ANSICHTSKARTE Ammon, Sophie von Author: Ammon, Sophie von Recipient: Haeckel, Ernst Dating: 05.04.1910
BRIEF [O.A.] Bonardi, Edoardo Author: Bonardi, Edoardo Recipient: Haeckel, Ernst Corporation: Medico Primario Ospedale Maggiore Dating: 29.12.1910
BRIEF [O.A.] Walther, Johannes Author: Walther, Johannes Recipient: Haeckel, Ernst Dating: 14.10.1910