BRIEF [O.A.] Maschmeyer, Chas... Author: Maschmeyer, Chas... Recipient: Haeckel, Ernst Dating: 21.02.1903
BRIEF [O.A.] Molenaar, Heinrich Author: Molenaar, Heinrich Recipient: Haeckel, Ernst Corporation: Zeitschrift "Die Religion der Menschheit" Dating: 23.11.1903
BRIEF [O.A.] Olivier, Julius von Author: Olivier, Julius von Recipient: Haeckel, Ernst Dating: 06.01.1903
BRIEF [O.A.] Stubenrauch, Max von Author: Stubenrauch, Max von Recipient: Haeckel, Ernst Dating: 24.06.1903
BRIEF [O.A.] Stubenrauch, Max von Author: Stubenrauch, Max von Recipient: Haeckel, Ernst Dating: 27.06.1903
BRIEF [O.A.] Hirth, Georg Author: Hirth, Georg Recipient: Haeckel, Ernst Corporation: Jugend Dating: 12.01.1903