. Fundamentals of botany. Botany. SEED-BEARING PLANTS 439 392. The Female Gametophyte.^IMegaspores are probably not formed in tetrads by two divisions of a megaspore-mother-cell, but the ancestral-cell of the female. Fig. 325.—Dog's-tooth violet (Erylhronium). i, embryo-sac, binucle- ate stage, the two nuclei dividing; 2, four nucleate stage; 3, mature embryo- sac (es); the pollen-tube {) has reached the egg-apparatus and fertiliza- tion has just taken place; the male and female nuclei are both visible in the fertilized egg. The synergids are not shown; 4, polyembryony; four embryos have de
. Fundamentals of botany. Botany. SEED-BEARING PLANTS 439 392. The Female Gametophyte.^IMegaspores are probably not formed in tetrads by two divisions of a megaspore-mother-cell, but the ancestral-cell of the female. Fig. 325.—Dog's-tooth violet (Erylhronium). i, embryo-sac, binucle- ate stage, the two nuclei dividing; 2, four nucleate stage; 3, mature embryo- sac (es); the pollen-tube {) has reached the egg-apparatus and fertiliza- tion has just taken place; the male and female nuclei are both visible in the fertilized egg. The synergids are not shown; 4, polyembryony; four embryos have developed from the embryogenous tissue, one embryo at the left of a not shaded; 5, longitudinal section of an embryo {em); s, suspensor; r, 2, and 5, E. albidum (after Schaifner); 3 and 4, E. americaniim (after Jeffrey). Only one of the multiple embryos persists. gametophyte {archesporial cell) functions directly as a megaspore, without division. In very early spring the megaspore begins to germinate, increasing in size, and. 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 Gager, C. Stuart (Charles Stuart), 1872-1943. Philadelphia, P. Blakiston's son & co.
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Keywords: ., bookauthorgag, bookcentury1900, bookdecade1910, booksubjectbotany
