164 NERVOUS SYSTEM. 



symptom of paralysis of these muscles is inability to corru- 

 gate the brow upon one side, as in frowning. 



Paralysis of the muscles that dilate the nostrils has been 

 shown to have an important influence upon respiration 

 through the nose. It was the synchronism between the 

 acts of dilatation of the nostrils and the movements of in- 

 spiration which first led Sir Charles Bell to regard the facial 

 as a respiratory nerve. In instances of complete paralysis 

 of the nostril of one side, there is frequently some difficulty 

 in inspiration. Sir Charles Bell refers to a case in which, 

 when " the patient lay with the sound side against the pil- 

 low, he was under the necessity of holding the paralytic 

 nostril open with the fingers, in order to breathe freely." 

 In the horse, the movements of the nostrils are essential to 

 respiration, the animal being unable to breathe through the 

 mouth. When both facial nerves are divided in this animal, 

 the nostrils collapse and are occluded with each effort at in- 

 spiration, and death takes place from suffocation. 3 



Sir Charles Bell 3 and others have also noted the inter- 

 ference with olfaction, due to the inability to inhale with 

 one nostril, in cases of facial paralysis. The influence of 

 the nerve in the act of conveying odorous emanations to 

 the olfactory membrane is sufficiently evident after what 

 we have remarked concerning the action of the facial in 

 respiration. 



The effects of paralysis of the other superficial muscles 

 of the face are manifested in the distortion of the features, 

 from the unopposed action of the muscles upon the sound 

 side ; a phenomenon which is sufficiently familiar to the prac- 



1 BELL, The Nervous System of the Human Body, London, 1844, p. 54. The 

 case referred to is No. VI., in the Appendix ; but this seems to be an error, as 

 no such circumstance is mentioned in this case. Still the fact illustrated is not 

 to be doubted. 



2 BERNARD, Lemons sur la physiologie et la pathologic du systeme nerveux, Paris, 

 1858, tome ii., p. 38. 



3 BELL, Of Smelling as influenced by the Portio Dura of the Seventh Ntrve.* 

 The Nervous System, London, 1844, p. 134. 



