shelly suit a size too small for him!

Now look at his suit. It is a hard coat, a complete suit of armour to
protect his soft body. Our picture shows the Lobster, the Crab's cousin.
The Shrimp and Prawn and Lobster are relations of the Crab; these
_crustaceans_, as they are called, are all cased up in a hard _crust_,
which will not stretch the slightest little bit. But the Crab's body
_must_ grow! What is he to do?

At first he starves himself, and so his body shrinks inside its old
shell. He loosens himself as well as he can. Soon the shell breaks
across, and the Crab struggles to get free. At last he backs out, and
leaves his old suit for ever. It is a wonderful performance, for he has
withdrawn even from the legs, claws, feelers, bristles, eye-stalks and
eyes! The old shell is left quite whole--a perfect Crab, but with no
Crab inside it!

Now the Crab, in his new suit, hides away. He knows that he is a soft,
flabby creature at this time, and that other animals, even Mrs. Crab,
would be glad to meet him--and eat him. While his covering is yet soft
he grows quickly. When it is hard, he ventures out again, ready to
quarrel and fight.

This change of shell happens often to young Crabs. Older ones change
only once a year. All the different kinds of Crab begin life as _larvae_
or _zoeas_, and cast their shells as we have seen.

Crabs can see and hear and smell; and they must also have a fine sense
of touch. I was once watching a big Crab eating his dinner under a rocky
ledge in a large glass tank. As he tore his food, some of the bits, no