BRIEF OHNE UMSCHLAG Allmers, Hermann Author: Allmers, Hermann Recipient: Haeckel, Ernst Dating: 16.01.1886
BRIEF OHNE UMSCHLAG Allmers, Hermann Author: Allmers, Hermann Recipient: Haeckel, Ernst Dating: 13.02.1886
BRIEF [O.A.] Gumprecht, Ferdinand Author: Gumprecht, Ferdinand Recipient: Haeckel, Ernst Dating: 01.04.1886
BRIEF OHNE UMSCHLAG Paetel, Hermann Author: Paetel, Hermann Recipient: Haeckel, Ernst Corporation: Verein für Deutsche Literatur Dating: 27.12.1886
BRIEF [O.A.] Schorer, Jacob Hendrik Author: Schorer, Jacob Hendrik Recipient: Haeckel, Ernst Corporation: Das Echo - Schorers Familienblatt Dating: 01.09.1886
BRIEF [O.A.] Vogel, Hermann Wilhelm Author: Vogel, Hermann Wilhelm Recipient: Haeckel, Ernst Dating: 27.04.1886
