BRIEF OHNE UMSCHLAG Aigner, Eduard Author: Aigner, Eduard Recipient: Haeckel, Ernst Dating: 31.10.1910
BRIEF OHNE UMSCHLAG Hertwig, Richard Author: Hertwig, Richard Recipient: Haeckel, Ernst Dating: 15.02.1910
BRIEF OHNE UMSCHLAG Hertwig, Richard Author: Hertwig, Richard Recipient: Haeckel, Ernst Dating: 12.06.1910
BRIEF OHNE UMSCHLAG Lasch, Wilhelm Author: Lasch, Wilhelm Recipient: Haeckel, Ernst Dating: 20.03.1910
BRIEF OHNE UMSCHLAG Haeckel, Ernst Author: Haeckel, Ernst Recipient: Hertwig, Richard Dating: 14.09.1910