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 dam and colt in the case of camels; but we can hardly argue from Ungulata to Primates.

However this may be, the objections to Morgan’s theories do not lose their strength.  Enough has perhaps been said of them from the point of view of theory.  We may look at them in the light of the known facts of social evolution among races of low stages of culture.

If we now turn for a moment to see what light Australian facts throw on the first two stages postulated by Mr Morgan, we find that the theoretical objections are amply supported by the course of evolution which can be traced in Australian social regulations.  It will be recollected that in his view father-daughter marriage disappeared first, then brother and sister marriage.  Totemism apart, there are in Australia, as we have seen, two kinds of organisation for the regulation of marriage—­phratries, the dichotomous division of the southern tribes, and classes, the four-fold or eight-fold division of the other areas as to which we have any knowledge.  Of these the