GESTURES MUSCLES OF THE FACE. 495 



face in expressing passion, or in some convulsive excitement of the 

 organ. In laughing and crying, the outer and more powerful muscle 

 is in action, gathering up the skin about the eye, and forcing back the 

 eyeball itself. In drunkenness, the power of volition over this muscle 

 is diminished; and there is an attempt to raise the upper eyelid by a 

 forcible elevation of the eyebrow. 



The muscles of the nostrils are; 1st, levator labii superioris alseque 

 nasi, which, as its name imports, raises the upper lip and nostril; 2dly, 

 compressor nasi, a set of fibres which compress the nostril; and 3dly, 

 depressor alse nasi, which lies under orbicularis oris, and whose function 

 is indicated by its name. The three muscles serve to expand and con- 

 tract the opening or canal of the nostril, moving in consent with the 

 muscles of respiration, and thus the inflation of the nostrils indicates 

 general excitement, and animal activity. 



The muscles of the lips are; 1st, levator labii proprius, which raises 

 the upper lip ; 2dly, levator anguli oris, which raises the angle of the 

 mouth; and 3dly, the zygomatic muscle, which is inserted into the angle 

 of the mouth. Sometimes an additional muscle of the name exists: 

 zygomaticus minor. These last muscles raise the upper lip and angle 

 of the mouth, so as to expose the canine teeth. If they be in action 

 contrary to the orbicularis oris, there is a painful and bitter expression ; 

 but if they be influenced along with the orbicularis oris, and orbicularis 

 palpebrarum, if the former of these muscles be relaxed, and the latter 

 contracted, there is a fulness of the upper part of the face, and a 

 cheerful, smiling expression of countenance. The orbicularis oris closes 

 the mouth; and, when allowed to act fully, purses the lips. The nasalis 

 labii superioris draws down the septum of the nose. The triangularis 

 oris or depressor labiorum indicates, by its name, its function. The 

 quadratus menti is a depressor of the lower lip. The levatores menti, 

 by their action, draw up the chin, and project the lower lip; and the 

 buccinator is chiefly for turning the alimentary bolus in the mouth; and, 

 in broad laughter, retracts the lips. The orbicularis muscle is affected 

 in the various emotions of the mind; trembling and relaxing in both 

 grief and joy: it relaxes pleasantly in smiling. 



The union of these various muscles at the angle of the mouth pro- 

 duces the fleshy prominence noticed in those who have thin faces ; and 

 who are, at the same time, muscular. When the cheeks are fat and 

 ful! 5 the action of these muscles produces the dimpled cheek. The 

 angle of the mouth is full of expression, according as the orbicularis, 

 or the superior or inferior muscles inserted into it have the preponder- 

 ance. 



Lastly; the temporal is a strong muscle, which raises the lower jaw. 

 It is assisted by the masseter, a deep-seated muscle, which lies on the 

 outside of the lower jaw; arises from the jugum, and is inserted into 

 the angle of the jaw. 



Two different nerves are distributed to these muscles, the fifth pair, 

 and portio dura or facial of the seventh; the latter of which, according 

 to the experiments of Sir Charles Bell, is concerned in the instinctive 

 movements of expression; and comparative anatomy exhibits, that the 

 number and intricacy of these nerves vary in proportion to the animal's 



