BRIEF [O.A.] Doerflinger, Carl Author: Doerflinger, Carl Recipient: Haeckel, Ernst Dating: 15.03.1877
BRIEF [O.A.] Dominicis, Saverio F... de Author: Dominicis, Saverio F... de Recipient: Haeckel, Ernst Dating: 18.07.1877
BRIEF [O.A.] Engelmann, Rudolf Author: Engelmann, Rudolf Recipient: Haeckel, Ernst Corporation: Wilhelm Engelmann Verlagsbuchhandlung Dating: 25.08.1877
BRIEF [O.A.] Engelmann, Rudolf Author: Engelmann, Rudolf Recipient: Haeckel, Ernst Corporation: Wilhelm Engelmann Verlagsbuchhandlung Dating: 11.09.1877
BRIEF OHNE UMSCHLAG Eckstein, Ernst Author: Eckstein, Ernst Recipient: Haeckel, Ernst Corporation: Deutsche Dichterhalle Dating: 10.07.1877
