BRIEF [O.A.] Grube, Adolf Eduard Author: Grube, Adolf Eduard Recipient: Haeckel, Ernst Dating: 20.10.1876
BRIEF [O.A.] Grube, Adolf Eduard Author: Grube, Adolf Eduard Recipient: Haeckel, Ernst Dating: 14.12.1876
BRIEF [O.A.] Fürstenberg, Landgraf von Author: Fürstenberg, Landgraf von Recipient: Haeckel, Ernst Dating: 04.11.1876
BRIEF [O.A.] Herzeele, A... von Author: Herzeele, A... von Recipient: Haeckel, Ernst Dating: 15.06.1876
BRIEF [O.A.] Herzeele, A... von Author: Herzeele, A... von Recipient: Haeckel, Ernst Dating: 02.07.1876
