224 



MINUTE MARVELS OF NATURE 



species will often use a variety of substances 

 which happen to be near at hand. Fig. 149 



Fig. 149. .Specimens of the cases built by caddis-worms. 



Natural size 



.shows a number of these cases made of various 

 substances and in many forms. The first is built 

 of water-loo-ged bits of stick cut to suitable sizes 



