y takes place
according to a curious criss-cross scheme. These exogamous
subdivisions, which are peculiar to Australia, are known as
matrimonial classes. Dr. Frazer thinks that they are the result of
deliberate arrangement on the part of native statesmen; and certainly
he is right in his contention that there is an artificial and man-made
look about them. The system of phratries, on the other hand, whether
it carves up the tribe into two, or, as sometimes in North America
and elsewhere, into more than two primary divisions, under which the
clans tend to group themselves in a more or less orderly way, has all
the appearance of a natural development out of the clan-system. Thus,
to revert to the imaginary case of the Cockatoos and Crows practising
exogamy across the river, it seems easy to understand how the numbers
on both sides might increase until, whilst remaining Cockatoos and
Crows for cross-river purposes, they would find it necessary to adopt
among themselves subordinate distinctions; such as would be sure to
model themselves on the old Cockatoo-Crow principle of separate
totemic badges. But we must not wander off into questions of origin.
It is enough for our present purpose to have noted the fact that, within
the tribe, there are normally other forms of social grouping into which
a man is born, as well as the clan.

[Footnote 5: From a Greek word meaning "brotherhood," which was applied
to a very similar institution.]

Now we come to the tribe. This may be described as the political unit.
Its constitution tends to be lax and its functions vague. One way of
seizing its nature is to think of it as the social union within which
exogamy takes place. The intermarrying groups naturally hang together,
and are thus in their entirety endogamous, in the sense that marriage
with pure outsiders is disallowed by custom. Moreover, by mingling
in this way, they are likely to attain to the use of a common dialect,
and a common name, speaking of themselves, for instance, as "the men,"
and lumping the rest of humanity together as "foreigners." To act
together, however, as, for instance, in war, in order to repel
incursions on the part of the said foreigners, is not easy without
some definite organization. In Australia, where there is very little
war, this organization is mostly wanting. In North America, on the
other hand, amongst the more advanced and warlike tribes, we find
regular tribal officers, and some approach to a poli