BRIEF [O.A.] Rességuier, Oliver [Graf] Author: Rességuier, Oliver [Graf] Recipient: Haeckel, Ernst Dating: 15.09.1907
BRIEF OHNE UMSCHLAG Elmers, Fritz Author: Elmers, Fritz Recipient: Haeckel, Ernst Corporation: Zoologische Station des Berliner Aquariums Rovigno Dating: 22.10.1907