BRIEF [O.A.] Graff, Ludwig von Author: Graff, Ludwig von Recipient: Haeckel, Ernst Corporation: Zool.-Zoot. Institut der K. K. Carl-Franzens-Universität Dating: 14.02.1906
BRIEF [O.A.] Scheidemantel, Herman Author: Scheidemantel, Herman Recipient: Haeckel, Ernst Dating: 08.05.1906