girls belonging to the same sub-clan and clan. Finally by an extension which goes beyond the usual limits of classificatory terminology, it becomes synonymous with "all women not of the same clan as the sister." It should be realized that the ordinary extensions of classificatory terminology go only to the limits of the clan. The widest sense in which the word for mother is used embraces all the women of the mother's clan. But the word tabugu, in its meaning of "lawful woman," extends over three clans, and embraces roughly three-quarters of female humanity, in contrast to the one-quarter which is forbidden. But this subject—the intricacies of the kinship system and of the kinship nomenclature—leads us beyond the limits of the present inquiry, and will have to be deferred to the future publication already mentioned.
The keynote to sexual morality and sexual freedom lies, as we have found, in the opposition between the two classes designated by luguta and tabugu ("sister" and "paternal cross-cousin") respectively. The taboo against incest between brother and sister is the most important and most dramatic feature of the Trobriand social organization; the more so because of a singular rift in traditional doctrine, a dogmatic inconsistency, which makes love and the magic of love derive from brother and sister incest. To the account of this important myth we shall now proceed in the last chapter.
