TELEGRAMM Marx, Leopold Christian Author: Marx, Leopold Christian Recipient: Haeckel, Ernst Dating: 04.08.1892
TELEGRAMM Recipient: Haeckel, Ernst Corporation: Sternwarte der Plagwitzer Strasse, Leipzig Dating: 20.08.1892
TELEGRAMM Geyer, ?; Schlutius ? Author: Geyer, ?; Schlutius ? Recipient: Haeckel, Ernst Dating: 20.08.1892