Acknowledgments: The publishers and the director acknowledge their indebtedness for aid and advice in preparing the text and the illustrations to the artist, to Miss M. Hagenbach, to private and public collections, to photographers, to Ralph Manheim for his very able translation, to Bernard Karpel for his extensive bibliography and to Mrs. C. Giedion-Welcker for her contribution, reprinted in a revised version by permission of “Horizon,” London. Jean Arp and Hans Arp are identical, Mr. Arp using both first names according to the language employed. Mr. Arp has corrected and frequently chan texts and poems which have appeared previously in a different version. The frontispiece and insert are original woodcuts, especially made by the artist for this occasion. For literary sources and original publications refer to the bibliography. Copyright, 1948, by Wittenborn, Schultz, Inc. All rights reserved under international and Pan-American copyright conventions. Published by Wittenborn, Schultz, Inc., 38 East 57th Street, New York 22, N.Y.