Adult teeth of a gorilla (Fig. A), adult teeth of a chimpanzee (Fig, 2), juvenile teeth of a gorilla (Fig. 3), juvenile teeth of a chimpanzee (Fig. 4), male sexual organs of a gorilla (Figs. 5-8), male sexual organs of a chimpanzee (Fig. 9-10), larynx and respiratory organs (Fig. 11). Published in Paris.