Chap. TIL] THE RACES OF MAN. 231 



mals — of the fossil horse, for instance, which disappeared 

 from South America, soon afterward to be replaced, with- 

 in the same districts, hj countless troops of the Spanish 

 horse. The New-Zealander seems conscious of this paral- 

 lelism, for he compares his future fate with that of the 

 native rat almost exterminated by the European rat. 

 The difficulty, though great to our imagination, and real- 

 ly great if we wish to ascertain the precise causes, ought 

 not to be so to our reason, as long as we keep steadily in 

 mind that the increase of each species and each race is 

 constantly hindered by various checks ; so that if any new 

 check, or cause of destruction, even a slight one, be super- 

 added, the race will surely decrease in number ; and as it 

 has everywhere been observed that savages are much op- 

 posed to any change of habits, by which means injurious 

 checks could be counterbalanced, decreasing numbers will 

 sooner or later lead to extinction ; the end, in most cases, 

 being promptly determined by the inroads of increasing 

 and conquering tribes. 



On the Formation of the JRaces of Man. — It may be 

 premised that when we find the same race, though broken 

 up into distinct tribes, ranging over a great area, as over 

 America, we may attribute their general resemblance to 

 descent from a common stock. In some cases tlie cross- 

 ing of races ali'eady distinct has led to the formation of 

 new races. The singular fact that Europeans and Hin- 

 doos, who belong to the same Aryan stock and speak a 

 language fundamentally the same, differ widely in ap- 

 pearance, while Europeans differ but little from Jews, who 

 belong to the Semitic stock and speak quite another lan- 

 guage, has been accounted for by Broca^" through the 

 Aryan branches having been largely crossed during their 



2^ " On Anthropology," translation, ' Anthropolog. Review,' Jan. 18G8, 

 p. 38. 



