S6 MEANS OF EXPRESSION Chap. IV. 



will ever be given. We know that some animals, after 

 being domesticated, have acquired the habit of utter- 

 ing sounds which were not natural to them. 1 Thus do- 

 mestic dogs, and even tamed jackals, have learnt to bark, 

 which is a noise not proper to any species of the genus, 

 with the exception of the Cams latrans of North Ameri- 

 ca, which is said to bark. Some breeds, also, of the do- 

 mestic pigeon have learnt to. coo in a new and quite 

 peculiar manner. 



The character of the human voice, under the influ- 

 ence of various emotions, has been discussed by Mr. Her- 

 bert Spencer 2 in his interesting essay on Music. He 

 clearlv shows that the voice alters much under different 

 conditions, in loudness and in quality, that is, in reso- 

 nance and timbre, in pitch and intervals. Xo one can 

 listen to an eloquent orator or preacher, or to a man call- 

 ing angrily to another, or to one expressing astonish- 

 ment, without being struck with the truth of Mr. Spen- 

 cer's remarks, It is curious how early in life the modu- 

 lation of the voice becomes expressive. With one of my 

 children, under the age of two years, I clearly perceived 

 that his humph of assent was rendered by a slight modu- 

 lation strongly emphatic; and that by a peculiar whine 

 his negative expressed obstinate determination. Mr. 

 Spencer further shows that emotional speech, in all the 

 above respects is intimately related to vocal music, and 

 consequently to instrumental music; and he attempts 

 to explain the characteristic qualities of both on physio- 

 logical grounds — namely, on " the general law that a 

 feeling is a stimulus to muscular action." It may be 



1 See the evidence on this head in my ' Variation of 

 Animals and Plants under Domestication,' vol. i. p. 27. 

 On the cooing" of pigeons, vol. i. pp. 154, 155. 



2 ' Essays, Scientific, Political, and Speculative,' 1858. 

 ' The Origin and Function of Music,' p. 359. 



