THE CHAROPHYTA 385 



NODAL CELL ^OOSPHERE^^ ENVELOPING CELLS 



ENVELOPING 

 CELLS 



CORONULA 



OOSPHERE 



TURNING 

 D CELL 



VELOPING 

 CELLS 



Fig. 368. — Chara vulgaris. Development of the oogonium. A, Forma- 

 tion of oosphere. B and C, Origin of the enveloping cells. D, 

 Septation of enveloping cells to form coronula. E, Twisting of 

 enveloping cells. F, Mature oogonium. {After de Bory atid Migula.) 



Coronula 



Oosphere 



Er)veloping cells 



Node cell 



Fig. 369. — Chora fragilis. Mature oogonium 

 containing an oosphere. 



