278 



ELIMINATION AND SELECTION. 



" Tliis term," sayy Mr. Darwin, " I uso in a largo and meta- 

 phorical sense," which he then jn'ocoods to explain. It 

 would seem, in the suggested phraseology, to be the result 

 of a throe-fold process of elimination. l"'irst, elimination 

 by the direct action of surrounding conditions; secondly, 

 elimination by enemies ; and thirdly, elimination by com- 

 petition.* 



As an example of the first kind, of elimination, Darwin 

 tells us that in the winter of 1864 ~B, four-fifths of the birds 

 in his grounds perished from the severity of the weather. 

 My collcagxie, Mr. Munro Smith, informs mo that, in culti- 

 vating microbes, certain forms, such as Bacillus violaceus 

 and Micrococcus prodigiosus, remain in the field during cold 

 weather when other less hardy microbes have perished. At 

 the edge of a coral reef, minute, active, free-swimming coral 

 embryos are set free in immense numbers. Presently they 

 settle down for life. Some settle on a muddy bottom, others 

 on a cold bottom, others at too great a depth. All these are 

 eliminated. Only the few who chance to take up a favour- 

 able position are preserved. The parable of the Sower gives 

 us another case in point. Examples could be multiplied 

 indefinitely. I imagine that dnri]ig the oncoming of the 

 glacial epoch there was much pitiless elimination of this 

 order. Among civilized human folk this form of elimina- 

 tion is only seen in military campaigns, in Arctic expedi- 

 tions, and in arduous travels. But in early times and among 

 savages it must be a more important factor. 



Elimination by enemies scarcely needs exemplification. 

 Battle within battle must, throughout nature, as Mr. Darwin 

 says, be continually recurring with varying success. Tlio 

 Stronger devour the weaker, and wage war with each other 



* Cf, " Origin of Species," pp. 50 and 53. 



