NATU.RAL HISTORY OF MAN. 469 



The question as to the singleness of origin of the human 

 race may be said to govern the whole subject; since if this 

 fact be admitted or proved, many subordinate questions are 

 settled at once. If, for instance, it should be rendered 

 certain to our belief that all mankind throughout all ages 

 of human existence on the globe, and in all their innumerable 

 varieties of form, colour, customs, and language had been 

 derived from one single pair, nothing remains but to in- 

 vestigate the causes, physical and moral, which have pro- 

 duced from this unity of origin the wonderful diversities 

 everywhere visible. A subject wide enough in truth to 

 satisfy the most eager speculator ! yet well denned in its 

 limits, and even in many of the paths through which research 

 must be pursued. But this simpler form of the question is 

 not permitted to us. The point is one upon which natural- 

 ists of eminence have held very different opinions. It has 

 been contended not only that there is no proof of the deri- 

 vation of mankind from a single pair, but that the probability 

 is against it. Some have ventured to suppose an original 

 and absolute difference of species. Many have adopted the 

 idea of detached acts of creation, through which certain of 

 the more prominent races had their origin in different locali- 

 ties ; interblending afterwards, so as to give rise to those 

 subordinate varieties seen so numerously around us. Others 

 again, putting aside the notion of the immutability of 

 species, have boldly hazarded the belief that inferior animal 

 organisations, either fortuitously, or by necessities or latent 

 laws of nature, may have risen into the human form : and 

 this under conditions so far unlike, as to give origin to those 

 varieties which have perplexed our ideas of unity, and 

 puzzled both philosopher and physiologist to explain. 



Before going farther, we may briefly advert to a point 

 which must already have occurred to every reader. Has not 

 this question been long ago settled on the authority of 



