CYCADALES 



153 



M 



f-» 





y^ I 



n 



«v 



t" 



183 



^Ci 



ik 



I 





185 



Figs. 183-185. — Dioon edule: development of proembryo; fig. 183, base of 

 proembryo, showing character of segmentation at a stage when the entire egg is seg- 

 mented; X108; fig. 184, diagram of entire proembryo at the stage shown in fig. 183; 

 the segmentation is disappearing in the upper region; X20; fig. 185, permanent walls 

 at the base, but as yet no differentiation into regions; free nuclei above; membrane (m) 

 of egg not yet ruptured; X108. — After Chamberlaxn CvqI, 



