i VARIATION AND HEREDITY 81 



its organs, and also of passing on the variation so 

 acquired to its descendants. A certain number of 

 biologists hold a doctrine of this kind to-day. The 

 variation that results in a new species is not, they 

 believe, merely an accidental variation inherent in the 

 germ itself, nor is it governed by a determinism sui 

 generis which develops definite characters in a definite 

 direction, apart from every consideration of utility. It 

 springs from the very effort of the living being to adapt 

 itself to the circumstances of its existence. The effort 

 may indeed be only the mechanical exercise of certain 

 organs, mechanically elicited by the pressure of external 

 circumstances. But it may also imply consciousness 

 and will, and it is in this sense that it appears to be 

 understood by one of the most eminent representatives 

 of the doctrine, the American naturalist Cope. 1 Neo- 

 Lamarckism is therefore, of all the later forms of 

 evolutionism, the only one capable of admitting an 

 internal and psychological principle of development, 

 although it is not bound to do so. And it is also 

 the only evolutionism that seems to us to account for 

 the building up of identical complex organs on in 

 dependent lines of development. For it is quite 

 conceivable that the same effort to turn the same 

 circumstances to good account might have the same 

 result, especially if the problem put by the circum 

 stances is such as to admit of only one solution. But 

 the question remains, whether the term a effort &quot; must 

 not then be taken in a deeper sense, a sense even more 

 psychological than any neo-Lamarckian supposes. 



For a mere variation of size is one thing, and a 

 change of form is another. That an organ can be 



1 Cope, The Origin of the Fittest, 1887 ; The Primary Factors of Organic 

 Evolution, 1896 



G 



