BRIEF [O.A.] Beust, Ludolf Author: Beust, Ludolf Recipient: Haeckel, Ernst Corporation: Ludolf Beust, Verlags-Buchhandlung
BRIEF [O.A.] Marshall-Ward, H... Author: Marshall-Ward, H... Recipient: Haeckel, Ernst Corporation: Botanisches Labor Dating: 26.07.1882
BRIEF [O.A.] Goette, Alexander Author: Goette, Alexander Recipient: Haeckel, Ernst Dating: 05.03.1875
BRIEF [O.A.] Benecke, Ernst Wilhelm Author: Benecke, Ernst Wilhelm Recipient: Haeckel, Ernst Dating: 16.03.1885
BRIEF [O.A.] Benecke, Ernst Wilhelm Author: Benecke, Ernst Wilhelm Recipient: Haeckel, Ernst Dating: 23.11.1885