TELEGRAMM Wahl, Bruno; Heinricher, Emil Johann Lambert Author: Wahl, Bruno; Heinricher, Emil Johann Lambert Recipient: Haeckel, Ernst Dating: 16.02.1904
BRIEF [O.A.] Herberger, Cajetan Author: Herberger, Cajetan Recipient: Haeckel, Ernst Dating: 11.10.1904
BRIEF [O.A.] Haberlandt, Gottlieb Author: Haberlandt, Gottlieb Recipient: Haeckel, Ernst Dating: 14.02.1904