BRIEF [O.A.] McIntosh, William C... Author: McIntosh, William C... Recipient: Haeckel, Ernst Dating: 25.03.1880
BRIEF OHNE UMSCHLAG Ihering, Hermann von Author: Ihering, Hermann von Recipient: Haeckel, Ernst Dating: 02.05.1880
BRIEF [O.A.] Zeppenfeld, Victor Author: Zeppenfeld, Victor Recipient: Haeckel, Ernst Dating: 04.11.1880
BRIEF OHNE UMSCHLAG Strasburger, Eduard Author: Strasburger, Eduard Recipient: Haeckel, Ernst Dating: 25.03.1880
BRIEF OHNE UMSCHLAG Rolle, Friedrich Author: Rolle, Friedrich Recipient: Haeckel, Ernst Dating: 08.03.1880
BRIEF [O.A.] Rottenburg, Paul von Author: Rottenburg, Paul von Recipient: Haeckel, Ernst Dating: 04.07.1880
BRIEF [O.A.] Rottenburg, Paul von Author: Rottenburg, Paul von Recipient: Haeckel, Ernst Dating: 28.07.1880
BRIEF [O.A.] Rottenburg, Paul von Author: Rottenburg, Paul von Recipient: Haeckel, Ernst Dating: 30.12.1880