BRIEF OHNE UMSCHLAG Andeer, Justus Author: Andeer, Justus Recipient: Haeckel, Ernst Dating: 30.03.1885
BRIEF OHNE UMSCHLAG Ritter, Paul von Author: Ritter, Paul von Recipient: Haeckel, Ernst Dating: 07.01.1885
BRIEF OHNE UMSCHLAG Andres, Angelo Author: Andres, Angelo Recipient: Haeckel, Ernst Dating: 10.02.1885
BRIEF OHNE UMSCHLAG Dodel-Port, Arnold Author: Dodel-Port, Arnold Recipient: Haeckel, Ernst Dating: 23.02.1885
BRIEF OHNE UMSCHLAG Dodel-Port, Arnold Author: Dodel-Port, Arnold Recipient: Haeckel, Ernst Dating: 09.03.1885
BRIEF [O.A.] Dreyer, Friedrich Author: Dreyer, Friedrich Recipient: Haeckel, Ernst Dating: 06.07.1885