Email Record: A Calendar of the correspondence of Charles Darwin, 1821-1882 / editors, Frederick Burkhardt, Sydney Smith ; associate editors, David Kohn, William Montgomery ; managing editor, Stephen V. Pocock ; assistant editors, P. Thomas Carroll, Charlotte Bowman ; research associates, Anne Schlabach Burkhardt, Nora Caroll Stevenson ; research assistants, Doris E. Andrews [and others].