Practical Dry-Fly Fishing 



are dropped into tlie water in large 

 numbers by the females. They have 

 three or four modes of life when in the 

 larval state; some form tubes in the 

 mud or clay in which they live, some 

 live beneath stones, while others swim 

 and crawl among the water plants. 

 They are carnivorous and also feed 

 upon vegetable life. When the insect 

 has reached full growth in its aquatic 

 form, after from six months to three 

 years of existence, it seeks the surface 

 of the water. Its thorax splits down 

 the back, and it appears in its winged 

 shape. It is not as yet perfect, though 

 it has the form of a perfect insect and 

 can fly. In this stage it is called pseud- 

 imago, sub-imago, or pro-imago. But 

 there remains a pellicle, or case, com- 

 pletely covering it which has yet to be 

 shed. Soon after the insect has ap- 

 peared in this winged foi^m it finds a 

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