BRIEF [O.A.] Bunge, Gustav von Author: Bunge, Gustav von Recipient: Haeckel, Ernst Dating: 28.12.1904
BRIEF [O.A.] Burckhardt, Rud... Author: Burckhardt, Rud... Recipient: Haeckel, Ernst Dating: 26.02.1899
BRIEF [O.A.] Ziegler, Heinrich Ernst Author: Ziegler, Heinrich Ernst Recipient: Haeckel, Ernst Dating: 14.10.1899
BRIEF [O.A.] Friedmann, Hermann Author: Friedmann, Hermann Recipient: Haeckel, Ernst Dating: 20.01.1901
BRIEF [O.A.] Friedmann, Hermann Author: Friedmann, Hermann Recipient: Haeckel, Ernst Dating: 15.04.1901
BRIEF OHNE UMSCHLAG Friedmann, Hermann Author: Friedmann, Hermann Recipient: Haeckel, Ernst Dating: 19.04.1901
BRIEF OHNE UMSCHLAG Friedmann, Hermann Author: Friedmann, Hermann Recipient: Haeckel, Ernst Dating: 11.06.1901
BRIEF OHNE UMSCHLAG Friedmann, Hermann Author: Friedmann, Hermann Recipient: Haeckel, Ernst Dating: 03.09.1901
BRIEF OHNE UMSCHLAG Friedmann, Hermann Author: Friedmann, Hermann Recipient: Haeckel, Ernst Dating: 25.09.1901
BRIEF OHNE UMSCHLAG Becker, Franz Johann Jakob Emil Author: Becker, Franz Johann Jakob Emil Recipient: Haeckel, Ernst Dating: 26.09.1906
