58 HEREDITY AND SELECTION IN SOCIOLOGY 



butterflies, it seems reasonable to suppose mutation to have 

 been the origin of such distinctions. 



It is necessary now to say a few words concerning the applica- 

 tion of the theory of germinal selection to the higher intellectual 

 faculties of mankind. We are confronted by two sets of facts 

 which seemingly contradict each other : the undoubted constancy 

 throughout immense periods of certain species, and the adapta- 

 bility of organic life in general. But between this constancy 

 and this adaptability there is no real antithesis. Constant species 

 are old species ; they are spec^tes which are adapted definitely 

 to definite conditions, and these conditions being constant, the 

 necessity of readaptation has not presented itself, and the deter- 

 minant complex of these species has become fixed in accordance 

 with these conditions. That is to say, those variations which 

 tended to bring the species into disharmony with its environ- 

 ment have been constantly eliminated, until at last the specific 

 determinant complex, adapted to the specific vital conditions 

 of the species, has obtained so overwhelming a majority in the 

 germ-plasm of every individual of the species that variations 

 can no longer attain biological value. Variations, when they 

 occur, are eradicated simply by adverse intragerminal influences. 

 Such constant species are not non-adaptable ; they have adapted 

 themselves, and have passed through a series of successive 

 adaptations, until equilibrium between them and their environ- 

 ment was established. And this equilibrium, owing to the con- 

 stancy of the environing conditions, has not been since dis- 

 turbed. Younger species, less constant, and apparently more 

 adaptable, are merely undergoing before our eyes a period of 

 instabihty which constant species underwent in past ages, 

 before their equihbrium with surrounding conditions was 

 attained. 



Let us apply the theory of germinal selection to specific 

 psychical characteristics, such as the talent for music or for 



