BRIEF [O.A.] Kampffmeyer, Hans Author: Kampffmeyer, Hans Recipient: Haeckel, Ernst Dating: 08.05.1917
BRIEF [O.A.] Graedener, Hermann Author: Graedener, Hermann Recipient: Haeckel, Ernst Dating: 06.04.1908
BRIEF [O.A.] Kutzschenbach, Arthur von Author: Kutzschenbach, Arthur von Recipient: Haeckel, Ernst Dating: 31.12.1910
POSTKARTE Kutzschenbach, Arthur von Author: Kutzschenbach, Arthur von Recipient: Haeckel, Ernst Dating: 25.01.1911
BRIEF OHNE UMSCHLAG Kanoldt, Edmund Author: Kanoldt, Edmund Recipient: Haeckel, Ernst Dating: 03.10.1889
BRIEF OHNE UMSCHLAG Kanoldt, Edmund Author: Kanoldt, Edmund Recipient: Haeckel, Ernst Dating: 15.02.1894
BRIEF OHNE UMSCHLAG Kanoldt, Johanna Author: Kanoldt, Johanna Recipient: Haeckel, Ernst Dating: 11.01.1905