EVOLUTION AS SHOWN BY PLANTS 347 



and pistils are members of a sexless generation, or sporo- 

 phyte. They themselves are sporophylls or spore-pro- 

 ducing leaves. The stamens produce that very obvious 

 and well-known product of flowers the pollen; and the 

 grains of pollen are microspores or sexless spores, which 

 upon germination will produce the male generation of the 

 plant; but they themselves are not to be confused with the 

 male element. They have been thus confused largely on 

 account of the process of transfer of pollen from stamen to 

 stigma at the top of the pistil. This process is commonly 

 called fertilization and that is the name of the sex process, 

 and if this were fertilization the pollen certainly would be 

 the male element. But this process is not fertilization. 

 It is pollination, and pollination is no more fertilization 

 than the delivery of a bar of steel at a watch factory is 

 the manufacture of a delicately tempered watch spring. 

 Fertilization occurs after pollination — it may be hours or 

 days or even weeks after — and it is a process which occurs 

 down at the very base of the pistil among those "baby 

 seed" organs known as ovules. It is wholly distinct and 

 separated by an entire generation of life history from the 

 deposit of the pollen grain by insect visit or uncertain breeze 

 upon the sticky stigma. It is also separated in position by 

 the commonly elongated "style" of the pistil down which 

 the pollen tube must grow, and it is this pollen tube which 

 carries the male cells. 



In flowers, in addition to having the differentiation of 

 two kinds of spores, which we found also in some of the 

 fern group, we have also the differentiation of two kinds of 

 sporophylls. That is, the stamen is one kind of sporo- 

 phyll: it bears microspores which are commonly known as 



