232 Journal of Comparative Neurology. 



ception, could be traced conclusively. The peripheral rela- 

 tions of the motor axones of the third root of the vagus are 

 doubtful. 



/. — TJie Lateral Line Root. 



The first or most anterior root of this complex is t]ie later 

 alts root of the vagus {X. /, ). It arises at about the same horizontal 

 level with the origin of the lateralis VII root, and but a short 

 distance posteriorly of the latter. The root inclines caudad and 

 rapidly ventrad until it comes in contact with the dorsal surface of 

 the root of the glossopharyngeus. It then continues directly cau- 

 dad closely compressed upon the ninth nerve, and comes in con- 

 tact with the emerging second root of the vagus. In some older 

 specimens, however, this contact does not take place. As the 

 lateralis X root enters the ganglion it comes to lie mesially of 

 the root of the ninth, but remains perfectly distinguishable from 

 the second root of the vagus with which it sometimes comes in 

 contact. 



The ganglion of the lateralis root forms the most dorsal 

 portion of the ganglionic complex. In the anterior part of the 

 ganglion a small division extends laterad about the border of 

 the ear capsule and emerges as the r. supratemporalis X. A 

 second division projects latero-caudad and gives rise to the 

 lateralis component of the r. auricularis vagi. The remainder 

 of the ganglion extends caudad along the dorsal surface of the 

 complex and gives rise to the lateralis axones which are more 

 or less fused with the r. visceralis vagi. 



2. — TJie Root of t lie GlossopJiaryngetis. 



The root of the ninth nerve emerges from the medulla at 

 a transverse level immediately posterior to the exit of the later- 

 alis root of the vagus, but from the extreme lateral border of 

 the medulla ventrally of the latter root. It is composed of com- 

 munis and motor fibers. The motor fibers, in reaching the 

 surface of the medulla, pass across the ventral side of the fasci- 

 culus communis at the point where the communis component of 

 the nerve leaves the fasciculus, and the two components emerge 

 from the medulla as a single root. 



