GNETALES— EPHEDRA 383 



bryo nucleus passes into the tube, followed by the suspensor nu- 

 cleus, and a wall is formed between them, beginning at the outside 

 and progressing to the center (fig. 364 Z)). 



The embryo cell then divides and the embryo develops. While 

 three or four may reach the stage shown in fig. 364 C, the ripe seed 

 scarcely ever contains more than one embryo. If conditions are 

 favorable, there is no resting period: the seed germinates at once 

 and the seedling becomes established the same season. 



