SPERMATOPHYTES 



305 



Only one of the macrospores develops into a Gametophyte, 

 which remains enclosed in the sporangium. Several archegonia 



1 



FIG. 151. Cycas revoluta. 



which are somewhat simpler than those of the Pteridophytes are 

 developed at the micropolar end. The microspores (or pollen 

 20 



