THE INDIAN CORN 



163 



sists of a radicle, which is turned toward the base of the kernel, 



and a plunmle, which is turned upward. The plumule bears 



several small secondary leaves. Wrapped about the radicle 



and plumule is a single broad, thick seed leaf (instead of the 



two seed leaves of the bean) ; 



this seed leaf separates the 



radicle and plumule on the inner 



side from the endosperm, and 



covers them on the outer side 



also, except for a very narrow 



strip. The wall of the ovary, 



which becomes the fruit coat 



(corresponding to the pod of the 



bean), remains thin and comes 



to be very closely united with 



the seed coat. Thus the corn 



kernel is a fruit containing a 



single seed ; but, because the 



fruit coat and seed coat have 



grown so closely together, it is 



only by studying the way in 



which the kernel has developed 



from the ovary of the flower 



that we can make sure that the 



outer covering of the kernel is really something more than 



a seed coat. 



At or near the free end of the kernel and on its upper side 

 (that is, on the side turned toward the tip of the ear) is a 

 small, sharp projection. This is the style ; the stigma (silk) 

 dried and withered after pollination but still remains at- 

 tached to the style. The end of the kernel that is attached 

 to the ear corresponds, of course, to the base of the ovary. 

 Near this place are the micropyle and the point of attach- 

 ment of the ovule within the ovary. But since these points 

 are both covered by the fruit coat they cannot be seen from 



Fig. 102. — A, z. side view of 

 a kernel of Indian corn, with a 

 portion of the fruit coat and seed 

 coat removed so as to show the 

 position of the embryo. B, a 

 lengthwise section of a kernel, cut 

 through the embryo ; a, style ; 

 b, horny endosperm; c, starchy 

 endosperm ; d, plumule, with sec- 

 ondary leaves ; e, thick seed leaf, 

 wrapped about the rest of the 

 embryo ; /, radicle ; g, point at 

 which the kernel was attached to 

 the cob. 



