BRIEF OHNE UMSCHLAG Leitem, Rudolph Author: Leitem, Rudolph Recipient: Haeckel, Ernst Dating: 10.10.1907
TELEGRAMM Recipient: Haeckel, Ernst Corporation: Deutscher Monistenbund, Ortsgruppe Nürnberg Dating: 15.02.1914
POSTKARTE Banzhaff, Ludwig Author: Banzhaff, Ludwig Recipient: Haeckel, Ernst Corporation: Nordbayerische Zeitung Dating: 10.02.1906
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Haeckel, Agnes Dating: 23.08.1868
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Haeckel, Carl Gottlob; Haeckel, Charlotte Dating: 23.08.1868