Therefore large or remote islands are, as a rule, distinguished by the unity of their inhabitants in point of civilization and race characteristics.

Witness Great Britain, Ireland, Japan, Iceland, as also Australia and New Zealand at the time of their discovery.

The highlands of the Southern Appalachians, which form the "mountain backyards" of Kentucky, Tennessee and North Carolina, are peopled by the purest English stock in the United States, descendants of the backwoodsmen of the late eighteenth century.

Difficulty of access and lack of arable land have combined to discourage immigration.

In consequence, foreign elements, including the elsewhere ubiquitous negro, are wanting, except along the few railroads which in recent years have penetrated this country.