CH. VIII] 



SPIROGYRA. 



117 



The zygospore clothes itself with a thick resisting cell- 

 wall, and after a period of rest germinates and gives origin 

 to a new Spirogyra filament. 



FIG. 51. 

 SPIROGYRA. 



A. G, represent various stages in the process of conjugation. 

 H, fully formed zygoapores. 



Note the loop-like folds in the cross-walla ; they are connected with 

 the mode of growth of the cells. 



