DIVERSITY OP SSl,ECTlON THROUGH DIVERSITY OP USE. 197 



active and passive selection, and under passive selection I place 

 natural and artificial selection. Selection depending on the relations 

 of the members of a species to each other I call reflexive selection, the 

 chief forms of which I call conjunctional, dominational, impregna- 

 tional, and institutional selection.* 



(4) It must be carefully noted that diversity of selection depending 

 on diversity in the relations of the organism to the environment does 

 not necessarily involve the exposure of the organism to different 

 environments. In other words, change in even environal selection 

 does not necessarily involve either change in the environment or the 

 entrance of the species into a new district. Darwin's teaching seems, 

 at times, to be in conflict with this statement, but there are passages 

 in his writings which distinctly state that variations in instinct may 

 lead to different habits of sustentation, and it is evident that this 

 would naturally lead to a difference in the congenital qualities that 

 win success in the different sections and so to difference in the envi- 

 ronal selection. 



It should be remembered, however, that the meaning of anyone's 

 statements on this subject will depend on his definitions of the words 

 used. What is meant by environment, external conditions, and 

 other similar terms? Until we define we shall only beat the air, how- 

 ever exact our statements may seem to be. I therefore repeat what 

 I have elsewhere stated, that, according to my definition, change in 

 the environment is always change in activities that lie outside of the 

 species, or of the segregated group, of individuals that is under 

 consideration. In Darwin's usage the phrase "change in external 

 conditions" seems to carry the same meaning; but in some cases this 

 can hardly be the case. 



Diversity in the uses to which isolated sections of one species put 

 their powers, when appropriating resources from the same environ- 

 ment, must produce diversity in the forms of variation that are most 

 successful in the different sections. This I call active selection as con- 

 trasted with passive selection, which varies according to differences 

 in the environments, f AH diversities of environal selection that do 

 not vary according to differences in the environments must be classed 

 as diversities of active selection, for they must have originated in 

 some variation in the powers of the organism or in the diversity of 

 uses to which it has put its powers. Diversity in the successful use 

 of the powers of the species in dealing with the environment, whether 



* To these I now add prudential selection. 



t For "active" and "passive" selection, I often substitute "endonotnic" and 

 ' ' heteronomic ' ' selection. 



