Introduction. 13 



is the same thing, of the Neo-Darwinian school of 

 Weismann. Next we may turn, by way of antithesis, 

 to the so-called " Neo-Lamarckian " school of the 

 United States. For, by a curious irony of fate, while 

 the Neo-Darwinian school is in Europe seeking to 

 out-Darwin Darwin by assigning an exclusive pre- 

 rogative to natural selection in both kingdoms of 

 animate nature, the Neo-Lamarckian school is in 

 America endeavouring to reform Darwinism in 

 precisely the opposite direction — viz. by transferring 

 the sovereignty from natural selection to the 

 principles of Lamarck. Without denying to natural 

 selection a more or less important part in the process 

 of organic evolution, members of this school believe 

 that much greater importance ought to be assigned 

 to the inherited effects of use and disuse than was 

 assigned to these agencies by Darwin. Perhaps 

 this noteworthy state of affairs, within a decade of 

 Darwin's death, may lead us to anticipate that his 

 judgement — standing, as it does, between these two 

 extremes — will eventually prove the most accurate 

 of all, with respect to the relative importance of 

 these factors of evolution. But, be this as it may, 

 I must now offer a few remarks upon the present 

 position of the matter. 



In the first place, to any one who (with Darwin and 

 against Weismann) admits not only the abstract pos- 

 sibility, but an actual working, of the Lamarckian 

 factors, it becomes difficult to determine, even 

 approximately, the degrees of value which ought to 

 be ascribed to them and to natural selection respec- 

 tively. For. since the results are in both cases identical 

 in kind (as. adaptive changes of organic types j, where 



