Page:Popular Science Monthly Volume 13.djvu/619

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THE ORIGIN OF FRUITS.

bright sunshine, it will produce healthy green leaves, which help it to flower and to carry on its other physiological actions without depending entirely upon its previous accumulations; but if we place it in some dark corner, away from the sun, though its leaves will be blanched and sickly-looking, it will still have sufficient nutriment of its own to support it through the blossoming season without the external aid of fresh sunshine.

Where did this nutriment come from, however? It was stored up, in the case of the seed, by the mother-plant; in the case of the bulb, by the hyacinth itself. The materials produced in the leaves were transferred by the sap into the flower or the stem, and were there laid by in safety till a need arose for their expenditure. All last year—perhaps for many years before—the hyacinth-leaves were busily engaged in assimilating nutritive matter from the air about them, none of which the plant was then permitted to employ in the production of a blossom, but all was prudently treasured up by the gardener's care in the swelling bulb. This year, enough nourishment has been laid by to meet the cost of flowering, and so our hyacinth is enabled to produce, through its own resources, without further aid from the sun, its magnificent head of bright-colored and heavily-scented purple bells.

Each species of plant must, of course, solve for itself the problem, during the course of its development, whether its energies will be best employed by hoarding nutriment for its own future use in bulbs and tubers, or by producing richly-endowed seeds which will give its offspring a better chance of rooting themselves comfortably, and so surviving in safety amid the ceaseless competition of rival species. The various cereals, such as wheat, barley, rye, and oats, have found it most convenient to grow afresh with each season, and to supply their embryos with an abundant store of food for their sustenance during the infant stage of plant-life. Their example has been followed by peas and other pulses, by the wide class of nuts, and by the majority of garden-fruits. On the other hand, the onion and the tiger-lily store nutriment for themselves in the underground stem, surrounded by a mass of overlapping or closely-wound leaves, which we call a bulb; the iris and the crocus lay by their stock of food in a woody or fleshy stalk; the potato makes a rich deposit of starch in its subterraneous branches or tubers; the turnip, carrot, radish, and beet, use their root as the storehouse for their hoarded food-stuffs; while the orchis produces each year a new tubercle by the side of its existing root, and this second tubercle becomes in turn the parent of the next year's flowering stem. Perhaps, however, the common colchicum or meadow-saffron affords the most instructive instance of all; for during the summer it sends up green leaves alone, which devote their entire time to the accumulation of food-stuffs in a corm at their side; and, when the autumn comes round, this corm produces, not leaves, but a naked flower-stalk, which pushes its way through the moist earth, and stands solitary before the October winds,