POSTKARTE Stichling, Gottfried Theodor von Author: Stichling, Gottfried Theodor von Recipient: Haeckel, Ernst Dating: 23.01.1884
POSTKARTE Van de Velde-Sethe, Maria Author: Van de Velde-Sethe, Maria Recipient: Haeckel, Ernst Dating: 14.09.1902
POSTKARTE Schultze, L.; Battel Rapen; Friese; Eug. Andreae Author: Schultze, L.; Battel Rapen; Friese; Eug. Andreae Recipient: Haeckel, Ernst Dating: 26.07.1902
POSTKARTE Bölsche, Johanna; Bölsche, Wilhelm Author: Bölsche, Johanna; Bölsche, Wilhelm Recipient: Haeckel, Ernst Dating: 03.11.1908