terests of freedom--that is, they limited the choice of
a wife to an extent that proved inconvenient.[771]

+425+. An almost universal feature of the marriage rules of low tribes
is the classificatory system of relationship. According to this system,
the community being divided into groups, terms of relationship indicate
not kinship in blood but tribal status in respect of marriageability;
thus, the same term is used for a child's real father and for every man
who might legally have become the husband of his mother, and the same
term for the real mother and for every woman whom the father might have
married; the children of such possible fathers and mothers are the
child's brothers and sisters; all possible spouses are called a man's
"wives" or a woman's "husbands"; and similarly with all
relationships.[772]

+426+. The system has many varieties of form, and gives way in time to
the formal recognition of blood kinship. It has been held to point to an
earlier system of "group marriage," in which all the men of one group
had marital relations with all the women of another group, and further
to a primitive custom of sexual promiscuity.[773] In the nature of the
case these hypotheses do not admit of proof or disproof. All that is
certain is that the classificatory system has been and is an
accompaniment of one stage of social and religious development.

+427+. The effect of exogamous arrangements has been to prevent marriage
between persons related in blood.[774] In totemic organizations, when
the totem is inherited, a division into two exogamous groups makes
marriage of brother to sister impossible, since all the children of one
mother are in the same group; and if there are four such groups and
children are assigned to a group different from that of the father and
that of the mother, marriage between parent and child is impossible.
When the totem is not inherited (as is the case among the Australian
Arunta) similar results are secured by a further subdivision.

+428+. The particular exogamic customs vary considerably among early
tribes, the differences following, in general, differences of social
organization. In some more settled savage communities (as, for example,
the Kurnai of Southeast Australia), in which there are neither classes
nor totemic clans, marriage is permitted only between members of certain
districts.[775] Well-organized social life tends to promote individual
freedom in marriage as in other things. M