In many cases philological evidence based on the derivation of the root syllable of the word ‘sister, a word which in the tongues of peoples still obedient to this law is from a root implying ‘Avoidance,’ may afford affirmative proof, as circumstantial as unexpected, that this custom was once as universal as my theory would require.’[8] If difficulty is felt in the acceptation of an hypothesis of such wide significance, simply based on an obscure lower custom so little noted in anthropological literature as to permit doubts of its existence, I can only repeat that a cognisance of the traits of this particular habit of avoidance and its effect as a factor in savage life demands such conditions of residence and chances of observation, as can fall to the lot of few. I may add that it is one of the very first customs to disappear after contact with whites, especially missionaries, being, as it is, in such extreme divergence with the economy of the European family, in regard to the mutual attitude of brother and sister. It is more than a quarter of a century since the author had his attention first drawn to the practice. The evolution of the idea of its possible identity with the Primal Law has led to a continued and close observation; he is thus able to certify as to its rapid disappearance. Brother and sister avoidance was at that time, thirty years ago, quite universal in New Caledonia; now in many places it is unknown, even as a tradition, among the younger aborigines. In view of the probability of a similar oblivion among other peoples, the immediate collection of evidence is urgent, and further delay seems dangerous and even culpable. Thus, however much to the present advantage of the theory as regards the custom it would have been to cull larger proofs from that vast field of literature only to be procured in older lands, it has seemed desirable to make this thesis public without further delay. As we have said, if the theory is correct, wider students will bring forward cogent facts in further proof from existing knowledge, whilst continued research should afford evidence so complete of the widespread existence of the custom in the present and past of the human race, as to render my speculation as to its origin less seemingly illegitimate.[9] [Footnote 1: Mr. Atkinson’s theory is based on the idea that our supposed anthropoid ancestor was eminently unsocial.--A. L.] [Footnote 2: Darwin, _Descent of Man_, ii. 361-363 (1871).] [Footnote 3: I ought to have said ‘within the community, whether local or of recognised kindred, indicated by the totem name.’--A. L.] [Footnote 4: This was written before the appearance of Mr. Crawley’s _Mystic Rose_ (1902).] [Footnote 5: Cf. V. de Rochas, _La Nouvelle-Calédonie_, p. 239; Crawley, _Mystic Rose_, p. 217.] [Footnote 6: _Native Tribes of Central Australia_, pp. 88, 89.--A. L..] [Footnote 7: Mr. Atkinson’s forecast was correct. Brother and sister avoidance is very widely diffused.--A. L.]