This bean bears on one of its edges an oval scar, very distinctly marked, called the _hilum_. This was the point of attachment of a short column, by which the seed was united to one of the sutures of a long pod, in the interior of which it lay, in company with several others like itself. This great legume or pod had been the bottom of the pistil of a papilionaceous flower, crowned by a tiny stigma, lodged in a sheath formed by the united stamens, and surrounded by a corolla of refulgent scarlet petals. Of course such a flower was not an independent organism; it was one of many that adorned a great tree, the history of whose life would carry us back through several generations of human years. [Illustration: GARDEN TULIP. Fig. 1. A flower with two petals removed, to show the ovary, _a_. Fig. 2. The same ovary, more mature, divided longitudinally; _b_, the unripe seeds, packed on each other; _c_, a portion of the same carpel, from which the seeds have been removed.] This single infolding leaf, that is just shooting from the soil, so small and feeble,--what of this? There are certainly no concentric cylinders of timber here: can we trace a previous history of this? Yes: by carefully removing the soil from the base, we see that it originates in a flat yellow seed--the seed of a Tulip. Here again we have no difficulty in detecting evidence of its former attachment. A great number of these seeds were once closely packed one on another, in each of the three carpels that constituted the capsule. And this capsule had been the oblong, three-sided ovary, which formed the body of the pistil in some beautiful Tulip. Do you observe these two round fleshy leaves, just peeping from the sandy earth? They are the earliest growths of a plant of _Arachis hypogaea_. In this case again, to understand the true relations of this organism, we must expose it wholly to view. Beneath the surface of the earth, then, I find that these seed-leaves are the two halves (_cotyledons_) of a kind of pea, which was formerly enclosed in a wrinkled skinny pod. But what is most interesting is that the pod is here, the cotyledons shooting out of it. And, attached to one end of the pod, here is a slender stalk, now withered and dry, which projects out of the ground into the air. [Illustration: GERMINATION OF EARTH-PEA.]