necessity for agricultural and pastoral industries led inevitably to a life of social intercourse, and to a patriarchal system under which the land belonged to the ayllu. The arable land was assigned annually to the heads of families, while the pasture and woodland continued to be the common property of the ayllu. There were doubtless frequent wars respecting boundaries and rights of pasturage with neighbouring ayllus, but there were also confederations of ayllus for defence, and for the construction of works for the common good, which would be beyond the powers of a single ayllu—such as works of irrigation, and terraced cultivation. The unit was the head of a family, called puric, the united purics formed the ayllu, which occupied the cultivable land called marca.
There is abundant evidence that this patriarchal system, with rules established by long custom, had existed from remote antiquity. The development of agriculture and the domestication of animals could not have been continued for centuries without the existence of an ordered social life, pointing to a head or heads to rule and direct. Moreover, the traditions and ancestral descents of the ayllus were most carefully preserved down to the very last, and this no doubt led to the worship of ancestors, and to all the ceremonial services which it involved.
In course of time the neighbouring ayllus, in many instances, united not only for purposes of defence, but also for social and industrial objects,
