BRIEF [O.A.] Rottenburg, Paul von Author: Rottenburg, Paul von Recipient: Haeckel, Ernst Dating: 28.07.1881
BRIEF OHNE UMSCHLAG Haeckel, Marie Author: Haeckel, Marie Recipient: Haeckel, Charlotte Dating: 30.06.1881
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Strasburger, Eduard Dating: 24.05.1881
POSTKARTE Haeckel, Ernst Author: Haeckel, Ernst Recipient: Haeckel, Agnes (geb. Huschke) Dating: 11.10.1881
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Rodenberg, Julius Dating: 30.07.1881
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Rodenberg, Julius Dating: 28.08.1881