FLOWERS: POLLEN ATION AND FERTILIZATION 109 



organs called the sepals. This is the calyx. Its function is to pro- 

 tect the flower in the bud condition and to help support the other 

 parts when it opens. 



Inside the calyx comes the corolla consisting of a row of colored 

 parts called petals. These are often for the attraction of insects 

 as we shall see when studying 

 pollenation, and may also 

 help to protect the inner and 

 more essential parts. 



Next inside the corolla 

 we will come to several 

 knobbed, hair-like organs. 

 These are the stamens. The 

 knobs at their tops (anthers) 

 are very important, as they 

 produce and scatter a yellow, 

 dust-like substance known as 

 pollen. They are placed on 

 these thread-like supports 

 (filaments) so that the pollen 

 will have a better chance to 

 be distributed. 



In the very center of the 

 flower is the pistil consisting 

 of a sticky knob at the top 

 (stigma) to catch pollen, a 



slender stalk (style) to support the stigma, and an enlarged portion 

 at .the base (ovary) which contains the undeveloped seeds (ovules) 

 and later develops into the fruit. 



Pollenation. In order that a flower may produce seed, the pollen 

 must be transferred from the anther to the stigma, and usually it 

 must be from the anther of one flower to the stigma of another of 

 the same kind. This transfer of pollen from anther to stigma is 

 called pollenation. If, as in most cases, it is between different 

 flowers, it is called cross pollenation and is the process for which the 

 flower parts are adapted. Insects and wind are the two chief 



S. $,**!.. (CM 



P. ftTAi., ft 



STYLt 



OvAftr 



OVULES 



FIG. 32. The flower is provided with 

 means for seed production. 



