NATURAL HISTORY OF MAN. 499 



familiar facts, common to no other animal with him, we 

 have the history of his distribution over the globe ; and can 

 conciliate this with the belief that he had his origin in one 

 spot alone. We have adverted to the deficiencies of history 

 respecting the early migrations of mankind and their gather- 

 ing into communities and nations. And we are obliged to 

 admit further, that we can in no satisfactory way explain the 

 peopling of the many remote isles of the ocean, seemingly 

 inaccessible to Man in the ages to which such events must be 

 referred. Still the difficulties of solution do not alter the 

 facts to be solved. The human race is actually spread over 

 the earth and the islands of the sea ; single, as we have seen, 

 in all that constitutes the proper definition of a species. 

 Such is the nature of this distribution, that the difficulties 

 are not better obviated by supposing two, three, or more 

 centres of creation than one only. We must, in contradiction 

 to the analogy of other animal species, make the number 

 incalculably great, to satisfy this method of solving a case, 

 which, after all, is reducible to probabilities perfectly justified 

 to our reason. A more momentous and difficult question is 

 that of the time involved in this early part of Man's history, 

 and requisite to explain his actual dispersion and multipli- 

 cation over the surface of the globe. But this question 

 applies itself equally to all parts of the subject; to the 

 variations of bodily type, as well as to the local distribution 

 of races and nations, and the growth of the many languages 

 which have become the use of mankind. The theme, thus 

 defined, is far too vast to be submitted to a mere outline like 

 that on which we are now engaged. All we can here affirm 

 is, that no positive measure of time has yet been obtained 

 for the term of human existence on earth ; but that we are 

 bound upon various evidence to admit a longer period than 

 any denoted in our actual chronologies ; a period which, in 



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