Towering over the fields of art and photography of the 20th century-as a promoter, practitioner and publisher-Alfred Stieglitz requires little by way of introduction. Numerous volumes of his photographs and writings have been published along with critical commentary on his gallery activities, including last year's Modern Art and America (Cat# BF163H $75). This new two-volume boxed set is the definitive catalogue of the Alfred Stieglitz Collection of Photographs at the National Gallery of Art, Washington. Donated by Georgia O'Keeffe, artist and widow of the photographer, it is the most comprehensive Stieglitz holding in existence, numbering 1,642 photographs. No library is complete without this magnificent set.