DARWIN. 175 



" evolution " is not his word. He felt, perhaps, 

 that most systems of philosophy are like air-plants 

 which thrive equally well in any soil. With just 

 facts enough for their roots to cling to, they may 

 grow and bloom perennially, without other food 

 than the air. 



From the standpoint of the naturalist the great 

 work of Darwin has been the total change in our 

 conception of the meaning of species. It was de- 

 clared by Linnaeus, and repeated by his successors, 

 that " there are as many different species now as 

 there w^ere different forms created in the beginning 

 by the Infinite Being." In accordance with this 

 statement we have been taught to look upon a spe- 

 cies in biology as a fixed entity, a perennial suc- 

 cession of individuals, similar to one another, from 

 the creation at one end of the series to the extinc- 

 tion at the other. We have been told over and 

 over again that the variations of a species are kept 

 within fixed limits by definite laws, and that one 

 species can never encroach on the traits of any 

 other species, nor ever permanently assume any 

 characters other than those with which it was cre- 

 ated. Darwin maintained that the form under 

 which any species is known to us is simply a phase 

 in the history of the succession of living forms 

 which constitute that species. He has shown that, 

 in fact, species are not thus held in check, — that 

 with the line of descent goes gradual modification. 

 Thus the living representatives of no species to- 

 day are quite like their ancestry of centuries ago. 



The two things which most impress the mind of 

 the student of Nature are these: First, the enor- 



