BRIEF [O.A.] Blochmann, Friedrich Author: Blochmann, Friedrich Recipient: Haeckel, Ernst Dating: 04.03.1911
BRIEF [O.A.] Behm, Hans Wolfgang Author: Behm, Hans Wolfgang Recipient: Haeckel, Ernst Dating: 23.01.1911
BRIEF [O.A.] Baege, Max Hermann Author: Baege, Max Hermann Recipient: Haeckel, Ernst Corporation: Wissenschaftliche Rundschau Dating: 02.03.1911
BRIEF OHNE UMSCHLAG Amplewitz, Rudolf Author: Amplewitz, Rudolf Recipient: Haeckel, Ernst Dating: 12.04.1911
BRIEF OHNE UMSCHLAG Amplewitz, Rudolf Author: Amplewitz, Rudolf Recipient: Haeckel, Ernst Dating: 06.06.1911
BRIEF OHNE UMSCHLAG Bockelmann, Friedrich Author: Bockelmann, Friedrich Recipient: Haeckel, Ernst Dating: 15.02.1911
