Page:Popular Science Monthly Volume 25.djvu/453

Rh pastures it grows abundantly. It flowers above-ground, enticing the bees to fertilize its long, white, tubular blossoms by a copious store of pure and fragrant honey; but as soon as its wee pods have been fairly impregnated with pollen from a neighboring head, it screws its stalk down spirally into the ground, by the aid of some queer little corkscrew gimlets developed near the tip, and so buries the precious seeds well out of all danger from the close-nibbling teeth of its dreaded foes upon the sheep-walk.

Last of all, a few words must be said about the structural homologies of the hickory-nut. In principle, most fruits consist of three separate coats or layers, inclosing the seed or seeds. These three layers are very well seen in the peach, which consists, first, of an external skin; next, of a fleshy edible portion; and, finally, a hard inner covering—the stone—which contains the actual seed, or, as we oftener call it in practical language, the kernel. Now, in the hickory-nut, these three layers are still preserved, though in a very different apparent form: the outer surface, or membrane of the rind, answers to the skin of the peach; the bitter and stringy interior of the rind answers to the edible part of the peach; the nut-shell, or inner hard layer, answers to the stone of the peach; and the nut, or actual seed, answers to the kernel of the peach. This example shows very well by what slight changes in the development of various parts a fruit may seem to practical human eyes quite unlike some other one, which is, nevertheless, at bottom, layer for layer, absolutely identical with it. The only important difference, after all, between the peach and the hickory-nut is, that in the fruit the middle layer becomes soft, sweet, and succulent; while in the nut it becomes stringy, bitter, and nauseating. The almond even better enforces this simple evolutionary lesson; for it is, in reality, nothing more or less than a very dry and stringy peach—a very slightly divergent descendant of the same ancestor: its outermost layer answers exactly to the peach-skin; its tough, fibrous rind is the. altered analogue of the flesh in the peach; and its nut (which part alone, shelled or unshelled, we generally see at table) is the equivalent of the peach-stone. But if you cut open a young walnut, a young hickory-nut, a young almond, a young peach, and a young plum, you will be surprised to find how exactly they answer to one another, part for part, and how entirely the conspicuous adaptive differences in the mature nuts or fruits are due to small varieties of development in the very latest stages of the ripening process. Pour a little sweet juice into the middle coat of the almond, and it would be a peach; add a little woody material to the cell-walls of the flesh in the peach, and it would be a very decent almond indeed.