32 LUTHER BURBANK 



origin of mutation has full validity, whether or 

 not it be accepted as the sole explanation. 



We shall see the truth of this contention 

 illustrated in scores of cases in the course of these 

 studies. 



THE FINAL INTERPRETATION 



Meantime for the purposes of present illus- 

 tration it is necessary to revert to the case of our 

 fragrant calla. 



After what has just been said it will be obvious 

 that I would explain this mutation as a reversion 

 due to cross-fertilization. 



In other words, some remote ancestors of the 

 calla may have been fragrant, and a chance ming- 

 ling of ancestral germ plasms in the course of the 

 production of thousands of seedlings of the calla, 

 may have led to such a union of submerged here- 

 ditary factors as enabled this latent propensity 

 to make itself manifest. 



According to this view, the case is comparable 

 to that illustrated by an experiment in which 

 Professors Bateson and Punnett hybridized two 

 white-flowered peas of different strains and pro- 

 duced offspring bearing flowers colored blue and 

 pink and purple. 



The white parent forms were so nearly identi- 

 cal as to be entirely indistinguishable except that 



Vol. 2 Bur. A 



