TASTE 359 



The Gustatory Apparatus consists chiefly of certain afferent nerve 

 end-organs called taste-buds, of certain afferent nerves, and of the 

 central regions to which they transmit their impulses. 



THE TASTE-BUDS (Schwalbe) are minute flask-shaped organs 

 composed of four sorts of elongated fusiform cells, of which three are 

 perhaps sijstentacular in function and only one gustatory. The buds 

 average about 0.075 mm. deep by perhaps 0.040 mm. in diameter 

 (see Fig. 211). The gustatory cells proper, neuro-epithelial, are 

 elongated and fusiform with the nucleus in the thickest part of the cell, 

 and have stiff slender filaments projecting above them into the open 

 taste-pore. They are encircled by nerve-fibrils. This pore is often 

 0.01 mm. deep and is filled with the liquid of the mucous membrane 

 around. From one to ten of the taste-cells are found in each bud. 

 The buds are found on the back, edges, and root of the tongue, on the 

 soft palate, the uvula, the pillars of the fauces, the under surface of the 

 epiglottis (Nicholson) and posteriorly in small numbers, in the larynx, 

 and in the olfactory region of the nose. Thousands of them are found in 



FIG. 212 



The nerve-filaments about the taste-cells. In A the taste-cell is indicated also; in B not. 



(Duval.) 



two of the three sorts of papillae which beset the tongue's dorsum, namely, 

 in many of the fungiform papillae scattered over the surface of the tongue, 

 and especially in the sides of the circumvallate papillae of the back of 

 that organ. They are not present apparently in the filiform papillae, 

 but are present in the level mucous membrane. 



THE NERVES OF THE SENSE OF TASTE are still not certain. There 

 is, however, excellent evidence that the ninth cranial (glosso-pharyngeal) 

 nerve is one of them, supplying the rear third of the tongue. The pars 

 intermedia of Wrisberg, running in the trunk of the seventh (facial), is 

 another taste-nerve, supplying the soft palate and the rest of the tongue. 

 The doubt now lies chiefly as to whether the superior laryngeal branch 

 of the tenth (vagus) nerve carries taste-impulses or not, the strong prob- 

 ability at present being (Zwaardemaker) that it supplies taste to the 

 region of the central circumvallate papilla (foramen cecum), to the 

 epiglottis, and to the inside of the larynx. The trigeminal (fifth cranial) 

 nerve supplies without doubt the taste-buds recently found in the olfac- 

 tory region of the nasal mucosa called the Schneiderian membrane. 



