118 



PLANT BIOLOGY 



field, or meadow, we should doubtless witness a life and death 

 struggle for existence (1) between individual plants, of the same 

 kind, (2) between individual plants of different kinds, and (3) be- 

 tween plants and animals. 



Charles Darwin in his great book on the "Origin of Species," 

 published in 1859, a book which has doubtless influenced human 

 thought more than any other book of modern times, closes his 

 chapter on the "Struggle for Existence" with the following words: 

 "When we reflect on this struggle we may console ourselves with the 

 full belief that the war of nature is not incessant, that no fear is 



felt, that death is gen- 

 erally prompt, and that 

 the vigorous, the 

 healthy, and the happy 

 survive and multiply." 1 



129. The survival of 

 the fittest. We have 

 seen in our study thus 

 far (1) that no two in- 

 dividual plants even of 

 the same kind are ex- 

 actly alike, (2) that 

 enormous numbers of 

 seeds are produced by 

 plants, and (3) that 

 there is inevitable com- 

 petition or struggle for 

 existence. The ques- 

 tion, then, that con- 

 fronts us is this : Which 

 of the many competi- 

 tors will survive in the 

 struggle, reach maturity, and finally reproduce themselves ? Obvi- 

 ously those individual plants that vary from the rest in such a 



FIG. 55. Dandelion plant. (Bailey.) 



1 Darwin's " Origin of Species," p. 72, 



