206 NEW YORK STATE MUSEUM 



In this table the food species have been arranged in what 

 seemed to be the order of their importance as constituents of the 

 food of the trout at the time and place taken. The totals, 

 counting larvae and pupae of a species together, are 2906 

 Chironomus, 156 Corethra, 14 trichopter larvae, 2 nymphs of 

 Aeschna constricta, 7 nymphs of Callibaetis, 8 A t a x 

 crassipes, 250 (approximately) Daphnidae, and a. few wholly 

 unimportant things listed as miscellanies. The numerical ra»tio 

 of these is 116.24 Chironomts, 6.24 Corethra, 10 Daphnidae, .56 

 trichopter larvae, .32 Atax, .28 Callibaetis, .08 Aeschna to each 

 of the 25 trout. What may be the relative food value of these 

 species is, of course, wholly undetermined. In arranging them 

 in the foregoing table, I have taken into account only their 

 relative size. I should be inclined to regard only the three 

 first named in the table as of any considerable importance to 

 the trout. 



To my mind the chief value of this table is that it clearly 

 indicates one species of economic importance to trout culture — 

 the Chironomid of whose larvae and pupae an average of 116 

 specimens had been eaten by each trout. The largest number 

 eaten by a single trout was 351, while three trout had eaten 

 none at all. It is possibly significant, possibly only accidental, 

 that the May fly nymphs were eaten chiefly by those trout that 

 bad found no Chironomids. 



NOTES ON THE FOOD SPECIES OF THE TABLE 



1 Chironomus sp.? 



There can be no doubt that in Bone pond this is an exceed- 

 ingly important species. Unfortunately, the day this fact be- 

 came apparent, in the cursory examination of the food as taken 

 from the stomachs, was the last day of study permitted us at 

 the pond. What the species is, consequently remains unknown. 

 Mr Johannsen has studied the larva and pupa systematically, 

 and has treated them in part 3. His figures [pi. 49] should 

 make the recognition of the species possible when other larvae 

 shall have been obtained and bred. 



