BRIEF [O.A.] Lendenfeld, Robert von Author: Lendenfeld, Robert von Recipient: Haeckel, Ernst Dating: 10.03.1907
BRIEF [O.A.] Schwaab Edler von Wildenfried, Hugo Author: Schwaab Edler von Wildenfried, Hugo Recipient: Haeckel, Ernst Dating: 11.03.1907