102 FERN-SEED 



delicate young fern-fronds of minute size shoot up by 

 vertical growth (Fig. 8, B). The method of the reproduc- 

 tion of ferns and the proof of the seed-like nature of the 

 spores was now regarded as at last demonstrated. The 

 mystery of " fern-seed" was thought to be at an end. But 

 this was really far from the case. 



It seems to many of us a commonplace though doubt- 

 less it is news to some that flowering plants produce 

 " germs," or egg-cells in the centre of the flowers in that 

 part called the pistil and that the heads of the stamens 

 produce a powder of fine granules called the"" pollen-grains," 

 which either fall or are carried by wind or by insects (or 

 by the gardener, when he carries out " artificial pollina- 

 tion ") on to the sticky end of the pistil (called the stigma) 

 and there grow down into the inside of the pistil as deli- 

 cate threads, so that they reach the germs or ovules fuse 

 with them, and so " fertilise " them. The fertilised ovules 

 then undergo a growth, swell up and become ripe " seeds." 

 Yet this process of " the fertilisation of flowers," and the 

 significance of pollen as the male fertilising element, was 

 quite unknown until a little over two hundred years ago, 

 when it was discovered by one Nehemiah Grew (who was 

 in 1677 secretary of the Royal Society of London) in the 

 old Physick Garden opposite Magdalen College at Oxford. 

 Seventeen years later it was placed on a sure footing by 

 the experiments of Jacob Camerarius, who proved that 

 " seed " does not become fertile unless fecundated by pollen. 



It is a singular fact that the ancients had no conception 

 of the existence of male and female reproductive particles 

 in plants. They seem to have regarded " pollen " as 

 meaningless dust. Aristotle expressly declares that plants 

 have no males and females, though he says he knew some 

 facts which led him to conclude that some trees " aid " others 

 in the production of fruit, as in the case of the fig-tree and 

 the capri-fig. The aid given in that case is now known 



