BRIEF [O.A.] Kleinenberg, Nicolai Author: Kleinenberg, Nicolai Recipient: Haeckel, Ernst Dating: 08.04.1870
BRIEF OHNE UMSCHLAG Jaeger, Gustav Author: Jaeger, Gustav Recipient: Haeckel, Ernst Dating: 16.02.1870
BRIEF [O.A.] Jeffreys, F... Gwynn Author: Jeffreys, F... Gwynn Recipient: Haeckel, Ernst Dating: 04.10.1870
BRIEF OHNE UMSCHLAG Strasburger, Eduard Author: Strasburger, Eduard Recipient: Haeckel, Ernst Dating: 04.08.1870
BRIEF OHNE UMSCHLAG Strasburger, Eduard Author: Strasburger, Eduard Recipient: Haeckel, Ernst Dating: 07.08.1870
BRIEF [O.A.] Zülken, Chr... Author: Zülken, Chr... Recipient: Haeckel, Ernst Corporation: Universitetets Zoologiske Museum Dating: 16.07.1870
BRIEF OHNE UMSCHLAG Spencer, Herbert Author: Spencer, Herbert Recipient: Haeckel, Ernst Dating: 24.09.1870
