596 LOUIS AGASSIZ. 



theory of the unity of mankind it is assumed 

 that the different races have become what 

 they are in consequence of their settlement in 

 different parts of the world, and that the 

 whole globe is everywhere a fit abode for hu- 

 man beings who adapt themselves to the con- 

 ditions under which they live. According to 

 the theory of a multiple origin of mankind the 

 different races have first appeared in various 

 parts of the globe, each with the peculiarities 

 best suited to their primitive home. Aside 

 from these theoretical views the fact is, that 

 some races inhabit very extensive tracts of the 

 earth's surface, and are now found upon sep- 

 arate continents, while others are very limited 

 in their range. This distribution is such that 

 there is no reason for supposing that the 

 negro is less fitted permanently to occupy at 

 least the warmer parts of North and South 

 America, than is the white race to retain pos- 

 session of their more temperate portions. As- 

 suming our pure black race to be only two 

 millions, it is yet larger than the whole num- 

 ber of several races that have held uninter- 

 rupted possession of different parts of the 

 globe ever since they have been known to 

 the white race. Thus the Hottentots and the 

 Abyssinians have maintained themselves in 



