BRIEF [O.A.] Ziegler, Heinrich Ernst Author: Ziegler, Heinrich Ernst Recipient: Haeckel, Ernst Dating: 05.08.1902
BRIEF [O.A.] Schultze, Leonhard Author: Schultze, Leonhard Recipient: Haeckel, Ernst Dating: 03.08.1902
BRIEF [O.A.] Schultze, Leonhard Author: Schultze, Leonhard Recipient: Haeckel, Ernst Dating: 20.09.1902
BRIEF [O.A.] Edler, Wilhelm Author: Edler, Wilhelm Recipient: Haeckel, Ernst Corporation: Landwirtschaftliches Institut der Universität Dating: 12.08.1902
BRIEF [O.A.] Haeckel, Agnes (geb. Huschke) Author: Haeckel, Agnes (geb. Huschke) Recipient: Haeckel, Ernst Dating: 21.08.1902