. Nature and development of plants. Botany. 124 GERMINATION OF THE GAMETOSPORE surrounded tby a cell wall and attached to one side of the female gametophyte, which is henceforth called the embryo sac (Fig. §1, A).'. By a series of divisions the gametospore now forms a. Fig. 8i. Germination of the gametospore of peppergrass, Lepidium: A: micropylar end of the embryo sac showing that the gametospore, g (fertilized female gamete), has developed a cell wall and become attached to the wall of the embryo sac. Compare, Fig. 80. B, later stage in the germination—e, embryo cell; s, suspensory cells; en
. Nature and development of plants. Botany. 124 GERMINATION OF THE GAMETOSPORE surrounded tby a cell wall and attached to one side of the female gametophyte, which is henceforth called the embryo sac (Fig. §1, A).'. By a series of divisions the gametospore now forms a. Fig. 8i. Germination of the gametospore of peppergrass, Lepidium: A: micropylar end of the embryo sac showing that the gametospore, g (fertilized female gamete), has developed a cell wall and become attached to the wall of the embryo sac. Compare, Fig. 80. B, later stage in the germination—e, embryo cell; s, suspensory cells; en, endosperm cells. C, the embryo cell has formed two cells. D, later stage. The embryo cell by further division has formed a spherical mass of cells, here shown in section. Note the appear- ance of an outer layer of cells, the epidermis, and a central or stem region, s, a few of the suspensory cells. E, still later growth. Two growing regions, the cotyledons are appearing on the side of the stem. F, the micropylar end bf the embryo sac, showing the stage of development where the parts of a small plant can be clearly recognized—c, cotyledons; st, stem ending in root, r, to .which is still attached the supensory cells; en, endosperm cells, now pro- vided with walls, are being absorbed as the plant or embryo enlarges. Note that the embryo and embryo sac are slightly bent to the left. This curvature is the fact that the ovule in a great many plants becomes curved in itg development with the result that the embryo sac assumes a curved or U-shaped form. This form of the ovule results in a complete bending over of the cotyledons against the stem, as shown in the next Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Curtis, Carlton Clarence, 1864-1945. New York, H. Holt
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