. The cell in development and inheritance. Cells; Cells. J M /Ao D. H 7 f K 90 L Fig. 92. — Reduction in the spermatogenesis of Ascaris niegalocephala, var. bivalens. [Brauer.] 1 A-G. Successive stages in the division of the primary spermatocyte. The original reticulum undergoes a very early division of the chromatin-granules which then form a doubly split spireme- thread, B. This shortens (C), and breaks in two to form the two tetrads {D in profile, E viewed endwise). F. G. H. First division to form two secondary spermatocytes, each receiving two dyads. /. Secondary spermatocyte. J. K. The sa
. The cell in development and inheritance. Cells; Cells. J M /Ao D. H 7 f K 90 L Fig. 92. — Reduction in the spermatogenesis of Ascaris niegalocephala, var. bivalens. [Brauer.] 1 A-G. Successive stages in the division of the primary spermatocyte. The original reticulum undergoes a very early division of the chromatin-granules which then form a doubly split spireme- thread, B. This shortens (C), and breaks in two to form the two tetrads {D in profile, E viewed endwise). F. G. H. First division to form two secondary spermatocytes, each receiving two dyads. /. Secondary spermatocyte. J. K. The same dividing. L. Two resulting spermatids, each with two single chromosomes and a centrosome. formed by their aggregation. Hence each chromosome has a dis- tinct and definite character of its own, representing a particular group of hereditary qualities. From this it follows that the number of ^ For division of the spermatogonia see Fig. 39 ; for the corresponding phenomena in var. univalens see Fig. 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
