GNETALES— WELWITSCHIA 



405 



ward the center. The wall is complete before another mitosis takes 

 place, so there is no free nuclear stage (fig. 379). 



Fig. 380. — Wdwitschia mirabilis: seedling in greenhouse at the University of Chi- 

 cago 



The upper cell elongates and becomes the primary suspensor: 

 the embryo is derived from the lower cell. The primary suspensor 

 cell elongates but does not divide. The inner cortical ring cells 

 elongate immensely (compare icr in B and C of fig. 379), sur- 

 rounding the primary suspensor cell. The outer cortical ring cells 



