220 NERVE COMPONENTS OF BONY FISHES. 



Separating from the IX ganglion, the trunk follows a 

 big blood vessel along the outer wall of the cranium nearly 

 to the foramen of the truncus hyomandibularis, running 

 at the level of the ventral edge of the membranous 

 labyrinth, which lies within the cranium. Throughout 

 this portion of its course ganglion cells are scattered freely 

 along the trunk, which has about the same number and 

 character of fibres as in its post-vagal course through the 

 body. Along with the vessel above referred to, it enters 

 a foramen in the cranial wall which communicates with 

 that of the truncus hyomandibularis, and a sympathetic 

 ganglion which is here formed {s_y. j) applies itself closely 

 to the ventral side of the mixed truncus hyomandibularis 

 and r. palatinus within this foramen, and a portion runs 

 out into these nerves. The ganglionic chain continues 

 {sy. 2) into a similar foramen cephalad of that of the 

 truncus hyomandibularis, which is occupied by a large 

 blood sinus and by the caudal extension of the Gasserian 

 ganglion from which arises the caudal root of the general 

 cutaneous component of the truncus hyomandibularis, 

 where it applies itself to the ventral side of the extra- 

 cranial part of the Gasserian ganglion (Fig. 2, sy. 2) and 

 follows it back into the cranium. 



From this point cephalad the sympathetic ganglion is 

 intimately fused with the ventral face of the Gasserian 

 ganglion and sympathetic fibres can be seen to enter that 

 ganglion. Others were traced into the infra-orbital and 

 supra-orbital trunks and, as before stated, into the r. 

 lateralis accessorius. 



Sanders ('79, p. 745) describes in Merlangus an extra- 

 cranial connection between the IX ganglion and the Gas- 

 serian, which conforms to my sympathetic nerve. He, 

 however, does not regard it as sympathetic, but errone- 



