BRIEFABSCHRIFT Ritter, Paul von Author: Ritter, Paul von Recipient: Haeckel, Ernst Dating: 07.01.1886
BRIEF OHNE UMSCHLAG Harnier, Eduard von Author: Harnier, Eduard von Recipient: Haeckel, Ernst Dating: 30.05.1886
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Reimer, Ernst Dating: 22.06.1886
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.] Grodtczinsky, N... Author: Grodtczinsky, N... Recipient: Haeckel, Ernst Dating: 28.11.1886
BRIEF OHNE UMSCHLAG Erdmann, Gustav Adolf Author: Erdmann, Gustav Adolf Recipient: Haeckel, Ernst Dating: 15.02.1886
BRIEF OHNE UMSCHLAG Erdmann, Gustav Adolf Author: Erdmann, Gustav Adolf Recipient: Haeckel, Ernst Dating: 24.03.1886