CHAPTER VII. 



PHYSIOLOGY OF GUSTATION. 



Contents. — 1. Location of Taste. 2. Gustatory stimulus. 

 3. Qualities of Taste. 4. The Sour Taste. 5. The Saline 

 Taste. 6. The Bitter Taste. 7. The Sweet Taste. 8. 

 Inadequate Stimuli. 9. Distribution of Tastes on the 

 Tongue. 10. Action of Drugs on Taste. 11. Substances 

 with two Tastes. 12. Latency of Taste Sensations. 13. 

 Taste Alterations ; After-tastes. 14. Gustatory Contrasts. 

 15. Taste Compensations and Mixtures. 16. The Gusta- 

 tory Senses. 17. Comparative. 18. Bibliography. 



1. Location of Taste. Although in man taste is not 

 strictly limited to the mouth, for it spreads into some 

 of the adjacent cavities, it is primarily located in the 

 buccal space and is especially a function of the tongue. 

 When the mouth of a normal adult is explored with solu- 

 tions of sapid substances, many parts such as the lips, 

 the gums, the floor, the lower surface of the tongue, the 

 inner surfaces of the cheeks, and the hard palate are 

 found to be insensitive to taste. Even the uvula which, 

 according to many of the older workers, was regarded as 

 having a gustatory function, has been shown by Kiesow 

 and Hahn (1901) not to be concerned with taste. All 

 these regions are well known to be devoid of taste-buds. 

 Whether the pillars of the fauces and the tonsils have 

 to do with taste is a matter of dispute. Hanig (1901) 

 believed that these parts have a gustatory function, but 

 Kiesow and Hahn (1901) regarded them as usually in- 

 sensitive. The mucous membranes of the following parts 



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