98 



THE LIVING CYCADS 



41 



42 



c 



43 



44 



Figs. 41-45. — Dioon edide: development of the archegonium : 

 Fig. 41, the archegonium initial; Fig. 42, the archegonium initial di- 

 \dded, forming a primary neck cell and a central cell; Fig. 43, the pri- 

 mary neck cell divided, giving rise to the two neck cells; Fig. 44, the central 

 cell divided, giving rise to the ventral-canal nucleus (the smaller nucleus 

 at the top) and the egg, with the larger nucleus; Fig. 45, the archegonia 

 at a later stage, showing the depression (archegonial chamber) above the 

 archegonia. Figs. 41-44 highly magnified; Fig. 45 much less magnified. 



