50 
The Food of Fishes . 
fish” of the country schoolboy and the picnic party. It 
is the constant companion of the ‘ ‘ hull-head” (Amiurus) 
and “shiner” (Notemigonus) in the„ small stagnant 
ponds of the prairie regions, and of the “chub minnow” 
(Semotilus) in muddy creeks. It was found abundant 
with Centrarchus, Aphredoderus and Amiurus catus, in 
the rapidly drying mud-holes,* only a few feet across, left 
by the retreating overflow of the Mississippi bottoms, in 
Union county. 
Food of the Young. 
The smallest of nineteen specimens studied, was one 
inch in length — taken in July, in a prairie pond near Nor- 
mal. Ninety-five per cent, of its food was Cyclops and 
three per cent. Daphnids. The trifling remainder con- 
sisted of a Corixa just hatched, and a Chironomus larvae. 
Nine specimens, ranging from one to two and a fourth 
inches in length, vary so little in food that it is not worth 
while to treat them separately. These were taken from 
various ponds, streams and lakes in central Illinois. 
Their food was distributed quite generally through the 
various orders of insects and crustaceans accessible to 
them, showing the indifferent appetite of this fish and 
the general effectiveness of its collecting apparatus. 
Larvae of Chironomus, Dytiscidae, Staphylinidae, Cor- 
ixas, Epliemerid larvae, Decapoda, Isopoda, Cladocera, 
Cyprids and Copepoda were all found in considerable 
quantities in the food of these specimens. As usual, the 
most important insects were Corixas and May-flies — six- 
teen per cent, of the former and twenty-nine per cent, of 
the latter. About eight per cent, of the food was Cla- 
docera (Daphnia, Simocephalus, Pleuroxus, Chvdorus). 
Food of the Adidt. 
The eight adults, from northern and southern Illinois, 
differed from the young in the disappearance of En- 
the specimens taken from these holes, so muddy that the water 
was almost opaque, were of a peculiarly bleached appearance — many of 
them almost colorless — a fact of interest relative to the laws of coloration 
among: fishes. 
