VIII 



THE DEVELOPMENT OF HUMAN RACES UNDER THE LAW OF 



NATURAL SELECTION 



AMONG the most advanced students of man there exists a 

 wide difference of opinion on some of the most vital questions 

 respecting his nature and origin. Anthropologists are now, 

 indeed, pretty well agreed that man is not a recent introduc- 

 tion into the earth. All who have studied the question now 

 admit that his antiquity is very great ; and that, though 

 we have to some extent ascertained the minimum of time 

 during which he must have existed, we have made no approxi- 

 mation towards determining that far greater period during which 

 he may have, and probably has existed. We can with toler- 

 able certainty affirm that man must have inhabited the earth a 

 thousand centuries ago, but we cannot assert that he positively 

 did not exist, or that there is any good evidence against his 

 having existed, for a period of ten thousand centuries. We 

 know positively that he was contemporaneous with many now 

 extinct animals, and has survived changes of the earth's 

 surface fifty or a hundred times greater than any that have 

 occurred during the historical period; but we cannot place 

 any definite limit to the number of species he may have 

 outlived, or to the amount of terrestrial change he may 

 have witnessed. 



Wide differences of opinion as to Man's Origin 

 But while on this question of man's antiquity there is a 

 very general agreement, and all are waiting eagerly for 



1 First published in the Anthropological Revieio, May 1864 ; reprinted in 

 Contributions, etc., with some alterations and additions. 



