Male and Female 



23 



Some of the pollen is carried by the wind or by 

 insects to the sticky or hairy upper end of the 

 pistil, called the stigma. The pollen grains each 

 thrust out a tiny thread of their living substance, 

 finer than a hair, that grows 

 down through the tissue of 

 the pistil until it reaches an 

 ovule (Fig. 3). The thread 

 penetrates the ovule and 

 grows into the egg. Then a 

 part of the living substance 

 of the pollen grain unites 

 with the living substance of 

 the egg. This is called fertili- 

 zation. 



It is only after this has 

 been accomplished that the egg proceeds to 

 grow into the Httle plant. The fertilized egg 

 divides and subdivides and the resulting cells 

 grow larger. Subdivision and growth continue 

 until a mass of many, many cells is formed. 

 The mass changes shape and molds itself into 

 the little leaves and bud and stem that consti- 

 tute the embryonic plant. Meanwhile the rest 



Fig. 3. — Diagram 

 of the fertilization 

 process. 



