The Nature of Plants n 



passageway through which the pollen can reach the 

 ovules. Even the stamens and anthers are merely 

 supports on which the pollen rests.' We need to con- 

 cern ourselves but little about these parts of the flower ; 

 but we must study the action of the ovules and the 

 pollen, for they produce the new plant. 



When the flower opens, the pollen, which is a very What a 

 fine powder, falls upon the stigma or is carried there by ^ain does 

 the wind or by insects. This is called " pollination." 

 Immediately the pollen grains begin to grow, not up- 

 ward, but down through the style. Like a delicate 

 rootlet a pollen tube is sent downward until it touches 

 the ovule at the bottom of the style. 



We can see the pollen grain and also the ovule ; but 

 now, to make clear a wonderful process, we must speak 

 of something which we cannot see without the aid of a 

 powerful microscope ; namely, the nucleus. The ovule 

 has within it a nucleus ; the pollen grain also contains 

 a nucleus. When these nuclei meet, they grow together 

 and the ovule becomes a seed. But for the coming of 

 the pollen grain the ovule would shrivel and drop off, 

 never becoming a seed or fruit (Fig. n and Exp. 10). 



The seed consists of three principal parts: (i) the The parts 

 germ or embryo (a baby plant), (2) the food material 

 needed by the growing germ, and (3) the seed coat. 

 When we plant the seed, it first absorbs moisture through How the 

 the seed coat. (Exp. n.) This starts the germ, which 

 is already a tiny plant, to growing, and causes the 

 starchy food material within the seed coat to begin to 

 ferment. The fermentation prepares the food substance 

 for use by the little plant as it grows. Even before the 



