LUTHER BURBANK 



rather than the improvement in the other qualities 

 of the plant, is obviously the one that requires 

 explanation. Remarkable improvement in size 

 and in other desired qualities through selection, 

 is a more or less familiar method of plant devel- 

 opment. 



But the production of a race of pieplant that 

 departs radically from the most pronounced and 

 characteristic trait of the rhubarb family, namely 

 brief period of bearing, is something that requires 

 explanation. 



A clue to the explanation is found when we 

 recall that the plants were sent me from a region 

 lying on the other side of the equator. The plants 

 were exceptional even there in that they had 

 shown a tendency to bear — that is to say to pro- 

 duce juicy leaf-stalks — during the cold season. 

 Through some unexplained freak of heredity or 

 unheralded selective breeding, they had developed 

 a hardiness that had enabled them to put forth 

 their leaves much earlier than is customary with 

 all other races of rhubarb. 



The difference was only a matter of weeks, and 

 was of no greater significance, perhaps, than the 

 observed difference in time of bearing between 

 different varieties of other vegetables and fruits. 

 Everyone knows that there are early and late- 

 bearing varieties of most commonly cultivated 



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