BRIEF OHNE UMSCHLAG Watts, Charles A. Author: Watts, Charles A. Recipient: Haeckel, Ernst Dating: 07.09.1883
BRIEF [O.A.] Rottenburg, Paul von Author: Rottenburg, Paul von Recipient: Haeckel, Ernst Dating: 26.09.1883
BRIEF [O.A.] Rottenburg, Paul von Author: Rottenburg, Paul von Recipient: Haeckel, Ernst Dating: 15.01.1883
BRIEF [O.A.] Rottenburg, Paul von Author: Rottenburg, Paul von Recipient: Haeckel, Ernst Dating: 16.07.1883
BRIEF [O.A.] Hearne, Walter R... Author: Hearne, Walter R... Recipient: Haeckel, Ernst Dating: 16.11.1883