BRIEF [O.A.] Camerano, Lorenzo Author: Camerano, Lorenzo Recipient: Haeckel, Ernst Dating: 30.11.1899
BRIEF [O.A.] Gestro, Raffaello Author: Gestro, Raffaello Recipient: Haeckel, Ernst Corporation: Museo Civico di Storia Naturale Dating: 10.03.1899
BRIEF OHNE UMSCHLAG Canaro, Antonio Author: Canaro, Antonio Recipient: Haeckel, Ernst Corporation: R. Istituto Veneto di Scienze, Lettere ed Arti Dating: 27.06.1899
BRIEF [O.A.] Capellini, Giovanni Author: Capellini, Giovanni Recipient: Haeckel, Ernst Dating: 03.03.1899
POSTKARTE Capellini, Giovanni Author: Capellini, Giovanni Recipient: Haeckel, Ernst Dating: 17.06.1899
TELEGRAMM Capellini, Giovanni Author: Capellini, Giovanni Recipient: Haeckel, Ernst Dating: 13.10.1899
BRIEF [O.A.] Capellini, Giovanni Author: Capellini, Giovanni Recipient: Haeckel, Ernst Corporation: Senato del Regno Dating: 16.10.1899