アフガンナキウサギの舌乳頭の比較解剖学的研究

Abstract

The tongue and lingual papillae of the Afghan pika were observed by the optical and the scanning electron microscope. The results obtained were as follows : 1. The tongue was narrow and long, and its appearance was similar to that of the domestic rabbit. A median dorsal sulcus, terminal sulcus, and foramen cecum were absent on the dorsal surface, whereas the intermolar prominence was present on. Four types of papillae were present on the dorsal surface : filiform or conical, fungiform, circumvallate, and foliate papillae. 2. The filiform papillae covered the oral part almost completely and the anterior pharyngeal part partially. Some differences in form and size of the papillae by their location were observed : large and conical on the anterior side of the intermolar prominence and the frontal margin of the prominence, small and sharp conical on all of other regions ; and the apical portion of the former papillae bent toward the anterior direction and those of the latter ones toward the posterior direction. 3. The fungiform papillae existed scantily on the dorsal side of the lingual apex. On the ventral side of the apex, a group of the fungiform-like papillae was observed. One to two taste buds were observed within the epithelium between the papillae. 4. The circumvallate papillae, three to four in number, were present in the posterior side of the tongue and formed a triangle with its base directed to the anterior side. The outline of the circumvallate papillae appeared to be round in shape, but the papillae were not completely separated from a vallum but fused partially into the vallum at both sides without a continuous trench. 5. The foliate papillae which located in the anterior margin of the palatoglossal fold at the tongue base had nine to twelve ridges. The long axis of a papilla bent roughly to the epiglottis.