MEANS OF THE EXPRESSION OF THE EMOTIONS. 269 



half-tones ; so that this monkey, " alone of brute mam- 

 mals, may be said to sing." From this fact, and from 

 the analogy of other animals, I have been led to infer 

 that the progenitors of man probably uttered musical 

 tones before they had acquired the power of articulate 

 speech ; and that, consequently, when the voice is used 

 under any strong emotion, it tends to assume, through the 

 principle of association, a musical character. 



EEECTION OF THE HAIE. 



The enraged lion erects his mane. The 

 bristling of the hair along the neck and back 

 of the dog, and over the whole body of the cat, especially 

 on the tail, is familiar to every one. With the cat it ap- 

 parently occurs only under fear ; with the dog, under 

 anger and fear ; but not, as far as I have observed, under 

 abject fear, as when a dog is going to be flogged by a 

 severe gamekeeper. If, however, the dog shows fight, as 

 sometimes happens, up goes his hair. I have often no- 

 ticed that the hair of a dog is particularly liable to rise 

 if he is half angry and half afraid, as on beholding some 

 object only indistinctly seen in the dusk. 



p ^ Birds belonging to all the chief orders ruf- 



fle their feathers when angry or frightened. 

 Every one must have seen two cocks, even quite young 

 birds, preparing to fight with erected neck-hackles ; nor 

 can these feathers when erected serve as a means of de- 

 fense, for cock-fighters have found by experience that it 

 is advantageous to trim them. The male EufE {Machetes 

 pugnax) likewise erects its collar of feathers when fight- 

 ing. When a dog approaches a common hen with her 

 chickens, she spreads out her wings, raises her tail, ruf- 



