To sum up briefly: criticism of statements has in the first place to ascertain the exact and correct verbal meaning of each of them. In the second place many general but sure hints are afforded by a detailed analysis of the conditions under which the evidence was obtained and set forth by the author. The important points here are: quality of the material under observation; modes in which evidence was obtained (by inquiries from natives, by immediate observation, etc.); character, profession, and training of the informant, including possible bias, theoretical, moral, and personal. All these points appear at first sight rather impalpable, but as shown above they may afford good hints, especially if taken into account simultaneously. Now we pass to the second point indicated above on page 18, namely, the discussion of the local differences which may introduce some apparent contradictions into the statements. Assuming the possession of a series of statements, the correctness of which we accept within certain limits, there may still be some contradictions between them, due to the differences between the tribes, to which these statements refer. The task will be consequently to indicate these differences and to give certain reasons why some of the contradictions may be dealt with in this way and why others cannot be reduced to local differences. In the first place, in order to facilitate the application of the geographical point of view, the survey of the statements will always be made in the same geographical order. I begin with the south-east end of the continent and proceed then westwards and northwards, enumerating first the tribes of Victoria, then the tribes of the South territory of South Australia. I proceed over New South Wales to the Central and Northern tribes; then to Queensland, ending with West Australia. The order is kept only roughly without pedantic accuracy, which cannot be achieved, as many writers do not even trouble to localize their statements with anything approaching exactitude.