This fixity of race characteristics has enabled the several national varieties of men to go forth from their nurseries, carrying the qualities bred in their earlier conditions through centuries of life in other climes. The Gothic blood of Italy and of Spain still keeps much of its parent strength; the Aryan's of India, though a world apart in its conditions from those which gave it character in its cradle, is still, in many of its qualities, distinctly akin to that of the home people. Moor, Hun and Turk--all the numerous folk we find in the present condition of the world so far from their cradle-lands--are still to a great extent what their primitive nurture made them. On this rigidity which comes to mature races in the lower life as well as in man, depends the vigor with which they do their appointed work. 2. Geographical Isolation and Maritime Contact[113] Greece, considering its limited total extent, offers but little motive, and still less of convenient means, for internal communication among its various inhabitants. Each village or township occupying its plain with the inclosing mountains, supplied its own main wants, whilst the transport of commodities by land was sufficiently difficult to discourage greatly any regular commerce with neighbors. In so far as the face of the interior country was concerned, it seemed as if nature had been disposed from the beginning to keep the population of Greece socially and politically disunited by providing so many hedges of separation and so many boundaries, generally hard, sometimes impossible, to overleap. One special motive to intercourse, however, arose out of this very geographical constitution of the country, and its endless alternation of mountain and valley. The difference of climate and temperature between the high and low grounds is very great; the harvest is secured in one place before it is ripe in another, and the cattle find during the heat of summer shelter and pasture on the hills, at a time when the plains are burnt up. The practice of transferring them from the mountains to the plain according to the change of season, which subsists still as it did in ancient times, is intimately connected with the structure of the country, and must from the earliest period have brought about communication among the otherwise disunited villages.