BRIEF OHNE UMSCHLAG Haeckel, Karl Author: Haeckel, Karl Recipient: Haeckel, Carl Gottlob; Haeckel, Charlotte Dating: 03.06.1846
BRIEF OHNE UMSCHLAG Sethe, Heinrich Author: Sethe, Heinrich Recipient: Haeckel, Ernst Dating: 09.07.1846
BRIEF OHNE UMSCHLAG Bleek, Theodor Author: Bleek, Theodor Recipient: Haeckel, Ernst Dating: 29.12.1846