The principle of communal property rarely survives this change, for by long possession the families acquire a prescriptive right to the portions which they cultivate, and those who manure their land well naturally object to exchange it for land which has been held by indolent, improvident neighbours.

In Russia, however, this change has not destroyed the principle of communal property.

Though the three-field system has been in use for many generations in the central provinces, the communal principle, with its periodical re-allotment of the land, still remains intact.
For the student of sociology the past history and actual condition of the Don Cossacks present many other features equally interesting and instructive.

He may there see, for instance, how an aristocracy can be created by military promotion, and how serfage may originate and become a recognised institution without any legislative enactment.

If he takes an interest in peculiar manifestations of religious thought and feeling, he will find a rich field of investigation in the countless religious sects; and if he is a collector of quaint old customs, he will not lack occupation.
One curious custom, which has very recently died out, I may here mention by way of illustration.