378 LUTHER BURBANK 



No one who has experimented widely will 

 doubt that it is possible by a series of selections 

 extending over several generations to accentuate 

 a given character, say to bring out the crinkled 

 formation of the poppy petal, or the corruga- 

 tions in the leaf of a wild geranium, or an added 

 row of petals in a balloon-flower. And it goes 

 without saying that, according to the modern 

 terminology, the character thus isolated must be 

 represented by a hereditary factor which was 

 present in each successive generation utilized in 

 our experiment, but which for some reason was 

 not enabled to make its influence so potentially 

 felt in earlier generations as it was in later ones. 



And the only logical explanation appears to 

 be that in each successive generation of the 

 plants carefully selected and inbred, there was 

 a new redistribution of factors, always along 

 Mendelian lines, which isolated, in the case of 

 the individual we selected, the particular char- 

 acter which we had under observation more and 

 more completely. 



Whereas, in a simple case of Mendelian 

 heredity, where one pair of factors is in mind, 

 there is complete isolation of the recessive fac- 

 tor in one case in four; in this complex case 

 there is isolation of groups of factors, and in 

 one case among thousands there may occur such 



