. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. GROWTH OF NUCLEUS 111 appears that the cessation of the taking- in of more material would indicate that after the nucleus has reached a certain size it controls the action of the cytoplasm, since it has been observed many times that when this amoeboid activity ceases and the rounding-up process takes place there are many pseudocells very opportunely placed so that the cytoplasm of the egg could take them in with, may I be permitted to say, very little effort. Would this not indicate that the nucleus is through with its growt
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. GROWTH OF NUCLEUS 111 appears that the cessation of the taking- in of more material would indicate that after the nucleus has reached a certain size it controls the action of the cytoplasm, since it has been observed many times that when this amoeboid activity ceases and the rounding-up process takes place there are many pseudocells very opportunely placed so that the cytoplasm of the egg could take them in with, may I be permitted to say, very little effort. Would this not indicate that the nucleus is through with its growth, since it allows no more additions to the cyto- plasm, and that, at least at this period, it has a definite nucleo-cytoplasmic relation? This growth (to a certain size in relation to the cytoplasm) having been reached, the nucleus goes into the process of maturation during which the nuclear material is reduced. During this process the cytoplasm remains comparatively dormant and does not take any part. TEXT FIG. Nuclear membrane from normal to maturation stage. X 847. in the cell's activity until the nucleo-cytoplasmic relation has been restored by the entrance of the sperm, which again restores the relation that previously existed. THE NATURE OF THE GROWING NUCLEUS By the methods employed in this study, one is unable to see the small dark ovoid body near the nucleus or to measure the relation of the nucleus to the cytoplasm with any accuracy except in the later stages. The nucleus of the young egg, however, can always be dis- tinguished from the nuclei of the surrounding enlarged interstitial cells. This distinction lies in its different refraction of the light and its more solid appearance. The nucleoli vary greatly in number during the growth of the nucleus and are apparently produced by the fusion of the many small nucleoli which are constantly being formed. The larger nucleolus apparently grows also in proportion to a certain nuclear. Please note that these images are ext
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
