BRIEF OHNE UMSCHLAG Allmers, Hermann Author: Allmers, Hermann Recipient: Haeckel, Ernst Dating: 14.09.1896
BRIEF [O.A.] Bather, Francis Arthur Author: Bather, Francis Arthur Recipient: Haeckel, Ernst Corporation: British Museum (Natural History) Dating: 17.10.1896
BRIEF OHNE UMSCHLAG Allmers, Hermann Author: Allmers, Hermann Recipient: Haeckel, Ernst Dating: 31.12.1896