84 ■ CORN CROPS 



each region has had some effect in modifying the 

 original type. 



SUMMARY 



60. The early culture of corn probably originated in 

 the high plateau region of southern Mexico, about the 

 beginning of the Christian Era. From here it spread 

 north and south, its culture being general throughout 

 North and South America by the year 1000 a.d. 



The Indians grew flint and flour corns chiefly, probably 

 because of their keeping and germinating qualities. 



Most of the modern varieties in general use in North 

 America have been developed during the past century, 

 though the principal types have probably been in existence 

 for many hundred years. 



Selection, both artificial and natural, accounts for the 

 origin of many varieties ; while crossing, sometimes in- 

 tentional, but often accidental, has furnished a great many 

 variations from which to choose. 



References on early culture : — 

 See, References on early history ; p. 24. 



References on origin of varieties : — 

 Mo. Agr. Exp. Sta., Bui. S7 : 113. 

 Nebr. Agr. Exp. Sta., Bui. 83 : 12. 

 U. S. Dept. Agr. Yearbook, 1907 : .3.31. 

 Bowman and Crossly. Corn, p. ilA. 



