122 Permanence and Evolution. 



natural selection will explain how the higher 

 races were evolved out of the lower. Natural 

 selection tends to make races improve only in 

 the sense of such modifications being preserved 

 as tend to better adaptation to the circumstances 

 under which they are placed. 



It is not that this implies greater complexity 

 of organs, or what we generally mean by higher 

 development. I think existing facts point rather 

 to the idea that the lowest forms are those 

 which best fill their places in nature. It does 

 not appear that it would be easier to extir- 

 pate vermes than frogs, or frogs than mammals. 

 It seems, on the contrary, that insects and 

 fish swarm as higher beings never do. The 

 way in which natural selection would be most 

 likely to act would be by conferring fertility, 

 hardiness, and early maturity fertility to make 

 up for losses by enemies or disease ; hardi- 

 ness to enable the creature to live on little 

 food, or various kinds of food, and resist 



