BILDPOSTKARTE Haeckel, Ernst Author: Haeckel, Ernst Recipient: Heldburg, Helene von Dating: 31.12.1909
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Grober, Julius Dating: 01.11.1909
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Vollert, Max Corporation: Zoologisches Institut der Universität Jena Dating: 19.04.1909
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Meyer, Hans; Meyer, Elisabeth, geb. Haeckel Dating: 25.07.1909
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Meyer, Hans Corporation: Universität Jena Dating: 06.05.1909
