TELEGRAMM Drugievic, Ferdinand Author: Drugievic, Ferdinand Recipient: Haeckel, Ernst Dating: 15.02.1908
TELEGRAMM Wahl, Bruno; Heinricher, Emil Johann Lambert Author: Wahl, Bruno; Heinricher, Emil Johann Lambert Recipient: Haeckel, Ernst Dating: 16.02.1904
TELEGRAMM Graff, Ludwig von Author: Graff, Ludwig von Recipient: Haeckel, Ernst Corporation: Zoologisches Institut Graz Dating: 16.02.1909