BRIEF OHNE UMSCHLAG Ammon, Sophie von Author: Ammon, Sophie von Recipient: Haeckel, Ernst Dating: 05.02.1909
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Haeckel, Karl Dating: 12.03.1890
BRIEF [O.A.] Vignin De Author: Vignin De Recipient: Haeckel, Ernst Corporation: Station Zoologique d`Alger Dating: 30.05.1890
BRIEF [O.A.] Niguier, D... Author: Niguier, D... Recipient: Haeckel, Ernst Corporation: Station Zoologique d`Alger Dating: 06.12.1889
BRIEF [O.A.] Niguier, D... Author: Niguier, D... Recipient: Haeckel, Ernst Corporation: Station Zoologique d`Alger Dating: 27.06.1890