BRIEF [O.A.] Gaedechens, Rudolph Author: Gaedechens, Rudolph Recipient: Haeckel, Ernst Dating: 13.02.1885
ABSCHRIFT Reiß Author: Reiß Recipient: Haeckel, Ernst Corporation: Gesellschaft für Erdkunde Dating: 25.06.1885
BRIEF OHNE UMSCHLAG Dodel-Port, Arnold Author: Dodel-Port, Arnold Recipient: Haeckel, Ernst Dating: 23.02.1885
BRIEF OHNE UMSCHLAG Dodel-Port, Arnold Author: Dodel-Port, Arnold Recipient: Haeckel, Ernst Dating: 09.03.1885