BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Reimer, Georg Dating: 18.04.1876
BRIEF OHNE UMSCHLAG Haeckel, Agnes (geb. Huschke) Author: Haeckel, Agnes (geb. Huschke) Recipient: Haeckel, Ernst Dating: 15.03.1876
BRIEF OHNE UMSCHLAG Petersen, Bertha; geb. Sethe Author: Petersen, Bertha; geb. Sethe Recipient: Haeckel, Ernst Dating: 14.05.1876
BRIEF [O.A.] Haeckel, Ernst Franz Max Author: Haeckel, Ernst Franz Max Recipient: Haeckel, Ernst Dating: 18.07.1876