Morphology of the lingual papillae in the chimpanzee.

We microscopically examined the dorsal lingual surface of an adult chimpanzee (Pan troglodytes). The tongue of the chimpanzee was about 13 cm long. Filiform papillae were distributed over the entire dorsal surface of the lingual body. There were many fungiform papillae scattered among the filiform papillae. At the posterior end of the lingual body, a triangular arrangement of the vallate papillae, with the apex of the triangle directed posteriorly, was observed. The filiform papillae on the lingual apex consisted of a main papilla and secondary papillae. The filiform papillae on the lingual body had several pointed processes. There were dome-shaped fungiform papillae scattered among the filiform papillae. The vallate papillae were surrounded by grooves and were flattened-oval shaped. Many foliate papillae were observed on the posterolateral regions of the tongue.