76 THE FOUNDATIONS OF ZOOLOGY 



I, for one, have found little to interest me in the interminable 

 dispute as to the inheritance or non-inheritance of the effects of 

 the conditions of individual life, because the gist of the whole 

 matter has seemed to me to lie in the deeper question whether 

 these effects are inherently adaptive ; and I am forced to ask for 

 evidence that the " Lamarckian factors" can give rise to even the 

 incipient stages of adaptive modification, before I care to inquire 

 whether they are or are not inherited. We are told that, " Inas- 

 much as we know to what a wonderful extent adaptive modifica- 

 tions are secured during individual lifetime, by the direct action 

 of the environment on the one hand, and by increased or dimin- 

 ished use of special organs and mental faculties on the other, it 

 becomes obvious of what importance even a small measure of 

 transmissibility on their part would be, in furnishing to natural 

 selection ready made variations in required directions, as distin- 

 guished from promiscuous variations in all directions." 



This a priori argument to prove that the effect of these 

 "factors" must be inherited, because if so, it would be so useful, 

 has seemed plausible to many ; but its fallacy is clear, unless the 

 inheritance of nurture can be proved to be beneficial prior to selec- 

 tion ; for, while the ways to use our bodies and our faculties are 

 few and definite, the ways to abuse them are innumerable ; and 

 the inheritance of all the effects of the conditions of life would 

 seem more likely to lead to cumulative destruction than to cumu- 

 lative adaptation. Unless the " Lamarckian factors " can be shown 

 to have, prior to selection, a determinate influence in beneficial 

 lines, it seems, on the whole, rather fortunate than otherwise that 

 evidence of the inheritance of their effects is so hard to find. 



When bodily structure is improved and developed by use, we 

 find structural adjustments, which themselves require explanation, 

 for bringing this useful end about ; nor does there seem to be 

 any reason to believe the case is any different when intellectual 

 and moral improvement are in question. Here, as elsewhere, we 

 are benefited by training and practice and education because our 

 nature fits us for improvement by judicious nurture. 



Capacity for individual development and improvement, muscu- 

 lar or mental or moral, under the normal conditions of life, is an 

 adaptation, — by far the most wonderful and admirable of adapta- 



