BRIEF OHNE UMSCHLAG Günther, Franz Author: Günther, Franz Recipient: Haeckel, Ernst Dating: 08.12.1886
BRIEF OHNE UMSCHLAG Günther, Franz Author: Günther, Franz Recipient: Haeckel, Ernst Dating: 24.12.1886
BRIEF [O.A.] Froelich, Heinrich Author: Froelich, Heinrich Recipient: Haeckel, Ernst Dating: 23.02.1913
BRIEF [O.A.] Froelich, Heinrich Author: Froelich, Heinrich Recipient: Haeckel, Ernst Dating: 27.05.1914
BRIEF [O.A.] Gronkowsky, C... v. Author: Gronkowsky, C... v. Recipient: Haeckel, Ernst Dating: 09.12.1904
BRIEF [O.A.] Renard, Karl von Author: Renard, Karl von Recipient: Haeckel, Ernst Corporation: Die Kaiserliche Naturforschende Gesellschaft in Moskau Dating: 12.02.1873
BRIEF OHNE UMSCHLAG Hertwig, Richard Author: Hertwig, Richard Recipient: Haeckel, Ernst Dating: 14.11.1881