[524] Which are dealt with at length in the second part of this chapter. [525] Westermarck, _loc. cit._, p. 105. [526] _Ibid._, p. 106. [527] _Ibid._ [528] _Loc. cit._, pp. 9-18. [529] Rivers, _The Todas_, pp. 517 _sqq._ But the most noteworthy cases in regard to the present subject are those where fatherhood in its social sense is not consanguineous owing to the ignorance of the physiological laws of reproduction (a state of things mentioned already as obtaining in Central Australia). This ignorance is of general sociological importance, because there are well-founded reasons for believing that it was once universal amongst primitive mankind, as may be held to be proved by Mr. E. S. Hartland in his thorough treatise on _Primitive Paternity_. For the detailed argument the reader must be referred to this fundamental work.[530] Mr. Sidney Hartland has besides drawn sociological conclusions from those facts in their bearing upon paternal kinship. In Chapter IV of the first volume he gives numerous examples of peoples among whom there is no tie of consanguinity between father and son.[531] [530] Mr. Sidney Hartland has given an exceedingly exhaustive collection of stories "of birth other than what we know as the only natural cause"; of customs in which the "means to which in these stories birth is attributed are or have been actually adopted for the production of children"; and he has compared this folkloristic material with the Australian beliefs. Besides this weight of facts, the author adduces other important reasons why it is extremely probable that "such ignorance was once greater and more widespread than now." The book of Mr. Sidney Hartland is undoubtedly the most thorough and most scientific discussion of the present problem. The strength of his arguments and the mass of evidence strongly support his conclusions. The contrary opinion, viz. that the Australian nescience is an accidental result of some animistic beliefs, an opinion chiefly represented by Mr. A. Lang, seems to be based more on speculation than on facts. The view that the ignorance of paternity was widespread in primitive mankind is shared by Prof. Frazer, M. A. van Gennep, and Frhr. von Reitzenstein. (For references, see below, p. 208, footnote 1.) [531] How far Mr. Hartland's results appear incomplete on the sociological side will be discussed hereafter.