. Elementary botany [microform]. Botany; Botanique. 4 ROOT AND SHOOT the testa is occupied by the embryo. The embryo (fig. 2) has a small rod-like main axis, which is composed of the primary or main root, the radicle (f); the primary or main stem (//); and a i)art of the axis, the hy}>ocoiyl{/ip), which connects the root and stem. The tip of the young root lies close within the pore of the testa. No lateral roots occur on the radicle at this stage. The main body of the embryo is constituted of the two large fleshy leaves—the cotyledons {cot), which are attached to that. Fig. I.—Seed of
. Elementary botany [microform]. Botany; Botanique. 4 ROOT AND SHOOT the testa is occupied by the embryo. The embryo (fig. 2) has a small rod-like main axis, which is composed of the primary or main root, the radicle (f); the primary or main stem (//); and a i)art of the axis, the hy}>ocoiyl{/ip), which connects the root and stem. The tip of the young root lies close within the pore of the testa. No lateral roots occur on the radicle at this stage. The main body of the embryo is constituted of the two large fleshy leaves—the cotyledons {cot), which are attached to that. Fig. I.—Seed of Fig. 2.—Knibryo of Hcaii, with Cotyledons separated. portion of the axis which is termed the hypocotyl. Lying hidden between the two cotyledons is the minute main stem, which terminates in a small bud. Thus, beginning at the root, the axis has no lateral members on its root-portion: above succeeds the hypocotyl* with two lateral cotyledons: still higher the axis represents the young main stem, and bears a few lateral commencements of leaves. When the seed germinates, the various parts of the embryo emerge. The radicle elongates and becomes the primary root: it grows downwards and produces lateral roots which may branch in their turn. The little stem grows upwards and sends out from its sides, leaves, branches, and flowers; its branches may in turn bear, not only leaves, but also branches of their own. We thus see that the development of this flowering plant from its embryo consists in the elongation of its primary axis, and the production of lateral members on that axis. The parts possessed by a mature flowering plant, whether it be a large tree or a small herb, are all to be traced back to the primary axis. * It is impossible to define exactly the limits of the hypocotyl unless the compound microscope be Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of t
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