Daston before his five-month leave of absence, only 80 stained 

 negatives remaining to be processed. 



Mrs. Lenore B. Warner continued to catalogue and file nega- 

 tives and prints of the type-photograph collection of flowering 

 plants. She checked all work processed by Assistant Daston, han- 

 dled orders and exchanges, continued the preparation of a generic 

 index for the Macbride photograph collection, indexed and pre- 

 pared herbarium sheets to be photographed for the general collec- 

 tion, prepared a numerical index for all Liebmann plates (also 

 indexed in the collection of Mexican plants), and sent out a total 

 of 1,197 type photographs in exchange. Reorganization of the 

 photograph collection of plant models, exhibits, plant products, 

 habitats, etc., was begun by Mrs. Dorothy Gibson, Departmental 

 Secretary, who was assisted in this project during part of the year 

 by Miss Adams and Miss Moreen. 



Exhibits— Botany 



The Hall of North American Trees (Hall 26, Charles F. Millspaugh 

 Hall) was reopened on Members' Night, May 8 (see page 34), when 

 about 60 per cent of the reorganization of the hall had been com- 

 pleted. Before the end of the year 84 exhibits of North American 

 trees (including 26 wood exhibits) were reconditioned and nearly 

 all of them had been reinstalled. Chief Curator Just and Curator 

 Thieret prepared 84 new labels for these exhibits and Curator of 

 Exhibits Emil Sella recolored 36 transparencies of forest types. 

 Five new exhibits were installed in Hall 26: "Trees of the Past," 

 "Dutch Elm Disease," "How a Tree Lives," and "Forests of the 

 United States" were placed in four central wallcases and a Car- 

 boniferous stump of Stigmaria (gift of the American Museum of 

 Natural History) was mounted in the center of the hall with illu- 

 mination from the ceiling. For Members' Night Associate Curator 

 Smith prepared for the Department of Botany a display "America's 

 Oldest Herbarium," which featured several plant specimens of espe- 

 cial interest from the herbarium of Rev. G. H. E. Muhlenberg, 

 including a Linnean isotype collected near Uppsala, Sweden, by 

 the originator of modern classification. Most of the work on the 

 various exhibits was done by Curator Sella, Artist-Preparator Sam- 

 uel H. Grove, Jr., Technician Frank Boryca, and Preparator Walter 

 Huebner. Parts of the special exhibit of Darwiniana in Stanley 

 Field Hall during November and December (see pages 25 and 76) 

 were prepared by Artist Grove and Artist Dean Randall. 



57 



