BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Schultze, Leonhard Dating: 24.05.1907
BRIEF OHNE UMSCHLAG Retzius, Gustaf Author: Retzius, Gustaf Recipient: Haeckel, Ernst Dating: 19.11.1895
BRIEF [O.A.] Lidforss, Gärda; Videgren, Karin Author: Lidforss, Gärda; Videgren, Karin Recipient: Haeckel, Ernst Dating: 25.10.1890
BRIEF [O.A.] Lidforss, Gärda; Videgren, Karin Author: Lidforss, Gärda; Videgren, Karin Recipient: Haeckel, Ernst Dating: 30.07.1890
BRIEF [O.A.] Lindhagen, D... G... Author: Lindhagen, D... G... Recipient: Haeckel, Ernst Corporation: Académie Royale des Sciences Dating: 06.01.1883
BRIEF OHNE UMSCHLAG Lovén, Sven Author: Lovén, Sven Recipient: Haeckel, Ernst Corporation: Zoologiska Riks-Museum Dating: 16.12.1882