Page:The Book of the Aquarium and Water Cabinet.djvu/140

This page has been validated.
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

LARVÆ 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 removed a cad, if you throw him into a tank you will learn