Crops. 185 



heavy soils is probably due to excessive production of nitrates 

 from humus or manure, Avhich induces a rank growth of weak- 

 stemmed plants. 



Oat grain consists of approximately 70 per cent kernel and 

 30 per cent hull. The large proportion of hulls accounts for the 

 high fiber and ash content of the grain and reduces its digest- 

 ibility. On the other hand it appears to be of value for its 

 mechanical, laxative effect upon the digestive tract. This grain 

 is notable among the cereals on account of its high content of 

 fat. The ground, hulled kernels, known as "oatmeal," is much 

 used for "breakfast foods." The residual grain and poorer 

 kernels are worked into oat feeds. Whole oats is much prized by 

 the horse feeder. It has been supposed that the grain possesses 

 peculiar tonic properties, due to a specific compound, but there 

 are no scientific data in support of this view. 



Oat straw is more palatable than the other cereal straws and 

 possesses some value as a food for cattle and sheep. 



Corn, or maize, has formed over 50 per cent of the acreage 

 of cereals in the United States for several decades. In 1900 it 

 formed 56 per cent of the value of cereals and 28.5 per cent of 

 the value of all crops. The white man discovered it under cul- 

 tivation by the American Indian and gave to it the name Indian 

 corn. Continuous breeding has developed many improved va- 

 rieties, which differ widely in size, form, color and chemical com- 

 position. The common varieties of corn fall under three sub- 

 species : dent, flint and sweet corn. By far the greatest number 

 of varieties are of the dent species. This species derives its name 

 from the characteristic indentation of its crown, due to shrinkage 

 of the starch cap as the grain dries. Flint corn is characterized 

 by a smooth, firm coat, supported by a layer of hard or horny 

 starch, so that the grain retains its shape as it dries. Sweet corn 

 is characterized by a high percentage of sucrose and develops a 

 prominently wrinkled surface, as a result of shrinkage in drying. 



Examination of a longitudinal section of a corn grain made 

 by splitting it across the thin dimension, shows it to consist of 



