hose of sisters and brothers--on the
other hand produced more vigorous children, and tended to perpetuate
themselves. Whereas originally there was no tendency either one way or
the other, some families developed from unknown causes, which, whatever
they were, were neither moral nor utilitarian, the practice of brother
and sister marriage. This diathesis followed the ordinary laws of
descent, and eventually those families which were fortunate enough to be
affected in that way exterminated their rivals.

Now, as will be shown immediately, this course of events seems to be in
contradiction with the facts of savage society at the present day and
with all probability. Apart from that however, how does Mr Morgan
suppose his eugenic diathesis to be transmitted? It can hardly be
maintained that this was the result of the different social conditions
of the families in which brothers and sisters intermarried. Obviously
there would be nothing to prevent the male in one of these unions from
reverting to the other type of marriage. This would indeed be highly
probable for reasons to be developed in the next paragraph. But if
social conditions were not the determining factor, we are left with the
somewhat grotesque theory of innate ideas. It is hardly necessary to
refute this origin of social evolution.

Perhaps the strongest objection, however, to Mr Morgan's theory is the
fact that in the most primitive communities the female tends to be
younger, often much younger, than her mate. It is a readily
ascertainable fact, though it seems to have been neglected by Mr Morgan,
that the age of puberty does not coincide with the greatest development
of the physical powers, but precedes it in the human subject by many
years. The result of this is that the younger males are, as a rule, in
the case of many mammals, held in subjection by the patriarch of the
herd, the result being what I have termed above patriarchal polygyny, as
long as the old male retains his powers. We have, it is true, no
evidence of any such conditions among the anthropoids; but it must not
be forgotten that we have no evidence of the consanguine family either
among anthropoids, other mammals or human beings.

It tells against the hypothesis of patriarchal polygyny that both among
horses and among camels there is evidence of the existence of actual
sexual aversion between both sire and filly and dam and colt in the
first case; and, as Aristotle tells us, at least between