NERVE OF EXPRESSION. 327 



CONJOINT ACTION OP THESE MUSCLES IN EXPRESSION. 



If the orbicularis palpebrarum and pijramidales nasi act 

 together, the expression is " heavy and lowering." If these 

 yield to the influence of the frontal, the eyehrow is arched 

 and the expression is "cheerful and inquiring." If the 

 corrugator supercilii act, it is said by Mr. C. Bell to indi- 

 cate " more or less of mental anguish, or painful exercise 

 of thought." If it combine its action with the frontal por- 

 tion of the occipito-frontalis, the eyebrow is drawn upwards, 

 and the forehead wrinkled, giving an expression more of 

 "weak anxiety and querulousness." 



The compressor nasi, in conjunction with the levator 

 labii superioris alceque nasi, and depressor nasi, by com- 

 pressing, depressing and expanding the nostrils, indicate 

 " general excitement and animal activity, and give spirit to 

 the whole countenance." 



It may be proper to notice in this connection that all the 

 muscles attached to the mouth are also muscles of expres- 

 sion, though they have been described in another place 

 under the head of prehension. We will only notice, further, 

 in reference to their relations with expression, that when 

 the orbicidaris oris, or sphincter muscle of the mouth, con- 

 tracts, while the lateral, or zygomatic muscles are in action, 

 there is "a painful and bitter expression." If, on the con- 

 trary, the orbicularis of the mouth be relaxed, while the 

 orbiculares of the eyelids are contracted, then, by the action 

 of the lateral muscles, there is produced a " cheerful and 

 smiling expression of the countenance." 



The depressor anguli oris is said to be, like the corrugator 

 supercilii, peculiar to man ; and when it combines its ac- 

 tion with the levator menti produces "the most contempt- 

 uous and proud expression." 



The eye is also full of expression, and so are other portions 

 of the body, all of which will be examined in their appro- 

 priate places. 



Nerve of Expression, Fig. 97, (the facial nerve,) called also 

 the portio-dura of the seventh pair, is the great nerve of 



