12 DEVELOPMENT AND HEREDITY. 



merely a negative factor, and can only nullify those 

 influences (the crossing of useful with detrimental 

 variations) which would retard or end the career 

 of development. Upon analysis, it is found that 

 the actual working of natural selection has been 

 merely to cut off without posterity all organisms 

 except the direct ancestors of the present generation. 

 It may do as a form of popular expression to say 

 that, because the less fit are killed, therefore the 

 fittest survive, but, in nature, organisms do not con- 

 tinue to live becatise some others die. The causes of 

 life and death are totally distinct, and the death of 

 one organism does not cause the continued life and 

 development of others. It might, perhaps, be re- 

 garded as a secondary reason for their not being 

 other than they are, but it is in no true sense the 

 cause of their being what they are, any more 

 than the fact that the earth was not destroyed by 

 an astral collision a thousand years ago is the cause 

 of our living to-day in our present state of civilisa- 

 tion. The development and the civilisation we know 

 to be each the combined effects of a multitude of 

 real causes. 



Natural selection merely prevents the retardation 

 of the more developed individuals, by preventing 

 their crossing with the less developed — the latter 

 being killed off. Such retardation has, however. 



