is clearly at variance with the fact that the earliest national developments, of Egypt and western Asia, were in the warmer latitudes, where frosty seasons are absent or not very marked, but where periods of dryness produce conditions in the plant world analogous to the effects of a winter. With the less rigorous, but no less effective, spur of a dry, rather than a cold, season, the fertile protected valleys of the Nile and of the Euphrates naturally developed nations earlier than those localities where the hard conditions of cold winters meant a longer struggle to rise above mere physical needs. The constant operation of this factor of degree of rigor in the off season is seen in the successive development of true nationality in the less favored localities, with the least favored advancing slowest of all. Thus the comparatively mild Mediterranean sections of Europe were logical successors of Egypt and western Asia, just as the milder maritime sections of western Europe were the logical predecessors of the more rigorous continental portions, so far as the time of national development was concerned. This climatic factor, therefore, adds another important reason for the slower national evolution in the open plains of north central and eastern Europe, as compared with Britain or France.
Variability of Climate.—Variability of climate may be either periodic, at regular or irregular intervals, or it may be in the nature of apparently permanent change in one direction. Such variation as the latter, whether the change be toward wet, dry, hot or cold, must greatly alter the course of any national evolution already started, as indicated by the evidences of permanent desiccation and consequent depopulation of important sections of the old world. Too much periodic variability of climate, that is, from year to year, or in the form of too long an off season, especially when it is marked by prolonged cold, are almost as great handicaps as the extremes of cold or heat and moisture combined. The unreliability of the Australian climate in practically all the habitable portions, has been, and apparently must be, one of the most important controlling factors in the entire economic development of that country. It is in effect a large scale example of the conditions which brought the Kansas boom, in this country, to a disastrous end two decades ago. The variability of the Indian climate from year to year imposes burdens on the people which hinder greatly the chances for reaching the higher stages in the evolution of India as a nation.
In the same way, too long an off season, particularly a long and cold winter, is a serious obstacle to the best development. Much of the agricultural population of Russia, for example, is forced into idleness through half the year by the length of the Russian winter. Inactivity in itself is hostile enough to progress, but when combined at the same time with the burden of providing against the extreme severities of the long winter, it brings much of Russia close to the border line of those