204 PHYSICAL INVESTIGATION. [PART I. 



grations of peoples have taken place, consequently they cannot 

 all have originated in the localities they now occupy. But the 

 principle that man can only have originated in a warm climate 

 where all the conditions for his preservation exist, is in conflict 

 with the multiplication of regions considered as the cradle of 

 mankind, at least until it is proved that the age of humanity 

 reaches beyond the present geological epoch. 



On recapitulating the results of our investigation, we may 

 admit that though, in some respects, Agassiz's theory cannot 

 be refuted, it is considered, as a whole, too special and specu- 

 lative to be accepted. The principle which may be assented to 

 in this theory is, that in the hot zone there may have been 

 several spots in which men originated, and from which they 

 spread. In taking into consideration the circumstance that 

 neither the African, nor the Austral-Negroes and New Hol- 

 landers, perform sea-voyages, that they possess only miser- 

 able boats scarcely fit for river and coast navigation, that there 

 is no indication of their having been navigators or traders at 

 remote periods, we feel little inclined to assume that the black 

 populations of the South Sea are immigrants from Africa. 

 Whoever, on the other hand, assumes only a single region as 

 the cradle of mankind, looks for that region in south Asia, 

 whence the Negro races spread in a north-easterly and north- 

 westerly direction. Again, he who assumes several cradles of 

 humanity, would be obliged, on account of the little capacity 

 for immigration possessed by Negro peoples, to look for them 

 in south Asia, Africa, and New Gruinea. The latter theory, 

 namely, the assumption of several cradles of humanity, though 

 incapable of positive proof, is mainly supported by the facts of 

 differentiation between the chief types by climate, and the re- 

 semblance of the African and Australian Negro to the ape. 



To determine the scope of the first fact, the climatic sepa- 

 ration of the chief types, is difficult, as it is not yet sufficiently 

 ascertained; for peoples of essentially different types frequently 

 live in close vicinity (compare the examples quoted in the se- 

 quel) ; and however certain it may be that the Whites cannot 

 perpetuate themselves as a people in all Negro regions, and 

 that acclimatization, in sudden transitions from one climate 



