The hollowed out tree trunk with or without a plank gunwale is general, usually with a single outrigger, though plank-built canoes occur in the Solomons, characteristically ornamented with shell inlay. Pottery is an important industry in parts of New Guinea and in Fiji; it occurs also in New Caledonia, Espiritu Santo (New Hebrides) and the Admiralty Islands. Bark-cloth is made in most islands, but a loom for weaving leaf strips is now found only in Santa Cruz. A division of the community into two exogamous groups is very widely spread, no intermarriage being permitted within the group. Mother-right is prevalent, descent and inheritance being counted on the mother's side, while a man's property descends to his sister's children. At the same time the mother is in no sense the head of the family; the house is the father's, the garden may be his, the rule and government are his, though the maternal uncle sometimes has more authority than the father. The transition to father-right has definitely occurred in various places, and is taking place elsewhere; thus, in some of the New Hebrides, the father has to buy off the rights of his wife's relations or his sister's children. Chiefs exist everywhere, being endowed with religious sanctity in Fiji, where they are regarded as the direct descendants of the tribal ancestors. More often, a chief holds his position solely owing to the fact that he has inherited the cult of some powerful spirit, and his influence is not very extensive. Probably everywhere public affairs are regulated by discussion among the old or important men, and the more primitive the society, the more power they possess. But the most powerful institutions of all are the secret societies, occurring with certain exceptions throughout Melanesia. These are accessible to men only, and the candidates on initiation have to submit to treatment which is often rough in the extreme. The members of the societies are believed to be in close association with ghosts and spirits, and exhibit themselves in masks and elaborate dresses in which disguise they are believed by the uninitiated to be supernatural beings. These societies do not practise any secret cult, in fact all that the initiate appears to learn is that the "ghosts" are merely his fellows in disguise, and that the mysterious noises which herald their approach are produced by the bull-roarer and other artificial means. These organisations are most powerful agents for the maintenance of social order and inflict punishment for breaches of customary law, but they are often terrorising and blackmailing institutions. Women are rigorously excluded.