Flies for May. 49 



the stem of some aquatic plant a foot or so below 

 the surface, and by means of a gelatinous secretion 

 fastens them to the stem. There they remain till 

 hatched. When they reach the larval stage the 

 little creatures attach to themselves, by a glutinous 

 cement, fragments of leaves, sticks, grass stems, 

 shells, and grains of sand, until they have formed 

 hard tubular cases ; and in these remarkable habita- 

 tions they pass the whole of their larval and pupal 

 existence. In some species the caddis-cases are 

 carried about by the larvae ; in others they are 

 affixed to stones. When about to pass into the 

 quiescent and helpless pupal state, the caddis for- 

 tifies its dwelling against the predatory hordes of 

 the water by spinning a wonderful network across 

 each end, which sufficiently protects it till the final 

 stage is reached. In assuming the perfect form the 

 larger species burst this network, and crawling up 

 the stems of plants, find their way to the banks ; 

 while the smaller make use of their cases as rafts, 

 on which they stand and spread out their bright 

 new wings to the sun. 



The green-tail is not a particular favourite with 

 anglers, especially if the banks of the river are well 

 wooded, as the insects find their nourishment in 

 the leaves of the trees, from which they issue forth 

 in swarms, to be in their turn nourishment for the 

 expectant trout ; and as said trout exercise a wise 



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