TELEGRAMM Schillings, Carl Georg Author: Schillings, Carl Georg Recipient: Haeckel, Ernst Dating: 28.05.1911
BRIEF OHNE UMSCHLAG Schillings, Carl Georg Author: Schillings, Carl Georg Recipient: Haeckel, Ernst Corporation: Hotel "Vier Jahreszeiten" Dating: 28.05.1911
BRIEF OHNE UMSCHLAG Hertwig, Richard Author: Hertwig, Richard Recipient: Haeckel, Ernst Dating: 17.05.1911
BRIEF [O.A.] Kreuzpointner, Josef Author: Kreuzpointner, Josef Recipient: Haeckel, Ernst Dating: 17.06.1911
BRIEF [O.A.] Kreuzpointner, Josef Author: Kreuzpointner, Josef Recipient: Haeckel, Ernst Dating: 22.06.1911
BRIEF [O.A.] Langheinrich, N.N. Author: Langheinrich, N.N. Recipient: Haeckel, Ernst Corporation: Jugend Dating: 15.07.1911