128 THE WATER CABINET, 
members. As soon as he enters the world, he begins to 
show his skill in tailoring, and by means of silken threads 
and gluten constructs his case of bits of stick, straw, 
dead leaves, or shells, in fact, whatever he can get, and as 
long as he retains the worm-like form the case is his 
castle, and he can defy the world. The case outside is 
generally a rough affair, but if you draw out the cad you 
cE. WuHi NIPER BF. 
LARVA AND IMAGO OF CASE FLY. 
will see that inside it is perfectly cylindrical, smooth, and 
polished, and around the doorway, through which the 
larva makes acquaintance with the world, it is neatly 
finished with a very circular rim. When you have re- 
moved a cad, if you throw him into a tank you will learn 
