440 CRANIAL NERVES. 



dilated at each inspiration, so that breathing takes place in 

 great part by the opposite side, and if both are cut in the 

 horse, which breathes through the nose only, suffocation 

 ensues ; the lips on the injured side hang downward, and 

 cannot be used for the prehension of aliments ; and, lastly, 

 the aliments masticated collect in pellets inside the cheek, 

 from the inability of the buccinator muscle to bring them be- 

 tween the teeth. The movements of the tongue also become 

 more restricted, and the sense of taste is impaired or lost, 

 not from the filament it supplies to the tongue (chorda tym- 

 pani) being a nerve of taste, but rather from the want of a 

 perfect adjustment of the organ, which seems necessary to 

 the proper exercise of the sense. 



Bernard has found that this nerve presides to a consider- 

 able extent over the secretion of saliva. He cut down on 

 the side of the digastricus muscle, and raised the chorda 

 tympani, separating it from the lingual nerve. He placed 

 a tube in the duct of the submaxillary gland, and found 

 that when the nerve was stimulated, saliva flowed abun- 

 dantly, but ceased quickly on the removal of the stimulus. 

 This phenomenon was repeated as often as the stimulus 

 was applied and withdrawn. The sublingual gland like- 

 wise secreted actively when the chorda tympani was stimu- 

 lated, and stopped with the cessation of the stimulus. The 

 filament from the superior cervical ganglion of the sympa- 

 thetic, which is connected with the submaxillary gland, has 

 some control over the secretion, since its stimulation led to 

 a greater viscidity of the saliva, and after a time to its com- 

 plete cessation. Stimulation of the facial nerve within the 

 cavity of the middle ear leads to a free secretion from the 

 parotid gland, though the galvanising of the chorda tym- 

 pani at its exit from the bone has no such effect. 



Glosso-pharyngeal. The ninth cranial nerve arises from 



