246 METHODS AND RESULTS OF ETHNOLOGY iv 



infusions of fresh European blood ; but there is 

 the broad fact, that not a single indigenous Negro 

 exists either in the great alluvial plains of tropical 

 South America, or in the exposed islands of the 

 Polynesian Archipelago, or among the populations 

 of equatorial Borneo or Sumatra. No satisfactory 

 explanation of these obvious difficulties has been 

 offered by the advocates of the direct influence of 

 conditions. And as for the more important modifi- 

 cations observed in the structure of the brain, and 

 in the form of the skull, no one has ever pre- 

 tended to show in what way they can be effected 

 directly by climate. 



It is here, in fact, that the strength of the 

 Polygenists, or those who maintain that men 

 primitively arose, not from one, but from many 

 stocks, lies. Show us, they say to the Mono- 

 gen ists, a single case in which the characters of 

 a human stock have been essentially modified 

 without its being demonstrable, or, at least, highly 

 probable, that there has been intermixture of 

 blood with some foreign stock. Bring forward 

 any instance in which a part of the world, formerly 

 inhabited by one stock, is now the dwelling-place 

 of another, and we will prove the change to be 

 the result of migration, or of intermixture, and 

 not of modification of character by climatic 

 influences. Finally, prove to us that the evidence 

 in favour of the specific distinctness of many 

 animals, admitted to be distinct species by all 



