The Food of Fishes. 85 



Twelve of this species were examined, two of which 

 were under three inches in length, and the others adult. 



t ood f the Yo ung . 



A specimen two inches long, taken in the Illinois R,., at 

 Pekin, June 2, 1880, had eaten only a minute fish. One, 

 two and a half inches long, taken at the same place in 

 June, 1878, had also eaten a small fish and a few Entomos- 

 traca (Cyprididfi? aud Daphniida?). The appearance of 

 these Entomostraca in the food of a fish of this size, makes 

 it altogether probable that Stizostethium, like Perca, 

 wholly depends on these minute Crustacea, when very 

 young. 



Fo od of the Adult. 



The remaining specimens, taken from three localities, 

 had eaten nothing but fishes, one-half of them only the 

 hickory-shad or skip-jack (Dorysoma cepedianuni) . In one 

 other specimen, this species was associated with a minnow 

 (Cyprinidae), and in still another with a small sunfish with 

 three anal spines (Centrarchidae). One of the remaining 

 stomachs contained only an unrecognizable fish, and the 

 the other two contained Cyprinidae, including the creek 

 chub, Semotilus corporalis. 



The two species of this genus agree so closely in food 

 that they may well be discussed together. Apart from 

 their exclusively j)iscivorous habit, the most interesting 

 fact shown is the importance of the hickory-shad as food 

 for this fish. We shall find accumulating evidence that 

 this shad, utterly useless for human food, is, notwithstand- 

 ing, one of the most valuable fishes in our streams. Nev- 

 ertheless, not the slightest attention is paid to its preser- 

 vation, much less to its encouragement. The fishermen 

 commonly regard these fishes as a mere nuisance, and leave 

 them to die on the bank by hundreds, rather than take the 

 trouble to return them to the water. They are a very del- 

 icate species, and are easily killed by rough handling in 

 the seine, but the majority of those captured might be 

 saved with a little care. 



The abundance of these fishes as compared with some 



