THE COD. 127 



and fonvards, the greater part of it going to the upper jaw ; a branch 

 given off near its origin (palatonasal, V-t") goes directly forwards, 

 parallel with and close to the parasphenoid : the third division (mandi- 

 bular, V3), passes forwards, downwards, and outwards to the lower jaw, 

 upon reaching which it divides into two chief branches, one passing 

 above, the other below Meckel's cartilage. The cutaneus quinti (V':) 

 arises from the main trunk. The seventh nerve takes a direction out- 

 wards, downwards, and backwards, and soon divides into two branches 

 which pass through the two foramina in the hyomandibular (§ 40) : the 

 anterior of these divisions soon divides again, the hindermost branch 

 going to the operculum, the other (chorda tympani) to the lower jaw : 

 the posterior division takes a cui-ve inwards, backwards, and down- 

 wards, reaches the inner side of the epihyal, and passes along the inner 

 face of the hyoidean arch. 



194. The sixth pair of nerves (abducent, VI), each 

 arising by tvi^o delicate roots from the ventral surface of 

 the medvilla oblongata. 



195. The eighth pair of nerves (auditory, VIII), each 

 arising by three large roots from the lateral surface of 

 the medulla ; these pass directly outwards to the auditory 

 organ. 



196. The ninth (glossopharyngeal, IX) and tenth 

 (vagus or pneumogastric, X) nerves, arising together 

 from the lateral surface of the medulla; the vagus arises by 

 two large roots which pass outwards and backwards and 

 join one another just before leaving the cranial cavity; the 

 glossopharyngeal arises by one main root, a little posterior 

 to the anterior root of the tenth, to the ventral side of 

 which it passes to make its exit from the skull. 



On leaving the skull, the glossopharyngeal divides into two branches, 

 the anterior and smaller of which goes to the pseudobranchia, the 

 posterior to the anterior face of the first branchial arch. 



The va^us, on leaving the skull, sends off branchial nerves which 

 supply the branchial arches in the same manner as in the skate (p. 81, 

 § 214),. it then divides into two trunks, one passing ventral wards and 



