584 



COMPAKATIVE PHYSIOLOaT. 



Gustatory impulses from the anterior end and lateral edges 

 of the tongue are conveyed by th-e lingual (gustatory) branch 

 of this nerve. Many are of opinion, however, that the fibers 

 of the chorda tympani, which afterward leave the lingual to 

 unite with the facial nerve, alone con- 

 vey such impressions. The subject 

 can not be regarded as quite settled. 

 Tactile sensibility in the tongue is very 

 pronounced, as we have all experi- 

 enced when a tooth, etc., has for some 

 reason presented an tuiusual surface 

 quality, and become a source of con- 

 stant offense to the tongue. 



The ganglia of the fifth nerve, so 

 far as the functions of their cells are 

 concerned, are enigmatical at present. 

 They are doubtless in some sense tro- 

 phic at least. With each of these are 

 nerve connections (" roots " of the gan- 

 glia), which seem to contain different 

 kinds of fibers. These ganglia are 

 connected with the main nerve-centers 

 by both afferent and efferent nerves, 

 and also with the sympathetic nerves 

 themselves. Some regard the ganglia 

 as the representatives of the sympa- 

 thetic system within the cranium. 



I. The Ciliary {Ophthalmic, Lerir 

 ticular) Ganglion. — Its three roots 

 are : 1. From the branch of the third 

 nerve to the inferior oblique muscle 

 (motor root). 2. From the aasal 

 branch of the ophthalmic division of 

 the fifth. 3. From the carotid plexus 

 Fig. 426.— Unipolar cell from of the S3Tnpathetic. The efferent 



Gasserian ganglion (after •, ^ j. j.i • • i ■ j 



Schwaibe) iv if iV, nuclei branches pass to the ins, are derived 

 rngS'anJde^ifXS*" chiefly from the sympathetic, and 

 cause dilatation of the pupil. There 

 are also vaso-motor fibers to the choroid, iris, and retina. The 

 afferent fibers are sensory, passing from the conjunctiva, cor- 

 nea, etc. 



II. The Nasal or Spheno-Palatine Ganglion. — The motor 



