POLLINATION 23 



The plant is also able to prevent injury to its leaves by 

 taking on that noticeably wavy form which gives them 

 elasticity. 



Pollination. The blossom of corn is imperfect. Its 

 staminate or male flower is borne on the tassel, and 

 its pistillate flowers, known as the silks, on the ears. 

 There are a sufficient number of silks so that if each is 

 pollinated and produces a kernel of corn, a perfect ear is 

 formed. 



A single tassel is able to shed eighteen million pollen 

 grains, consequently great clouds of pollen are spread 

 over cornfields during the blossoming season. The vast 

 amount of pollen grains present in a field of corn renders it 

 possible for each silk to be fertilized and produce a kernel. 

 The silks at the butt of the ear come forth first, and those 

 up through the center of the ear follow toward the tip. If 

 a very dry or a very wet spell comes during the early part 

 of the pollinating season, the butt silks will not be perfectly 

 pollinated, and if the dry or wet spell comes during the 

 latter part of the season the tip silks will not be properly 

 fertilized, and defective ears will result. (See Fig. 9.) 



Pollen grains may be carried from a fourth to a half mile 

 by a strong wind and often a field of choice corn may be 

 crossed by an inferior variety grown in a neighboring field. 

 In order to keep the variety of corn pure it is necessary to 

 plant it a safe distance from other fields. If a small grove 

 or a hill lies between the fields, there is little danger of cross- 

 ing. The prevailing wind blows quite steadily from one 

 direction during the pollinating season and if one variety 

 of corn is planted on the side of the field next to the prevail- 

 ing wind, little crossing will occur from the pollen of other 

 corn growing in the same field. 



