THE CELL AND PROTOPLASM. 



115 



twenty-four. During this process of the forma- 

 tion of the chromosomes the nucleoli disappear, 

 sometimes being absorbed apparently in the 

 chromosomes, and sometimes being ejected into 

 the cell body, where they disappear. Whether 

 they have anything to do with further changes 

 is not yet known. 



The next step in the process of division appears 



FIG. 27. 



FIG. 28. 



FIG. 27. This and the following figures show stages in cell division. 



Fig. 27 shows the resting stage with the chromatin, cr, in the form 



of a network, within the nuclear membrane and the centrosome, 



ce, already divided into two. 

 FIG. 28. The chromatin is broken into threads or chromosomes, cr. 



The centrosomes show radiating fibres. 



in the region of the centrosomes. Each of the 

 two centrosomes appears to send out from itself 

 delicate radiating fibres into the surrounding cell 

 substance (Fig. 28). Whether these actually 

 arise from the centrosome or are simply a re- 

 arrangement of the fibres in the cell substance 

 is not clear, but at all events the centrosome 

 becomes surrounded by a mass of radiating fibres 



