r 3 c PLANT-BREEDING 



ference between the variability among the races and within 

 the races themselves, and only a comparison with the phe- 

 nomena observed in other plants will lead to a clear and use- 

 ful distinction. 



The history of the breeding of corn is a very short one. 

 It dates from the discovery of the principle of single-ear se- 

 lection, ten years ago. The observation of the individuality 

 of the progeny of one single ear is the basis of this method. 

 It enables us to estimate the hereditary value of an ear by the 

 inspection of its progeny. It is in full accord with the 

 methods of Hays and Von Lochow, who applied them to 

 wheat and rye, and with the Svalof method. It is different 

 from them only on account of the impurity of the fertilization 

 of the selected ear, as we have already described. Since 

 the discovery of this principle of single ear selection, corn 

 breeding has rapidly developed and it is now holding a 

 pre-eminent place among the methods of increasing the yield 

 of this valuable crop. 



Previous to 1897, little was done in the way of breeding 

 corn systematically. It is even as in the case of the Euro- 

 pean cereals, where but few farmers had the idea of im- 

 proving their crop by selecting their seed, and became the 

 originators of some few ameliorated varieties. But they 

 did not attain to any influence upon the farmers at large. 

 Working only for the improvement of their cultures, they 

 failed to persuade others of the validity and the importance 

 of their views. 



Among these men J. L. Learning, of Wilmington, Ohio, 

 began his work about 1825. He simply selected the best 

 ears of his field for his seed corn, and in doing so he soon 

 improved his strain of corn to such a degree that other 

 farmers secured his seed-corn for their own farms, and it 

 was soon imported into Illinois. There it has since been 

 improved by subsequent repeated selection, and the Learning 



