Kl'ElIMATOPIIYTES ; (; VlINrjSl'KKMS 



349 



danger of becoming confused and of forgetting that pollen 

 grains are asexual sj)ores. 



229. Megasporophylls. — The strobili composed of mega- 

 sporophylls become much larger than the others, forming 



Fif!. 310, P'nui^ a'v/''''-^V/7"a'. sliowinc: niiUurc oono parlly PfftinTinil. nnd slinwine r!lr- 

 pels isq, f^q^, t^-q^ with SL-t^ds in their axils (f/), in wliicli the ciiihryns i< /// \ in;iy lie 

 distinguished ; A, a yonng carpel with two niet^asporatigia ; Ji. an old carpel ^virh 

 mature seeds (r/t), the nrieropyle being helow (J/").— After Bessey. 



the well-known cones so characteristic of pines and their 

 allies (Fig. 308, «, I', r). Each sporophyll is somewhat 

 leafdike, and at its base upon the upper side are two 

 megasporangia (Fig. 310). It is these sporangia which are 

 peculiar in each producing and retaining a solitary large 

 megaspore. This niegaspore resembles a sac-like cavity in 



