POSTKARTE Aigner, Eduard Author: Aigner, Eduard Recipient: Haeckel, Ernst Corporation: A. V. f. d. O. Dating: 10.11.1913
BRIEF [O.A.] Basso, Fritzi von Author: Basso, Fritzi von Recipient: Haeckel, Ernst Dating: 07.07.1913
BRIEF OHNE UMSCHLAG Suschitzky, Willi Author: Suschitzky, Willi Recipient: Haeckel, Ernst Corporation: Anzengruber-Verlag Dating: 31.08.1913
BRIEF OHNE UMSCHLAG Suschitzky, Philipp Author: Suschitzky, Philipp Recipient: Haeckel, Ernst Corporation: Anzengruber-Verlag Dating: 07.07.1913
BRIEF [O.A.] Graedener, Hermann Author: Graedener, Hermann Recipient: Haeckel, Ernst Dating: 16.02.1913
BRIEF OHNE UMSCHLAG Schenk, Heinrich Author: Schenk, Heinrich Recipient: Haeckel, Ernst Dating: 20.03.1913