384 GENERAL SUMMARY [Part II. 



iiKiIs, birds, reptiles, and fisli, could have acquired the 

 liigh standard of taste which is implied by the beauty of 

 the males, and which generally coincides with our own 

 standard, should reflect that in each member of the verte- 

 brate series the nerve-cells of the brain are the direct off- 

 shoots of those possessed by the common progenitor of 

 tlie whole group. It thus becomes intelligible that the 

 brain and mental faculties should be capable under similar 

 conditions of nearly the same course of development, and 

 consequently of performing nearly the same functions. 



The reader who has taken the trouble to go through 

 the several chaj^ters devoted to sexual selection will be 

 able to judge how far the conclusions at which I have ar- 

 rived are supported by sufficient evidence. If he accepts 

 these conclusions, he may, I think, safely extend them to 

 mankind ; but it would be superfluous here to repeat what 

 I have so lately said on the manner in which sexual selec- 

 tion has apparently acted on both the male and female 

 side, causing the two sexes of man 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 low- 

 ly-organized jn-ogenitors. 



He who admits the principle of sexual selection will 

 be led to the remarkable conclusion that the cerebral sys- 

 tem not only regulates most of the existing functions of 

 the body, but has indirectly influenced the progressive de- 

 veloi)nient of various bodily structures and of certain men- 

 tal qualities. Courage, pugnacity, perseverance, strength 

 and size of body, weapons of all kinds, musical organs, 

 both vocal and instrumental, bright colors, stripes and 

 marks, and ornamental appendages, have all been indi- 

 rectly gained by the one sex or the other, through the 

 influence of love and jealousy, tlirough the appreciation 

 of the beautiful in sound, color, or form, and through the 

 exertion of a choice ; and these powers of the mind mani- 



