26 



CELLS. 



-Centrosome. 

 -Centrosphere. 



-Chromosomes. 



, Central 



spindle. 

 -Nucleolus. 



Centrosome. 



Crown of 

 ' chromo- 

 some. 



x Crown of 

 chromo- 

 some. 



FIG. 5. 



FIG. 6. 



FIG. 7. 



FIGS. 2-7. Diagrammatic representation of the processes of mitotic cell- and 



nuclear division (Bohm and Davidoff). 

 FIGS. 2-4, Prophases ; FIGS. 6, 7, metaphases. 



FIG. 2, Eesting nucleus ; FIG. 3, coarse skein or spirem ; FIG. 4, fine skein or 

 spirem ; FIG. 5, segmentation of the spirem into single chromosomes ; FIG. 6, longi- 

 tudinal division of the chromosomes ; FIG. 7, bipolar arrangement of the separated 

 chromosomes. 



