BRIEF OHNE UMSCHLAG Bessels, Emil Author: Bessels, Emil Recipient: Haeckel, Ernst Corporation: Smithsonian Institution Dating: 15.11.1874
BRIEF [O.A.] Hoeber, E... W... Author: Hoeber, E... W... Recipient: Haeckel, Ernst Corporation: New York Liberal Club Dating: 13.08.1874
BRIEF [O.A.] Rhyn, G... A... F... van Author: Rhyn, G... A... F... van Recipient: Haeckel, Ernst Dating: 20.03.1874
BRIEF [O.A.] Rhyn, G... A... F... van Author: Rhyn, G... A... F... van Recipient: Haeckel, Ernst Dating: 05.05.1874
BRIEF [O.A.] Rhyn, G... A... F... van Author: Rhyn, G... A... F... van Recipient: Haeckel, Ernst Dating: 19.10.1874