BRIEF [O.A.] Rottenburg, Paul von Author: Rottenburg, Paul von Recipient: Haeckel, Ernst Dating: 28.07.1881
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Man, Johannes Govertus de Dating: 10.02.1881
BRIEF [O.A.] Davidoff, Michael von Author: Davidoff, Michael von Recipient: Haeckel, Ernst Dating: 10.07.1881
BRIEF OHNE UMSCHLAG Deubler, Konrad Author: Deubler, Konrad Recipient: Haeckel, Ernst Dating: 21.02.1881
BRIEF OHNE UMSCHLAG Deubler, Konrad Author: Deubler, Konrad Recipient: Haeckel, Ernst Dating: 28.07.1881
BRIEF [O.A.] Cunningham, D. J. Author: Cunningham, D. J. Recipient: Haeckel, Ernst Dating: 27.08.1881
BRIEF OHNE UMSCHLAG Carneri, Bartholomäus von Author: Carneri, Bartholomäus von Recipient: Haeckel, Ernst Dating: 09.08.1881
BRIEF [O.A.] Green, Staniforth Author: Green, Staniforth Recipient: Haeckel, Ernst Dating: 25.11.1881