BRIEF OHNE UMSCHLAG Ammon, Sophie von Author: Ammon, Sophie von Recipient: Haeckel, Ernst Dating: 05.02.1909
BRIEF [O.A.] Ashcroft, Edgar A... Author: Ashcroft, Edgar A... Recipient: Haeckel, Ernst Dating: 27.01.1905
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Haeckel, Karl Dating: 12.03.1890
BRIEF [O.A.] Galli, Gottfried Author: Galli, Gottfried Recipient: Haeckel, Ernst Corporation: Kaiserlich Deutsches Consulat Dating: 19.02.1890