LESSON XXXVIII.
SEA-STARS.
Now we come to another animal who seems to be made on the star plan. Here you see pictures of him in the water, where he has his home. Is he not a pretty thing?
The jelly-fish has one of his names from his shape, and another name from his power to sting. This fish gets one name from his shape,—star-fish. And he has a long, hard name from his coat. His coat is a thick, tough skin. It has upon it prickles much like those of a hedge-hog. Most of them have five rays, or ten, because each single ray has been made into two, and so on.
All of the star-fish do not keep to the plan of five. The sun-star has twelve rays. He is of a splendid, bright-red color. These animals seem to be made on the star plan; the grown-up sea-stars show this shape most clearly, but it is never perfect; the young ones are two-sided, not star-like.
From their general shape they are called “stars,” from their skins, “rough or hedge-hog coated.” This skin is really their skeleton: they have their bones outside like the crabs and some other creatures.
The Ray Family at Home.
The crab’s skeleton is hard, the sea-star’s is more like a tough skin filled with little plates or spikes of shelly stuff. Sometimes these little plates lock together, sometimes they merely lie near each other, so some of the stars have much softer coats than the others. In the water these coats are tough and bend like leather. When they are dry they are brittle. If you want a dead star-fish to bend, drop it into water.
I will tell you of some kinds of star-fish, and then will tell you how they grow.