FACIAL NERVE, OR NERVE OF EXPRESSION. 623 



sense of taste in the anterior portion of the tongue. Without citing all of the experi- \ 

 ments and pathological observations bearing upon this question, it is sufficient to state 1 

 that, in cases of disease or injury in which the root of the facial is involved so that the 

 chorda tyinpani is paralyzed, in addition to the ordinary phenomena of paralysis of the 

 superficial muscles of the face, there is loss of taste in the anterior portion of the tongue 

 upon the side corresponding to the lesion. Numerous cases of this kind are quoted in 

 works on physiology, which will be referred to more fully in connection with the subject 

 of gustation. 



In 1863, we had under observation, for several months, a soldier who received a gun- 

 shot-wound, the ball passing through the head, entering just above the ala of the nose upon 

 the left side and emerging behind the mastoid process of the right temporal bone. The 

 wound was nearly healed while he was under observation, and the usual symptoms of 

 complete facial paralysis were manifested upon the right side. The buccinator and the 

 orbicularis oculi were completely paralyzed. Vision in the right eye was slightly im- 

 paired, but was improving. The hearing was perfect, and there were no abnormal phe- 

 nomena except those apparently due to injury of the facial. The sense of taste was 

 entirely abolished in the anterior portion of the tongue upon the right side. Experiments 

 upon this point were repeatedly made with salt, pepper, and other sapid substances. This 

 patient was exhibited in two successive years to the class at the Bellevue Hospital Medi- 

 cal College, when the above-mentioned facts were demonstrated. 



Physiologists have observed loss of taste in the anterior portion of the tongue, in 

 dogs, cats, and other animals, following section of the root of the facial or of the chorda 

 tympani. Some observers, it is true, have failed to note the phenomena satisfactorily, 

 and there is some difference of opinion with regard to the real origin of the gustatory 

 filaments ; but the fact that the chorda tympani influences the taste can hardly be doubted. 

 Adopting this view, we shall defer the full consideration of the functions of the chorda 

 tympani until we come to treat of the special sense of taste. 



Schiff, in 1851, was the first to note the influence of the chorda tympani upon the 

 secretion of the submaxillary gland. In his experiments, the chorda tympani was 

 exposed and the flow of the submaxillary saliva noted. Upon division of the chorda 

 tympani, the flow of saliva was momentarily increased, but was soon arrested ; and sub- 

 sequently, stimulation of the gustatory sense failed to induce secretion, as it does when 

 the nerve is intact. Similar experiments, upon a much more extended scale, were made 

 by Bernard, in the following way : 



The duct of the submaxillary gland was exposed in a dog, and into it was fixed a 

 silver canula. The nervous filaments going to the gland from the lingual branch of the 

 fifth were then isolated. A little vinegar introduced into the mouth caused an abundant 

 flow of saliva from the tube. The chorda tympani was then divided, by introducing a 

 sharp instrument through the membrane into the tympanic cavity. After division of the 

 nerve, the introduction of vinegar into the mouth failed to excite the salivary secretion. 

 From this and similar experiments, Bernard concludes that the chorda tympani is the 

 motor nerve of the submaxillary gland. After having arrested the secretion by section 

 of the chorda tympani, the action of the gland was excited by galvanization of the pe- 

 ripheral end of the nerve. Section of the facial after its passage out of the stylo-mastoid 

 foramen did not arrest the action of the parotid ; but section of the nerve within the cra- 

 nium arrested the secretion, both of the parotid and submaxillary. 



These observations show conclusively that the facial, either through branches from 

 its proper roots or its filaments of communication with other nerves, regulates the secre- 

 tion of at least two of the salivary glands. 



Influence of Various Branches of the Facial upon the Morcmcnt* of the Palate and 

 Uvula. There can be little doubt that filaments from the facial animate certain of the 

 movements of the velum palati and uvula. It has been observed that, in certain cases 

 of facial paralysis, the palate upon one side is perfectly flaccid and the uvula is drawn to 



