44 



THE REPORT OF THE 



No. 19 



natural history of the smaller forms of life upon which they feed. In this 

 connection a knowledge of the life histories of the aquatic insects is of con- 

 siderable importance, forming as they do a large part of the food of some 

 of the fish. The food of the brook-trout for example as Prof. Needham 

 has shown (Aquatic Insects in New York State, Bulletin 68, N.Y. State 

 Museum) consists almost entirely of certain aquatic insect larvae, particu- 

 larly those of a certain Chironomid fly, while other small dipterous larvse, 

 caddis worms, etc., contribute a considerable proportion. 



At Go Home Bay we frequently found the stomachs of the common 

 sucker filled almost exclusively with the full-grown nymphs of the large 

 May-fly {Hexagenia hilineata) which breeds in enormous numbers in the 

 bays and channels in that locality, and many other instances could be given 

 of insects forming an important part of the food of fish. 



A considerable portion of the two months which I spent at the Station 

 was accordingly devoted to this branch of the work, most attention having 

 been given to the Dragon-flies, as the group with which I was moat 

 familiar and one which was very abundantly represented there. 



Fig. 4. Dragon-fly. 



Fig. 5. Nymph. 



Fig. 7. Damsel- fly. 



Fig. 0. Larva seizing its prey and the Dragon-fly emerg- 

 ing from the Nymph. 



Fig. 8. Nannothemis 

 bella. 



