354 CONCLUDING REMARKS Chap. XIV. 



force of habit and association, with those directly re- 

 sulting from the excitement of the cerebro-spinal sys- 

 tem. This seems to be the case with the increased action 

 of the heart under the influence of any strong emotion. 

 When an animal erects its hair, assumes a threatening 

 attitude, and utters fierce sounds, in order to terrify an 

 enemy, we see a curious combination of movements 

 which were originally voluntary with those that are invol- 

 untary. It is, however, possible that even strictly in- 

 voluntary actions, such as the erection of the hair, may 

 have been affected by the mysterious power of the will. 



Some expressive movements may have arisen spon- 

 taneously, in association with certain states of the mind, 

 like the tricks lately referred to, and afterwards been 

 inherited. But I know of no evidence rendering this 

 view probable. 



The power of communication between the members 

 of the same tribe by means of language has been of para- 

 mount importance in the development of man; and the 

 force of language is much aided by the expressive move- 

 ments of the face and body. We perceive this at once 

 when we converse on an important subject with any per- 

 son whose face is concealed. Nevertheless there are no 

 grounds, as far as I can discover, for believing that any 

 muscle has been developed or even modified exclusively 

 for the sake of expression. The vocal and other sound- 

 producing organs, by which various expressive noises 

 are produced, seem to form a partial exception; but I 

 have elsewhere attempted to show that these organs were 

 first developed for sexual purposes, in order that one sex 

 might call or charm the other. Nor can I discover 

 grounds for believing that any inherited movement, 

 which now serves as a means of expression, was at first 

 voluntarily and consciously performed for this special 

 purpose, — like some of the gestures and the finger-Ian- 



