The significance of the forest as a boundary has also made itself felt in the internal history of the Ukraine. For the grade of culture upon which the Ukraine remained thruout the Middle Ages and in the early centuries of the modern era, the forests constituted good boundaries. The forest divided the population into small groups, which lived apart in separate clearings, every group living its own life. The forest made communication difficult and did not permit the organization of a powerful central state. The forest character of the old Ukraine was the natural chief cause of the formation of principalities in the ancient Kingdom of Kiev, and advanced that fateful particularism. It is not by mere accident that Kiev lies on the border of [243]the forest zone of the Ukraine. Together with other causes, the thinner forests were an aid to the more rapid development of the Kiev principality, and made it the natural starting point for the great expansion under the reigns of Oleh, Sviatoslav, Volodimir. From his original territory the Ukrainian took with him his great preference for trees, a love of trees which causes the white huts of a typical Ukrainian village to be bordered with the fresh green of leaves. The green of the trees in which the Ukrainian huts disappear, enables us immediately to differentiate a Ukrainian from a Russian village, which seems to be afraid of trees. Consequently, the steppe is not originally native to the Ukrainian. The words of the Cossack song, “The steppes so wide, the joyous land” were not composed until the latter days of the Cossack organization. For centuries the steppe meant to the Ukrainian the terrible, mysterious, “wild field,” from which at every moment the nomad hosts, like a swarm of locusts, invaded the Ukraine. The struggles of the Kingdom of Kiev with the nomads show an anthropogeographer very plainly the reason of their final failure. The ancient Ukrainians, being forest dwellers, simply could not successfully fight the riders on the natural steppe or the artificial steppe of their own fields. The ancient Ukrainians did not feel at home in the steppe. A long evolution was necessary before the Ukrainians adapted themselves to the steppe, and the beginning of this adaptation was the Ukrainian Cossack organization. Not until after the formation and development of the Cossack organization could the Ukrainian people successfully advance into the steppe zone and colonize it. Yet the denser settlement of the steppes did not take place until toward the end of the 18th Century. Some of these early Ukrainian settlements have, to this day, not lost the character of new colonies. But these steppe districts were colonized by so great a [244]mass of Ukrainian colonists, and they increased so rapidly in the fertile country, that today more than half the Ukrainians live in the steppe zone, and thereby favor the widespread commonplace that the Ukrainians are a steppe people.