The First Food of the Common White-Fish. 
101 
fragments of Gammarus and nothing else. Ninety specimens 
from the same lot were examined February 25, and food was 
found in fourteen. Four of these had eaten Gammarus frag- 
ments; two, larvae of gnats; one, a small Cypris, and eight con- 
tained small fragments of the leaves and stems of vascular plants, 
including a bit of a netted-veined leaf and a little piece of pine 
wood. Thirty-nine specimens, the last of the lot, .were received 
March 15, and food was found in fourteen. I dissected nine of 
these, finding fragments of Gammarus in four, a larva of a gnat, 
a Chironomus larva, a larva of some undetermined fly, a minute 
vegetable fragment, a Cyclops, a Cypris, and an undetermined 
Entomostracan each in one. Three hundred and forty fry from 
the hatching house were examined in all, in forty-seven of which 
(fourteen per cent.) more or less food was discernible. Of the 
thirty-five dissected, eighteen had eaten Gammarus fragments; 
five, minute insect larvae; four, Entomostraca, and eight, small 
particles of vegetation. 
Only four lots were received from the spring, on the 9th, 14th, 
17th, and 25th of February, after which all died of starvation. In 
the first hundred only one was found which had taken food, and 
this had eaten a trace of filamentous Algae and a minute fragment 
of the parenchyma of* some higher plant, with a few diatoms. 
But one of the second hundred contained even a trace of food, a 
minute quantity of some thread-like Alga, the cells of which still 
contained a little chlorophyll. In the third hundred likewise, food 
was found in but one. This consisted of a few particles of veget- 
able parenchyma, doubtless derived from the decaying plant struc- 
ture in or around the water. In the third lot of only forty-two 
specimens, six showed traces of food, consisting almost entirely of 
a few filamentous Algae (including a fragment of Oscillatoria) and 
a little vegetable parenchyma. Desmids and diatoms were ob- 
served in trivial numbers. 
The total number received from the spring was two hundred 
and forty-two, of which but eight were found to have eaten any- 
thing (a little over three per cent, of the whole), and these had 
taken only Algae and vegetable fragments. 
An example of the water of the spring sent me contained many 
Algae but no animals larger than rotifers. The water of the 
hatchery, being exposed in ponds of considerable size, afforded a 
