136 



THE NERVOUS SYSTEM. 



points near the ventral and dorsal longitudinal sinuses respec- 

 the two roots unite at their point of exit from the ver- 

 tebral canal through 



Fig. 97. the intervertebral for- 



amen ; each dorsal root 

 possesses a ganglion. 



The nervous system of Rana es- 

 culenta, from the ventral sur- 

 face. (From Icones physiolo- 

 gicae by A. Ecker. PL XXIV, 

 Fig. i.) 



F Facial nerve. 



G Ganglion of pneumogas- 

 tric nerve. 



He Cerebral hemisphere. 



Lc Optic tract. 



Lop Optic lobe. 



M Boundary between me- 

 dulla oblongata and spi- 

 nal cord. 



/Mi 10 Spinal nerves. 



MS Connection between fourth 

 spinal nerve and sympa- 

 thetic chain. 



2f Nasal sac. 

 : Ni Sciatic nerve. 



No Crural nerve, 



o Eyeball, 



<S Trunk of sympathetic. 



Si 10 Sympathetic ganglia. 



Sin Kami communicantes of 

 sympathetic. 



Sp Continuation of sympa- 

 thetic into head. 

 _ / Olfactory nerve. 



// Optic nerve, 



III Motor oculi nerve. 



IV Trochlear nerve, 



V Trigeminal and facial 



nerves. 

 Va Ram us ophthalmicus of 



trigeminal. 

 Vc Bamus maxillo-mandibu- 



laris of trigeminal. 

 VA Mandibular branch of 



trigeminal. 

 Ve Hyomandibular branch of 



facial. 



Vfl Gasserian ganglion. 

 Vs Upper end of sympathetic 



trunk in connection with 



Gassedan ganglion, 



VI Abducens nerve. 



VII Facial nerve. 



VIII Auditory nerve. 



X Glossoplmryngeal. and 

 pneumogastric nerves. 



A"i Ramus anterior of glosso- 

 pharyugeal. 



A'2 Ramus posterior of glosso- 

 pharyngeal. 



A~3 4 Branches of pneumogas- 

 tric. 



i. 5 



