of food.  In the former case it may legalise the custom of “exposing” infants, as was done in ancient Greece; or it may regularly sell a large portion of the young women and children, as was done until recently in Circassia; or the surplus population may emigrate to foreign lands, as the Scandinavians did in the ninth century, and as we ourselves are doing in a more peaceable fashion at the present day.  The other alternative may be effected either by extending the area of cultivation or by improving the system of agriculture.

The Russo-Slavonians, being an agricultural people, experienced this difficulty, but for them it was not serious.  A convenient way of escape was plainly indicated by their peculiar geographical position.  They were not hemmed in by lofty mountains or stormy seas.  To the south and east—­at their very doors, as it were—­lay a boundless expanse of thinly populated virgin soil, awaiting the labour of the husbandman, and ready to repay it most liberally.  The peasantry therefore, instead of exposing their infants, selling their daughters, or sweeping the seas as Vikings, simply spread out towards the east and south.  This was at once the most natural and the wisest course, for of all the expedients for preserving the equilibrium between population and food-production, increasing the area of cultivation is, under the circumstances just described, the easiest and most effective.  Theoretically the same result might have been obtained by improving the method of agriculture, but practically this was impossible.  Intensive culture is not likely to be adopted so long as expansion is easy.  High farming is a thing to be proud of when there is a scarcity of land, but it would be absurd to attempt it where there is abundance of virgin soil in the vicinity.

The process of expansion, thus produced by purely economic causes, was accelerated by influences of another kind, especially during the seventeenth and eighteenth centuries.  The increase in the number of officials, the augmentation of the taxes, the merciless exactions of the Voyevods and their subordinates, the transformation of the peasants and “free wandering people” into serfs, the ecclesiastical reforms and consequent persecution of the schismatics, the frequent conscriptions and violent reforms of Peter the Great—­these and other kinds of oppression made thousands flee from their homes and seek a refuge in the free territory, where there were no officials, no tax-gatherers, and no proprietors.  But the State, with its army of tax-gatherers and officials, followed close on the heels of the fugitives, and those who wished to preserve their liberty had to advance still further.  Notwithstanding the efforts of the authorities to retain the population in the localities actually occupied, the wave of colonisation moved steadily onwards.