BRANCHES — BRANCHIAL NERVES OF FISHES 139 



of them. The vagus root contains general sensory, communis, 

 and motor fibers, and becomes united with the root of the lineae 

 laterahs vagi inside the cranial cavity. From this root an intra- 

 cranial branch is given off, this branch arising from the dorsal 

 surface of the root, in the line between its communis and general 

 sensory portions, and it is impossible to tell, in my specimens, of 

 what fibers it is composed. The branch, on both sides of the 

 head of one specimen and on one side of the other, runs upward 

 in the cranial cavity, perforates the cartilage, and joins and 

 anastomoses completely with a closed circuit formed by the 

 anastomosis of branches of the rami supratemporalis vagi, 

 supratemporalis glossopharyngei, and oticus trigemini. On the 

 other side of the one specimen the branch is joined b}^ a branch 

 that arises from the general sensory ganglion of the vagus, the 

 branch so formed then joining the ramus supratemporalis vagi. 

 No ganglion cells could be found in the root of the nervus vagus 

 at, near, or anterior to the point of origin of this branch, and no 

 cells are found at anj^ point along the branch, the branch thus 

 apparently having no ganglion cells related to it and apparently 

 agreeing in this with the nerves of Amphioxus. 



After giving off the above-described intracranial branch, the 

 combined roots of the nervi vagus and lineae lateralis traverse 

 the vagus foramen, which gives passage also to a vein which 

 falls into the vena jugularis, and to a small artery which arises 

 from a dorsal branch of the first efferent branchial artery, the 

 vena jugularis lying ventral to the root of the nerve. As the 

 root traverses its foramen, ganglion cells form on the general 

 sensory fibers, and from it four bundles of fibers arise. One of 

 these bundles runs forward along the lateral surface of thechon- 

 drocranium and, separating into two parts, anastomoses with 

 the general sensory and communis components of the nervus 

 hyomandibularis facialis as that nerve issues from its foramen. 

 This branch lies morphologically internal to the hyomandibula 

 and hence is not the homologue of the anastomosis, found in 

 Amia and certain of the Teleostei, between the ramus supra- 

 temporalis vagi and the ramus opercularis facialis. A second 

 bundle of fibers is sent to the ramus supratemporalis vagi, a 



