Fig. 192. The root and peg.
Fig. 193. Third day of root growth.
Fig. 194. The plant breaking out of the seed.
Fig. 195. The operation further progressed.
Fig. 196. The plant just coming up.
It may happen, however,—as it did in a pan of seed which I sowed a few days ago—that one or two of the plants may look like that shown in [Fig. 190]. Here the seed seems to have come up on top of the plant; and one is reminded of the curious way in which beans come up on the stalk of the young plant. If we were to study the matter, however,—as we may do at a future time—we should find a great difference in the ways in which the squashes and the beans raise their seeds out of the ground. It is not our purpose to compare the squash and the bean at this time, but we are curious to know why one of these squash plants brings its seed up out of the ground whilst all the others do not. In order to find out why it is, we must ask the plant, and this asking is what we call an experiment. We may first pull up the two plants. The first one ([Fig. 189]) will be seen to have the seed-coats still attached to the very lowest part of the stalk below the soil, but the other plant has no seed at that point. We will now plant more seeds, a dozen or more of them, so that we shall have enough to examine two or three times a day for several days. A day or two after the seeds are planted, we shall find a little point or root-like part breaking out of the sharp end of the seed, as shown in [Fig. 191]. A day later this root part has grown to be as long as the seed itself ([Fig. 192]), and it has turned directly downwards into the soil. But there is another most interesting thing about this germinating seed. Just where the root is breaking out of the seed (shown at a in [Fig. 192]), there is a little peg or projection. In [Fig. 193], about a day later, the root has grown still longer, and this peg seems to be forcing the seed apart. In [Fig, 194], however, it will be seen that the seed is really being forced apart by the stem or stalk above the peg for this stem is now growing longer. The lower lobe of the seed has attached to the peg (seen at a, [Fig. 194]), and the seed-leaves seem to be backing out of the seed. [Fig. 195] shows the seed a day later. The root has now produced many branches and has thoroughly established itself in the soil. The top is also growing rapidly and is still backing out of the seed, and the seed-coats are still firmly held by the obstinate peg.