BRIEF [O.A.] Ercolani, G... B... Author: Ercolani, G... B... Recipient: Haeckel, Ernst Dating: 18.02.1877
BRIEF [O.A.] Ercolani, G... B... Author: Ercolani, G... B... Recipient: Haeckel, Ernst Dating: 24.03.1880
BRIEF [O.A.] Aschieri, Ettor Luigi Author: Aschieri, Ettor Luigi Recipient: Haeckel, Ernst Dating: 16.09.1891
BRIEF [O.A.] Aschieri, Ettor Luigi Author: Aschieri, Ettor Luigi Recipient: Haeckel, Ernst Dating: 17.12.1891
BRIEF [O.A.] Cavazzi, Alfredo Author: Cavazzi, Alfredo Recipient: Haeckel, Ernst Corporation: R. Accademia delle Scienze dell' Istituto di Bologna Dating: 31.03.1909
BRIEF [O.A.] Carati, Ernesto Author: Carati, Ernesto Recipient: Haeckel, Ernst Corporation: R. Università di Bologna Dating: 19.01.1909
BRIEF [O.A.] Foresti, Lodovico Author: Foresti, Lodovico Recipient: Haeckel, Ernst Dating: 10.12.1875