GEEEN AND GKEY DRAKE LARV^. 201 



pebbles. This I can believe, as it is the natural habit 

 of the stone-fly to hide underneath the stones and large 

 gravel by the river-side during the height of the day ; 

 hence its name of the stone-fly ; and it only comes abroad 

 on the wing, morning and evening. During their seasons, 

 both the larva and the fly are very common, and in 

 some districts abundant in the rough stony streams of 

 Northumberland, Cumberland, Westmoreland, Scotland, 

 and Wales ; but in muddy rivers they are never seen. 

 This larva gets the name of piper caddis from its hollow 

 wooden case, closely resembling the drone reeds in a set 

 of bagpipes. The fly generally appears in the perfect 

 state towards the middle or end of April or beginning 

 of May, according to the forwardness of the season and 

 the earliness of the locality, and disappears again in 

 July. 



The larvae of the green and grey drakes form their 

 tubes of longitudinal pieces or slips of coarse straw, 

 glued lengthways together, and are the next in size to that 

 of the stone-fly, being three-quarters of an inch in 

 length. This caddis usually abounds in all the rills 

 and pools in the vicinity of rivers running over muddy 

 or sandy bottoms, but seldom exists to any extent in 

 the neighbourhood of swift stony streams, and is like- 

 wise a large, conspicuous, and excellent bait for most 

 fish. The fly usually appears from the 20th or end of 

 May to the middle of June, according to the locality 

 generally about the latter period in Northumberland. 



Other species form their cases of short pieces of rush 

 and stalks of grass, while others again use nothing but 



