V-e-A-^-cA 



THE ASSOCIATION OF CHARACTERS IN 

 PLANT-BREEDING 



A. ASSOCIATION OF CHARACTERS TN NATURE 



The doctrine of evolution is so closely associated with 

 the interests of man that each phase of its broad lines of 

 teaching commands our special attention. Amelioration 

 of domestic animals and plants is one of the prevailing feat- 

 ures in agriculture and horticulture. The laws which 

 govern these practical endeavors as well as the scientific 

 investigations are now being slowly disclosed. Many of 

 the common questions which puzzle the horticulturists can 

 be answered only by appealing to these laws. The problems 

 involved are, however, many-sided and in order to gain a 

 distinct knowledge and a clear insight into their different 

 methods of research it is nowadays unavoidable to divide 

 the subject into its separate parts. 



Some lines of research may guide us along the paths of 

 anatomical and histological development; others are related 

 to the more common but equally significant facts, which may 

 be gathered by observations in the field. These latter are 

 vitally related to the study of organic evolution, and often 

 have a direct bearing on the practical processes of breeding. 

 Agricultural plant-breeding is the evolving of useful qual- 

 ities. But what are qualities and how may they be.disceraed 

 and studied? 



For many years this question has been considered as a 

 very simple one, easily to be answered on the basis of our 

 common knowledge. Of late, however, this attitude has 

 completely changed, and the intimate nature of qualities 

 and characters has become an object of most intense inter- 

 est for the practical breeder as well as for the student of 



2 37 



