The bean on the damp cotton grows as well at first as that planted in the earth, but it cannot get food enough to continue growth unless it can thrust its roots into the earth. What enables it to grow at all on the cotton, since that does not supply food, but only holds the moisture, without which the bean could not sprout? There must be food somewhere, and it is found packed away in the thick seed-leaves, which contain a great deal of starch and a little of some other things.
The Bean—Embryo-Leaves, Compound Leaves, and Beginning of Stem
The young plant, under the influence of warmth and moisture, is able to draw out the nourishment from the seed-leaves. If we examine the seed-leaves after the seed has sprouted we shall find them less hard and firm; they have given part of their substance to the embryo. They have also turned greenish in color, while, as we know, the leaves of the embryo, which at first were so white and tiny, have also turned green and grown larger. Between the two embryo-leaves there is a little growing tip.
The young plant now no longer depends upon the seed-leaves for its food. Down in the earth the roots are taking in nourishment, and up in the air the little green leaves are also busy supplying food to the growing plant. The little growing tip lengthens into a stem from which a leaf is seen unfolding. This new leaf is not shaped like the embryo-leaves nor like the seed-leaves. It has three leaflets. The stem continues to lengthen, and soon another compound leaf appears. Thus the stem lengthens and leaves keep coming, the little growing tip at the end of the stem always pushing upward.
Very soon the stem becomes too long and slender to stand upright. Then it does a strange thing. It circles about as though in search of something. It moves very slowly, but if you notice which way it is pointing in the morning, and again at noon, and again at night, you will see that it has changed its position. Why does it do this? It wishes to twine about a support, and will continue circling about until it finds one. If there is none, the slender stem, unable to stand upright as it lengthens, will in time bend to one side or even lie on the ground; but the end still continues to circle about, and when at last it touches a stick or the stem of another plant or anything else about which it can twine, it continues its circling motion about the new support, and the vine as it lengthens finally becomes twined about it.
How does the food which the plant takes from the earth and the air find its way to the different parts of the plant to nourish them?
The plant food is in a liquid form called sap, which runs through channels in the roots and stems and leaves, and is thus carried to all parts of the plant. To a certain extent it is like the blood of animals, which finds its way all through the body and supplies food to the tissues.
The plant is alive; it eats, it breathes; sometimes it even moves. It breathes the same air that we do, only it takes it in through tiny pores in the leaves. Eating and breathing, the plant continues to grow, leaf after leaf unfolding. At last, in the axil of one of the leaves there comes a little bud that does not unfold into a leaf but into a flower.
The appearance of this first blossom on the plant the child has himself raised from the seed will be watched with eagerness, and its advent can be made a subject of general pleasure and notice in the home. The child's pleasure in his flower will be greatly increased if he finds that others are also watching and enjoying it.