CH. MI.] 



NERVES OV TASTE. 



709 



however, ultimately derived from the glosso-pharyngeal by its 

 communication with the chorda tympani in the tympanic plexus. 

 Sir William Gowers, on the other hand, holds that the true 



Fig. S3'- Taste-goblet from dog's epiglottis (laryngeal surface near the base), precisely 

 similar in structure to those found in the tongue, a, depression in epithelium over 

 goblet ; below the letter are seen the fine hair-liko processes in which the cells termi- 

 nate ; c, two nuclei of the axial (gustatory) cells. The more superficial nuclei belong 

 to the superficial (encasing) cells ; the converging lines indicate the fusiform shape of 

 the encasing cells, x 400. (Schofield.) 



nerve of taste is the fifth, and that the taste-fibres in the glosso- 

 pharyngeal come ultimately from the fifth. 



Tastes may be classified into 



i. Sweet. 2. Bitter. 



3. Acid. 4. Saline. 



Sweet is antagonised by acid as well as by bitter tastes. Acids 

 and salines apparently affect nerves of tactile sense as well as 

 those of taste proper. Sweet tastes are best appreciated by the 

 tip, acid by the side, and bitter tastes by the back of the tongue. 

 Flavours are really odours. 



The substance to be tasted must be dissolved ; here there is a 

 striking contrast to the sense of smell. In testing the sense of 

 taste in a patient, the tongue should be protruded, and drops 

 of the substance to be tasted applied with a camel's hair brush to 

 the different parts ; the subject of the experiment must signify 

 his sensations by signs, for if he withdraws the tongue to speak, 

 the material gets widely spread. The more concentrated the 

 solution, and the larger the surface acted on, the more intense is 

 the taste ; some tastes are perceived more rapidly than others, 

 saline tastes the most rapidly of all. The best temperature of 

 the substance to be tasted is from 10 to 35 C. Very high or 

 very low temperatures deaden the sense. 



It is possible by chewing the leaves of an Indian plant 



