. The cell in development and inheritance. Cells; Cells. Fig. 75. — Pathological polyspermy. A. Polyspermy in the egg oi Ascaris ; below, the egg-nucleus ; above, three entire spermatozoa within the egg. [Sala.] B. Polyspermy in sea-urchin egg treated with nicotine-solution; ten sperm-nuclei shown, three of which have conjugated with the egg-nucleus. C. Later stage of an egg similarly treated, showing polyasters formed by union of the sperm-amphiasters. [O. and R. HERTWIG.] centrosomes (Fig. 75). Such eggs either do not divide at all or undergo an irregular multiple cleavage and soon pe
. The cell in development and inheritance. Cells; Cells. Fig. 75. — Pathological polyspermy. A. Polyspermy in the egg oi Ascaris ; below, the egg-nucleus ; above, three entire spermatozoa within the egg. [Sala.] B. Polyspermy in sea-urchin egg treated with nicotine-solution; ten sperm-nuclei shown, three of which have conjugated with the egg-nucleus. C. Later stage of an egg similarly treated, showing polyasters formed by union of the sperm-amphiasters. [O. and R. HERTWIG.] centrosomes (Fig. 75). Such eggs either do not divide at all or undergo an irregular multiple cleavage and soon perish. If, how- ever, only two spermatozoa enter, the &g'g may develop for a time. Thus Driesch has determined the interesting fact, which I have con- firmed, that sea-urchin eggs into which two spermatozoa have acci- dentally entered undergo a double cleavage, dividing into four at the first cleavage, and forming eight instead of four micromeres at the. 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 Wilson, Edmund B. (Edmund Beecher), 1856-1939. New York : The Macmillan company
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectcells, bookyear1896
