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THE AMEBIC AX NATURALIST [Vol. XLIII 



because they may easily be seen and handled. The true 

 reason why some deny reality to species lies, it may be 

 said, not in the nature of our knowledge, but in the nature 

 of the groups of objects which we conveniently designate 

 as species. 



Species, it may be stated, are not sharply delimited 

 groups of individuals; species pass into each other and 

 into varieties by insensible gradations. Species are not 

 permanent but transient assemblages of individuals ; spe- 

 cies change as environment changes. In short, an exag- 

 gerated Darwinistic conception of the nature and origin 

 of specific groups may be advanced as a reason for deny- 

 ing them full objective reality. We all know Darwin's 

 conception of species, as accentuated varieties, which 

 were in turn due to accentuation and multiplication of 

 individual differences. Genera, too, he viewed as over- 

 grown species, in which variation and extinction, together 

 with other less obvious causal factors, had led to segre- 

 gation into minor groups, now, in their turn become 

 species. Species were expanded varieties; genera ex- 

 panded species. 



But certainly this view did not imply, in Darwin's own 

 mind, the non-existence, the unreality of species in nature ; 

 though it did imply their derivation by interniedliate 

 stages, one from another. If we recall his work definitely 

 we shall remember that he found it necessary to introduce 

 a long and labored analysis to account for the very fact 

 of the sharp segregation between allied species— how it 

 was that characters diverged and genera became broken 

 into compact and contrasting groups rather than remain- 

 ing a sheer chaos of connected and interlacing forms. 



In short, if species are not realities, what aberration of 

 intellect led Darwin to work twenty years collecting facts 

 as to their origin? If species are "concepts only," why 

 did he go to sheep-breeders for light on their nature and 

 genesis instead of to logicians and psychologists! It is 

 these latter who tell us of the nature and origin of con- 

 cepts. Why did not Darwin entitle his work, ' ' The Non- 

 existence of Species?" 



