IMPROVEMENT OF MAIZE 1 93 



Starch) is usually inversely proportional to that of the protein 

 and fat. If maize were bred for the manufacture of starch or 

 glucose, only low protein content would be desired, since the 

 fat or maize oil, which is a by-product of the manufacture of 

 starch, is worth more per pound than the starch. 



262. Advantage of Breeding for Composition. — Throughout 

 the North Central and Eastern States, and especially in those 

 States which raise a great surplus of maize, stock foods gener- 

 ally contain too small a proportion of digestible protein. The 

 protein is, therefore, the most expensive ingredient of stock 

 foods, being several times more expensive per pound than maize 

 itself. The raising of maize with a higher percentage of protein 

 would reduce the need of purchasing more expensive nitrogenous 

 foods, and would thus cheapen the food supply, provided the 

 yield of maize is not reduced as the per cent of protein is 

 increased. In the Southern States, the food supply for live 

 stock is highly nitrogenous, due to large surplus of cotton seed, 

 cottonseed meal and cowpeas. In this section, a high starch 

 content may be desirable. Large quantities of maize are an- 

 nually used for the manufacture of starch and glucose. The 

 Glucose Sugar Refining Company ^ says : 



"A bushel of ordinary corn, weighing 56 pounds, contains about 4 1-2 pounds 

 of germ, 36 pounds of dry starch, 7 pounds of ghiten and 5 pounds of bran or hull, 

 the balance in weight being made up of water, soluble matter, etc. The value of 

 the germ lies in the fact that it contains over 40 per cent of corn oil, worth, say, 5 

 cents per pound, while the starch is worth i 1-2 cents, the gluten i cent and the 

 hull about 1-2 cent per pound. 



" It can readily be seen that a variety of corn containing, say, one pound more 

 oil per bushel would be in large demand." 



263. Disadvantage of Breeding for Composition. — One disad- 

 vantage of breeding for composition and yield at the same time 

 is that breeding for two characteristics at one time is several 

 times more difficult than breeding for one. An objection to 

 breeding for high protein is that the 4imount of nitrogen re- 



l 111. BuL82 (1902), p. 526. 



