Part 33

John says he would like to know some more.

Well, then, I will tell you about their rings.

You can see the rings of the grasshopper people very plainly in their abdomens.

Here is a picture of a grasshopper. It is not all drawn. The legs and wings are not shown, and the abdomen is drawn by itself so you can see it easily.

There are ten rings, you see.

The rings are covered with a hard, horny substance.

This horny substance is what makes the body of the insect so stiff. It would be soft but for the chitin, as the horny substance is called.

It is better for the insect to have a chitinous covering.

If you had no bones, you would be glad to have your skin hardened with chitin.

You see how it is, you wear your skeleton inside. Your skeleton is of bones; it is an inside skeleton.

The grasshoppers and all the insects wear their skeleton outside. It is made of chitin; it is an outside skeleton.

Insects have no bones.

They do not need any. They are kept stiff by the chitin.

Each ring in the insect's abdomen is made of four pieces, the back piece, the side pieces, and the under piece. You can see the back piece and one side piece in the picture, but you cannot see the other side piece nor the under piece without turning the insect over.

The rings are made in pieces so the insect can move.

Suppose each ring were made of one stiff piece like a finger ring. What a poor stiff, old grasshopper it would be! The rings are called segments.

Segment number one has only a back piece, you see.

All the other segments have four pieces.

Segments two, three, four, five, six, seven, and eight are alike.

Segments nine and ten are modified to form the ovipositor.

The segments are fastened together by skin. The skin is soft so the segments can move back and forth.

The segments can be crowded close together to shorten the abdomen.

The segments can be separated from each other to lengthen the abdomen.

There is no chitin in the skin between the segments. It is soft so the segments can move.

Do you know how a telescope is made?

The abdomen of the insect can lengthen and shorten somewhat like a telescope.

It is easy to see the rings in the abdomen of the locust or grasshopper.

Now, what about the thorax?