BRIEF OHNE UMSCHLAG Darwin, Charles Author: Darwin, Charles Recipient: Haeckel, Ernst Dating: 23.06.1870
BRIEF OHNE UMSCHLAG Greeff, Richard Author: Greeff, Richard Recipient: Haeckel, Ernst Dating: 21.11.1870
BRIEF [O.A.] Gümbel, Wilhelm von Author: Gümbel, Wilhelm von Recipient: Haeckel, Ernst Dating: 10.11.1870
BRIEF [O.A.] Engelmann, Theodor; Engelmann, Theodor Wilhelm Author: Engelmann, Theodor; Engelmann, Theodor Wilhelm Recipient: Haeckel, Ernst Dating: 14.03.1870
BRIEF OHNE UMSCHLAG Engelmann, Theodor Wilhelm Author: Engelmann, Theodor Wilhelm Recipient: Haeckel, Ernst Dating: 17.04.1870
