BRIEF OHNE UMSCHLAG Pfungst, Arthur Author: Pfungst, Arthur Recipient: Haeckel, Ernst Dating: 15.02.1909
TELEGRAMM Wille, Bruno; Westphal, ? [et al.] Author: Wille, Bruno; Westphal, ? [et al.] Recipient: Haeckel, Ernst Corporation: Freidenker-Kongress Dating: 12.06.1908
TELEGRAMM Recipient: Haeckel, Ernst Corporation: Senckenbergische Naturforschende Gesellschaft Frankfurt a.M. Dating: 16.02.1894
TELEGRAMM Kahl, August; Kaufmann, Marie Author: Kahl, August; Kaufmann, Marie Recipient: Haeckel, Ernst Dating: 16.02.1909
TELEGRAMM Naumann, Virginie; Naumann, Egmont Author: Naumann, Virginie; Naumann, Egmont Recipient: Haeckel, Ernst Dating: 16.02.1909
TELEGRAMM Römer, Fritz Author: Römer, Fritz Recipient: Haeckel, Ernst Corporation: Senckenbergische Naturforschende Gesellschaft; Senckenberg-Museum Dating: 16.02.1909
BRIEF OHNE UMSCHLAG Pfungst, Arthur Author: Pfungst, Arthur Recipient: Haeckel, Ernst Dating: 21.01.1908
BRIEF OHNE UMSCHLAG Henning, Max Author: Henning, Max Recipient: Haeckel, Ernst Corporation: Neuer Frankfurter Verlag G.m.b.H. Dating: 26.02.1909