thus it undergoes a process of change which leads it further and further from its primitive constitution. [Sidenote: Influences affecting the tribe.] Two leading features of this process can, however, without difficulty be detected, and may be assumed as tolerably certain. These are, first, that private property in land did not exist at first, but emerged from a right of common property vested in the community. Personal property or individual property in moveables must at all times have existed, but real property or individual property in the soil is of much later origin, and is an excrescence upon the common use or property of the land occupied by the tribe, and is inconsistent with its original constitution. The second feature is, that the social unit was not the individual or the family but the community or tribe. The original bond of union between the members of the tribe was no doubt the belief in a common origin, a common descent from the _eponymus_, whether mythic or historic, from whom it took its name; but in the early period to which we must refer the pure primitive tribe, when the sanctions of marriage were unknown, and a loose relation between the sexes existed, which is faintly shadowed forth in a few scattered notices by the Roman authors of this relation among the Celtic inhabitants of Britain and Ireland, descent through the females rather than the males must have been viewed as the more certain link; and it is probable that here as elsewhere female succession preceded a representation through males, and that the sons belonged to the tribe of their mothers.[160] [Sidenote: Effect of the introduction of Christianity.] The early state of the tribe, however, soon became modified not only by internal changes but also by external influences. Of these external influences not the least powerful, and probably the first in order, was the introduction of Christianity and the adaptation of the Christian Church to the tribal system. The tribe was thus brought into contact with a higher civilisation and a purer code of morals. The lax relations between the sexes, which still survived, must have been checked and controlled, the sanction of marriage enforced, by which the father is placed in his legitimate position as head of the family, and the rights of the children were clearly defined, and the older connection of the members of the tribe through females reduced in some cases to an occasional right of succession through the mother, while in others it entirely disappeared. [Sidenote: Land originally held in common.]