ish Ducks_, pp. 8, 63), the Shoveler
duck, though normally monogamic, will become polyandric when
males are in excess, the two males being in constant and amicable
attendance on the female without signs of jealousy; among the
monogamic mallards, similarly, polygyny and polyandry may also
occur. See also R.W. Shufeldt, "Mating Among Birds," _American
Naturalist_, March, 1907; for mammal marriages, a valuable paper
by Robert Mueller, "Saeugethierehen," _Sexual-Probleme_, Jan.,
1909, and as regards the general prevalence of monogamy, Woods
Hutchinson, "Animal Marriage," _Contemporary Review_, Oct., 1904,
and Sept., 1905.

There has long been a dispute among the historians of marriage as
to the first form of human marriage. Some assume a primitive
promiscuity gradually modified in the direction of monogamy;
others argue that man began where the anthropoid apes left off,
and that monogamy has prevailed, on the whole, throughout. Both
these opposed views, in an extreme form, seem untenable, and the
truth appears to lie midway. It has been shown by various
writers, and notably Westermarck (_History of Human Marriage_,
Chs. IV-VI), that there is no sound evidence in favor of
primitive promiscuity, and that at the present day there are few,
if any, savage peoples living in genuine unrestricted sexual
promiscuity. This theory of a primitive promiscuity seems to have
been suggested, as J.A. Godfrey has pointed out (_Science of
Sex_, p. 112), by the existence in civilized societies of
promiscuous prostitution, though this kind of promiscuity was
really the result, rather than the origin, of marriage. On the
other hand, it can scarcely be said that there is any convincing
evidence of primitive strict monogamy beyond the assumption that
early man continued the sexual habits of the anthropoid apes. It
would seem probable, however, that the great forward step
involved in passing from ape to man was associated with a change
in sexual habits involving the temporary adoption of a more
complex system than monogamy. It is difficult to see in what
other social field than that of sex primitive man could find
exercise for the developing intellectual and moral aptitudes, the
subtle distinctions and moral restraints, which the strict
monogamy practiced by animals could afford no scope for. It is