I^jiin^l f 



THE MITOTIC CYCLE 





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Figure 57 Stages in mitosis and cell division of Spirogyra 

 setiformis a — e X 1050; f , g X 850; h X 2000. a Nucleus 

 in metaphase. b Early anaphase; nuclear membrane 

 ruptured, c Later anaphase, d Still later anaphase; 

 vacuolar swelling in spindle, e Telophase, f Later telo- 

 phase. Vacuole very large. Early stage in the formation 

 of the diaphragm, g Diaphragm nearly complete. 

 h Detail of formation of diaphragm at stage g From 

 McAllister^*! ^jjy courtesy, Amer. J. Bot.), 



It is probable that our general understanding of cell division could be 

 deepened by an extended comparison of the process seen in plants and 

 in animals. The difference in the nature of the cell wall in both groups 



148 



