CHAPTER V 



MIGRATIONS AND THEIR EUGENIC 

 SIGNIFICANCE 



1. Primitive Migrations 



The human species has come to occupy the entire habitable 

 globe. This fact is mute testimony of man's migratory ca- 

 pacity and tendencies. Just as the Norwegian lemming has 

 been observed, in consequence of several years of favorable 

 conditions for breeding in its mountain home, to spread over 

 the surrounding territory in great bands seeking less crowded 

 breeding-grounds; even as the army worm and the grass- 

 hopper swarm from their native territory; so man, also, under 

 the pressure of crowded conditions, poverty and oppression 

 or lured by brighter prospects elsewhere, may move in hordes 

 to other lands that seem to offer better opportunities. Thus 

 Asia seems to have debouched her surplus population upon 

 Europe in the shape of the Huns during the fourth and fifth 

 centuries of our era and the Turks during the fourteenth and 

 fifteenth centuries. So the Anglo-Saxons and the Normans 

 successively swarmed upon England. So, among savages, 

 the Masai of Africa moved upon the neighboring tribes and 

 estabhshed themselves over much of southeastern Africa. 

 So in the last three centuries the Americas and Australia 

 have witnessed the greatest migrations that the world has 

 ever seen, hundreds of thousands annually coming from over- 

 crowded Europe and Asia to the "New World." 



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