XL 



SEXUAL SELECTION AS AS AGENCY TO AC- 

 COUNT FOR THE DIFFEEENCES BETWEEN 

 THE EACES OP MAN. j 



Descent ^^ ^^'^^ ^^^^ ^^^ been baffled in all our 



ojE Man, attempts to account for the difEerences be- 

 P^^^ tween the races of man ; but there remains 



one important agency, namely, sexual selection, which ap- 

 pears to have acted powerfully on man, as on many other 

 animals. I do not intend to assert that sexual selection 

 will account for all the difEerences between the races. An 

 unexplained residuum is left, about which we can only 

 say, in our ignorance, that as individuals are continually 

 born with, for instance, heads a little rounder or nar- 

 rower, and with noses a little longer or shorter, such 

 slight differejices might become fixed and uniform, if the 

 unknown agencies which induced them were to act in a 

 more constant manner, aided by long-continued inter- 

 crossing. Such variations come under the provisional 

 class, alluded to in our second chapter, which for the 

 want of a better term are often called spontaneous. Nor 

 do I pretend that the effects of sexual selection can be 

 indicated with scientific precision ; but it can be shown 

 that it would be an inexplicable fact if man had not been 

 modified by this agency, which appears to have acted 



