The _kind_ of evidence from which we predicate this unity, is evidently of a cumulative kind; and it is merely the statement of its being of this sort that has been laid before the reader: the _details_ would require either a larger volume than the present, or a special monograph. It may also be added, that as the Australian tribes differ more from one another in language than in any other respect, it is the philological portion of their ethnography that presents the most difficulties. In respect to their manners, morals, and social customs, the similarity, lying less below the surface than it does with respect to their languages, has drawn less attention on the part of investigators. Still the way in which it shows itself is the same. Two neighbouring tribes shall differ more than two distant ones: so that similar customs shall re-appear in distant localities. As to the physical conformation of the Australians, I believe that it is so uniform throughout the island, that it has never been made the basis of a division;--indeed I am inclined to believe that (like the _dis_similarity of language) the _similarity_ of external appearance has been over-rated; nevertheless, it is certain that there are deviations from the general slim and underfed condition of the body; and (what is of more importance), from the usual straight character of the hair. Such is the case, according to Mr. Earle, with the trepang fishers of Arnhem Bay who are bulky men, with broad chests, the lower extremities being but indifferently formed, and the crooked shin being common. Then as to the hair--with the Jaako, or Croker Island tribe, it is coarse and bushy (the whiskers being thick, and curly) and so short, crisp, and abundant about the breast and shoulders as to conceal the skin; whereas on the other hand, the Oitbo, or Bidjenelumbo, have straight silky hair, arched eyebrows, fair complexion, and occasionally the oblique eye. The lowest form of humanity has been sought for in Australia, whilst the physical condition of the country and the absence of those animals and herbs that supply human food, have made it a likely quarter to exhibit it. Whether, however, so low a rank in scale of human development be, upon the whole, a fact or exaggeration, it is certain that, upon several points, there has been considerable overstatement. One sample of this sort is the accredited opinion as to the absolute incapacity of the Australian of forming even the rudest elements of a mythology--an opinion which engenders the notion that their intellects are too sluggish for even the evolution of a superstition.