64 ON EPHEMERAL FLIES. 



terise them individually, from their numbers and 

 varieties. The short period of their existence, 

 limited to a few days at most, and in some to a 

 few hours only, renders a constant succession ne- 

 i cessary to fill up the void. They have been 

 grouped under the comprehensive term of duns, 

 which has become so conventional, that it would 

 be extremely difficult to disjoin them; although 

 whoever examines the yellow and the orange 

 varieties, which equally pass under the same 

 name, will find they have little of a dun hue 

 about them. There are, however, extreme ex- 

 ceptions, for it is very certain that in most other 

 varieties there is a predominating bluish grey 

 tinge. Were it not for the successional changes 

 which take place in their tribes, they might 

 perhaps be conveniently and appropriately divided 

 into brown, red, and yellow ephemera ; of each 

 of these the modifications are almost infinite. 



" Of the brown ephemera, or duns, some are 

 very dark, approaching a claret colour, which is 

 best imitated by a dark blue, mixed with a reddish 

 brown. These are usually found in the earliest 

 ' part of the fly-fishing season, and to them usually 

 succeed a mixture of red and coloured varieties, 

 followed by a new series, which are gradually 

 softened into the different hues of dun, orange, or 

 yellowish ash. Of the trae dun ephemeral flies 

 the variety is equally endless, from the early 



