From these systems of nomenclature Mr. Morgan draws very far-reaching conclusions, assuming that they are necessarily to be explained by early marriage customs. Thus, from the “Malayan system,” he infers the former prevalence of “marriage in a group” of all brothers and sisters and cousins of the same grade or generation; or, more correctly, his case is, that if we can explain the “Malayan system” on the assumption that such a general custom once existed, then we must believe that it did formerly exist. “Without this custom,” he says, “it is impossible to explain the origin of the system from the nature of descents. There is, therefore, a necessity for the prevalence of this custom amongst the remote ancestors of all the nations which now possess the classificatory system, if the system itself is to be regarded as having a natural origin.”[441] The family resulting from this custom he calls, in his latest work, the “consanguine family,” and in this, consisting of a body of kinsfolk, within which there prevailed promiscuity, or “communal marriage,” between all men and women of the same generation, the family in its first stage is recognized.[442] Mr. Morgan believes, however, that as a necessary condition antecedent to this form of the family, promiscuity, in a wider sense of the term, may be theoretically deduced, though, as he says, “it lies concealed in the misty antiquity of mankind beyond the reach of positive knowledge.”[443] It is needless here to consider whether the last conclusion holds good. I shall endeavour to prove that Mr. Morgan’s inference of a stage of promiscuous intercourse even within the prescribed limits is altogether untenable. All depends on the point whether the “classificatory system” is a system of blood-ties, the nomenclature having been founded on blood-relationship, as near as the parentage of individuals could be known. Mr. Morgan assumes this, instead of proving it.