POSTKARTE Graupner, Ludwig Author: Graupner, Ludwig Recipient: Haeckel, Ernst Corporation: D.M.B. Dating: 21.08.1914
BRIEF [O.A.] Haeckel, Walther Author: Haeckel, Walther Recipient: Allmers, Hermann Dating: 14.05.1885
BILDPOSTKARTE Haeckel, Emma Author: Haeckel, Emma Recipient: Haeckel, Ernst & Agnes [Eltern] Dating: 22.04.1911
BRIEF OHNE UMSCHLAG Köhler, Franz Eugen Author: Köhler, Franz Eugen Recipient: Haeckel, Ernst Corporation: Fr. Eugen Köhler's Verlag Gera-Untermhaus und Leipzig J. G. Bach's Verlag Fr. Eugen Köhler Dating: 28.07.1908
TELEGRAMM Borcherdt, Oscar; Köhler; Wittig Author: Borcherdt, Oscar; Köhler; Wittig Recipient: Haeckel, Ernst Dating: 16.02.1909
