CORN, WHEAT, OATS, BARLEY, RYE 47 



States produces some corn, although the acreage may be small. 

 The following table indicates the relative imxiortance of corn in 

 the different divisions of the United States : 



Origin of corn.— Corn was i^robably first brought under 

 cultivation in the plateaus of Central America. From there, it 

 probably spreads in both directions. By the time C()luml)ns dis- 

 covered America, corn was under common cultivation through- 

 out both continents. From America it soon spreads to Europe 

 where it has become of considerable importance, as shown by 

 the foregoing tables. 



So far as the biological origin is concerned, it is uncertain 

 what wild plant is the ancestor of corn. There are two wild 

 plants, gama grass and teosinte, which are closely related to 

 corn, and there is good evidence that corn may have originated 

 from one or the other or some closely related form. 



Classification of corn. — There are six principal types of corn 

 in cultivation, most of which have a large number of varieties. 

 These types are: Pop corn, flint corn, dent corn, soft corn, 

 sweet corn, pod corn. 



This classification is based very largely on the character of 

 the kernel. The first four are distinguished from each other 

 by the character of the starch within the kernel. Pop corn has 

 a very hard and flinty kernel ; flint corn is nearly as hard and 

 flinty but much larger and usually contains a small amount of 

 soft starch in the center; dent corn is not more than one-half 

 hard and flinty while the rest of the kernel is soft starch, the 

 larger part of which occurs at the top of the kernel which when 

 dry causes the denting; soft corn is made up entirely of soft 

 starch with a kernel shaped very much like that of flint; the 

 sweet corns differ from the others by possessing a sugary 

 instead of a starchy endosperm, the sugar failing to change 

 to starch as it does in the other types; the pod corns may be 

 any of the above types, whose indi\adual kernels are surrounded 

 bv small scales or pods. 



