LUTHER BURBANK 



All that I had done, to be sure, was to trans- 

 plant the original geranium to a bed where it was 

 isolated from any other plants of its species. But 

 such isolation in itself served to provide that the 

 pistils of the plant should be fertilized with pollen 

 from its own flowers. 



In other words, by isolating this heuchera with 

 crinkled leaves it had been determined that the 

 pollen and ovules from the selected plant should 

 combine to produce the seed germs for the next 

 generation. And in so doing I made sure that both 

 hereditary strains — that brought by pollen and 

 that brought by ovule — should have the same 

 hereditary factors, because they were borne on 

 the same plant. 



This, then, was a case of inbreeding, or 

 "intensification" which has been mentioned 

 previously. It was as far removed as possible 

 from the hybridizing experiments we have wit- 

 nessed in which species of widely different type, 

 say the strawberry and the raspberry, were inter- 

 bred. In such a case as that, the pollen and the 

 ovule bring groups of hereditary factors that are 

 widely divergent. And even in the usual cases of 

 cross-fertilization within a species, where pollen 

 of one plant is brought to the pistil of the flower 

 of a neighboring plant, there is a certain oppor- 

 tunity for the mingling of diverse hereditary 



[16] 



