Two circumvallate papillae and well developed foliate papillae are observed with fungiform and filiform papaillae on the dorsum. The vallate and foliate papillae are supplied with abundant plexiform nerves concentrated in the lateral area of the papilla, its thin, non-cornified lateral wall being furnished with many taste buds. The trench wall lined by a nerve plexus is provided with a few taste buds. The ganglion cells are found between the serous glands plentiful in these regions.

Fungiform papillae on the dorsum and inferior surface are covered with highly cornified stratified squamous epithelium. They are richly supplied with nerve fibers from a large, thick-sheathed nerve plexus in the middle portion of the papilla, but they are furnished with no taste buds. Absence of the taste bud seems to be related with high keratinization of their upper epithelium.

Filiform papillae are poor in nerve supply. The tongue has the peculiar structure taking the form of flat, horny plate, which consists of many highly cornified filiform papillae on the anterior part of the dorsum. This finding suggests that the filiform papilla is a basic structure of this peculiar papilla.

In the area posterior to the vallate papillae there are many mucous glands deep in the muscles. The duct with a wide orifice has cystic dilatations on its course in the mucosa.