THE LAWS OF HEREDITY 



of this is found in the fact that in the next gener- 

 ation a certain proportion of the progeny will 

 bear white berries. This reappearance of a sub- 

 merged trait in the second and in subsequent 

 generations furnishes one of the most striking 

 and interesting aspects of the entire subject of 

 heredity. 



THE PKODUCTION OF MUTANTS 



Mr. Burbank had not proceeded far in his 

 studies of hybridization before he discovered that 

 the most astonishing segregation and redistribu- 

 tion of characters may take place in second- 

 generation hybrids. 



If he crossed two parent strains that were more 

 or less divergent, he might find the traits of the 

 parents variously blended in the hybrids of the 

 first generation ; but if he interbred these hybrids, 

 he was almost sure to get in the next generation 

 a conglomerate fraternity, showing the traits of 

 the grandparental forms reasserted into almost 

 every imaginable combination. More than that, 

 there were likely to appear forms that diverged 

 markedly from either of the grandparents. 



It would seem that the mingling of divergent 

 germ-plasms had made possible the rejuvenescence 

 of ancestral traits that had long been submerged. 



Mr. Burbank found that by carefully inbreed- 

 ing individuals that showed the new or revived 

 trait he could accentuate the quality and in many 

 cases produce new varieties so markedly different 



[279] 



