SEA-FISHERIES LABORATORY. 283 



secondary and unimportant connection with the vagus, 

 and the N. vagus sensu stricto. There are no intracranial 

 branches from the vagus - complex, as stated by 

 Stannius. 



R. lateralis vagi (r. lab. x.). — Arises from the tuber- 

 culum acusticum, like the auditory nerve and other lateral 

 line nerves, but appreciably below the exit of the latter 

 and considerably above and somewhat in front of the root 

 of the glossopharyngeus. It also arises considerably in 

 front of the roots of the true vagus. The root (r. lab. x. 1 ) 

 passes downwards and backwards, lying immediately 

 external to that of the vagus proper, and for a time 

 between it and the posterior division of the acusticus, as 

 above described. It has, however, no connection with 

 either, and passes out of the same foramen (indicated by 

 a ring in the chart) as the rest of the vagus, but external 

 to the latter. As in Menidia the lateralis consists mostly 

 of the large strongly myelinated nerve fibres, but also has 

 many smaller ones. 



Immediately on leaving the skull the lateralis gives 

 off the R. supratemporalis vagi (r. sb. x.), at the base of 

 which is a small ganglion distinct from the main lateralis 

 ganglion. The supratemporal branch, as shown in the 

 chart, is distributed on the ocular side to the 4 sense 

 organs so far developed in the supratemporal portion of 

 the lateral canal, and also to the first two sense organs in 

 the main portion of the same, i.e., sense organs 1 to 6. 

 After giving off this branch the lateralis expands into the 

 lateralis ganglion {I. g. x.). The nerve arising from the 

 ganglion passes upwards, and divides, as in the Cod, into 

 the 11. lateralis superficialis vagi (r. lot. sup. x.), coursing 

 just under the skin in the neighbourhood of the main 

 portion of the lateral canal the sense organs of the anterior 

 half of which it supplies, and the R. lateralis profundus 



