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STATE BOARD OP AGRICULTURE. 



IMPROVING QUALITY. 



This has reference to changing the physical characteristics of the ear 

 and kernel and the chemical composition of the kernel. Physical 

 changes are brought about both by selection and by cross-fertilizing. At 

 the present time selection is emplo^^ed to accomplish chemical changes, 

 and the chemical changes usually sought are in the starch, oil and 

 protein content, depending, of course, upon whether the corn is grown 

 for feeding purposes or for the starch factory. 



The oil is obtained from the germ, and the quantity of oil depends 

 upon the size and upon the quality — chiefly upon the size — of the germ. 



Fig. 19 — A studv of the structure of the kernel of corn, showing the location of the germ with the 

 embryo, and the distribution of tlie starch and the horny starch. The light portion is the starch. 

 The very dark portion is the horny starch. 



(a) Shows especially well the position and appearance of the embryo. 



(d) Shows a cross section of a kernel like (b) just above the horny starch. . 



(e) Shows a cross section of the same kernel just below the upper end of the horny starch. 



(f) Shows cross section of the same kernel at upper end of germ, 

 (c) Shows a larger proportion of horny starch than does (b). 



Fig. 19 shows the structure of kernels of corn. The light portion of 

 the kernel is the starch, the darkest portion is called the horny starch. 

 The greater part of the protein comes from the horny starch ; therefore, 

 the greater the amount of horny starch, the greater the amount of 

 protein. 



If large oil content is sought, ears having kernels with large germs 

 are selected for seed. 



If large protein content is sought, the ears having kernels with a 

 large amount of horny starch are selected for seed. It is claimed that 

 in ears of the same breed, one has little difficulty in distinguishing with 



