54 THE BROOK BOOK 



which could be removed bodily without destroying 

 it. Most of them were stretched between the 

 edges of two stones, and could not be taken. "The 

 Man with the Boots" found one, and the artist 

 made a picture of it for me. The large end of 

 the funnel was up stream, and held open by bent 

 twigs. Being to all intents and purposes savages 

 and cannibals, these creatures think nothing of fish- 

 ing with their miniature seines regardless of the 

 laws of the land. The survival of the fittest is the 

 only law they recognize, and that holds good all 

 the year round. 



But we will not quarrel with them for this strange 

 appetite. Indeed they should be looked upon as 

 benefactors, inasmuch as they are said by an emi- 

 nent authority to be the one dire enemy of the 

 black fly larvae, their neighbors in the swift streams. 

 It seems that these larvse which cling to the stones 

 like patches of velvety moss, sometimes let go, 

 and, since they cannot swim, are washed down 

 stream by the current. Straight into the stretched 

 nets of the caddice-worms the hapless larvs are 

 cast, and their adventures are soon over. 



Hydropsyche alone of all the caddice-worms is 

 carnivorous. His cousins with the immovable 

 stone houses, and those insect householders which 

 wander from place to place in the water — all 

 these are vegetarians. They have little in common 

 save their family tree. They all pass through the 

 same four stages. 



Strenuous life for a caddice-worm ends with the 

 larval period of development. Hydropsyche re- 



