THE VISCERAL AFFERENT DIVISION. 



I6 7 



and glossopharyngeus nerves. Those in the mouth an- >upplied 

 by the palatine and hyomandibular rami of the facialis, by the 

 pharyngeal ramus of IX which extends into the roof of the mouth, 

 and by the ramus lingualis of the IX nerve. Those on the surface 

 of the head and body in ganoids and bony fishes are supplied 

 by components of the ophthalmic and maxillary rami and by a 

 great system of superficial nerves which have been known under 

 the name of ramus later alls accessorius (or nerve of Weber). The 

 name is unfortunate because it is likely to suggest some relation 

 with the lateral line nerve, with which this nerve is to be sharply 

 contrasted. The present nerve (Figs. 63, 88) arises from the 

 visceral afferent root of VII and sometimes in smaller part from 



FIG. 87. A taste organ from the skin of an adult Lampetra. 



the corresponding root of X, passes up through the cranium to 

 the dorsal surface of the head and is distributed to the back, 

 the tail and the fins, wherever taste buds are found. It has been 

 definitely shown that taste buds, wherever they are situated, 

 arc always innervated by fibers derived from the visceral afferent 

 roots of the VII, IX and X nerves and ending centrally in the 

 visceral lobe. Where the taste buds are very numerous in the 

 skin they are always innervated from the root of the facialis nerve 

 and there is developed a special pars facialis of the visceral lobe. 

 The innervation of the taste buds in man is still somewhat 

 in doubt. It was long supposed that fibers were supplied to 



