Hundreds of other plants attach these little sails to their seeds. You can hardly walk a step in the fall along the country roads without meeting these masses of feathery fruit made up of just such seeds. So now we come back to our questions, “Where are they going? What are they doing?” [Illustration: FIG. 59] [Illustration: FIG. 60] And as you have learned why the apple tree and the partridge vine pack their seeds in pretty cases, and why the burdock and the stick-tight cover theirs with hooks and bristles, you ought to answer these questions very easily. You found that those plants wished to send their little seeds abroad, so that they might get a better foothold in some piece of earth that was not used already by plants hungry for the very food that they most needed. This is just what the thistle and milkweed and dandelion and aster want for their seeds; and this is why they fasten them to little sails, and send them far away on a voyage of discovery. WINGED SEEDS Many of the trees also send their seeds on air voyages, in the hope of finding some piece of land that will give them a chance to grow into new, strong trees. [Illustration: FIG. 61] The seeds of the willow (Fig. 62) have silky white sails such as we have found already in the plants of the milkweed and willow herb; and the cottonwood tree is so called because its tufted seeds remind one of the famous cotton seeds from which we get our cotton thread (Fig. 63). [Illustration: FIG. 62] There are other trees which use wings instead of sails when they send their seeds flying through the air. [Illustration: FIG. 63] Here you have the winged fruits of the maple (Fig. 64). In summer you see these winged fruits hanging in clusters from the trees; and later in the year they are thickly scattered along the village street and in the city squares. [Illustration: FIG. 64] You can understand how easily the maple seeds inside these cases would be carried upon the breeze by their wings. Each seed of the elm tree is winged nearly all the way round. The picture (Fig. 65) shows you a cluster of these as they look upon the tree. [Illustration: FIG. 65] [Illustration: FIG. 66] Here is a bunch of the long-winged seeds of the ash (Fig. 66). Next comes a fruit cluster from the hop hornbeam (Fig. 67), and above is a single fruit (Fig. 68). [Illustration: FIG. 67] The seeds of the pine tree are hidden away in the pine cone (Fig. 69) you know so well, and those of the hemlock in the hemlock cone (Fig. 61). When they are quite ripe, they break away from these cones. In so doing, each one carries with it a little piece of the cone, which acts as a wing to the seed (Fig. 70). [Illustration: FIG. 68] [Illustration: FIG. 69] [Illustration: FIG. 70]