CHAPTER XXXI. 



TASTE AND SMELL. 

 SENSE OF TASTE. 



Next to the sense of touch, which is distributed more or less over 

 the whole cutaneous surface, taste is the least localized anatomi- 

 cally. Though confined to the cavity of the mouth, its more accu- 

 rate limitations are not easily fixed. The point, sides, and posterior 

 part of the dorsum of the tongue can most accurately appreciate 

 tastes ; and probably parts of the palate also have the power, but 

 in a much less degree. Indeed, though " the palate" is often spoken 

 of as if it were the seat of taste, it really enjoys this function in an 

 insignificant degree when compared with the tongue. 



The power of being stimulated by various tastes is not re- 

 stricted to the terminals of any one nerve, but is shared by some 

 of those of at least three trunks, which also transmit impulses 

 arising from other forms of stimulation. The glosso-pharyngeal 

 division of the eighth pair sends branches to the posterior part 

 of the tongue, which are no doubt connected with the special taste 

 organs. The lingual branches of the fifth commonly called the 

 gustatory nerves have also terminals capable of being excited 

 by taste, and probably some fibres of the chorda tympani are also 

 employed in this function. 



In the furrows around the circumvallate papillae, and also, but 

 more sparsely, on the sides of the fungiform papillae of the tongue, 

 are found peculiar organs called " taste buds " or " taste goblets." 

 They are imbedded in the stratified epithelium, with the cells of 

 which their outer layers are intimately connected. They are 

 flask-shaped bodies, composed of concentric series of modified 

 epithelial cells arranged like the staves of a barrel, pinched to- 

 gether at the base and at the free surface, where they seem to 

 inclose the projecting points of the central thread-like elements, 

 so that the whole reminds one somewhat of the construction of 

 the head of an artichoke. 



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