BRIEF [O.A.] Hermann, Bernhard Author: Hermann, Bernhard Recipient: Haeckel, Ernst Dating: 22.07.1872
BRIEF [O.A.] Lortet, Louis Author: Lortet, Louis Recipient: Haeckel, Ernst Corporation: Museum d´Histore Naturelle Dating: 25.03.1872
BRIEF [O.A.] Marshall, William Author: Marshall, William Recipient: Haeckel, Ernst Dating: 08.11.1872
BRIEF [O.A.] Martens, Eduard von Author: Martens, Eduard von Recipient: Haeckel, Ernst Dating: 12.01.1872
BRIEF [O.A.] Martens, Eduard von Author: Martens, Eduard von Recipient: Haeckel, Ernst Dating: 09.10.1872