A survey of different points of Australian folk-lore has been made in order to find some kinship ideas corresponding to the definition given on page 183. From all the results obtained, the most certain and best founded one is the negative fact that the majority of the Australian tribes are wholly ignorant of the physiological process of procreation. This result, although at first sight a negative one, leads, when viewed in the proper light, to sociological conclusions of some importance. In regard to the discussion on consanguinity (given pp. 176 _sqq._), it follows from this fact that we cannot speak of paternal consanguinity among these tribes in the social sense of this word,[650] and that the individual tie of kinship, which does nevertheless exist between father and child, must be conceived of by the natives in some different way. This conclusion is also very important, for it obviously tears asunder the intimate connection between the sexual side of marriage and kinship, a connection that has often been assumed hitherto. The lack of sexual exclusiveness found in Australia does not affect the structure of the individual family, of which kinship is the index. Waiving the question whether this holds good for primitive mankind in general, it may be assumed as quite a final result for the majority of Australian tribes. [650] It has been already remarked above on page 179, that there can be no question of physiological consanguinity for other reasons. The positive ideas of kinship enumerated in this survey fulfil the two conditions set up on page 183; they refer to the individual relation between father and child,[651] and they affirm a close tie between the two. But in order to prove that such ideas are sociologically relevant ideas of kinship, it must yet be shown that they possess some social functions; that is to say, that they play an essential part in the collective formulation of the various norms regulating individual parental kinship. Now it was not possible to find any data on this point, so this gap remains unfilled, and therefore the results arrived at here must be considered as incomplete. It was necessary to introduce the conjectural assumption that all the facts known which give sociological evidence of individual parental kinship stand in close connection with the beliefs in question. Nevertheless, this assumption is neither arbitrary nor scientifically barren, as far as I see. It may first be remarked that the complete absence in our ethnographic information of any attempt to connect the data of folk-lore and the facts of sociology is not astonishing at all, as it is the consequence of one of the shortcomings in social science at the present day. This lack is due to reasons connected with the ethnographer and not with the material. The intimate relation which must exist between social beliefs and social functions was quite a sufficient justification for the introduction of this assumption.