152 THE SENSES. 



Describe the fungiform papillae. 



They are chiefly distributed over the sides and tip of the organ, 

 and sparsely upon the dorsum. They are larger at the surface 

 than at the base, club-shaped, and are supplied with blood-vessels 

 and nerves. Their function is probably sensory. 



Describe the circumvallate papillae. 



They are somewhat similar in shape to the fungiform, but con- 

 siderably larger. They are situated at the posterior portion of the 

 dorsum in a V-shaped arrangement, and number only eight or ten. 

 In the circumvallate papillae are the taste-goblets, or gustatory buds, 

 which are the form of nerve-ending characterizing the parts where 

 this sense is developed. 



What other functions are dependent upon the tongue besides 



taste ? 



The sense of touch is very highly developed here, and with it 

 the sense of temperature, pressure, pain, etc. : upon these touch 

 and muscular senses to a great extent depend the accuracy of the 

 tongue in many of its important uses speech, mastication, deglu- 

 tition, sucking. The tactile sense is very important, too, in the 

 sense of taste, for with many substances the taste is largely due 

 to their mechanical condition : this is the case with mucilaginous, 

 oily, and chalky tastes. 



What relation has the sense of smell to taste ? 



It is important, for with many substances particularly aromatic 

 substances of food and drink the association of smell and taste is 

 very essential to a thorough appreciation of a flavor. Most cooked 

 foods lose their savor if the nose is obstructed ; thus with a " cold " 

 in the nose " everything tastes alike." 



What kinds of flavors are appreciated by the tongue? 



The principal tastes are sweet, bitter, acid, alkaline, and saline. 

 Besides these, the general sensibility of the tongue detects pungent 

 or caustic and styptic tastes, as well as the oily and mucilaginous 

 tastes. 



What degree of taste-sensibility has the tongue ? 



It is quite acute. A solution of acid or bitter substances is tasted 

 when very dilute : strychnine is said to be tasted in a 1 : 600,000 

 solution; sulphuric acid, 1:1000. 



