150 APPLIED BIOLOGY 



is, one bean flower produces several embryos. A bean pod with one 

 seed would be equivalent to a grain of corn because it would be one 

 seed produced by one pistil. 



Examine arrangement of grains on the cob. The attachment of 

 each grain corresponds to the flower-stalk or pedicel of the bean- 

 pod. At the opposite (free) end of the grain is the withered base 

 of the style, best seen as a sharp point in some varieties of pop- 

 corn. In immature ears it is easy to see that a thread of so-called 

 "corn silk" (each thread is really a greatly elongated style) is at- 

 tached to the free end of each grain. The "silk" extends from each 

 grain in the groove between two rows of grains to the end of the cob 

 where the surrounding "leaves" or "husks" are arranged so that the 

 ends of the "silks " are exposed. These exposed ends are the stigmas, 

 one for each flower (represented by a pistil, and in the mature ear 

 by a grain). Pollen-dust from the tassels (which are flowers with 

 stamens only) falls or is blown by the wind upon the exposed "silks" 

 or stigmas. Down each "silk" or style a pollen- tube grows to the 

 ovule in the ovary. Then the ovary with its ovule develops into 

 a grain of corn with an embryo corn plant. 



Examine grains of field, sweet, and pop-corn and notice on one of 

 the flat sides of each grain an oval patch (usually a groove in dry 

 grains) which marks the position of the embryo beneath the covering 

 of the grain. Look at an ear of sharp-pointed pop-corn and deter- 

 mine whether the embryo is on the side toward the stalk or toward the 

 free end of the ear, and also note in which direction the remains of 

 the style is turned. Do you see any reason for this in reference to 

 position of the "silks" ? Now look at an ear of "field" corn and 

 compare. The style is not so prominent in this variety, but it is a 

 small elevation between embryo and end of grain. 



Imagine an ear of corn split longitudinally, and make a diagram 

 showing relation of grains to cob, and also indicate by dotted lines 

 the position of "silks" extending from a few grains. 



Remove the covering from a water-soaked grain or from "green" 

 corn (fresh or preserved in formalin). This covering is the "hull" 

 which is removed when making hominy or samp. In the old- 

 fashioned method of preparing hominy the grains were first boiled 

 in lye from wood ashes which loosened the hull, and then soaked in 

 water to remove the lye. 



With the sharp point of a knife, lift out the corn embryo (some- 

 times called the "germ"). The remainder of the grain (endosperm) 

 is food for the embryo. In the yellow varieties of corn the endo- 

 sperm is yellow and the embryo whitish in color. 



