One of these is the scale bug that supplies shellac, and all that comes from it to our markets. These curious bugs give forth a resinous substance that envelops the eggs and glues them to the twigs whose juices the bug sucks out. It is this resinous substance that is collected by breaking off the twigs where the insects are. It is used for varnishes, as you know, and for polishing wood and other substances. There are other scale bugs that secrete wax, and some of them produce it so abundantly, and of such good quality, that it has become an article of commerce. China wax, which is wax of a very fine quality, is secreted by a Chinese scale bug, and the wax is used for making fine candles, as well as for other purposes. In Mexico we have the cochineal insect, which is a scale bug that lives on a cactus that grows in Mexico. Like many others of the scale bugs, the cochineal males have wings and are not so scalelike as their helpless mates. But they are of no use to us. It is only the female cochineal we use. She is raised in great numbers in cactus gardens planted on purpose. Here is the picture of a cactus with cochineal insects upon it. [Illustration] These insects contain a very brilliant, red coloring matter that is used by us in dyeing leather and wool, and in making paints. The insects are gathered and dried, and thus sent to market. Although a few of them are useful to us, the scale bugs, on the whole, are a serious pest; and they are found on nearly all kinds of plants all over the world. You should think all the plants would soon be gone, so many insects eat them? Well, they would, only other things eat the insects. Insects have a great many enemies, after all. Sometimes the weather is bad for them, the season is too hot or too cold, too wet or too dry, and then they do not appear in large numbers. Sometimes one kind of insect eats another kind. Sometimes tiny plants, like moulds, grow on the insects and kill them; and birds destroy a very large number. If the farmers only knew how much good the birds do them, they would never allow one to be killed. Even the crows that pull up their corn are worth many times the corn they eat in the insects they destroy. There is scarcely a bird but what is of value to the farmer. The hawks that catch his chickens catch more mice and moles in his fields, than chickens in his barn-yard. And as for the robins, the blue jays, and all the small birds, they do more to save the growing plants, than all the soap suds and kerosene emulsion that were ever made. No one should ever shoot a bird. The birds are our natural protectors against the vast armies of insects, that, but for the birds, would soon destroy us by eating up our food plants. What is that, May? You belong to an Audubon Society for the protection of the birds? Yes, I know you do, and so do John and Ned and Mollie and little Nell.