20 



Fig. 31. A (main figure): Ephedra monosperma; section through an acetolyzed 

 pollen wall, x 19,000. B (lower right-hand corner): Cycas reuohita; section 

 through part of an acetolyzed pollen wall, x 35,000. The black horizontal 

 lines indicate 1//. (EMG; from Afzelius in Grana palynologica, 1:2, 1956.) 



