32 LUTHER BURBANK 



most necessary attribute if progress in 

 evolution of new forms is to occur, as 

 they have progressed through the ages 

 and as we now see them progressing on 

 this planet." Furthermore, he has in- 

 sisted that the ' 'power to vary in plants 

 or animals is itself a feature as readily 

 transmissible as is stability of character. 

 The quality of varying to meet varying 

 environments is therefore one of the 

 hereditary traits which the plant breeder 

 must consider, and which may itself be 

 extended or overcome by the processes 

 of crossing and selection 



"It is increasingly necessary (he says) 

 to impress the fact that there are two 

 distinct lines in the improvement of any 

 race: the environment which brings indi- 

 viduals up to their best possibilities; the 

 other, ten thousand times more impor- 

 tant and effective, selection of the best 

 individuals through a series of genera- 



Vol. 1 Bur. A 



