BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Heldburg, Helene Freifrau von Dating: 29.06.1894
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Heldburg, Helene Freifrau von Dating: 21.10.1894
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Heldburg, Helene Freifrau von Dating: 22.02.1894
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Heldburg, Helene Freifrau von Corporation: Zoologisches Institut Dating: 30.12.1894