I want here to express my thanks and appreciation to Mr. Lessing J. Rosenwald, through whose kindness this unique Doctrina was presented to the Library of Congress and with whom the idea of this publication originated. His interest and enthusiasm made possible my work, and his friendly advice and encouragement have been both valuable and heart-warming.

            I also wish to thank others who have given me great assistance. They are Dr. A.S.W. Rosenbach to whom I continually turned for advice, Dr. Lawrence C. Wroth of the John Carter Brown Library and Dr. Leslie W. Dunlap of the Library of Congress who very kindly read over my manuscript and gave me the benefit of their suggestions and criticisms, Mr. David C. Mearns and Miss Elsie Rackstraw of the Library of Congress and Mrs. Ruth Lapham Butler of the Ayer Collection of the Newberry Library who so freely and generously made available to me the great collections of works on the Philippines in their libraries, Dr. John H. Powell of the Free Library of Philadelphia who helped me find reference books of the utmost importance, and the many librarians who courteously answered written queries about early Philippine material. Edwin Wolf 2nd.