78 THE BOOK OF CORN 



lar maturing of all parts of the ear. As the kernels 

 mature from the butt to the tip of the ear, the differ- 

 ence in time of maturing of the butt and the tip may be 

 so great that the silks on the tip do not become ready 

 for fertilization until the pollen of that variety is gone. 

 Now if the tip is filled at all it must be by pollen from 



Fig 24— Illustrating Pollen Grains 



Magnified. See Chapter IV 



some other later variety or else it remains unfertilized 

 and a poorly filled tip is the result. 



There are many illustrations of this in every field 

 of corn which has been grown by the side of another 

 field of a different color. For instance, a pure white 

 ear frequently has the tip filled out with yellow ker- 



