Panama, 1950 : to visit the Canal Zone Biological Area and to collect bird specimens in Chiman and along Rio Maje in Darien; Assisted by Watson M. Perrygo. Correspondence, reference materials, expense records, travel notes, film notes, and memorabilia. Correspondents include John Enos Graf, Louise M. Pearson, Herbert C. Clark, Karl P. Curtis, Charles Lewis Gazin, and Ratibor Hartmann