Horticulture, probably unknown to the Asiatic barbarians of the lower stage, arose not later than the middle stage of barbarism, as the forerunner of agriculture. The climate of the Turanian Highland does not admit of a nomadic life without a supply of stock feed for the long and hard winter. Hence the cultivation of meadows and grain was indispensable. The same is true of the steppes north of the Black Sea. Once grain had been grown for cattle, it soon became human food. The cultivated land belonged as yet to the tribe and was assigned first to the gens, which in its turn distributed it to the households, and finally to individuals; always for use only, not for possession. The users may have had certain claims to the land, but that was all. Two of the industrial acquisitions of this stage are especially important. The first is the weaving loom, the second the melting of metal ore and the use of metals in manufacture. Copper, tin, and their alloy, bronze, were the most essential of them. Bronze furnished tools and weapons, but could not displace stone implements. Only iron could have done that, but the production of iron was as yet unknown. Gold and silver were already used for ornament and decoration, and must have been far more precious than copper and bronze. The increase of production in all branches--stock raising, agriculture, domestic handicrafts--enabled human labor power to produce more than was necessary for its maintenance. It increased at the same time the amount of daily work that fell to the lot of every member of a gens, a household, or a single family. The addition of more labor power became desirable. It was furnished by war; the captured enemies were transformed into slaves. Under the given historical conditions, the first great division of social labor, by increasing the productivity of labor, adding to the wealth, and enlarging the field of productive activity, necessarily carried slavery in its wake. Out of the first great division of social labor arose the first great division of society into two classes: masters and servants, exploiters and exploited.