CRANIAL NERVES. 441 



the side of the oblong medulla within which its roots are 

 intimately connected with those adjacent as the trifacial, 

 facial, vagus, and hypoglossal. It leaves the cranium by 

 the large foramen at its base, and at this point has a gan- 

 glionic enlargement. Below this it sends communicating 

 filaments to the facial and spinal accessory. It is distributed 

 to the mucous membrane at the base of the tongue, to the 

 soft palate with its posterior pillars, to the middle ear, and 

 the anterior constrictor muscle of the pharnyx. 



Longet and Dr John Reid have shown that this nerve 

 is essentially sensory, and though its stimulation leads to 

 movements in the pharynx and upper part of the face, these, 

 after section of the nerve, can only be induced by stimu- 

 lating the cranial portion. Some motor power, which it 

 seems to possess toward its periphery, depends on filaments 

 derived from the spinal accessory. 



This is, moreover, the nerve of taste, for the root of the 

 tongue, the soft pa-late and its pillars for those parts indeed 

 where this sense is most acutely developed. 



The glosso-pharyngeal is the principal medium for the 

 conveyance from the pharynx of that impression which 

 gives rise to the reflex act of deglutition. Swallowing does 

 not depend on a reflex act conveyed through this nerve 

 alone, since it may still be induced by a stimulus on the 

 fauces after its section. The unnatural stimulation of this 

 nerve gives rise not to deglutition, but to vomiting, in 

 those animals in which this act can be performed. Tick- 

 ling of the fauces with a feather is accordingly often em- 

 ployed to effect this object. 



Pncumogastric. This nerve arises by numerous roots 

 from the lower border of the restiform bodies, and leaves 

 the cranium through the same opening as the last. At this 

 opening it has a ganglion, and just below this it cornmuni- 



