PREFACE. ix 



real insects for sale, as well as the artificial 

 imitations. A set of such specimens, pinned 

 in a small glazed case, lined with cork 

 about three-sixteenths of an inch in thick- 

 ness, would be a very useful illustration and 

 accompaniment of the present work. And 

 the difficulty will appear trifling, when it is 

 considered that while to an entomological 

 collector the rarity of a species enhances its 

 value, to a fly-fisher, on the other hand, the 

 frequent occurrence of a species, and its 

 being widely dispersed, or found upon all 

 ivaters, constitute the strongest reasons for 

 preferring it ; because the fish (ceteris pa- 

 ribus) feed upon such species the more 

 readily, as we see in the instances of the 

 green drake, and of various caddis flies. 



Another addition is the number of the 

 hook proper to be used in imitating each 

 fly, and remarks wherever a variation in 

 this respect is to be recommended. 



The fourth chapter of the work has also 

 received an Introduction of some length, 

 and the Plates have been corrected ; and 

 where the meaning of the Author seemed 

 imperfectly conveyed, a fuller explanation 



