466 GENERAL MORPHOLOGY OF PLANTS 



of the starch. Corn, therefore, can be selected so as to develop 

 two races, one for protein and oil, and one for starch. In 

 Illinois, where a great deal of attention is given to breeding corn, 

 the oil content has been raised from between 4-5 per cent to 7 per 

 cent, and in other races has been reduced to 2 per cent. The grains 

 of corn on a single ear all have nearly the same percentage of a 

 given constituent. A few kernels then can be examined on 

 different ears, and from the ear giving the highest percentage of 

 the desired constituent the remaining kernels can be planted. 

 The product from this seed can be subjected to a similar 

 selection, and so on each year until the high standard of excel- 

 lence or the desired hereditary percentage is reached. The ker- 

 nels from each ear are sown in separate rows or patches so that 

 the crop from the different ears can be compared. Thereafter 

 the process must be continued for the purpose of growing seed 

 in order to keep the race up to the high standard. This is true 

 in all selection as has been pointed out above. At this point seeds- 

 men can continue the selection and furnish seed to the growers, 

 or the grower can each year raise his own seed. 



A race of corn with high starch content is better for feeding 

 hogs, since a firmer and better quality of bacon is produced than 

 from corn with a high oil content. Glucose is manufactured from 

 the starch, but manufacturers of glucose from corn prefer a corn 

 having a high percentage of protein and oil, since in the process of 

 separating the starch from the kernels, the by-products, protein 

 and oil (from the horny layer and embryo) are cheaply obtained 

 and sold for a good price. Therefore they w r ould be glad to pay 

 a higher price for a race of corn containing a high percentage 

 of oil and protein even though the percentage of starch were 

 reduced. A company which manufactures glucose could afford to 

 pay five cents more per bushel for corn containing one pound 

 more of oil. For the 50,000,000 bushels which this company use 

 annually this would mean $2,500,000 more than for the same 

 amount of a common race of corn. 



650. In connection with breeding for these constituents corn 

 should be bred for physical perfection, which includes length and 





