NUCLEAR AND CELL-DIVISION. 



13 



Figs. 12-21. Ten stages of mitotic nuclear division from the oral epithelium of the 

 larva of a salamander. (Plate I, Sobotta and Huber's " Atlas and Epitome of Human 

 Histology," 1903) : Fig. 12, Cell with resting nucleus ; Fig. 13, cell with nucleus at the 

 beginning of mitosis; Fig. 14, nuclear membrane has disappeared, chromosomes in a 

 loose skein, pole field at the left; Fig. 15, monaster viewed from above ; Fig. 16, mo- 

 naster viewed from the side, achromatic spindle is also shown ; Fig. 17, monaster viewed 

 from the side, with chromosomes crowded closely about the equator of the spindle ; Fig. 

 18, stage of metakinesis ; Fig. 19, diaster with beginning constriction of the cell-body: 

 Fig. 20, dispirem with completion of the cell division ; Fig. 21, telophase. 



and centrosphere undergo important changes. This is the prepar- 

 atory stage. 



The metaphases, in which the division and the separation of the 

 chromatin take place. 



The anaphascs, in which the daughter nuclei are formed and the' 

 cell-protoplasm begins to divide. 



The telopliases, in which the division of the cell is completed. 

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