H2 PLANT-BREEDING 



In some of the bulletins of the agricultural experiment 

 stations, dealing with the improvement of corn, it has been 

 pointed out that we do not yet understand many of the prin- 

 ciples underlying corn-breeding, but that on the other hand 

 it is to the interest of each corn-grower to obtain as com- 

 plete a knowledge on this point as possible, in order thereby 

 to bring the factors of his selection under his control. 



From a scientific point of view, however, there can be 

 little doubt that the same laws that govern the variability 

 and the selection of cereals in general control the corres- 

 ponding phenomena for corn, too, and that the existing 

 differences are, as a fact, only due to those plain and easily 

 recognizable characters which contrast corn with the smaller 

 cereals. 



For this reason I propose to give a description of the 

 facts of variability and the methods of selection of corn, 

 based on the principles evolved for cereals in my previous 

 chapters. I shall conscientiously describe the facts, but shall 

 rely in their appreciation partly on the obtained results, and 

 partly on a comparison with the Swedish and German prin- 

 ciples. In doing so my chief aim is to awaken the interest 

 of all those who are in one way or another concerned in 

 corn-breeding, for a study of analogous questions in other 

 crops. 



The study of variability is the basis of all selection. 

 The more we are enabled to discern slight differences and 

 to appreciate their possible industrial value, the better we 

 shall be guided in our choice. 



Moreover, the term variability covers so wide a range 

 of phenomena, and the significance of the single constituents 

 of this large group for the purpose of race-breeding is so 

 widely different, that it is of pre-eminent importance to have 

 a critical survey of the most obvious cases. 



Everybody knows that corn is one of the most multiform 



