64 FLY FISHING AND SPINNING 



appearance just before the sub-imago state. The beautiful 

 illustrations of the larval, pupal and flying stages of the 

 water insects on Plates VI., VII. and VIII. were drawn for 

 me by Mr. Horace Knight, of the Natural History Museum. 

 Fig 1, Plate VI., shows the pupal stage of the larva of the 

 May-fly, Ephemera vulgata, twice its natural size. Fig. 3 

 represents the pupal stage of the larva of Cloeon rufulum, a 

 fly resembling the Red Quill. Fig. 2 shows the Ephemera 

 vulgata in its flying stage with the wings open. Fig. 4 

 shows the Cloeon rufulum in its flying stage with its wings 

 closed. The larval period of the different Ephemeridae 

 lasts from one to two years. 



There are several varieties of the larvae, corresponding to 

 the several kinds of Ephemeridae, and in each the appear- 

 ance and the habits differ some crawl, some burrow, and 

 others, again, swim but in all the varieties the larval 

 appearance alters as they attain full size, and beneath the 

 transparent integument covering their bodies can be 

 discerned the gradual development of the wings, thorax, 

 and legs, which will be used after the metamorphosis to the 

 flying condition (see Plate VI., Figs. 1 and 3). 



When the larvae are fully ready for this change, they 

 leave the haunts in which they have hitherto spent their 

 existence, and swim to the surface. When there the mask- 

 like membrane, under which the wings, etc., have been 

 visible (see Figs. 1 and 3, Plate VI.), splits open, and, 

 supported on this shell as on a raft, the insect gradually frees 

 every part of its body and unfolds its wings. As soon as 

 these wings are dried, and the body is clear of its shell, the 

 sub-imago, as it is now called, flies to the nearest bank, 

 where it shelters itself amid the grasses, leaves, etc. It is 

 commonly known in this state as a dun, and it appears at 

 various times, when the weather is favourable, in the 

 vicinity of the water during a period of from one day to two 



