GENERAL SUMMARY. 611 



female was created and endowed with the capacity of appreciating 

 such ornaments. I differ only in the conviction that the male 

 Argus pheasant acquired his beauty gradually, through the pref- 

 erence of the females during many generations for the more 

 highly ornamented males; the aesthetic capacity of the females 

 having been advanced through exercise or habit, just as our own 

 taste is gradually improved. In the male through the fortunate 

 chance of a few feathers being left unchanged, we can distinctly 

 trace how simple spots with a little fulvous shading on one side 

 may have been developed by small steps into the wonderful ball- 

 and-socket ornaments; and it is probable that they were actually 

 thus developed. 



Everyone who admits the principle of evolution, and yet feels 

 great difficulty in admitting that female mammals, birds, reptiles, 

 and fish, could have acquired the high taste implied by the beauty 

 of the males, and which generally coincides with our own stand- 

 ard, should reflect that the nerve-cells of the brain in the highest 

 as well as in the lowest members of the Vertebrate series, are 

 derived from those of the common progenitor of this great King- 

 dom. For we can thus see how it has come to pass that certain 

 mental faculties, in various and widely distinct groups of animals, 

 have been developed in nearly the same manner and to nearly 

 the same degree. 



The reader who has taken the trouble to go through the several 

 chapters devoted to sexual selection, will be able to judge how 

 far the conclusions at which I have arrived are supported by 

 sufficient evidence. If he accepts these conclusions he may, I 

 think, safely extend them to mankind; but it would be super- 

 fluous here to repeat what I have so lately said on the manner in 

 which sexual selection apparently has acted on man, both on the 

 male and female side, causing the two sexes to differ in body and 

 mind, and the several races to differ from each other in various 

 characters, as well as from their ancient and lowly-organized 

 progenitors. 



He who admits the principle of sexual selection will be led 

 to the remarkable conclusion that the nervous system not only 

 regulates most of the existing functions of the body, but has 

 indirectly influenced the progressive development of various bod- 

 ily structures and of certain mental qualities. Courage, pug- 

 nacity, perseverance, strength and size of body, weapons of all 

 kinds, musical organs, both vocal and instrumental, bright colors 

 and ornamental appendages, have all been indirectly gained by 

 the one sex or the other, through the exertion of choice, the in- 

 fluence of love and jealousy, and the appreciation of the beautiful 

 in sound, color or form; and these powers of the mind manifestly 

 depend on the development of the brain. 



