CONFLICT OF EXPEESSIONS IN THE FACE. 213 



flexion results. If strong and unequal nerve- 

 currents are sent to the opposing muscles, a quiver- 

 ing or tremor of the part moved by the muscles 

 may result. Such action is often seen about the 

 muscles of the mouth under the influence of " con- 

 flicting emotions." Suppose a child has hurt his 

 finger but is trying hard not to cry, we shall see the 



Fig. 30. Paralysis Agitans, in advanced stage. Face almost expressionless, with 

 loss of all the fine adjustments of expression ; it presented one dull monotony 

 of appearance. 



muscles of the mouth quiver, until finally the effect 

 of the injury to the finger acting upon the nerve- 

 centres is too strong for the action of his will, and 

 the angles of the mouth are depressed and the 

 outbreak of sobbing follows. The conflicting emo- 

 tions, or the conflicting nerve-currents acting upon 

 the muscles, cause the expression about the mouth. 



