AQUATIC INSECTS CADDIS WORM. 



293 



under water. PI ere arises a great difficulty ; the 

 wings of the insects thus placed, if wet with water, 

 would be unfitted for flight, and would probably 

 frequently lead to the death of the insect by 

 drowning. Yet it is to leave its sub-aqueous 

 abode, mount up through the waves overhead, and 

 finally emerge without a drop of water clinging to 

 its body, and from the glassy surface of the water 

 it is to take its flight into the air. Some will be 

 tempted to exclaim, "This is a clear impossi- 

 bility!" Far from it. The little worm so well 

 known to anglers as the " caddis-worm," performs 

 this feat with the greatest ease, and in the follow- 

 ing manner : 



It has been mentioned that the larva known 

 under this name constructs for itself a case of 



The Pupa-case, Larva and Fly of Caddis-worm. 



various materials in which it dwells at the bottom 

 of the waters, where the hand of the young angler 



