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MANUAL OF PHYSIOLOGY. 



special organ, so as to be easily found) they degenerate, and in 

 a few months disappear, after one of these nerves has been cut. 



The genuine taste sensations are very few. Much of what we 

 commonly call taste depends almost exclusively upon the smell 

 of the substance, and we habitually confuse the impressions 

 derived from these two senses.* The different tastes have been 

 divided into four, viz., sweet, sour, bitter and salt, under some 

 one or other of which headings all our tastes, properly so called, 

 would naturally fall. Though this classification has no just claim 



Section through depression between two circumvallate papillae, showing taste buds. 

 (Cadiat.) a, fibrous tissue of papilla; d and c, epithelial covering of papilla; 6, taste 

 buds. On the right, a, b show the separate cells of a taste bud. 



to being a chemical one, it is interesting to know that each taste 

 pretty well corresponds to a distinct group of substances chemi- 

 cally allied one to the other. Thus, acids are sour, alkaloids 



* Many of the comestibles, the taste of which we most prize, have 

 really no taste, but only a smell which we habitually confound with taste, 

 having mingled the experience obtained from the two senses. Thus, if 

 the draught of air be carefully excluded from the nose, wine, onion, etc., 

 may easily be proved to have no taste. Hence, the familiar rule of hold- 

 ing the nose adopted in taking "bad-tasting" medicine. 



