BRIEF OHNE UMSCHLAG Quillet, Aristide Author: Quillet, Aristide Recipient: Haeckel, Ernst Dating: 26.12.1912
BRIEF OHNE UMSCHLAG Tilden, George Horten Author: Tilden, George Horten Recipient: Haeckel, Ernst Dating: 27.04.1907
BRIEF OHNE UMSCHLAG Quillet, Aristide Author: Quillet, Aristide Recipient: Haeckel, Ernst Dating: 18.12.1912
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Haeckel, Charlotte Dating: 21.08.1878
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Haeckel, Agnes Dating: 30.08.1878
BRIEF OHNE UMSCHLAG Ritter, Paul von Author: Ritter, Paul von Recipient: Haeckel, Ernst Dating: 24.03.1894
BRIEF OHNE UMSCHLAG Ritter, Paul von Author: Ritter, Paul von Recipient: Haeckel, Ernst Dating: 29.03.1894