The Insect Folk | Page 4

pleases it darts out that lip, and any unlucky insect or snail may fall a prey to its greedy appetite.
It is said that the larv? of some dragon flies even eat pollywogs and small fishes.
Ned wants to know if "larv?" means the same as "larva."
Yes, it is the plural form of the word. When we speak of only one we say "larva"; when we speak of more than one, instead of saying "larvas," we say "larv?."
The dragon fly larv? are terrible gluttons, and hidden under the mask are strong jaws for chewing up their prey.
Their legs are quite large and strong, too, for they crawl about the bottom of the pond or up the stalks of the plants.
They do not move about very fast, but they do shoot out that under lip very, very, very fast indeed, so good-by to any little live thing in the pond that comes within reach of it.
The dragon fly larv? do not all look alike. They are different in the different species of dragon flies, and, like the rest of us, they change as they grow older.
Yes, May, you can keep the dragon fly larv? until they change into dragon flies.
You must supply them with fresh water and with enough to eat.
And you must put a net over the bowl or aquarium in which you keep them, otherwise as soon as they are able they will fly away.
How can they fly without wings?
Oh, but they are going to have wings. You know they are young dragon flies in spite of their strange appearance.
Be sure and feed them enough, or else they will eat each other, and that would be a pity; and be sure there are some water plants for them to hide under and crawl upon.
You can give them a little fresh fish or a tiny bit of very fresh meat, though they like best the living things they find in the bottom of the pond.
[Illustration]
When the dragon fly larva first hatches it is very small and its legs are rather long and spidery, but it eats and eats and eats,--my, how it eats!
And it grows and grows, and one day it finds its skin too tight.
A tight skin must be rather uncomfortable.
But the larva does not care much for its skin.
It merely splits it open down the back and pulls itself out.
Perhaps you think it must be yet more uncomfortable to be without a skin.
But it is not without a skin. It is covered by a new and soft one that soon hardens, and that is larger than the old one.
It wriggles out of its old skin as though it were an old coat, and leaves it clinging to the weeds in the pond.
Sometime you may find these cast-off dragon fly overcoats.
After it has shed its skin the dragon fly continues to grow. It keeps on growing until it has outgrown its new skin.
Then what do you think it does?
Yes, Charlie, that is right, it sheds this skin too.
[Illustration]
When it sheds its skin we say it moults.
It moults several times, and at last little short wings appear. At first it has no wings at all, you know.
Amy wonders how the larva breathes under water.
Ah, Master Ned, you are laughing too soon. You think insects do not have to breathe, but you are very much mistaken, sir.
Insects do have to breathe.
They would die if they could get no air to breathe.
Some of the dragon fly larv? have an odd arrangement for breathing under water. They have a sort of syringe in the end of the body, and there are breathing pores or gills in the syringe.
The water goes in and out of this syringe, and the larva breathes as the fish does, by means of its gills.
Yes, May, its gills are in its syringe, which seems very odd,--you see the dragon fly larva breathes at its tail end instead of at its head end.
Mollie thinks it is an upside-down, inside-out sort of a creature anyway. But it knows what it is about.
Ned wants to know how it can get any air to breathe when it lives under water.
The truth is, there is always air mixed in with water, and it is this air the larva breathes when the water goes in and out of the syringe.
It uses the syringe for another purpose too. When it pleases it can shoot out the water with great force, and thus propel itself quite a distance.
By means of the syringe it can leap through the water faster than it can move by its slow-going legs.
Mollie wants to know if we can see the syringe.
No, it is inside the body.
But there is a kind of dragon fly that has a pair of gills outside, at the end of the abdomen, instead of the syringe inside.
The best I can