Licence: Public Domain Mark
Credit: Elements of histology / by E. Klein. Source: Wellcome Collection.
Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.
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![[( hap. I. two points of the cell protoplasm; these points are called the foles, and the line midway between them— i.e., at the broadest part of the s])indle—is called the equator. At the poles the threads of tlie spindle are connected with a set of radiating iibrils of the cell protoplasm—the suns. The above sister-loops so arrange themselves about the equator of this spindle as to form a star—the moth,er-star, monaster, or' aster. In this arrangement the vertex of the loops is directed inwards, the open limbs outwai-ds. Been in pi'ofile the aster would appear like a narrow plate-—the nuclear plate. 4. Metakinesis : Of each pair of sister - loops forming the aster one loop migrates towards one, the other towards the other pole of the spindle, the vertex always leading. 5. Diaster : arrived at the pole, the loops form again an aster or daughter-star for each pole. 6. Dispireme: the threads of each star become convoluted. Now follows usually the division of the cell pro- toplasm in the line of the equator of the spindle. 7. In the last phase all traces of the spindle are lost ; a membrane appears around each of the two new nuclei, and the threads of the dispireme become branched and connected into a netwoi'k. From the foregoing it is clear that during division an intimate fusion between cell protoplasm and nucleus takes place : (a) by the fusion of the nuclear interstitial substance with the cell protoplasm after the disappearance of the nuclear membrane ; and (b) in the nuclear spindle, whose threads at the poles are joined to filaments of the cell protoplasm. In some cases the process of karyomitosis has been found to be atypical, inasmuch as some of the above phases are left out, as it were ; while in other cases the nuclear division takes place already during the](https://iiif.wellcomecollection.org/image/b24757238_0030.jp2/full/800%2C/0/default.jpg)
