4 LABORATORY LESSONS IN GENERAL SCIENCE 



much freedom of motion have the lips, and how is this se- 

 cured ? Name the several uses of the lips. 



What can be told of a person's feelings by noting the lips ? 

 How may lip expression be affected by an oft-repeated 

 emotion? Explain the redness of the inner surfaces of the 

 lips and of their edges. 



3. Of what use are the cheeks ? What is their structure ? 



4. Observe the rear wall of your mouth as seen in a small 

 mirror, and describe what you see. Name its various parts. 



What is the name 

 of the cavity farther 

 back? 



5. What is the 

 character of the roof 

 O f the mouth ? 



Wh | ch WftU of the 



nasal cavity is it? 

 It all the walls or 

 the mouth were of 



Tongue , . , 



bone, in what re- 

 spects would its use- 

 fulness be affected ? 



6. Describe the 

 structure, lining, 

 and general appear- 



FIG. 3. -The mouth cavity. anCC f the fl r 



of the mouth after 



studying it closely with the aid of a mirror. Note the 

 movements and the structure of the tongue, and explain its 

 mobility. With the finger-tips pressed against the outside 



