568 A MANUAL OF VETERINARY PHYSIOLOGY 



a provision to ensure this the papillae containing the buds are 

 situated close to glands. M'Kendrick states that in a single 

 circum vallate papilla of the ox 1,760 taste goblets have been 

 counted. The goblet cells are not strictly limited to the tongue, 

 but have been found in the palate, epiglottis, and even in the 

 larynx. 



Nerves of Taste. — It will be remembered (p. 519) that the 

 posterior third of the tongue is provided with sensation by the 

 glossopharyngeal nerve, the anterior two-thirds of the organ by 

 the lingual branch of the fifth pair. These two nerves, besides 

 endowing the tongue with sensation, are also concerned in carry- 

 ing those impulses connected with the sense of taste. The 

 cortical centre for taste is not definitely known, but is considered 

 to lie close to that of the olfactory sense in the hippocampal lobe. 

 It is believed that the taste fibres in the lingual branch of the 

 fifth pair are furnished by the chorda tympani of the seventh pair 

 after the latter leave the middle ear. Stimulation of these fibres 

 arouses a sense of taste ; this not only places their function 

 beyond doubt, but also proves that, apart from the stimulation 

 at the periphery, there is a specific taste reaction in the brain. 

 The fibres of the fifth pair are not connected with taste bulbs, 

 for none are found over the area of their distribution. The 

 taste bulbs are the essential nerve terminations of the glosso- 

 pharyngeal nerve, and if this nerve be cut the bulbs degenerate. 

 Motor power to the tongue is furnished by the hypoglossal or 

 twelfth pair ; section of these nerves prevents an animal from 

 masticating its food, the organ hanging helplessly from the mouth, 

 and receives injury from the incisor teeth. 



It is necessary for the purpose of taste that the substance 

 should be dissolved ; this is one of the functions of saliva, and 

 experiments on herbivora show that taste produces an abundant 

 secretion from the submaxillary and sublingual glands, though 

 not from the parotid. 



