This leads to a number of further changes. Tribal ownership of the land becomes more firmly established, as does also the custom of allotting a particular share to the clan. Personal property, moreover, comes to be more and more differentiated from the possessions of the group. Trade, which in primitive times was almost entirely restricted to secret barter, becomes public, and is finally widened into tribal commerce. When this occurs, great changes in external culture are inaugurated. Implements, weapons, and articles of dress and of adornment are perfected. This stage having been attained, the totemic age advances to a utilization of the soil in a way that is unknown to primitive man. The land is cultivated by means of agricultural implements. Of these, however, the hoe long continues to be the only one; though it supplants the digging-stick, its use depends on human power alone. The care and breeding of animals is also undertaken; the herdsman's or, as it is usually called, the nomadic, life is inaugurated. The breeding of useful domestic animals, in particular, is very closely connected with totemism. The animal, which at the beginning of the period was regarded as sacred, acquires the status of a work animal. It loses its dominion over mankind; instead, it becomes a servant, and, as a result, its cult significance gradually vanishes. The very moment, however, that marks the passing of the sacred animal into the useful animal also signalizes the end of the totemic era and the beginning of the age of heroes and gods.