'' NATIONALITY." 269 



of tropical regions, and overcrowding does not so often 

 lead to migrations ; but in these speculations we must take 

 account also of wholesale infanticide and other crimes. In 

 the cold inhospitable regions of the north, where man requires 

 more food-fuel than in the balmy south, hunger drives men 

 to migrate, and migration to the battlefield. All this is com- 

 plicated by facilities of route and by the resistance offered 

 by the invaded people. 



Periods of bad weather and dearth, or periods of prosperity 

 and the difficulties arising from a rapid growth of popula- 

 tion, set up great movements in the interior of the continents 

 that tend to the mixing and making of races. The nations 

 press on one another, as the Huns on the Goths and the Goths 

 on the Romans. Whether we have as the result au invading 

 army or a migrating horde of men, Avomen, and children, we 

 get a mixing or a supplanting of previous races, and very 

 often a dominant ruling race remaining long distinct from 

 the conquered people. 



But the sea, while it facilitates the mixing of the people 

 of the seaboard, is a bar to all migratory movements on a 

 large scale. As the races of the interior press on the 

 people of the coast these travel along the shore to regions 

 already well known to them where kindred folk are settled, 

 and where they are readily absorbed into the existing 

 population. Where there is a difference of blood, language, 

 and rehgion, two peoples may long live side by side with 

 little intercourse and practically no fusion. But we can 

 generally detect among the people the traces of any such 

 influx of a different type ; and even when history is silent 

 on the subject, we feel some assurance that there has been 

 such an inroad if we find among the people of any country 

 either a few villages or families or individuals occurring 

 sporadically who persistently exhibit the characteristics of 

 some other race. 



Phi/ steal Characters. 



The physical characters of a people change but slowly, 

 and in considering them we are dealing with that Avhich 

 man has in common with all the world of life and that Avhich 

 is governed by the same laws as those which regulate the 

 variation of form, colour, &c., among the lower animals. 

 It is, for instance, a well-known fact that some characters are 

 more unstable than others : that there are some races which 

 have greater prepotency of transmission than others ; that 



