Ri'RAL School Leaflet 1291 



Each wliite ovule thrusts its thread of silk upward luitil its tip pushes out 

 beyond the top of the husk; each silk is tipped with a stigma, which is 

 ready to reeei\'e the poUcn that falls upon it from the tassels of its own 

 stalk or that is blown upon it from the tassels of other corn plants. If one 

 of these ovules fails to receive pollen at the stigmatic tip of its long silken 

 st^de, it does not develop into a kernel of com, and the car ^^■ill then be 

 imperfect. Such undeveloped kernels are said to be blasted. The ovides 

 are set on the stem, or cob, in twin rows; thus each row is double, being 

 made up of pairs of ovules. If different varieties of corn are planted near 

 together, the pollen from one kind may be carried by the wind over to the 

 ears of the other kinds, and the restilt will be a mixture of two varieties 

 on the same cob. 



The ears are bonie at the joints, or nodes; and where the ear presses 

 against it, the stalk is grooved to hold it more snugly. The husks show 

 plainly that they are modified leaves, in the following ways: The husk 

 has the same structure as the leaf; the outside husks are green and 

 therefore do the work of leaves. The husk often changes to leaf shape 

 at the tip of the ear, thus showing that the husk itself is that part of 

 the leaf that nomiaUy clasps the stalk. As a matter of fact, the ear 

 of com is on a branch stalk, which has been much shortened so that the 

 nodes are ver}' close together, and the leaves therefore are arranged close 

 together. By stripping the husks back, one by one, from the outside stifl 

 green leaf to the inner stalk, the papery wrapping for the seed ma}' be seen 

 in all its stages. 



Formerly seed com was selected according to the following rule: 

 " The ear should be of good length, cyHndrical rather than pointed, 

 the cob firm and well filled from butt to tip with kernels uniformly 

 large, of good color, and in regtdar rows that show no space between." 

 The modem method requires that seed com be selected in the field from 

 thrifty, high-yielding plants. After the ears have been selected, typical 

 kernels should be germinated in a seed tester to prove the vigor of the 

 seed before it is planted. 



OBSERVATIONS FOR PUPILS 



1 . Describe the central stem of a stalk of ripe corn. How many joints, 

 or nodes, are there in it? Of what use to the plant are these nodes? 

 Are they near together at the top or at the bottom of the stalk? 



2. Cut a cornstalk across and describe its structure. Which is the 

 stronger, the outer or the inner portion? 



3 . Where are the leaves attached to the stem ? Take off a leaf and note 

 how miuch of it clasps the stem. (Jf what use to the plant is the extra 

 strength given by the clasping leaf? 



