82 THE DIPTERA : THE BLACK GNAT 



condition of a chrysalis or pupa. Changing from 

 the pupal to the flying imago condition within the 

 shelter of this retreat, it crawls to the surface and finally 

 takes flight. 



The best known form of this fly is the Alder. 



THE DIPTERA, OR TWO-WINGED FLY 



The very numerous varieties of this class of insect pre- 

 clude more than a brief reference to those forms which 

 the fisherman is most likely to copy as artificial flies. 

 These are : the Black Gnat, the Oak-fly, the Spider-fly, 

 the Cow-dung, the Golden Dun, the Hawthorn-fly, 

 and the Claret Smut, sometimes known as the Red 

 Quill Gnat. 



The larval and pupal characteristics of these flies 

 differ widely, and the student can do no better than 

 consult entomological works on this and the other 

 families of water insects. 



For choice, I should recommend to the student 

 Mr. Frederic M. Halford's work, " The Dry Fly Ento- 

 mology." 



THE RISE 



Trout rise to the fly at all hours and during all 

 weathers. In the early moments of dawn, during the 

 hottest hour of an autumn day, as the sun sinks, as 

 darkness descends, and during the stilly hours of a 

 midsummer night, distinct and noticeable rises of 

 trout may be witnessed. If, however, I had to select 



