176 PHYSIOLOGY. 



its existence. In serpents, it is forked, and susceptible of 

 considerable motion ; while in the frog, it is folded back in 

 the state of inactivity ; but when the animal is about to 

 seize an insect, it suddenly unfolds and projects it out of the 

 mouth. The tongue of a chameleon is contained within a 

 sheath, and admits of being projected to the extent of six 

 inches, and is besmeared with a glutinous secretion. In the 

 twinkling of an eye it is darted out to catch its food, which 

 consists chiefly of flies. Fishes have the mere rudiments of 

 a tongue, fixed near the throat, which is often furnished with 

 teeth. There is reason to believe that many of the inverte- 

 brated animals are endowed with taste, such as bees, wasps, 

 flies, and leeches. 



Questions. To what sense is that of taste allied ? What is sapid- 

 ity ? What is the chief organ of taste ? What other parts participate 

 in the function ? Describe the structure of the tongue. From what 

 source does the tongue derive its nerves ? Which is the nerve of 

 taste ? What are papillae ? How many kinds are there on the 

 tongue ? What is the office of the mucous papillae ? Of the conical 

 and fungiform ? What is the process of taste ? Can insoluble sub- 

 stances be tasted ? Why not ? What are the use of the salts in the 

 saliva ? How do we taste metals ? How is the taste excited by gal- 

 vanism explained ? Are there many savours ? Name some. Can 

 they be classified ?*" Why not? What articles leave a. taste in the 

 mouth the longest ? What use can be made of this fact ? How do 

 tasters manage ? Is taste under the influence of habit ? . What facts 

 show this ? To what is the pleasure of eating owing ? How is this 

 shown ? Is the taste a sure guide to what is safe and nutritious ? Do 

 animals differ as to taste ? Do they possess it in as great perfection as 

 man ? Does it ever become morbid in them ? When is taste most 

 delicate ? How is it impaired ? May the taste be improved ? Are 

 the advantages or disadvantages the greatest, which attend great deli- 

 cacy of taste ? Have any of the lower animals a tongue like that of 

 man ? Describe some peculiarities ? What apparatus have whales 

 for eating small sea animals ? What is said of the tongue of birds ? 

 of reptiles ? of fishes ? Do any of the invertebrated animals possess tha 

 faculty of taste ? 



