BRIEF OHNE UMSCHLAG Becker, Daniel Georg Author: Becker, Daniel Georg Recipient: Haeckel, Ernst Dating: 14.06.1904
BRIEF OHNE UMSCHLAG Borngräber, Otto Author: Borngräber, Otto Recipient: Haeckel, Ernst Dating: 09.02.1904
BRIEF OHNE UMSCHLAG Borngräber, Otto Author: Borngräber, Otto Recipient: Haeckel, Ernst Dating: 03.04.1904
BRIEF OHNE UMSCHLAG Bertheau, Georg Author: Bertheau, Georg Recipient: Haeckel, Ernst Dating: 10.02.1904
BRIEF OHNE UMSCHLAG Becker, Johann Author: Becker, Johann Recipient: Haeckel, Ernst Dating: 23.02.1904
POSTKARTE Bockelmann, Friedrich Author: Bockelmann, Friedrich Recipient: Haeckel, Ernst Dating: 12.02.1904
TELEGRAMM Bedriaga, Jacques von Author: Bedriaga, Jacques von Recipient: Haeckel, Ernst Dating: 16.02.1904
