BRIEFABSCHRIFT Haeckel, Ernst Author: Haeckel, Ernst Recipient: Eggeling, Heinrich von Dating: 03.11.1890
BRIEF [O.A.] Haeckel, Ernst Author: Haeckel, Ernst Recipient: Geddes, Patrick Dating: 1890 .??.?? [oder später]
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Unbekannt Corporation: Zoologisches Institut Dating: 29.12.1890
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Eggeling, Heinrich von Dating: 30.12.1890
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Eggeling, Heinrich Dating: 20.01.1890
BRIEFABSCHRIFT Haeckel, Ernst Author: Haeckel, Ernst Recipient: Eggeling, Heinrich Dating: 12.01.1890
