250 THE DESCENT OF MAN. Paet I. 



acted so powerfully on innumerable animals, both high 

 and low in the scale. It can further be shewn that the 

 differences between the races of man, as in colour, hairy- 

 ness, form of features, &c, are of the nature which it 

 might have been expected would have been acted on by 

 sexual selection. But in order to treat this subject in a 

 fitting manner, I have found it necessary to pass the 

 whole animal kingdom in review ; I have therefore de- 

 voted to it the Second Part of this work. At the close 

 I shall return to man, and, after attempting to shew 

 how far he has been modified through sexual selection, 

 will give a brief summary of the chapters in this First 

 Part, 



