WHAT ARE SPECIES 



were believed to have been always as distinct and separate as 

 they are now, and to have originated by some totally unknown 

 process so far removed from ordinary reproduction that it was 

 usually spoken of as " special creation." There was, then, no 

 question of the origin of families, orders, and classes, because 

 the very first step of all, the "origin of species," was believed 

 to be an insoluble problem. But now this is all changed. The 

 whole scientific and literary world, even the whole educated 

 public, accepts, as a matter of common knowledge, the origin 

 of species from other allied species by the ordinary process of 

 natural birth. The idea of special creation or any altogether 

 exceptional mode of production is absolutely extinct ! Yet 

 more : this is held also to apply to many higher groups as 

 well as to the species of a genus, and not even Mr. Darwin's 

 severest critics venture to suggest that the primeval bird, 

 reptile, or fish must have been " specially created." And this 

 vast, this totally unprecedented change in public opinion has 

 been the result of the work of one man, and was brought 

 about in the short space of twenty years ! This is the answer 

 to those who continue to maintain that the "origin of species" is 

 not yet discovered ; that there are still doubts and difficulties ; 

 that there are divergencies of structure so gi'eat that Ave 

 cannot understand how they had their beginning. We may 

 admit all this, just as we may admit that there are enomnous 

 difiiculties in the way of a complete comprehension of the 

 origin and nature of all the parts of the solar system and of 

 the stellar universe. But we claim for DarAvin that he is the 

 Newton of natural history, and that, just so surely as that the 

 discovery and demonstration by Newton of the laAV of gi'avita- 

 tion established order in place of chaos and laid a sure founda- 

 tion for all future study of the starry heavens, so surely has 

 DarAAdn, by his discovery of the law of natural selection 

 and his demonstration of the great principle of the preserva- 

 tion of useful variations in the struggle for life, not only thrown 

 a flood of light on the process of development of the whole 

 organic world, but also established a firm foundation fur all 

 future study of nature. 



In order to show the view Darwin took of his own work, 

 and what it was that he alone claimed to have done, the 

 concluding passage of the introduction to the Origin of 



