And I hand Mary my little pocket-lens through which she tries to look with both eyes at once. She could, of course, if she would keep her blessed eyes far enough away, but as she persists in holding the glass at the tip of her nose as she has seen me do, and as she cannot shut one eye and keep the other open, as I can, and have done now so many years that I have wrinkles all round the shut-up eye, why, she makes bad work of it. So she hands back the lens with a polite "thank you," and sticks to her own keen unaided eyes. And sees more than I do! For in the next breath she cries, with a little note of triumph in her voice: "But some of the ant babies _are_ walking. See there! And you said they have no legs. I can see them; little stumpy blackish legs sticking out from their soft white body! And some of the ants are carrying these babies with legs; I can see them!" I squirm around nearer Mary. True enough there are some little white chubby creatures walking slowly around in the narrow runways. But I _know_ they cannot be ant larvæ. For ant larvæ have no legs and simply can't walk. What are they? I get out the little pocket-lens. And the mystery is solved. They are the "ant-cattle," the curious little mealy-bugs that many kinds of ants bring into their nests and take care of for the sake of getting from them a constant supply of "honey-dew." This "honey-dew" which the mealy-bugs make and give off from their bodies is a sweetish syrupy fluid of which almost all ants, even those most fiercely carnivorous, are very fond. And as the mealy-bugs and plant-lice that make the honey-dew are quite defenceless, soft-bodied, mostly wingless and rather sedentary insects, the bright-witted ants establish colonies, or "herds," of them in their nests, or visit and protect colonies of them living on plants near the ant-nest. Some kinds of ants even build earthen "sheds," or tents, over groups of honey-dew insects on plant-stems. The mealy-bugs are white because they cover their soft little bodies with delicate threads or flakes of glistening white wax which they make in their bodies and pour out through tiny openings in the skin. We watch the busy, excited ants until they have carried all their babies and cattle down into the underground nursery chambers, out of harm's way. Then we put the stone carefully back in place, and roll back again to where we can watch the wonderful mountains in the west. The redwood-fringed crest stands so sharply out against the sky-line that we really can distinguish every tree that lifts its head above the crest, although they are several miles away from us. These great trees, which are the giants' jagged spears, are one hundred and fifty feet high, some of them, and as big around at the base as one of the massive columns in the Cologne Cathedral. Finally I say, rather lazily, "Mary, shall I tell you about the special way the clever little brown ant of the Illinois corn-fields takes care of its cattle?"