There is a notch in each side of his shell. He can let his eyes lie in that notch.[1] How can he do that? His eye-pegs are so long he can bend them down flat to the shell and keep them safe in the notch. FOOTNOTES: [1] See Picture in Lesson IX. LESSON IV. MR. AND MRS. CRAB GET A NEW COAT. [Illustration: SPIDER CRAB AND LITTLE PINNA.] Your skin is soft and fine. As you grow more and more, your skin does not break. Your skin gets larger as your body grows. But Mr. Crab is in a hard shell. The shell will not stretch. It gets too tight, and what can Mr. Crab do then? What do you do when your coat is too small? Now I will tell you a strange thing. When Mr. Crab finds that his shell is too small, he takes it off, as you take off your coat. He pulls his legs, his hands, and his back, out of his shell. He does that in his house. You do not undress out of doors. You go to your room. So does Mr. Crab. He slips out of his shell. He pulls out his feet and hands, as if he took off his boots and his gloves. Then he is a poor, soft, cold thing. But over all his body is spread a skin, soft as paste, like glue and lime. In a few days it gets hard. It is as big as Mr. Crab, and just fits his shape. It is a good, new shell! It has the right colors,--blue, brown, red, or gold. It has spots and rings. When Mrs. Crab changes her shell, Mr. Crab stays near, and tries to keep her from being hurt. The young crabs have to change their shells often, they grow so fast. Crabs that live in dark mud have dark brown or green shells. Some crabs have sand-colored shells,[2]--pale gray or brown shells, with close, fine specks like sand on them. There are more kinds of crabs than you could count. They live in all parts of the world. This book tells you of only a few of them. FOOTNOTES: [2] See Lesson XXXIII. LESSON V. WHAT THE CRAB DOES. [Illustration: FREE FIGHT.] The crab is quick to get cross. Are you? He likes to fight. In that he is like a bad boy. When he sees some other crab near his house, he is angry. Then he stands high on his toes. He pulls in his eye-pegs, for fear they will be hurt. He spreads out his big arm. Now he is ready to fight! He runs at his enemy! Each tries to hit the other with his big claw. This big claw, or hand, can cut and pinch hard. Sometimes one crab cuts off the hand or leg of the other crab. Or he bites the shell on his back. If only a leg is cut off, the crab may keep on fighting. But if his hand, or eye, or back shell is hurt, he must give up. He runs home to hide, until a new eye, or hand, or leg can grow. If your hand is cut off, will it grow again? When a crab is afraid, he runs home. But he is very brave, and does not much fear other crabs. He fears birds most; for birds eat small crabs; and the crab cannot fight a big bird. Swing a rag over a crab’s head. Up fly his eye-pegs! Up comes his big hand! There, he has caught the rag! He will not let go.