ALIEN IMMIGRATION 195 



individual whose blood is introduced is of pre- 

 potent reproductive fertility. The Paulistas of 

 Brazil illustrate very remarkably the stimulating 

 effect of a single alien strain. They are, perhaps, 

 the most forceful of the mixed races of South 

 America, and for many generations they exhibited, 

 in war and in slave hunting, a fierce energy which 

 made them the terror of their neighbours. It was, 

 indeed, their courage that preserved Southern 

 Brazil from Spanish domination. At the present 

 time their energy flows in more peaceful channels : 

 they grow the coffee which is the main staple of 

 Brazil and has so greatly enriched the province 

 of San Paolo. They claim descent from a 

 Portuguese sailor who was shipwrecked on the 

 coast early in the sixteenth century, and settled 

 amongst the Indians. When, thirty years later, 

 he was discovered by a party of explorers, he had 

 become the patriarch of a tribe of half-breeds. 



In cases where cross-breeding takes the form of 

 a general intermixture of two or more races, there 

 is a tendency for that strain to prevail whose repre- 

 sentatives are most numerous, whose peculiarities 

 are most deeply seated, or whose features and 

 characters are most in accord with the environal 

 influences of the country. Circumstances are, 

 then, usually in favour of the native strain, 

 especially when the natives have been spared 

 from slaughter in considerable numbers, for 

 those who have been long established in a country 

 have developed in directions that are favoured by 

 its climate or other conditions. This is especially 

 the case with strains of southern blood, which 

 appear to be so tenacious of their qualities as to 

 overpower, in the course of time, any northern 

 blood that comes into mixture with them in less 

 than greatly preponderating quantities. 



The gradual absorption of alien blood is no 



