46 PRIMEVAL MAN. 



which have preserved in wonderful perfection 

 the minutest organisms. So much for the 

 Past. 



As regards the Present, Organisms are 

 known to reproduce life, but always life which 

 is like their own. And if this likeness admits 

 of degrees of difference, the margin of variety- 

 is not known to be ever broad enough for 

 the foundation of a new species. This, too, 

 is remarkable, — that such margin of variety 

 as does ever exist among the offspring of the 

 same parents becomes smaller and smaller in 

 proportion as we rise in the scale of Organic 

 Life. That any organism, therefore, can ever 

 produce another which varies from itself in 

 any truly specific character, is an assumption 

 not justified by any known fact. No organism 



