92 FUNDAMENTALS OF AGRICULTURE. 



out or be shaken out by the wind, by which means they 

 are frequently wafted long distances. It has been es- 

 timated by the writer that each anther produces about 

 2,500 pollen grains, and that a single tassel bears 

 about 10,000 anthers, so that the plant produces about 

 25,000,000 pollen grains. The pistillate flowers are 

 protected by husks or modified leaves, which open at 

 the proper time to permit the projection of the stig- 

 matic portion of the silk or pistil. This stigma, in a 

 receptive condition, is moist with a sticky substance, and 

 covered with fine hairs. Pollen grains falling on the 



EAR OF CORN BORNE BY ISOLATED STALK, SHOWING LACK OF SELF 

 FERTILIZATION. 



receptive stigma are caught by these hairs, and under 

 the influence of the moisture of the stigma and heat 

 of the atmosphere germinate. 



The germinating pollen grain sends a pollen tube 

 through the hollow silk to the top of the ovule, where 

 the nuclei of the pollen grain unites with the egg cell 

 within the ovule, and fertilization takes place. The 

 fertilized egg cell begins growth, and together with the 

 surrounding ovary develops into the kernel of corn. 

 As a rule there are from 500 to 1,200 ovaries borne 

 by each cob, with a silk for each ovary. 



So it can be seen from the above description that 

 every silk must be pollinated by at least one pollen 

 grain in order for the production of mature corn 



