Dr. Howitt points to such sporadic peoples as the Veddahs, the Todas, the Ainu and others, Asiatic tribes which furnish just the characteristics required in the hypothetical invaders.
A careful geographical description of the tribes dealt with in the book forms the second chapter, illustrated with maps. The author then plunges into his main subject, first of all, both here and in the geographical description, carefully defining the terms he uses. This is especially necessary because the words are not all used in the ordinary anthropological sense, if such a sense can be attributed to them. Care and caution are indeed noticeable throughout the volume. Even when, as on page 170, the interpretation of a certain set of facts in a particular way would exactly suit a theory of the evolution of native institutions which he strongly holds, Dr. Howitt hesitates to adopt it, being of opinion that another interpretation is possible, and being, he says, "unable to quite satisfy myself" on the point. This gives confidence alike in his evidence (much of it collected at first-hand and the rest assiduously sifted), and in his conclusions, from which the student will only differ with very great respect, if at all.
The theory just referred to is that of a series of reformatory movements initiated from time to time by the elders of the tribe after mature deliberation. It is a theory à priori probable. The Australian race has been isolated from immemorial antiquity. The tribes are found in varying degrees of evolution. To produce this evolution the impulse must have come from somewhere. But it could not have come from any source external to the continent. The old men of a tribe collectively are the authority, and the only authority recognized. What they are agreed on is carried out. Here then we have a power which might effect reforms. A given reform once effected in a tribe might slowly spread by means of friendly intercourse between neighbouring tribes on different occasions. It might indeed be rejected in one tribe, but equally well it might be accepted and imitated in another. It might never reach the knowledge of distant or permanently hostile tribes, or only reach them as a vague rumour, and never be seriously considered; while they on their part might have received and acted on an impulse of the same kind, but varying in details, or directed to quite other