THE WINTER RHUBARB 105 



winter season, and natural selection preserved 

 only the races that showed this adaptability of 

 habit. Thus the common race of spring-bearing 

 rhubarb, as we know it, was developed. 



But the latent capacity to bear at all seasons 

 to live a fully rounded life throughout the year 

 which may be considered the normal and in- 

 herent propensity of all living things, and which 

 is observed to be the habit of tropical plants in 

 general, was never altogether lost. Submerged 

 generation after generation and century after 

 century, the hereditary factors that make for 

 perpetual growth were still preserved, capable, 

 under changed conditions, of being resuscitated 

 and of making their influence manifest. 



The changed conditions came, in case of the 

 rhubarb, when the plant found itself in the new 

 environment of California. 



New soil, new atmosphere, new climate all 

 these are stimulative. Then successive genera- 

 tions of the plants were bred from seeds, and 

 we have already seen that the mixture of strains 

 thus effected tends to have a disturbing influence 

 on the life forces permitting new combinations 

 of characters and resulting in the development 

 of new forms. 



We saw this in the case of the Shasta daisy 

 and very notably in the case of the hybrid wal- 



