BRIEF OHNE UMSCHLAG Althoff, Friedrich Theodor Author: Althoff, Friedrich Theodor Recipient: Haeckel, Ernst Dating: 25.10.1892
BRIEF OHNE UMSCHLAG Paetel, Elwin Author: Paetel, Elwin Recipient: Haeckel, Ernst Corporation: Verlagsbuchhandlung Gebrüder Paetel in Berlin Dating: 24.12.1892
BRIEF OHNE UMSCHLAG Allmers, Hermann Author: Allmers, Hermann Recipient: Haeckel, Ernst Dating: 06.03.1892
BRIEF OHNE UMSCHLAG Allmers, Hermann Author: Allmers, Hermann Recipient: Haeckel, Ernst Dating: 18.12.1892
BRIEF OHNE UMSCHLAG Bölsche, Wilhelm Author: Bölsche, Wilhelm Recipient: Haeckel, Ernst Dating: ??.03.1892