taken food. I 
dissected nine of these, and found fragments of Gammarus and nothing 
else. 
c. Received February 25. 
\ 
Ninety specimens examined. Food was found in fourteen. Four of 
these had eaten fragments of Gammarus ; seven, small particles of the 
leaves and stems of vascular plants; two, larvae of gnats; and one, 
a small Hntomostracan (Cypris) entire. 
d. Received March 15. 
There were thirty-nine specimens in this lot, and food was visible in 
fourteen. I dissected nine of these, finding fragments of Gammarus in 
four, larve of gnats in three, and a minute vegetable fragment, a 
Cyclops, a Cypris, and some undetermined Kntomostracan each in one. 
Thus there were 340 fry in all examined from the hatching house, in 
47 of which (14 per cent.) more or less food was discernible. Of the 35 
dissected, 15 had eaten fragments of Gammarus; five, minute insect 
larvee; four, Hntomostraca ; and eight, small particles of vegetation. 
Taking these facts in connection with the appearance of teeth on the 
lower jaw at the time the egg-bag is entirely absorbed, I am very well 
satisfied that the earliest food of this fish consists of Hntomostraca, 
with probably some admixture of filamentousalgaw. As the gill-rakers 
are not developed at this early age, I don’t think that any smaller ob- 
jects could be separated from the water, except by accident. 
The Gammarus “hash” evidently makes a very good substitute for 
the Entomostraca. It is, however, less nourishing, as much of the soft 
tissues of the Gammari must be lost in pulverizing the crust—a fact in- 
dicated also by the greater quantity of oil found in the intestines of 
those fishes which have taken Hntomostraea entire. 
Very truly, yours, S. A. FORBES 
The following, from a previous letter from Professor Forbes, is very 
valuable and interesting in this connection: 
‘“ An observation made to-day practically settles to my mind the ear- 
liest food of the whitefish. As you are of course aware, the adult fish 
_ is quite toothless. The young are likewise without teeth until the egg- 
