German art critic; born at Hamburg Jan. 15, 1863. After a short business career he devoted himself (1885) to the study of the history of art at the universities of Jena, Kiel, and Leipsic. He took his degree in 1889 with the dissertation "Lübecker Malerei und Plastik bis 1530," the first detailed analysis of the medieval art of northeast Germany. After traveling through Germany, Denmark, Sweden, the Netherlands, England, France, and Italy, on the presentation of his work "Der Albanipsalter in Hildesheim und Seine Beziehung zur Symbolischen Kirchenskulptur des 12. Jahrhunderts" (1893), he became privat-docent at the University of Berlin. His "Studien zur Geschichte der Sächsischen Skulptur in der Uebergangszeit vom Romanischen zum Gotischen Stil" (Berlin, 1902) traces the gradual development of German sculpture with reference to the period of its florescence in the thirteenth century. His "Die Kirchenthür des Heil. Ambrosius in Mailand" (1902) for the first time showed the door of the Church of St. Ambrogio in Milan to be a monument of early Christian art. He has also contributed a number of important articles on North-German painting, Saxon sculpture, and early medieval miniature manuscripts to the "Repertorium für Kunstwissenschaft," "Zeitschrift für Christliche Kunst," and "Jahrbuch der Kgl. Preussischen Kunstsammlungen."