It may be laid down as a general rule that all Australian tribes are divided into two moieties, which intermarry, but each of which is forbidden to marry within itself.

For these two moieties the term “classes” used by Dr. Lorimer Fison and myself, and since adopted by Messrs. Spencer and Gillen, and other writers on Australian anthropology, may now be regarded as the recognised term. The expression “tribe” has been used by some writers in this sense, but the “tribe” includes two organisations, the “local,” already described, and the “social,” to be dealt with now. The terms “clan” and “phratry” are both objectionable, because a definite meaning has become attached to them, which I do not desire to apply to the analogous organisations found in Australia; but have used the term “clan” to mean the principal geographical and territorial division of a tribe, in which descent is in the male line. Then some term seemed necessary to denote the divisions of a tribe in which descent is counted in the female line, and for this, as before stated, I use “horde,” without including in my meaning any reference to the use made of it by other writers on anthropological theories.

The division of the people of the tribe into two classes is the foundation from which the whole social organisation of the native tribes of Australia has been developed.