GREEN PLANTS SOLVE LIFE PROBLEMS 



263 



Thus we may have very rapid growth of some parts. 



Of What Use Are Flowers? If you will study the 

 picture of the flower on the opposite page, you will find 

 certain structures called stamens. They contain pollen 

 grains of which we will learn more later. In the center 

 of the flower we see another structure called the pistil. 

 The enlarged base of the pistil, called the ovary, holds 

 the structures which will later become seeds. If you cut 

 open an ovary, you will find the future seeds, called 

 ovules, fastened to the inner walls of the ovary. 



What Results from Pollination. If you have ever 

 visited a garden, you could not help but notice bees 

 visiting flowers. If you watch one 

 carefully to see what it is after, it 

 will be seen to poke its long tongue 

 down into the flower. It is after 

 nectar, the sweet secretion out of 

 which bees make honey. But bees 

 also gather pollen, the yellow tiny 

 grains which are made in the tiny 

 boxlike anther of the stamens. So 

 it often happens that the bees, in 

 their quest for food, transfer pollen 

 from the stamen of one flower to 

 the pistil of another flower of the 

 same kind. This process is called cross-pollination and 

 results in the growth of the pollen grains which light on 

 the end of the pistil. These grains grow a long tube down- 

 ward into the lower part of the pistil, called the ovary. 

 This tube carries with it several cells, one of which, a very 

 tiny body, is called the sperm cell, which unites with a 

 larger egg cell hidden in the ovary. This process is called 

 fertilization and results in the growth of the fertilized egg 

 into an embryo or baby plant. Only seeds with live 

 embryos will grow into young plants. It is thus seen 



Explain how a bee might carry 



pollen from one of these flowers 



to another. 



