PLANT BREEDING AND EVOLUTION 



195 



the amount of starchy endosperm, the width of the protein layer, 

 or the size of the embryo (Figs. 105 and 106). In this manner 



" one hundred sixty-three 

 ears of Burr White Maize 

 from the 1896 crop were 

 analyzed and the proper 

 selections in each case 

 planted in their respective 

 plots. In each plot from 

 twelve to twenty-four 

 rows were planted, and 

 each row contained only 

 the kernels from a single 

 ear. In succeeding years 

 a hundred or more ears 

 were analyzed from each 

 breeding plot, and those 

 ears from the high-protein 

 plot which showed the 

 highest per cent of protein 

 were saved to plant the 

 next year's high-protein 

 plot, while those from the low-protein plot were saved to plant the 

 low-protein plot of the next season. Like methods were followed 

 in the high-oil and low- 

 oil breeding plots." - ?- - 



By this method the oil, 

 which is called corn oil, 

 was increased in six years 

 in a strain of corn from 

 4.7 per cent to nearly 

 7 per cent, while the 

 protein used in making 

 hominy grits and for 

 feeding stock was increased from 10.6 per cent to 16 per cent. 

 The same general procedure outlined above for the produc- 

 tion of improved types of corn by the selection of favorable 



FIG. 1C5. Kernels of corn with high and 

 low percentage of oil 



A, AI, transverse section and face view of ker- 

 nels with large embryo having high oil content ; 



B, />!, same views of kernels with small embryos 

 having low oil content. From Bulletin 87, Uni- 

 versity of Illinois Agricultural Experiment Station 



A 



FIG. 106. Kernels of corn with high 

 percentage of protein 



A, high-protein kernel; />, low-protein kernel; 



e, embryo; s, starchy area; p, horny, or protein, 



layer.- From Bulletin 87, University of Illinois 



Agricultural Experiment Station 



