296 Journal of Comparative Neurology. 



vagal root of the r. lateralis accessorius. I do not find them. 

 The two nerves lie close together, but since this IX root is 

 motor, a connection with the r. lateralis accessorius would of 

 course be quite inexplicable. 



The first sensory root of the vagus complex is quite large 

 and is a mixed glossopharyngeus and vagus root. It runs out 

 under the r. lateralis vagi, the motor IX and the VIII roots, 

 becoming ganglionated at once. This intra-cranial ganglion is, 

 however, a small one and cannot pertain to more than a very 

 small proportion of the fibers of this root. It cannot be the 

 IX ganglion, as that is extra-cranial and the IX fibers can be 

 seen to run directly through this ganglion. It is, in fact, the 

 jugular, or general cutaneous ganglion of the vagus. 



From this first sensory root, fibers separate to join the 

 motor IX root and the mixed root thus formed runs out later- 

 ally and forwards to its extra-cranial ganglion in the usual way. 

 From the ganglion the first truncus branchialis turns backward 

 and outward, while the sensory bundle which accompanies the 

 sympathetic chain to form Jacobson's anastomosis separates 

 from the cephalic end of the ganglion. 



The first nerve to be given off from the truncus is the mo- 

 tor twig for the first internal levator arcus branchii. A little 

 farther out, the motor nerve for the first external levator arcus 

 branchii is given off. The arrangement of the branchial rami 

 of the IX and X nerves is in general as in Menidia. The post- 

 trematic ramus divides into two branches, inner and outer, one 

 following the concave, the other the convex surface of the 

 branchial bar, while the minute pre-trematic ramus of the next 

 following branchial nerve follows the convex surface parallel 

 and close to the much larger outer post-trematic of the same 

 gill. The outer post-trematic ramus lies at the base of one 

 demibranch, the pre-trematic over the other in each gill. In 

 Gadus, as in Menidia, the post-trematic nerve is evidently 

 mixed, the sensory fibers far out-numbering the motor. 



The pre-trematic IX nerve is exceedingly tenuous and I 

 found it impossible to trace it to the pseudobranch,- though 

 Stannius states that the pseudobranch is innervated from the 



