SENSE OF TASTE. 297 



We have also seen that the tip of the tongue has a very 

 keen sense of touch. By means of its mobility and sensitive- 

 ness the tongue hot only aids in mastication, but also cleanses 

 the teeth afterward by detecting and removing small particles 

 of food from the teeth. 



The sense of taste helps us in judging of the fitness of 

 anything that presents itself as a candidate for election as 

 food. By reflex action the taste of agreeable substances aids 

 in digestion by stimulating the glands, especially the salivary 

 glands. 



The surface of the tongue is covered with Papillae These 

 are of three kinds. Most numerous are the Filiform papillae, 



Papillae 



Glosso-pharyn- 

 geal Nerve (9th) 



Gustatory Branch of 

 Fifth Nerve 



Fig, 87. Diagram of Tongue, showing Nerves and Papillae. 



slender, cylindrical projections. Like the papillae of the skin, 

 they seem to be organs of touch. Scattered among the fili- 

 form papillae are small, bright red spots, which on examina- 

 tion are found to be shaped somewhat like a mushroom, the 

 Fungiform papilla?. Near the base of the tongue are about a 

 dozen larger papillse, arranged like a letter V with its apex 

 toward the base of the tongue. These are the Circumvallate 

 papillae, each having around it a deep circular furrow. 



On the sides of this furrow are small oval bodies called 



