The present edition of Kinship and Marriage in Early Arabia is no mere reprint of the work, which from its freshness and originality attracted the attention of Semitic scholars and anthropologists in 1885 and laid the foundation of all subsequent research in this department of studies. During the nine years which elapsed between its publication and his lamented death, Robertson Smith had collected additional notes and references in his own interleaved copy, and there were indications that he contemplated the preparation of a second edition, and had even marked out for himself certain features and lines of argument which he proposed to develop. When, in course of time, the call for a second edition began to make itself heard, it was felt that his new material however incomplete ought not to be withheld, and Professor Ignaz Goldziher of Budapest, a valued personal friend of the author, and the writer of a careful and discriminating review of the book in the Literatur blatt Orientalische Philologie, was invited to see the proposed work through the press. This task he unfortunately found himself unable to complete, and, when it passed into the hands of the present writer in May 1901, he very generously placed at the disposal of the latter such notes as he had already collected. In the discharge of this somewhat delicate task, the present editors aim has been to give effect, in the first instance, to all the authors corrections, alterations, and additions, all other matter whether contributed by himself or others being placed within square brackets. Kinship and Marriage itself arose out of that epoch-making paper in the Journal of Philology referred to below p. xiv, and simply marks a stage in the authors investigation of Semitic organisations, which was brilliantly followed up by the lectures on the fundamental institutions of the Semites. If in the Religion of the Semites primitive ritual rather than primitive society forms the chief theme, yet the two works are in a large degree complementary, and several points which are only lightly touched upon in Kinship and Marriage receive fuller treatment in the later work. Accordingly, it has seemed desirable to introduce into the present edition all necessary references to Religion of the Semites, more particularly in those cases though few in number where the author had modified his views.