In the South is a plant with a leaf like a jug. On the seam of this leaf hang drops of honey. Its juice can make the flies drunk.[14] Flies like this juice. But as soon as they get it they turn dizzy and act just like drunken men. They fall into the jug-like space of the leaf and soon die. One of these plants will kill many flies in one day. Many of our best birds live on flies, and if our birds were all dead we should have much greater trouble with the flies. In the autumn you will see flies sitting about as if they feel dull and ill. If you look carefully you will see that the back part of the body is white. It seems to be covered with meal or mould. Soon the fly dies. This white dust is a disease of the fly. It does not curl up its legs when it dies from this cause. They are stiff and spread out. The fly looks like a live fly. If you touch it, it crumbles to dust. All around such a dead fly you will see a ring of white mould. This is perhaps a real mould, or tiny plant, that seizes on the body of the fly. It uses up all the soft parts, and so kills it, leaving only the dry shell. There is another strange thing about this. The body of a fly that dies in this way is rent or burst open. The fly looks as if this dust or mould had grown large in the body and so torn it open. FOOTNOTES: [14] See Reader, Seaside and Wayside No. III., Lesson XIII. LESSON XIX. OF WHAT USE ARE FLIES? How often people cry out, “Oh, I wish there were no flies! What is the use of a fly?” But all things that God has made have their uses. And all God’s works are worthy of study. You have learned that worms are of great use. Let us see if Mrs. Fly does any good in the world. Mrs. Fly is of great use to man. She helps keep him in health. Do you think that very strange? People say, “Oh, these _dirty_ flies!” And yet these “dirty flies” help to keep the world clean! Now you know that over all the world, great numbers of animals die each minute, and many of their bodies lie on the ground and decay. Such bodies in decay cause disease and death to men. In winter, and in cold places, such things do not decay so fast, and so do not make these bad odors. But in hot days, if such dead things lie about, they will poison the air. Soon we should all be ill. The work of Mrs. Fly is to lay many eggs in these dead bodies. In a few hours these eggs turn to grubs, and these grubs to little live worms, which begin to eat as fast as they can. Soon they leave only dry bones, which can do no harm. They change the dead stuff into their own fat, live bodies. You know that the crabs are among the street-cleaners of the sea. So the flies are among the street-cleaners of the air and land. Did you ever watch flies dart about, here and there, with a flight like hawks? They are eating up small, evil things, too small for us to see. But these are yet big enough to hurt us if we should get them into our lungs. Ask your teacher to tell you a little about your lungs.