12 THE SCIENTIFIC EVIDENCES OF 



two hypotheses one is, intelligent design mani- 

 fested in creation ; and the other is, natural 

 selection manifested during the countless ages 

 of the past. Now it would be proof positive of 

 intelligent design if it could be shown that all 

 species of plants and animals were created — that is 

 suddenly introduced into the complex conditions 

 of their life ; for it is quite inconceivable that 

 any cause other than intelligence could be compe- 

 tent to adapt an organism to its environment 

 suddenly. On the other hand, it would be proof 

 presumptive of natural selection if it could be 

 shown that one species becomes slowly transmuted 

 into another — i.e., that one set of adaptations 

 may be gradually transformed into another set of 

 adaptations according as changing circumstances 

 require. This would be proof presumptive of 

 natural selection, because it would then become 

 amply probable that natural selection might have 

 brought about many, or most, of the cases of 



