BRIEFABSCHRIFT Ritter, Paul von Author: Ritter, Paul von Recipient: Haeckel, Ernst Dating: 07.01.1886
BRIEF OHNE UMSCHLAG Harnier, Eduard von Author: Harnier, Eduard von Recipient: Haeckel, Ernst Dating: 30.05.1886
BRIEF OHNE UMSCHLAG Harnier, Eduard von Author: Harnier, Eduard von Recipient: Haeckel, Ernst Dating: 18.05.1886
BRIEF [O.A.] Abayawira, M. P. Abraham Author: Abayawira, M. P. Abraham Recipient: Haeckel, Ernst Dating: 10.01.1886
BRIEF OHNE UMSCHLAG Anderson, Alexander Author: Anderson, Alexander Recipient: Haeckel, Ernst Corporation: Philosophical Institution Dating: 04.05.1886
BRIEF [O.A.] Abayawira, Don David Author: Abayawira, Don David Recipient: Haeckel, Ernst Dating: 05.06.1886
BRIEF [O.A.] Abayawira, Don David Author: Abayawira, Don David Recipient: Haeckel, Ernst Dating: 25.09.1886