BRIEF [O.A.] Hubrecht, Ambrosius A... W... Author: Hubrecht, Ambrosius A... W... Recipient: Haeckel, Ernst Dating: 16.06.1878
BRIEF [O.A.] Jong, Jac... J... de Author: Jong, Jac... J... de Recipient: Haeckel, Ernst Dating: 17.02.1914
DOKUMENT Man, Johannes Govertus de Author: Man, Johannes Govertus de Recipient: Haeckel, Ernst Corporation: Naturhistorisches Museum Leiden Dating: 18.09.1879
BRIEF OHNE UMSCHLAG Man, Johannes Govertus de Author: Man, Johannes Govertus de Recipient: Haeckel, Ernst Corporation: Naturhistorisches Museum Leiden Dating: 19.07.1869
BRIEF [O.A.] Hoffmann, Christian Karl Author: Hoffmann, Christian Karl Recipient: Haeckel, Ernst Dating: 13.11.1891
BRIEF [O.A.] Hoffmann, Christian Karl Author: Hoffmann, Christian Karl Recipient: Haeckel, Ernst Dating: 20.10.1895
BRIEF OHNE UMSCHLAG Martin, Karl Author: Martin, Karl Recipient: Haeckel, Ernst Corporation: `s Rijks Geologisch-Mineralogisch Museum Dating: 08.07.1897
BRIEF OHNE UMSCHLAG Salverda, Matthijs Author: Salverda, Matthijs Recipient: Haeckel, Ernst Dating: 22.08.1865