lity, this system of what has been called group
marriage, serving as it does to bind more or less closely
together groups of individuals who are mutually interested in one
another's welfare, has been one of the most powerful agents in
the early stages of the upward development of the human race"
(Spencer and Gillen, _Northern Tribes of Central Australia_, p.
74; cf. A.W. Howitt, _The Native Tribes of South-East
Australia_). Group-marriage, with female descent, as found in
Australia, tends to become transformed by various stages of
progress into individual marriage with descent in the male line,
a survival of group-marriage perhaps persisting in the
much-discussed _jus primae noctis_. (It should be added that Mr.
N.W. Thomas, in his book on _Kinship and Marriage in Australia_,
1908, concludes that group-marriage in Australia has not been
demonstrated, and that Professor Westermarck, in his _Origin and
Development of the Moral Ideas_, as in his previous _History of
Human Marriage_, maintains a skeptical opinion in regard to
group-marriage generally; he thinks the Urabunna custom may have
developed out of ordinary individual marriage, and regards the
group-marriage theory as "the residuary legatee of the old theory
of promiscuity." Durkheim also believes that the Australian
marriage system is not primitive, "Organisation Matrimoniale
Australienne," _L'Annee Sociologique_, eighth year, 1905). With
the attainment of a certain level of social progress it is easy
to see that a wide and complicated system of sexual relationships
ceases to have its value, and a more or less qualified monogamy
tends to prevail as more in harmony with the claims of social
stability and executive masculine energy.

The best historical discussion of marriage is still probably
Westermarck's _History of Human Marriage_, though at some points
it now needs to be corrected or supplemented; among more recent
books dealing with primitive sexual conceptions may be specially
mentioned Crawley's _Mystic Rose_, while the facts concerning the
transformation of marriage among the higher human races are set
forth in G.E. Howard's _History of Matrimonial Institutions_ (3
vols.), which contains copious bibliographical references. There
is an admirably compact, but clear and comprehensive, sketch of
the development of m