POSTKARTE Haeckel, Ernst Author: Haeckel, Ernst Recipient: Delle Grazie, Marie Eugenie Dating: 29.10.1896
POSTKARTE Haeckel, Ernst Author: Haeckel, Ernst Recipient: Carneri, Bartholomäus von Dating: 31.01.1896
POSTKARTE Haeckel, Ernst Author: Haeckel, Ernst Recipient: Rohlfs, Leontine, geb. Behrens Dating: 09.06.1896