SPERM ATOPH YTES : GYMKOSPEEMS 
349 
danger of becoming confused and of forgetting that pollen 
grains are asexual spores. 
229. Megasporophylls. The strobili composed of mega- 
sporophylls become much larger than the others, forming 
f -M 
FIG. 310. Pinus sylvestris, showing mature cone partly sectioned, and showing car- 
pels (sq, sq l , g 2 ) with seeds in their axils (g), in which the embryos (em} may be 
distinguished ; A, a young carpel with two megasporangia ; B, an old carpel with 
mature seeds (ch), the micropyle being below (M). After BESSEY. 
the well-known cones so characteristic of pines and their 
allies (Fig. 308, , #, c). Each sporophyll is somewhat 
leaf-like, 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 megaspore resembles a sac-like cavity in 
