Reprinted from, Vol. /, Number 2. American Breeders Magazine. 



HYBRIDIZATION METHODS IN CORN BREEDING. 



GEORGE HARRISON SHULL, Cold Spring Harbor, Long Island, N. Y. 



The simultaneous preparation of papers by three different authors 

 about a year ago, advocating the use of more or less definite hybrid- 

 ization in the breeding of Indian corn in lieu of the methods of selec- 

 tion and partial isolation now in general use, probably marks an 

 important step in the improvement of this exceedingly valuable 

 American crop ; for the appearance of these papers indicates a growing 

 appreciation of the real biological nature of Indian corn and the 

 requirements necessary to the attainment of the highest and most 

 permanent success in corn breeding. 



The three papers to which I refer are, ''The distinction between 

 development and heredity in inbreeding," by Dr. E. M. East, in 

 the American Naturalist for March, 1909; a circular of the U. S. 

 Department of Agriculture on "The importance of broad breeding in 

 corn," by Mr. G. N. Collins, issued in June, 1909 ; and my own paper 

 on "A pure-line method in corn breeding," read before this Associa- 

 tion at its last meeting at Columbia, Mo., in January, 1909, and pub- 

 lished in its last Annual Report. These three papers are in some 



