84 MEANS OF EXPRESSION Chap. IV. 



suffer great pain in silence; but when this is excessive, 

 and especially when associated with terror, they utter 

 fearful sounds. I have often recognized, from a dis- 

 tance on the Pampas, the agonized death-bellow of the 

 cattle, when caught by the lasso and hamstrung. It is 

 said that horses, when attacked by wolves, utter loud and 

 peculiar screams of distress. 



Involuntary and purposeless contractions of the mus- 

 cles of the chest and glottis, excited in the above man- 

 ner, may have first given rise to the emission of vocal 

 sounds. But the voice is now largely used by many ani- 

 mals for various purposes; and habit seems to have 

 played an important part in its employment under other 

 circumstances. Naturalists have remarked, I believe 

 with truth, that social animals, from habitually using 

 their vocal organs as a means of intercommunication, 

 use them on other occasions much more freely than other 

 animals. But there are marked exceptions to this rule, 

 for instance, with the rabbit. The principle, also, of as- 

 sociation, which is so widely extended in its power, has 

 likewise played its part. Hence it follows that the voice, 

 from having been habitually employed as a serviceable 

 aid under certain conditions, inducing pleasure, pain, 

 rage, &c, is commonly used whenever the same sensa- 

 tions or emotions are excited, under quite different con- 

 ditions, or in a lesser degree. 



The sexes of many animals incessantly call for each 

 other during the breeding-season; and in not a few cases, 

 the male endeavours thus to charm or excite the female. 

 This, indeed, seems to have been the primeval use and 

 means of development of the voice, as I have attempted 

 to show in my ' Descent of Man.' Thus the use of the 

 vocal organs will have become associated with the an- 

 ticipation of the strongest pleasure which animals are 

 capable of feeling. Animals which live in society often 



