The First Food of the Common White -Fish. 
107 
ine the subsequent lots in detail, but passed at once to the speci- 
mens taken on the 23d. Twenty-six of these were examined, and 
found to have eaten thirty-three individuals of Cyclops thomasi , 
fourteen of Diaptomus sicilis, and fourteen of the minute rotifer 
already mentioned ( Anurcea striata). Two had taken a few diat- 
oms ( Bacillar ia ) and one had eaten a filament of an Alga. Cy- 
clops was found in sixteen of the specimens, Diaptomus in nine, 
and Anurasa in eight, only two of them being empty. The 
amount of food now taken by individual fishes was much greater 
than before, one specimen dissected having eaten two Cyclops and 
six Diaptomus sicilis , male and female. Another had taken five 
Cyclops, one Diaptomus and five examples of Anurcea striata. 
Still another had eaten four of the Cyclops, four Diaptomus, and 
one Anuraea. 
Twenty-five specimens were examined from those removed on 
the 24th of the month, at which time the water of the tank was 
drawn off and all the remaining fishes bottled. Four of these had 
not eaten, but the twenty-one others had devoured fifty specimens 
of Diaptomus sicilis , forty-seven of Cyclops thomasi , fourteen of 
Anurcea striata , and a single Daphnici hyalina , the latter being 
the largest object eaten by any of the fishes. A few examples of 
their capacity may well be given. The ninth example had eaten 
six Diaptomus, two Cyclops thomasi and one Anurgea; the tenth 
had taken eight Diaptomus, two Cyclops and an Anurasa; and 
the twentieth, seven Diaptomus and three Cyclops thomasi. 
In two of these examples were small clusters of orange globules, 
probably representing unicellular Algae. 
Summarizing these data briefly, we find that of the 106 speci- 
mens dissected, sixty-three had taken food, and that the ratio of 
those which were eating increased rapidly, the longer the fishes 
were kept in the aquarium. Only one-fourth of those examined 
on the fourteenth of the month had taken food, while more than 
five-sixths of those bottled ten days later had already eaten. The 
entire number of objects appropriated by these sixty-three fishes 
was as follows: Cyclops thomasi , ninety-seven; Diaptomus sici- 
• Us , seventy-eight; Anurcea striata, , twenty-nine; Daphnia hyal- 
ina , one. Seven of the fishes had eaten unicellular Algae, two 
had eaten diatoms, and one, filamentous Algae. 
