IX 



THE LIMITS OF NATURAL SELECTION AS APPLIED TO MAN 



THROUGHOUT this volume I have endeavoured to show that 

 the known laws of variation, multiplication, and heredity, 

 resulting in a " struggle for existence " and the " survival of 

 the fittest," have probably sufficed to produce all the varieties 

 of structure, all the wonderful adaptations, all the beauty of 

 form and of colour, that we see in the animal and vegetable 

 kingdoms. To the best of my ability I have answered the 

 most obvious and the most often repeated objections to this 

 theory, and have, I hope, added to its general strength, 

 by showing how colour one of the strongholds of the ad- 

 vocates of special creation may be, in almost all its modifi- 

 cations, accounted for by the combined influence of sexual 

 selection and the need of protection. 1 I have also endeavoured 

 to show how the same power which has modified animals has 

 acted on man ; and have, I believe, proved that, as soon as 

 the human intellect became developed above a certain low 

 stage, man's body would cease to be materially affected by 

 natural selection, because the development of his mental 

 faculties would render important modifications of its form 

 and structure unnecessary. It will, therefore, probably ex- 

 cite some surprise among my readers to find that I do not 

 consider that all nature can be explained on the principles of 

 which I am so ardent an advocate ; and that I am now myself 

 going to state objections, and to place limits, to the power of 

 natural selection. I believe, however, that there are such 



1 Since writing this in 1870 I have come to the conclusion that sexual 

 selection has had little, if any, influence on colour. See chap. v. of " Tropi- 

 cal Nature " in this volume, and Dantnnism, chap. x. 



