BRIEF OHNE UMSCHLAG Müller, Hermann Author: Müller, Hermann Recipient: Haeckel, Ernst Dating: 07.06.1872
BRIEF OHNE UMSCHLAG Bleek, Auguste Author: Bleek, Auguste Recipient: Haeckel, Ernst Dating: 15.11.1872
BRIEF [O.A.] Beyrich, Clementine Author: Beyrich, Clementine Recipient: Haeckel, Ernst Dating: 19.06.1872
BRIEF [O.A.] Beyrich, Clementine Author: Beyrich, Clementine Recipient: Haeckel, Ernst Dating: 01.07.1872
BRIEF [O.A.] Grohmann, Wilh... Author: Grohmann, Wilh... Recipient: Haeckel, Ernst Dating: 31.05.1872
BRIEF OHNE UMSCHLAG Schultze, Fritz Author: Schultze, Fritz Recipient: Haeckel, Ernst Dating: 30.04.1872