BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Reimer, Ernst Dating: 22.06.1886
BRIEF [O.A.] Grodtczinsky, N... Author: Grodtczinsky, N... Recipient: Haeckel, Ernst Dating: 28.11.1886
BRIEF OHNE UMSCHLAG Erdmann, Gustav Adolf Author: Erdmann, Gustav Adolf Recipient: Haeckel, Ernst Dating: 15.02.1886
BRIEF OHNE UMSCHLAG Erdmann, Gustav Adolf Author: Erdmann, Gustav Adolf Recipient: Haeckel, Ernst Dating: 24.03.1886
BRIEF [O.A.] Dreyer, Friedrich Author: Dreyer, Friedrich Recipient: Haeckel, Ernst Dating: 14.02.1886
BRIEF [O.A.] Dreyer, Friedrich Author: Dreyer, Friedrich Recipient: Haeckel, Ernst Dating: 07.03.1886
BRIEF [O.A.] Dreyer, Friedrich Author: Dreyer, Friedrich Recipient: Haeckel, Ernst Dating: 14.03.1886
BRIEF [O.A.] Dreyer, Friedrich Author: Dreyer, Friedrich Recipient: Haeckel, Ernst Dating: 28.03.1886