W ORMS are found in all parts of the world. I have told you that they help to build the world, and make it fit for the home of man.
Man cannot live without food. He gets his food from the earth. The worms help to prepare the earth to bring forth the food of man.
Oh, this is very strange, that humble and dirty worms can be a help to man! Man is the highest of all animals. Worms are nearly the lowest. And can worms help man?
Now let us see how this is done. The worms live under ground. They make long, winding halls, like streets, some inches below the top soil. These halls, or little tunnels, help to keep the earth loose, so that the fine roots of the plants can grow well in it.
These tunnels also serve to help the air move more easily through the soil. By their constant motion below the surface the worms till the earth, as rakes, spades, or ploughs till it above.
All this is of great use, and people say, "Many worms, rich land." Now and then you will hear, on the other hand, that the worms have eaten up the seed sown. Or, people say the worms have bitten off the roots of the plants. Some say that the worms cut the vines below the soil.
You need not think the earth-worms did that. Not at all! The earth-worms never behave so ill. The "worms" that people mean, when they speak of this harm done, are the grubs or larvæ of some insects, as of the daddy-long-legs and others.
These grubs and cut-worms will eat living plants, but Mr. Worm likes dead leaves and stems best. He wants his food made soft by decay.
Now we come to the chief work of the true earthworms. When they make their halls and houses, they fill their long bodies with the earth. Some say it is their food.
Mr. Darwin says, "Oh, no! they fill their bodies with earth just to get it out of their way." If they get any food from the dirt it is not much. They turn themselves into baskets to carry the dirt out from their houses.
The worms work, work, work all the time, taking out earth, and carrying it to the top of the ground.
There they pile it in heaps, called worm-casts. Each piece is the shape of a small worm.
The earth takes this shape as the worm presses it out of its long, soft body. Early in the day you can find these worm-casts over all the garden paths. So you can after a rain. Go and look for them.
There are so many worms busy all the time that each year they bring up tons of earth. This shows you the power that is in small, weak things. In India there are worm-casts in heaps six inches high.
The worms make the earth fine and loose, by pinching it off with their mouths. Then they bring this rich soil from below, and lay it on top, and so on and on.
It is only some twenty years since this work of worms was known. At first people said, "Oh, no, no! It cannot be that little, soft worms could cover a great field, some inches deep, with new earth." But it was shown to be quite true.
Fields once stony and hard have become rich and fine. Things grow now where once scarcely anything would grow. Ashes and gravel, once on top, go two or three inches below.
All this is done by the busy worms. That is why I said that you could call the tail end of the worm the tool with which he helps to build the world.
Worms at work under ground have caused great walls and pavements to sink, as the earth sinks over mines. Also, they have helped to bury ruins and old cities, and to keep them safe hidden, until we found them. We are glad when we learn of the old world days, from ruins which the worms helped to hide.
Then, too, the worms help make the soil rich, by the dead leaves and stems which they drag into their holes to decay. When the worms die, their bodies also help to make the earth more fertile.