12 



INCREASE OF THE FOOD SUPPLY 



No. 72 



two forms figured below, which constituted the most important part of the animal 

 food of the ducks examined. 



Text Fig. A. Dragon Fly (Devil's Darning Needle) Nymph, after Needam, natural 

 size. This larval form remains in the water, living about two years on other 

 aquatic life before emerging into its commonly known adult winged form. Abund- 

 ant in streams and ponds and in the bays of larger bodies of water. 



Text Fig. B. Caddis Fly larva. After Furneaux, natural size. This form lives a year 

 or two with its body encased in a tube constructed of sticks, pebbles, shells, grass, 

 etc. After emerging and attaining its mature winged form it lives a short life, 

 flying along the shores, mating, laying eggs, and then disappearing. It is widely 

 distributed and abundant, like the Dragon Fly nymph. 



