POSTKARTE Kertscher, Herbert R. Author: Kertscher, Herbert R. Recipient: Haeckel, Ernst Dating: 21.06.1909
BRIEF [O.A.] Cruikshank, William J... Author: Cruikshank, William J... Recipient: Haeckel, Ernst Dating: 06.04.1910
BRIEF [O.A.] Carman, Arington H... Author: Carman, Arington H... Recipient: Haeckel, Ernst Dating: 09.01.1914
BRIEF [O.A.] Janes, Lewis G... Author: Janes, Lewis G... Recipient: Haeckel, Ernst Corporation: The Brooklyn Ethical Association Dating: 11.09.1895
BRIEF OHNE UMSCHLAG Doubleday, Russell Author: Doubleday, Russell Recipient: Scheffauer, Herman Corporation: Doubleday Page & Co., The Country Life Press Dating: 18.02.1916
BRIEF [O.A.] Arnot, Raymond H... Author: Arnot, Raymond H... Recipient: Haeckel, Ernst Dating: 02.11.1901
POSTKARTE Arnot, Raymond H... Author: Arnot, Raymond H... Recipient: Haeckel, Ernst Dating: 19.01.1906