What have you found now, John? Ah, yes, an alder branch, with a white, cottony substance on it. You have been poking into it with a little stick, and you think there are insects beneath it. What, May, you always thought that white stuff was a plant growth, like mould? We can easily find out. Get out some of the little things inside if you can, John. It is not easy to separate them from their cottony covering without crushing them, but now we can see quite well with the magnifying glass--and yes--you see they are little insects. We call them the woolly aphids. They also secrete honey dew. You say the ground below the alder bush was all sticky and black, John? That was the honey dew, blackened by a little plant something like mould, that grows on it. We often see woolly plant lice in the summer-time on different plants, and one species injures apple trees. It gets on the roots as well as on the tender bark of young trees and kills them. Yes, indeed, Mollie, the aphids are bugs. They belong to the bug order, which is a very large and important insect family, and contains some members that are exceedingly troublesome to us. SCALE BUGS What, May, you are tired out? What have you been doing? Oh, yes, washing the scales off the leaves of your mother's window fern. [Illustration] It must indeed have been a task; what did you wash them off with? Why did you use soap suds? Because your mother told you to; well, that is a good reason, but why do you think she told you to use soap suds? You say you don't know, but you think very likely these scales are some sort of bug, as everything nowadays seems to be bugs. Well, I don't know about everything being bugs, but those scales certainly are. They are scale bugs. Did you stop to look at them under the magnifying glass? [Illustration] No, but you brought a piece of the fern for us to look at. It will be necessary to put it under the microscope. There, now look. Yes, that scale looks like a tiny mussel shell; but look carefully, and you will see it has legs. Lift it up with the point of a pin, and under it you will find a mass of eggs. Yes, Ned; it is like a quantity of eggs under a dish cover. The cover is the female scale bug, and she has laid all those eggs. Yes, the scales we see on so many plants are the scale bugs. They are not all alike in shape, or size, or color; here is a different kind, you see. [Illustration] But they are all very prolific; that is to say, they produce a great many young, and do it in a short time. Yes, John, the tiny, dark-colored scales that look like little oyster shells on the skins of oranges are a form of scale bug, and a very troublesome one, too, to the orange grower. But though most of these insects are troublesome, the family is redeemed by a few members that are of great value to us.