PLANT BREEDING 



421 



feeding hogs for bacon, 

 especially for exporta- 

 tion. It has been found 

 possible, at the Uni- 

 versity of Illinois Ag- 

 ricultural Experiment 

 Station, to breed low- 

 protein corn with an 

 average percentage of 

 6.7 proteins, and high- 

 protein corn with an 

 average percentage of 

 14.4 proteins. At the 

 same station the average 

 low-oil corn contained 

 2.5 per cent of oil and 

 the high-oil corn 7.0 per 

 cent. The process of 

 selection must be kept 

 up, for the variations 

 thus obtained are not 

 permanent varieties. 



386. Method of corn 

 breeding. It may be 

 said in a general way 

 that the method of 

 breeding corn is based 

 on the same principles 

 as those adopted for 

 wheat and other cereals. 

 There are, however, 

 many variations in de- 

 tails, some of the most 

 important depending on 

 the fact that the plants 

 should be pollinated 



Pig. 336. Structure of an ear of corn (pistil- 

 late flower cluster) 



A, section of young ear before fertilization of the 

 ovules (grains) : ax, axis of spike (cob) ; si, ends 

 of silk (styles and stigmas). B, magnified sec- 

 tion through a grain, showing bracts around the 

 ovary, the ovule (o) , and the base of the style ; 

 C, upper portion of style, with the stigmas (st) 

 considerably magnified. After P. L. Sargent 



