496 



MUSCULAR MOTION. 



- 202 - power of expression. The 



nerves of the face and neck 

 of the monkey are numerous, 

 and have frequent connexions ; 

 but on cutting the seventh 

 pair, or respiratory nerve of 

 the face of Sir Charles Bell's 

 system, the features are found 

 to be no longer influenced by 

 the passions. Yet the skin 

 continues sensible, and the 

 muscles of the jaws and tongue 

 are capable of the actions of 

 chewing and swallowing. If 

 the respiratory nerve of one 

 side be cut, the expression of 

 that side is destroyed; whilst 

 the chattering, grinning, and 

 other movements of expres- 

 sion continue on the other. 

 In a dog, too, if the respira- 



1. Facial nerve, escaping from stylo-mastoid foramen, ^ Y J nerVC of the face be CUt, 

 and crossing ramus of lower jaw ; the parotid gland has V>p w ni fln-Vt 88 bittprlv hilt 

 been removed in order to see the nerve more distinctly. . "g^u ii^ciy , wu 



2. Posterior auricular branch; the digastric and stylo- With nO retraction of hlS llDS, 

 mastoid filaments are seen near origin of this branch. 3. -i-i. p ,1 



Temporal branches, communicating with (4) branches of Sparkling 01 the eye, Or 



frontal nerve. 5. Facial branches communicating with V^^lr rf fVio OQT-O 



1 tfcC ears. 



COtttinUC their office. 



Distribution of Facial Nerve. 



(6) infra-orbital nerve. 7. Facial branches, communicat- ln & ' 



ing with (8) mental nerve. 9. Ceryico-facial branches f ace Jg inanimate, although the 



communicating with (10) superficiahs colh nerve, and ' e. 



forming a plexus (11) over submaxillary gland. Distribu- mUSClCS 01 the laCC and laWS, 



tion of branches of the facial in a radiated direction over f ,1 r \. 



side of face constitutes the pes anserinus. 12. Auricularis SO lar aS they are HaDlC tO 



magnus nerve, one of ascending branches of cervical K 



plexus. 13. Occipitalis minor, ascending along posterior 



border of sterno-mastoid muscle. 14. Superficial and 



deep descending branches of cervical plexus. 15. Spinal pp. 



accessory nerve, giving off a branch to external surface of JLhe game-COCK, 111 the pOSl- 



trapezius muscle. 16 Occipitalis major nerve, posterior , r> r> i, i cc 



branch of second cervical nerve. tlOn Of lighting, Spreads a rutt 



of feathers around his head. 



The position of his head and the raised feathers are the expressions of 

 hostile excitement; but on the division of the respiratory nerve, the 

 feathers are no longer raised, although the pugnacious disposition con- 

 tinues. It has been found, moreover, that if the galvanic influence be 

 passed from one divided extremity of the respiratory nerve to the other, 

 the facial expression returns; and, in certain cases of incomplete hemi- 

 plegia, in which the movements of expression of the face were alone 

 rendered impracticable, the disease was found to have implicated only 

 the respiratory or facial nerve. The views of Sir Charles Bell regard- 

 ing the connexion alleged by him to subsist between the seventh pair 

 and the associated movements of respiration have, however, been con- 

 tradicted by the experiments of Mr. Mayo, 1 and his inferences regard- 

 ing the fifth pair as being jointly a nerve of sensation and of voluntary 

 motion have been considered to require qualification. By dividing the 



Outlines of Human Physiology, 4th edit., p. 254, London, 1837. 



