CLASSIFICATION OF CORN 49 



The flowers of corn are monecious; that is, the male and 

 female parts of the flower are borne on different parts of 

 the plant. The tassel bears the male part and the silk is 

 the visible part of the female flower. As in other plants, the 

 male flower produces the pollen which is to pollinate the 

 female flower. As it is produced at the top of the stalk, the 

 pollen easily falls by gravity, or more commonly, it is 

 blown from the tassel to the stigma of the female flower. 

 Because of the manner of pollination and because many 

 corn plants are usually grown together, crossing very gener- 

 ally results; that is, pollen from one plant fertilizes the 

 ovaries of other plants, so that corn is usually cross pollinated. 

 In fact, this habit is so general that a stalk growing by itself 

 seldom, if ever, produces a good ear, because of imperfect 

 fertilization of the flowers. 



50. Mixing of Varieties. The flowering habits of corn 

 make it extremely difficult to maintain pure varieties, as 

 they will mix for considerable distances. For this reason 

 it is highly desirable for a community to grow but one 

 variety. If adjoining farms produce different varieties, 

 each is very likely to be mixed with the other. In favorable 

 weather, the pollen grains may be carried by the wind at 

 least 200 rods if there is no obstruction in the way. The fact 

 that the prevailing winds in the corn belt are from the south- 

 west during the season of the year when corn is blossoming 

 is made use of to some extent by locating the seed plat 

 from which seed for the next year's crop is to be selected 

 where the wind blows from it to the other corn fields, rather 

 than from the other corn fields to it. 



CLASSIFICATION 



51. Variation. All the varieties now so common in every 

 section of the country are the result of selection and breed- 



