32 



PICEA:— 



Megaspore membrane: Picea ahies (Fig. 52). 

 Pollen grains: Picea jezoensis (Fig. iiU). 



lOLOGlCAL 

 .BORATORY 



iJ>BRARY 



WOODS HOLE, MASS. 

 VI H. 0. I. 



Fig. 52. Picea ahies; part of an acetolyzed megaspore membrane at high (a) 



and low (b) focus. 



