BRIEF [O.A.] Meyer Author: Meyer Recipient: Haeckel, Ernst Corporation: Bibliographisches Institut Dating: 28.05.1898
BRIEF [O.A.] Reichardt-Stromberg, Mathilde Author: Reichardt-Stromberg, Mathilde Recipient: Haeckel, Ernst Dating: 14.07.1898
POSTKARTE Ziegler, Heinrich Ernst Author: Ziegler, Heinrich Ernst Recipient: Haeckel, Ernst Dating: 31.01.1898
BRIEF [O.A.] Strauß, Emil Author: Strauß, Emil Recipient: Haeckel, Ernst Corporation: Emil Strauss Verlagsbuchhandlung Dating: 28.01.1898
BRIEF [O.A.] Reichardt-Stromberg, Mathilde Author: Reichardt-Stromberg, Mathilde Recipient: Haeckel, Ernst Dating: 14.02.1898
BRIEF OHNE UMSCHLAG Stoy, Fritz Author: Stoy, Fritz Recipient: Haeckel, Ernst Corporation: European & Colonial Industries Ltd. Dating: 27.07.1898
