PREPARATION AND PLANTING 185 



which are of only local importance, makes rather confusing 

 a study of experiments, in order to select the best varieties. 

 In some cases a number of varieties have had a common 

 origin and for a general discussion might be grouped to- 



FiG. 52. — Rough division of the United States into corn regions, accord- 

 ing to the types of corn grown. 



gether. There are other groups, originating from widely 

 different sources, which are yet very similar for all practi- 

 cal purposes. 



The eastern half of the United States, where most of 

 the corn is grown, may be roughly divided into large 



