THE DESCENT OF MAN. 



ling and the liabit of turning round were first acquired 

 jugh variation and sexual selection, and that afterward 

 3 habit was retained as a sign of pleasure or as a greet- 

 g through the principle of inherited association. This 

 principle apparently comes into play on many occasions; 

 thus it is generally admitted that the songs of birds serve 

 mainly as an attraction during the season of love, and that 

 the leks, or great congregations of the black grouse, are 

 connected with their courtsliip; but the habit of singing 

 has been retained by some birds when they feel happy, for 

 instance, by the common robin, and the iiabit of congre- 

 gating has been retained by the black grouse during other 

 seasons of the year. 



I beg leave to refer to one other point in relation to 

 sexual selection. It has been objected that this form of 

 selection, as far as the ornaments of the males are con- 

 cerned, implies that all the females within the same dis- 

 trict must possess and exercise exactly the same taste. It 

 should, however, be observed, in the first place, that 

 although the range of variation of a species may be very 

 large it is by no means indefinite. I have elsewhere given a 

 good instance of this fact in the pigeon, of which there are 

 at least a hundred varieties differing widely in their colors, 

 and at least a score of varieties of the fowl differing in 

 the same kind of way; but the range of color in tliese 

 two species is extremely distinct. Therefore the females of 

 natural species cannot have an unlimited scope for their 

 taste. In the second place, I presume that no supporter of 

 the principle of sexual selection believes that the females 

 select particular points of beauty in the males; they are 

 merely excited or attracted in a greater degree by one male 

 than by another, and this seems often to depend, especially 

 with birds, on brilliant coloring. Even man, excepting 

 perhaps an artist, does not analyze the slight differences in 

 the features of the woman whom he may admire, on which 

 her beauty depends. The male mandrill has not only the 

 hinder end of his body, but his face gorgeously colored and 

 marked with oblic^ue ridges, a yellow beard and other orna- 

 ments. We may infer from what we see of the variation 

 of animals under domestication that the above several 

 ornaments of the mandrill were gradually acquired by one 

 individual varying a little in one way and another indi- 

 vidual in another way. The males which were the hand- 



