VISITENKARTE Haeckel, Ernst Author: Haeckel, Ernst Recipient: Fischer, Kuno Dating: 1907.??.?? [davor]
BRIEF OHNE UMSCHLAG Thomson, Charles Wyville Author: Thomson, Charles Wyville Recipient: Haeckel, Ernst Dating: 02.16.????
KARTE Haeckel, Emma Author: Haeckel, Emma Recipient: Haeckel, Ernst & Agnes [Eltern] Dating: 15.10.1914
