TELEGRAMM Heitmueller, Franz Ferdinand Author: Heitmueller, Franz Ferdinand Recipient: Haeckel, Ernst Dating: 16.02.1904
BRIEF [O.A.] Steman, Friedrich Author: Steman, Friedrich Recipient: Haeckel, Ernst Dating: 15.02.1904
BRIEF [O.A.] Steman, Friedrich Author: Steman, Friedrich Recipient: Haeckel, Ernst Dating: 02.06.1904
BRIEF OHNE UMSCHLAG Kuhn, Carl Author: Kuhn, Carl Recipient: Haeckel, Ernst Corporation: Großherzoglich Sächs. Staatsministerium, Departement des Kultus Dating: 01.06.1904