TREATISE ON FLY-FISHING. 59 



they are prepared for their metamorphosis, and 

 quit the bottoms of the rivers, and the mud, and 

 stone, for the surface, and the light and air. 



The brown fly usually disappears before the 

 end of April but of the blue dun there is a suc- 

 cession of different tints, or species, or varieties, 

 which appear all the summer and autumn long. 

 The excess of heat seems equally unfavorable, 

 as the excess of cold, to the existence of the 

 smaller species of water insect, which during the 

 Intensity of sunshine seldom appear in summer, 

 but rise morning and evening. Towards the end 

 of August the ephemera appear again in the 

 middle of the day. To attempt to describe all 

 the variety that sport on the surface of the water 

 at different times of the day, throughout the year, 

 would be quite an endless labour. Some of them 

 appear to live only a few hours, none have their 

 existence protracted to more than a few days. 

 Of the beetle, there are many varieties fed on by 

 fishes. These insects are bred from eggs, which 



