ON ARTIFICIAL FLIES. 77 



comparatively sombre dress, appears as the fairy- 

 like Jenny spinner, with a body glassy and colour- 

 less in the middle, and a red-brown or orange patch 

 at the tail and shoulder. These spinners when 

 dancing up and down, occasionally just touching 

 the surface of the water, are in the act of laying 

 their eggs, which at once sink and adhere to the 

 gravel in the bed of the river, and the spinner, 

 having fulfilled its duty, falls lifeless on the stream. 

 In due time these eggs are hatched in the shape of 

 a very active grub without any sign of wings, which 

 preys on all kinds of minute aquatic insects. The 

 grub in its turn becomes a pupa or larva, in shape 

 resembling the fully-developed fly without wings, 

 but with the addition of two dark-coloured glossy 

 excrescences at its shoulders, which are, in fact, the 

 wings folded up in a pair of protecting coverings. 

 When fully developed, the larva rises to the sur- 

 face of the water, splits open the gauzy skin in 

 which it is enveloped, and, after balancing itself for 

 a moment on the empty case, emerges, floating 

 down the stream with its wings erect and its 

 tapering body and tail curved upwards. If it does 

 not fall a prey to one of its many enemies fish or 

 bird, trout or grayling, swallow or martin as soon 

 as its wings are dry, it essays a short first flight, in 

 which it is too often seized by the open-mouthed 

 swift ; if, however, it eludes this last danger, it 

 reaches the thick sedge on the bank in safety, 

 to become, in its turn, a spinner or perfect fly, 



