POSTKARTE Osborn, Henry Fairfield Author: Osborn, Henry Fairfield Recipient: Haeckel, Ernst Dating: ??.??.1906
BRIEF OHNE UMSCHLAG Dorsch, Hannah Author: Dorsch, Hannah Recipient: Haeckel, Ernst Dating: 14.02.1906
BRIEF OHNE UMSCHLAG Dorsch, Hannah Author: Dorsch, Hannah Recipient: Haeckel, Ernst Dating: 08.03.1906
BRIEF [O.A.] Dreste, Karl Author: Dreste, Karl Recipient: Haeckel, Ernst Corporation: Haushaltungs- Toilette- Seifen und Parfümeriefabrik Karl Dreste Dating: 16.02.1906
BRIEF [O.A.] DeWitt, E... L... Author: DeWitt, E... L... Recipient: Haeckel, Ernst Corporation: DeWitt & Hubbard Dating: 07.09.1906
BRIEF [O.A.] Daumann, Friedrich Author: Daumann, Friedrich Recipient: Haeckel, Ernst Dating: 09.02.1906
BRIEF [O.A.] Diederichs, Eugen Author: Diederichs, Eugen Recipient: Haeckel, Ernst Corporation: Eugen Diederichs Verlag Dating: 28.02.1906
BRIEF [O.A.] Dugan, Thomas Author: Dugan, Thomas Recipient: Haeckel, Ernst Corporation: John E. Dugan, Plumbing, Roofing and Haeting, Stoves and Gas Fixtures Dating: 28.01.1906