CKANIAL NERVES OF CAECILIANS 



537 



distinct kinds of cells in this latter ganglion; large cells situated 

 mostly dorsally along the tract of the lateralis fibers which run 

 through the ganglion; small and medium cells which we inter- 

 pret as visceral sensory or sympathetic in character. In the 

 adult Ichthyophis the ganglia and their relations are essentially 

 as in the larva, lacking, however, the lateralis elements. As 

 stated by Wiedersheim, there is an anastomosis between the 

 vagus and the sympathetic in the adult Ichthyophis. 



Fig. 37 A projection upon the sagittal plane of the ninth and tenth cranial 

 nerves, the occipital and first spinal nerves, and the ventral rami of the second 

 and third spinal nerves, together with the sympathetic trunk and ganglia, of 

 Geotrypetes petersii. X 27.5. 



In Geotrypetes the IX-X trunk passes out laterally, the fibers 

 of the vagus through a rather large root ganglion, until the sym- 

 pathetic trunk is reached, along whose dorsal border it runs pos- 

 teriorly (fig. 37). Soon ganglion cells appear between the two 

 trunks and shortly thereafter both are merged in a common 

 ganglion. This ganglion evidently represents a fusion of a sym- 

 pathetic, a glossopharyngeal, and a vagal trunk ganglion. 



In Caecilia the roots of the IX-X nerves are distinct, sepa- 

 rated by connective tissue as far out as the root ganglion of the 

 vagus. The latter has an unusual situation, far out laterally 



THE JOURNAL OF MORPHOLOOY. VOL. 31. NO. .'^ 



