I would also call attention to his ingenious and philosophical explanation of the repugnance to marriage between near relatives which is so very general both among savage and civilised man, and as to the causes of which there has been great diversity of opinion; and to his valuable suggestions on the general question of sexual selection, in which he furnishes an original argument against Darwin’s views on the point, differing somewhat from my own though in general harmony with it. Every reader of the work will admire its clearness of style, and the wonderful command of what is to the author a foreign language. PREFACE TO THE FIRST EDITION I need scarcely say how fully I appreciate the honour of being introduced to English readers by Mr. Alfred R. Wallace. I am also greatly obliged for his kindness in reading the proofs, and in giving me the benefit of his advice with regard to various parts of the subject. It is difficult for me to acknowledge sufficiently my obligations to Mr. James Sime for his assistance in preparing this book for the press. The work, as originally written, naturally contained a good many foreign modes of expression. Mr. Sime has been indefatigable in helping me to improve the form of the text; and, in our discussions on the main lines of the argument, he has made several important suggestions. I am sincerely obliged for the invaluable aid he has given me. My cordial thanks are due to Mr. Charles J. Cooke, British Vice-Consul at Helsingfors, who most kindly aided me in writing the first part of the book in a tongue which is not my own. I am indebted also to Dr. E. B. Tylor, Professor G. Croom Robertson, Mr. James Sully, and Dr. W. C. Coupland for much encouraging interest; to Mr. Joseph Jacobs for the readiness with which he has placed at my disposal some results of his own researches; and to several gentlemen in different parts of the world who have been so good as to respond to my inquiries as to their personal observation of various classes of phenomena connected with marriage among savage tribes. The information I have received from them is acknowledged in the passages in which it is used. A list of authorities is given at the end of the book—between the text and the index, and it may be well to add that the references in the notes have been carefully verified. E. W. LONDON, _May, 1891_. PREFACE TO THE SECOND EDITION In this new edition of my book I have made no essential changes, but here and there the argument has been strengthened by the addition of facts which have come to my knowledge since the appearance of the first edition. The most important of these new facts will be found in the second chapter. I take this opportunity of expressing my warm appreciation of the thorough way in which the ideas set forth in this book have been discussed by many critics in England and elsewhere. Translations of the work have appeared, or are about to appear, in German, Swedish, French, Italian, and Russian.