"That was once the stigma," he said. "You see, it is quite like one, even now. Of course, it was soft then, and the pistil below was soft, too. Then as it grew it became harder and harder until the shell formed, and it was really a nut. The calyx hardened, and made the hull. The pistil and the calyx of a flower are the parts that last longest, but the stamens and the corolla are just as useful in their way. They form a separate flower on the nut-trees. We will have to come to the woods next spring when they are in bloom." "Papa, don't hazelnuts and chestnuts belong to the same family?" asked little Prue, who had some of each in her chubby hands. "Why, yes, but why did you think so, Prue?" "Well, you see, they both have those white spots on them, and I thought mebbe it was a kind of family mark." "Wise little head, Prue. And now what else is there that has the family mark--we might call it the family seal?" The children were silent a moment, thinking. They were sitting under a big oak tree, and all at once Davy's eye caught something in the leaves, just by his hand. "This!" he shouted, and held up an acorn. "Right you are, Davy boy! The nut that stands at the head of the family. Few acorns are fit to be eaten, except by animals, but you see how round and perfect the family seal is, and though the acorn-cup is nothing like the chestnut-bur, or the husk of the hazel, it perhaps would be, if the green acorn itself was not so bitter that it does not need any other protection. The oak is one of the finest and most useful of all trees, and the hazel and chestnut and beech are probably very proud of belonging to the Oak family." "And how about hickory and walnuts?" asked Davy. "They are in a family together--the Walnut family. There are three kinds of walnuts--the English walnuts, the butternuts, and these. There are as many as half a dozen kinds of hickory nuts, and some of them are as bitter as the bitterest acorns." "Pignuts--I know those," said Davy. "They're awful. I tried to eat some last year." "You gave me one, too," said Prue. "I don't think that was very nice of you." Davy blushed and grinned, as he recollected the round, puckered face of little Prue, after she had tasted the bitter nut. "Never mind, Prue; we'll give him a mock-orange some day," said her mother. "The pecan is a hickory-nut, too," said the Chief Gardener, "a nut that has left all its bitterness in the shell." "Davy is a pecan-nut," said little Prue. "He's just bad outside." Then the little party made ready to go home. They had a good way to drive, and it grows chilly on October evenings. How still it seemed to have grown in the woods when they were ready to go. A squirrel scrambled up a hickory-tree, and sat chattering at them as they drove away. "He is scolding us for carrying off his winter food," said big Prue. "Oh, let's leave him some!" said little Prue, the tender-hearted.