To be of service to history each floating fragment of ancient custom and belief must not only be labelled "ancient," but it must be placed back in the system from which it has been torn away. To do this is to a great extent to restore the ancient system; and to restore an ancient system of culture, even if the restoration be only a mosaic and a shattered mosaic, is to bring into evidence the people to which it belongs. In the previous chapter it was necessary to lay somewhat special stress upon the system of social organisation known as totemism, which was not founded upon kinship. This was traced in survival among the pre-Celtic peoples of Britain. If we now turn to the Celts and Teutons of Britain we shall find that we have to deal with a social organisation founded definitely upon kinship; and if there are survivals of belief, custom, and rite, derived from this kinship system, existing side by side in the same culture area with survivals from the kinless system, it will be necessary to explain how two such opposite streams can have been kept flowing. It is not difficult in the case of countries occupied by Celtic or Teutonic peoples to ascertain what the particular institution was which linked together the beliefs of the people, though it is not easy to trace out all the phases of it. It is the tribe--that system of society which appears as the means by which Greek and Roman, Celt and Teuton, Scandinavian and Slav, Hindu and Persian, were able to conquer, overrun, and finally to settle in the lands which they have made their own. We know something of the Celtic tribe, less of the Teutonic tribe, but all we know is that it possesses features in common with the tribe of its kindred. There is no fact more certainly true as a result of comparative research than that the tribe is the common heritage of those people who have become the dominant rulers of the Indo-European world. I use this term "tribe" in no formal sense, not in the sense of its Roman derivation and use, which shows it quite as a secondary institution, but as the most convenient term to define that grouping of men with wives, families, and descendants, and all the essentials of independent life, which is found as a primal unit of European society in a state of unsettlement as regards land or country. The tie which bound all together was personal not local, kinship with a tribal god, kinship more or less real with fellow-tribesmen, kinship in status and rights. We meet with this tribal organisation everywhere in Indo-European history. It made movement from country to country possible. It made conquest possible. Celt and Teuton did not conquer in families any more than Greek or Hindu did. They conquered in tribes, and it was because of the strength of the tribal organisation during the period, first of migration and wandering and then of conquest, that the settlement after conquest was possible and was so strong. Everywhere we find these people conquerors and settlers.