CADDICE-WORMS. 



209 



their body, precisely the same as we should hold an um- 

 brella. 



Though caterpillars are frequently protected against injury 

 by tufts of hairs, by acrid secretions, by stinging properties, or 

 by closely resembling in colour the leaves upon which they feed, 

 yet concealment is their most ordinary mode of defence. Some- 

 times the whole brood spins a common web, like a large tent, 



Caddice-worms. 



under which all the community for a part of their lives reside ; 

 sometimes every individual rolls himself up in a leaf, like a 

 solitary hermit, so as to be completely hidden, and inaccessible 

 to his enemies. 



The caterpillars of the caddice-flies, so common in streams and 

 ponds of water, enclose themselves in moveable tubes, and crawl 

 about, like their representatives the hermit-crabs, at the bottom 



