NURTURE VERSUS NATURE 



now, under the changed conditions, coincides with 

 the summer season. 



The net result of these two sets of impulses 

 was that the plant continued to be a "winter rhu- 

 barb, ' ' yet was now a ' ' summer rhubarb ' ' as well. 



And by selecting for a few generations among 

 the plants that showed greatest tendency to pro- 

 long the seasons, Mr. Burbank was able to merge 

 winter bearing and summer bearing, bridging the 

 gaps of spring and autumn, until his perfected 

 plant, while he still designated it as a "winter 

 rhubarb/ ' was in reality practically an all-the- 

 year bearer. 



Meanwhile, by further selection, aided now by 

 hybridization, it was found possible, thanks 

 largely to the aid of the new environment, to 

 stimulate the plant to such unwonted vigor of 

 growth that the descendant of a plant which came 

 to California with a pencil-sized stalk now pro- 

 duced a stalk comparable rather to a broom- 

 handle, lifting its leaves several feet into the air, 

 and fully meriting the name of Giant Winter 

 Rhubarb. 



ENVIRONMENT VEKSUS HEEEDITY 



Here again, obviously, we are given a striking 

 illustration of the power of environment to bring 

 out concealed hereditary potentialities. We dare 

 not suggest that environment has introduced new 

 traits that did not exist in the hereditary mechan- 

 ism of the plant. To suggest this would be to im- 



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