. Cytology, with special reference to the metazoan nucleus. Cells. r c Fig. 12. Four stages in " amitotic " division in a tendon of a new-born mouse. (Nowikoff, , 1910.) of surface relative to volume, and that the lobes are withdrawn or the fragments fuse together again before mitosis. In Lepidosiren the spermatogonial nuclei during periods of nuclear inactivity become very irregular and deeply lobed. Preparations for mitosis are only found, however, in approximately spherical nuclei, implying that the lobes have been withdrawn. Meves (1891, 1895) found that the spermato- gonia o
. Cytology, with special reference to the metazoan nucleus. Cells. r c Fig. 12. Four stages in " amitotic " division in a tendon of a new-born mouse. (Nowikoff, , 1910.) of surface relative to volume, and that the lobes are withdrawn or the fragments fuse together again before mitosis. In Lepidosiren the spermatogonial nuclei during periods of nuclear inactivity become very irregular and deeply lobed. Preparations for mitosis are only found, however, in approximately spherical nuclei, implying that the lobes have been withdrawn. Meves (1891, 1895) found that the spermato- gonia of the salamander are lobed in the winter. In the spring the lobes are withdrawn and the now regularly rounded nuclei proceed to mitosis. In'the cleaving eggs of Triton (Rubaschkin, 1905) the nuclei are often completely divided into two, three or even more separate nuclei, though it is probable that in this case they have not been produced by the fragmentation of a single mother nucleus, but by the separation of the telophase chromosomes into groups, from each of which a separate Uttle nucleus is formed. In prophase, chromosomes arc formed in each one of the separate nuclei, which remain isolated till the nuclear membranes. 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 Agar, Wilfred Eade, 1882-. London, Macmillan
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectcells, bookyear1920
