LESSON XLIII.
A HAPPY CHANGE.
When the close of the pupa state draws near, the coming dragon-fly loses its fierce appetite. It seems to feel tired and heavy. It breathes slowly, as if it could not get air enough. The body has changed inside the horny case, and the time is near when it will leave the water for air, and walking for flying.
Once the larva wanted nothing better than to chase bugs about under water. Now, all at once, it longs for the free air and for the sun. It needs no one to tell it what to do. In some way it knows exactly how it should act.
This tired pupa now seeks the stem of some tall reed or grass that grows in the water. Slowly it crawls up the stem. The hooks on the feet take fast hold as it goes, and it keeps on until it is nearly a yard above water.
The hooks, though very small, are so sharp and hard that they can go into wood. When the pupa is as high up as he wants to be he drives the hooks into the stem. Thus it will hold firm even when it twists and struggles hard.
The pupa likes best to find two reeds or stemsnear, so that it can take hold of both and swing between the two. Then, like a child in a swing, it begins to sway to and fro. Now, as it sways, a strange thing happens. The hard pupa-case splits open upon the back, and look, inside the case, we see the perfect insect, with its wings!
The pupa-case is firmly held by its hooked feet, while the new insect twists and pulls, and so gets free; and little by little its head, legs, wings, and long body come forth, and finally hang only by the last ring of the body.
Then you would think it was dead. For after it stretches out first one leg and then the other, it hangs by its last ring, stiff and still. But it is only resting. After about fifteen minutes it awakes. Taking hold firm withits feet upon a stem or leaf, it lets go its hold upon the pupa-case. That is left hanging by its hooks in its place.
Here is now a dragon-fly, with large head, with two great cluster eyes, six legs, four wings, and long, bright-hued body! And now, at last, it can breathe freely through all those tubes and air-holes you have been told about.
Still the insect does not look like the full-made dragon-fly. The colors are dull, and the wings are folded up. The body is soft, damp, and too short. The big eyes are dim.
As if half asleep it still clings to the stem, not far from the case, which is the old shape of itself. Hanging to the reeds by the pond you will often find these old coffins, if you look for them.
The new insect is drawing in the sunshine and fresh air. It stands still and breathes hard, filling its new body with pure, dry air. Now and then its wings quiver.
As they quiver they spread out, fold after fold, as silken banners wave out upon the air. Then at last they are spread out wide, in all their beauty. The dragon-fly has reached its last and highest state. It can sail away where it pleases on its new wings.
As the wings grow larger, the eyes of the dragon-fly grow brave and bright; its body dries. Then it gleams like a jewel. Its fresh colors come out clearly. It feels strong and active.
Then, all at once, it uses its new wings. It rises into the air and flashes here and there, just as hungry and ten times swifter than ever before.
The flight of the dragon-fly is called hawking, for it is like the motion of that strong bird, the hawk. If it gets caught in a place where its wide wings cannot turn, it can fly backwards and get off safely. In a place where the wings might be injured by striking against leaves or branches, it flies out in this way.
When dragon-flies are dead, the great beauty of their bodies passes away. They fade and grow dull, as when they first came from the pupa-case. The scarlet, yellow, blue, or green turns to a dull drab. So you cannot keep them as well as you can keep beetles. It is life that gives the dragon-fly its splendid beauty.