PRODUCTION OF SENSATIONS 345 



cavity which communicates with the surface by a small 

 opening the gustatory pore. Within this cavity are many 

 slender, spindle-shaped cells which terminate in hair-like 

 projections at the end nearest the pore, but in short fibers 

 at the other end. Nerve fibers enter at the inner ends of 

 the buds and spread out between the cells (C, Fig. 146). 



~. ex 



FIG. 146. Sense organs of taste. A. Map of upper surface of tongue, 

 showing on the left the different kinds of papillae, and on the right the areas of 



taste (after Hall). Area sensitive to bitter ( ); to acid ( ); 



to salt ( ); to sweet ( ). B. Section through a 



papilla, n. Small nerve connecting with taste buds at d. e. Epithelium. 

 C. Single taste bud magnified, n. Nerve, the fibers of which terminate 

 between the spindle-shaped cells a. e. Epithelial cells. 



These fibers pass to the brain as parts of two pairs of 

 nerves those from the front of the tongue joining the 

 trigeminal nerve, and those from the back of the tongue, 

 the glossopharyngeal nerve. 



The gustatory, or taste stimulus, is some chemical or 

 physical condition of substances which is manifested only 

 when they are in a liquid state. For this reason only liquid 

 substances can be tasted. Solids to be tasted must first be 

 dissolved. 



