Similarly, no proof of the existence of paternal authority in the family throws any light on the question of whether the children belong to the kin of the father rather than of the mother.  Where the mother or mother’s brother is the guardian, we are usually safe in assuming that descent is or has been until recently matrilineal.  But from the undisputed existence of patria potestas no similar inference can be drawn.

Again, as will be shown below, not even the tie of blood between parent and child, confined though it may be in the opinion of the people whose institutions are in question, to a single parent, is an index to the way in which is determined the kinship organisation to which the child belongs.

It is therefore clear that the utmost discrimination is necessary in dealing with these questions; rules of descent must be kept apart from matters which indeed influence the evolution of the rules but are in no way decisive as to their form at any given moment.

Returning now to the alleged priority of matrilineal descent in determining the kinship organisation into which a child passes, it may be said that whereas evidences of the passage from female to male reckoning may be observed,[12] there is virtually none of a change in the opposite direction.  In other words, where kinship is reckoned in the female line, there is no ground for supposing that it was ever hereditary in any other way.  On the other hand, where kinship is reckoned in the male line, it is frequently not only legitimate but necessary to conclude that it has succeeded a system of female kinship.  But this clearly does not mean that female descent has in all cases preceded the reckoning of kinship through males.  Patrilineal descent may have been directly evolved without the intermediate stage of reckoning through females.

The problem is probably insoluble.  No decisive data are available, for the mere absence of traces of matrilineal descent does not necessarily prove more than that it had long been superseded by reckoning of kinship through males.  All that can be said is that in the kinship organisations known to us female descent seems to have prevailed in the vast majority of cases and probably existed in the residual class of indeterminable examples.

With patria potestas it is, of course, different.  There can be little doubt that it might and probably did develop in the absence of kinship organisations and in a state of society where consanguinity is no real bond after the children have reached puberty.  If therefore under such circumstances a kinship organisation were to come into existence, either independently or by transmission, it might well be that patrilineal principles prevailed from the first.  But of such a case we have no knowledge.  It may perhaps be questioned whether the actually existing peoples who appear to have no kinship organisations, such as the Hottentots, the Bushmen, the Veddahs and perhaps the Fuegians, are not in this state rather as a result of the break-up of their former organisation than because they have never evolved kinship groups.  But our knowledge in these matters is lamentably small and the problem is not one which calls for discussion here.