SEA-FISHERIES LABORATORY. 269 



and viith nerves, it may be mentioned that the Gasserian 

 ganglion is the only one to receive a prominent R. com- 

 municans from the sympathetic. There also arises from 

 the same ganglion a motor nerve which has traversed the 

 ganglion and passes to the M. depressor operculi 

 (m. d. op.). This is the most posterior nerve passing 

 through the trigemino-facial foramen. 



The trigemino-facial foramen (represented by a ring 

 in the chart) transmits the trigeminal nerve + the dorsal 

 lateral line root of the facial + a communis vii. com- 

 ponent. The jugular foramen (the posterior ring in the 

 chart) transmits the hyomandibular trunk, comprising the 

 remainder and greater part of the facial + a cutaneous 

 component from the trigeminus. 



The various nerve rami may now be described under 

 the names of the nerves to which they belong. 



Nervus Trigeminu s — V. 



1. Nervus ophthalmicus profundus (fig. 26, o. pr.). — 

 The root of this nerve (Radix ophthalmici profundi) arises 

 on the right side from the root of the trigeminus near the 

 brain, and proximal to the Gasserian ganglion. It passes 

 downwards and forwards over the inner face of the latter 

 ganglion between it and the brain, and enters the pro- 

 fundus ganglion, which, though closely opposed to the 

 inner face of the Gasserian, is absolutely distinct from it. 

 From the profundus ganglion an apparently single nerve 

 arises which leaves the skull cavity with the rest of the 

 vth and becomes intimately attached to the sympathetic. 

 We could not be certain whether a few fibres were not 

 given off to accompany the R. ophthalmicus superficialis 

 v., thus constituting a Portio ophthalmici profundi. The 

 nerve from the profundus ganglion passed with the sym- 

 pathetic through the skull wall again by a special small 



