SYMPATHETIC NERVE SYSTEM. 193 



inner side of the temporosphenoid lobes. There does not seem to be any 

 differentiation, up to this time, of these two centers. 



The center for tactile impressions was located by Ferrier in the hippocampal 

 region. Horsley and Schafer found that destructive lesions of the gyrus 

 fornicatus were followed by hemianesthesia of the opposite side of the body, 

 which was more or less marked and persistent. These observers conclude 

 that the limbic lobe "is largely, if not exclusively, concerned in the apprecia- 

 tion of sensations, painful and tactile." 



The superior and middle frontal convolutions appear to be the seats of the 

 reason, intelligence, and will. Destruction of these parts is followed by 

 proportional hebetude, without any impairment of sensation or motion. 



THE SYMPATHETIC NERVE SYSTEM. 



The sympathetic nerve system consists of a chain of ganglia connected 

 by longitudinal nerve filaments, situated on each side of the spinal column, 

 running from above downward. 



The chain of ganglia is divided into groups, and named according to the 

 location in which they are found viz., cranial, four in number; cervical, 

 three; thoracic, twelve; lumbar, five; sacral, five; coccygeal, one. Each gan- 

 glion consists of a collection of vesicular nervous matter, bundles of non-medul- 

 lated nerve-fibers, embedded in a capsule of connective tissue. The ganglia 

 are in connection with motor fibers from the cerebro-spinal nervous system. 



The ganglia give origin to nerve-fibers, from which branches are distrib- 

 uted to the glands, arteries, and non-striated muscles, in the walls of viscera. 



Cephalic Ganglia. 



1 . The ophthalmic or ciliary ganglion is situated in the orbital cavity, posterior 

 to the eyeball; it is of small size and of a reddish-gray color; receives fila- 

 ments of communication from the motor oculi ophthalmic branch of the 

 fifth pair, and the carotid plexus. Its filaments of distribution are the 

 ciliary nerves, which consist of 



(a) Motor fibers for the circular fibers of the iris and ciliary muscle. 

 (6) Sensor fibers for the cornea, iris, and associated parts. 



(c) Vaso-motor fibers for the blood-vessels of the choroid, iris, and retina. 



(d) Motor fibers for the dilator fibers of the iris. 



2. The spheno-palatine or Meckel's ganglion, triangular in shape, is situated 

 in the sphenomaxillary fossa; receives filaments from the facial (Vidian 

 nerve) and the superior maxillary branch of the fifth nerve. Its filaments 

 of distribution pass to the gums, the soft palate and associated parts. 



3. The otic or Arnold's ganglion is of small size, oval in shape, and situated 



13 



