ON ACQUIRED FACIAL EXPRESSION. 383 



the eyeball i. e., the internal rectus, which rolls the eye inward 

 toward the nose gets its nerve supply partly from the same 

 source as do the muscles for shortening the focus of the lens. 

 The latter, in far-sighted persons, are constantly being urged to 

 action by impulses proceeding from the brain along the nerve, 

 and part of the impulse invariably finds its way, owing to the 

 intimate relation of the parts, to the internal rectus muscle. This 

 muscle does not at first respond to the stimulus sufficiently to turn 

 the eye inward every time the lens is accommodated for near ob- 

 jects ; but the result of this nervous stimulation is in the long run 

 the same as if the internal rectus were constantly called into action 

 by a deliberate exercise of the will. It greatly increases in bulk 

 and strength, and outpulls its opponent on the outer side of the eye 

 (which gets its nerve supply from a different source), and so the 

 balance of power is destroyed and a hideous inward squint is pro- 

 duced. 



From this we can understand the effect of a long-continued 

 dominant emotion on the face, even although it may exist in an 

 individual too well bred to allow his countenance to be easily dis- 

 torted by the prevailing passion. Whenever the thoughts take 

 their habitual direction, a stream of nervous influence from the 

 brain to the hidden-expression muscles is the inevitable concomi- 

 tant. The closest observer may not notice the least change of out- 

 line or the vaguest tremor of movement at the time, and the sub- 

 ject himself may be unwarned as to what is going on. Yet in the 

 course of years the muscles so stimulated assert themselves over 

 the others, and a permanent expression in accordance with the 

 mental character comes out. 



Close observation of almost any face under favorable circum- 

 stances supports this view. While engaged in studying the phe- 

 nomena of sleep, I have repeatedly noticed that the apparent 

 placidity of the features during slumber is deceptive. Even in 

 dreams each fleeting emotion affects the facial muscles in some 

 degree, and the apparent calm on the surface covers many little 

 eddies and currents beneath, as one or other of them is thus pro- 

 voked into partial activity. When the thoughts are all-absorbing 

 and the owner of the face is off his guard, it does not require a 

 very acute observer to see how the expression follows what is in 

 the mind. 



The other day, while traveling by train, I witnessed the part- 

 ing of a pair of lovers. The damsel got into the carriage where 

 we were seated, and until the train started there was an eloquent 

 interchange of glances and smiles. As we steamed off, the last 

 smile of parting gradually faded on the lassie's face. She shut 

 her eyes and leaned back, so that she did not see that she was 

 under observation, and at the same time the light showed her 



