THE HUMAN FACE 205 



a dog infinitely more than the mere expression of our 

 features can do. The signs of emotion are extremely 

 varied, and shade into one another, so that a scientific 

 classification is hardly possible. Strong feeling may show 

 itself quite unmistakeably, and yet in a purposeless way, 

 the physical manifestation having no power to alter the 

 circumstances which excited the feeling. Thus we blush 

 with shame, turn livid or green with fear, tremble with 

 rage, catch our breath and become speechless with excite- 

 ment. None of these involuntary bodily symptoms are 

 serviceable to us, and they may be highly inconvenient. 

 They are apparently due to mental disturbance acting 

 through the nervous mechanism upon various sets of 

 organs, and primarily the organs of circulation and respira- 

 tion. There is a second ill- defined group of expressions 

 and gestures which may be called incipient acts ; perhaps 

 they were once purposive and useful, but now they have 

 often become habitual or even instinctive. The wild man, 

 like animals of other kinds, probably crouched to avoid 

 danger or to show submission, drew back his lips and 

 exposed his teeth when preparing to fight, opened his 

 mouth wide and shouted when suddenly startled. In 

 civilised society the emergencies of life are less imperious, 

 and we can better control our feelings. Nevertheless we 

 shrug our shoulders, that is, we begin to crouch, when in 

 real or feigned terror, sneer by raising the upper lip a 

 little, and open our mouths when surprised. Our savage 

 progenitors were probably used to accompany any sudden 

 fit of determination with muscular effort of some kind, 

 clenching the fist, setting the foot firmly on the ground, 

 or fixing the eye on a near object, and bringing down the 

 eyebrows to exclude superfluous light. Even now, when 

 we are displeased or intent upon some purpose, we some- 

 times clench our fists or stamp, but it generally relieves 

 our feelings sufficiently to frown. The habit of scrutinising 

 one another's faces soon gives a meaning even to these 

 vestiges of acts and intentions. The incipient acts shade 



