savages, and if admitted, it follows that the sentiment of
kinship within the clan was already established when the family terms
of relationship were devised, and therefore that the clan was prior
to the family as a social unit. This conclusion is fortified by the
rule of exogamy which prohibits marriage between persons of the same
clan between whom no blood-relationship can be traced, and therefore
shows that some kind of kinship was believed to exist between them,
independent of and stronger than the link of consanguinity. Further,
Mr. Hartland shows in _Primitive Paternity_ [92] that during the period
of female descent when physical paternity has been recognised, but the
father and mother belong to different clans, the children, being of
the mother's clan, will avenge a blood-feud of their clan upon their
own father; and this custom seems to show clearly that the sentiment
of clan-kinship was prior to and stronger than that of family kinship.

51. Clan kinship and totemism.

The same argument seems to demonstrate that the idea of kinship within
the clan was prior to the idea of descent from a common ancestor,
whether an animal or plant, a god, hero or nicknamed ancestor. Because
it is obvious that a set of persons otherwise unconnected could not
suddenly and without reason have believed themselves to be descended
from a common ancestor and hence related. If a number of persons not
demonstrably connected by blood believe themselves to be akin simply
on account of their descent from a common ancestor, it can only be
because they are an expanded family, either actually or by fiction,
which really had or might have had a common ancestor. That is, the
clan tracing its descent from a common ancestor, if this was the
primary type of clan, must have been subsequent to the family as
a social institution. But as already seen the sentiment of kinship
within the clan was prior to that within the family, and therefore
the genesis of the clan from an expanded family is an impossible
hypothesis; and it follows that the members of the clan must first
have believed themselves to be bound together by some tie equivalent to
or stronger than that of consanguineous kinship, and afterwards, when
the primary belief was falling into abeyance, that of descent from a
common ancestor came into existence to account for the clan sentiment
of kinship already existing. If then the first form of association
of human beings was in small group