THE ORIGIN OF SPECIES. 65 



nothing to do with the origin of species, but with the survival of already 

 formed species. Not selection of the fittest individuals, but the sur- 

 vival of the sufficiently fit species. 



There is a fundamental difference between the idea that fluctuating 

 variations become specific characters through accumulation by selec- 

 tion, and the idea that new species arise as definite variations, which, 

 with their appearance, characterize the new form as a new species. 

 According to the Darwinian theory, natural selection performs a double 

 duty, first, to build up new species, and, second, to maintain them in 

 competition with other species. According to the other view, species 

 are not formed by any kind of selection, and the question of survival 

 only concerns the maintenance of species, already formed. The pri- 

 mary problem is the problem of the ' origin of species.' The central 

 idea is not what species survive, but how species originate; no matter 

 whether they are going to become victorious or not. 



After a species has appeared it will surely be admitted by every one, 

 that forms that can survive will survive! If Darwin's theory meant 

 only this to those who adopted it, is it not surprising that such a 

 truism should have been hailed as a great discovery? Was not the 

 theory heralded because it seemed to explain how new species arose? 

 What shall we say then when we find a situation like that existing 

 at the present time, when we are told that after all the only difference 

 between Darwin's theory of natural selection and the theory of the 

 survival of definite variations is that in the one case fluctuating varia- 

 tions are selected, and in the other mutations, and that in both cases 

 natural selection is the key to the evolutionary process! Is not the 

 ' origin of species ' still the real point at issue ? 



I yield to no one in admiration for what Darwin has done in 

 behalf of the biological sciences, for he succeeded, where the great 

 French zoologists failed, in establishing the principle of evolution. 

 Furthermore no other hypothesis, that has as yet been proposed, ac- 

 counts so well for the widespread occurrence of adaptation of organ- 

 isms to the environment as does the principle of natural selection. 

 But appreciation of Darwin's claims in these directions need not blind 

 us to the insufficiency of the theory of natural selection to account for 

 the origin of species; nor to the fact that his followers have been 

 especially concerned in propounding and making application of this 

 side of the theory. They have shown little interest in selection as the 

 great conserving factor of evolution, and the reason for this is not 

 far to seek, because of the much greater importance that they have 

 attributed to natural selection as a creative factor in building up 

 individual differences into specific characters. 



VOL. LXVII. 



