BRIEF [O.A.] Faber, Emily M... Author: Faber, Emily M... Recipient: Haeckel, Ernst Dating: 22.02.1912
BRIEF OHNE UMSCHLAG Bornmüller, Josef Author: Bornmüller, Josef Recipient: Haeckel, Ernst Dating: 11.06.1912
BRIEF OHNE UMSCHLAG Bornmüller, Josef Author: Bornmüller, Josef Recipient: Haeckel, Ernst Dating: 20.06.1912
BRIEF OHNE UMSCHLAG Bornmüller, Josef Author: Bornmüller, Josef Recipient: Haeckel, Ernst Corporation: Herbarium Haußknecht Dating: 14.08.1912
BRIEF [O.A.] Hergt, Bernhard Author: Hergt, Bernhard Recipient: Haeckel, Ernst Corporation: Herbarium Haußknecht Dating: 20.06.1912
BRIEF [O.A.] Michel, August Author: Michel, August Recipient: Haeckel, Ernst Corporation: Deutscher Monistenbund, Ortsgruppe Weimar Dating: 27.09.1912
BRIEF [O.A.] Steman, Friedrich Author: Steman, Friedrich Recipient: Haeckel, Ernst Dating: 17.02.1912
BRIEF [O.A.] Steman, Friedrich Author: Steman, Friedrich Recipient: Haeckel, Ernst Dating: 05.03.1912
BRIEF [O.A.] Steman, Friedrich Author: Steman, Friedrich Recipient: Haeckel, Ernst Dating: 25.05.1912