They also distinguish very definitely between the offices of husband and wife. For example, when a man has brought a seal to land, it would be a stigma on his character to draw it out of the water, since that is the duty of the female.[51] In the Marquesas Islands, the use of canoes in all parts of the islands is rigorously prohibited to women, for whom it is death even to be seen entering one when hauled on shore; while Tapa-making, which belongs exclusively to women, is taboo to men.[30] Among the Betchuanas of South Africa the men will not let women touch the cattle.[52] The Baganda think that if a woman steps over a man's weapons they will not aim straight or kill until they have been purified.[21] Among many South African tribes, if a wife steps over her husband's assegais, they are considered useless from that time and are given to the boys to play with. This superstition rings many changes and is current among the natives of all countries. The taboos which have thus been exemplified and reviewed are based on the feeling that woman is possessed of a demonic power, or perhaps of a _mana_ principle which may work injury; or else upon the fear that she may contaminate man with her weakness. It is very probable that many of these taboos originated even as far back as the stage of society in which the line of descent was traced through the mother. There seems little doubt that the framework of ancient society rested on the basis of kinship, and that the structure of the ancient gens brought the mother and child into the same gens. Under these circumstances the gens of the mother would have some ascendancy in the ancient household. On such an established fact rests the assumption of a matriarchate, or period of Mutterrecht. The German scholar Bachofen in his monumental work "Das Mutterrecht" discussed the traces of female "authority" among the Lycians, Cretans, Athenians, Lemnians, Lesbians, and Asiatic peoples. But it is now almost unanimously agreed that the matriarchal period was not a time when women were in possession of political or economic power, but was a method of tracing descent and heritage. It is fairly well established that, in the transition from metronymic to patronymic forms, authority did not pass from women to men, but from the brothers and maternal uncles of the women of the group to the husbands and sons. Such a method of tracing descent, while it doubtless had its advantages in keeping the woman with her child with her blood kindred, would not prevent her from occupying a degraded position through the force of the taboos which we have described.[53]