io8 



THE LIVING CYCADS 



Fig. 55. — Stangeria paradoxal nucellus of ovule with pollen tubes, 

 in three of which the two sperms are shown. Highly magnified. 



Figs. 56-57. — Dioon edule: two stages in the development of the 

 pollen tube and body cell: Fig. 56, December condition, body cell 

 elongated and the blepharoplasts arranged in the long axis of the tube; 

 Fig. 57, several months later, the blepharoplasts having rotated until 

 they are transverse to the long axis of the tube. In both figures the 

 outer spore coat of the pollen grain is easily seen; the inner spore coat 

 has developed into the pollen tube. Highly magnified. 



