“Talk about gall cradles,” said a gall fly, “my sisters and I are the fairies who make them to perfection. Each of us has a different plant or tree which she prefers, and each follows her own fashion in making galls, and we puzzle even the wise men. Have you ever seen the brown galls that grow on oaks?” “Why, of course,” answered Ruth, glad the question was such an easy one. “Well that’s something, but I doubt if you have noticed the rosy coloured sponge that sometimes grows around the stem, or the mimic branch of currants drooping from the spot where the tree intended an acorn to be, or the tiny red apple-like ball on the leaf.” Ruth shook her head. “They must be very pretty,” she said. “Pretty? I should say so. They are all different kinds of galls too, and we gall flies make them. Sometimes we sting the leaf, sometimes the twig, and sometimes the stem, and always just the kind of cradle we intended grows from it, and the egg we laid there hatched into a baby grub, ready to eat the sap.” “Then you know about the one on the willow tree,” put in Ruth. “The one the housefly told about. It grows like a pine cone, and is made by some one with a dreadfully long name.” “That is something entirely different,” answered the gall fly. “We do not pretend to make all the galls, you understand. Some are made by insects belonging to quite another order. The willow tree cone is one. You may always know ours from the fact that we make no door for the babies to come out, as other insects do. Our babies make their own door when they are ready to leave their cradle. And now to show how much is in some names, I will tell you that those other gall insects are called gall gnats and belong to the order of flies, while we are called gall _flies_, and belong to the order Hymenoptera.” “Oh!” cried Ruth, clapping her hands. “Now I know the kind of tera you belong to, Hy-men-op-tera,” she repeated slowly. “Please tell me just what it means.” “No, I won’t,” was the ungracious answer. “I hate explanations.” “I’ll tell you,” said Mrs. Horntail. “I know all about it.” And as Ruth turned to her with grateful eyes she began: “Hymenoptera means membrane wing, and that’s the kind we have, though some of our order have no wings at all. The others have four wings, the front pair being larger, with a fold along the hind edge, that catches on hooks on the front edge of the hind wings; so we really seem to have but one pair. Do you understand that?” “Yes,” nodded Ruth. “Very well. We are divided into two sub-orders: stingers and borers. Our larvæ are called maggots. They are not like us, being white grubs, with round horny heads, pointed tails, six legs——” “Here, here!” said the ichneumon fly, “that does well enough for your children, but you know perfectly well that the babies of the rest of us have no legs.” “Yes, I know. Poor things! Legless children! How sad! Mrs. Saw Fly and I are the only exceptions.”