BRIEF [O.A.] Scherer, Jean Author: Scherer, Jean Recipient: Haeckel, Ernst Corporation: L`Illustration Dating: 05.04.1902
BRIEF OHNE UMSCHLAG Rottenburg, Paul von Author: Rottenburg, Paul von Recipient: Haeckel, Ernst Dating: 21.03.1901
BRIEF [O.A.] Grand-Carteret, John Author: Grand-Carteret, John Recipient: Haeckel, Ernst Dating: 22.03.1906
POSTKARTE Grand-Carteret, John Author: Grand-Carteret, John Recipient: Haeckel, Ernst Dating: 27.03.1906
POSTKARTE Grand-Carteret, John Author: Grand-Carteret, John Recipient: Haeckel, Ernst Dating: 01.03.1912
BRIEF OHNE UMSCHLAG Rottenburg, Paul von Author: Rottenburg, Paul von Recipient: Haeckel, Ernst Dating: 21.06.1889
