BRIEF [O.A.] Portela, Guillermina Author: Portela, Guillermina Recipient: Haeckel, Ernst Dating: 15.10.1902
BRIEF [O.A.] Morehouse, George W... Author: Morehouse, George W... Recipient: Haeckel, Ernst Dating: 31.08.1902
BRIEF [O.A.] Nienstaedt, Edw... Author: Nienstaedt, Edw... Recipient: Haeckel, Ernst Dating: 18.08.1902
BRIEF [O.A.] Nienstaedt, Edw... Author: Nienstaedt, Edw... Recipient: Haeckel, Ernst Dating: 18.08.1902
BRIEF [O.A.] Moritz von Sachsen-Altenburg [Herzog] Author: Moritz von Sachsen-Altenburg [Herzog] Recipient: Haeckel, Ernst Dating: 09.10.1902