THE BREEDING OF CORN 205 



according to Mendel's law, may be best understood by the 

 following simple illustration: 



If pure yellow corn be crossed with pure white corn the 

 result will be a hybrid containing both characters, yellow 

 and white. In this hybrid corn, however, all of the kernels 

 will appear yellow because of the fact that in corn the 

 character yellow is dominant over white and hence masks 

 the white color. In this case white is said to be recessive. 

 A plant produced from this hybrid seed will produce pollen 

 grains one-half of' which will represent yellow corn and 

 one-half white corn. The same is true with regard to the 

 ovaries. While the plant is hybrid, the sexual elements 

 remain pure. When fertilization takes place, whether 

 it be self-fertilization or close-fertilization, four different 

 combinations of male and female elements are possible as 

 shown below: 



All of the kernels resulting from the union of yellow X 

 white and white X yellow germ-cells will appear yellow 

 because of the dominance of that color. The kernels re- 

 sulting from the union of the germ-cells yellow X yellow 

 will show the yellow color because in this combination the 

 potentiality of white is entirely absent. The white color 

 will be apparent following the combination white X white 

 because here the potentiality of yellow is not present to 

 mask it. We will therefore have on each self -fertilized 

 hybrid ear three yellow kernels 'to one white kernel. Of 



