BILDPOSTKARTE Becker, Franz Johann Jakob Emil Author: Becker, Franz Johann Jakob Emil Recipient: Haeckel, Ernst Dating: 20.08.1917
BILDPOSTKARTE Ammon, Sophie von Author: Ammon, Sophie von Recipient: Haeckel, Agnes Dating: 1908.??.?? [?]
BILDPOSTKARTE Ammon, Sophie von Author: Ammon, Sophie von Recipient: Haeckel, Ernst Dating: 20.02.1913
BILDPOSTKARTE Bardeleben, Karl von et al. Author: Bardeleben, Karl von et al. Recipient: Haeckel, Ernst Dating: 27.10.1902