Page:Hofstede de Groot catalogue raisonné, Volume 6, 1914.djvu/10

vi PREFACE The catalogue includes all the portraits by Maes of sitters who can be identified, whether these portraits are in existence or are known only from sale - catalogues. It includes also the unidentified portraits whose present whereabouts is known to the author, or which he has himself seen at sales or in exhibitions without knowing where to find them now, and also the portraits in earlier sales which are described with precision or, above all, which are dated. But all other imperfectly described portraits in old sales and exhibitions have been omitted. This plan will be followed in the coming volumes in respect of imperfectly described sea-pieces by W. van de Velde, land- scapes by Van Goyen, night scenes by Van der Neer, flower- and fruit-pieces by Rachel Ruysch and Jan van Huysum. It will be applied more strictly as the artistic interest of the painter concerned diminishes. But care will be taken to mention all the pictures described by John Smith. The author has received assistance and encouragement from many quarters in preparing this volume, which includes the work of the great master of the Dutch school, and is therefore especially important. To all who have helped him he would express his most grateful thanks. The author's former helpers, Dr. Karl Lilienfeld and Heinrich Wichmann, have collaborated in the Rembrandt section, and Dr. Kurt Erasmus in the section devoted to Maes. C. HOFSTEDE DE GROOT. THE HAGUE, April 1915.