BRIEF OHNE UMSCHLAG Dorsch, Hannah Author: Dorsch, Hannah Recipient: Haeckel, Ernst Dating: 14.05.1908
BRIEF OHNE UMSCHLAG Sarasin, Fritz Author: Sarasin, Fritz Recipient: Haeckel, Ernst Dating: 14.09.1908
BRIEF OHNE UMSCHLAG Keller, Conrad Author: Keller, Conrad Recipient: Haeckel, Ernst Dating: 08.07.1908
BRIEF OHNE UMSCHLAG Sokolowsky, Alexander Author: Sokolowsky, Alexander Recipient: Haeckel, Ernst Dating: 13.07.1908