A scanning electron microscope was used to observe the lingual papillae and their connective tissue cores (CTCs) in five primates (tupai, tamarin, crab-eating monkey, mandrill, and human). There were some slender protrusions rising from the top of the filiform papilla in all five types of primate. After removing the epithelium the filiform, CTC from the tupai, tamarin and crab-eating monkey displayed a U-shaped arrangement of rod-shaped protrusions. The filiform CTC from the crab-eating monkey also had a columnar base. The human filiform CTC consisted of a primary columnar base, numerous short rod-shaped secondary protrusions from its upper periphery, and a few central protrusions. The filiform CTC from the Mandrill was fundamentally similar to that of the human, however, its base was shorter. The fungiform CTC from the tupai was column shaped, with several depressions for taste buds on the top. There were three vallate papillae in the tupai, tamarin, and mandrill, approximately four in the monkey, and between five and twelve in the human. Moderately developed foliate papillae were found in the tamarin, monkey, mandrill and human. The tupai, however, possessed a finger-like lateral organ instead. The lingual root area of the tupai, tamarin, crab-eating monkey and mandrill was relatively small with a smooth surface. Only the human had a tonsil structure, which was located on the surface of its larger lingual root.
