PISCES 



177 



IV. Trochlear or Pathetic. This nerve is motor and arises 

 in the roof of the brain between the optic lobes and the cere- 

 bellum. The pair of nerves form a chiasma and pass out from 

 the brain case by a number of small branches which are spread 

 into the superior oblique muscle of the eye. 



Inner buccal f - 

 Outer buccal 



Palatine-^ 



Hyomandib. 



Chorda tymp. 



Hyoid 



Spiracular 



Gastric 

 Lateral 



Olf. lobe 



Cer. hem. 



Thalamen- 

 cephalon 



Optic lobe 

 Cerebellum 



Restiform 

 body 



Medulla 

 oblongata 



Spinal 

 cord 



Brachial 

 plexus 



FIG. 89. Raia. Dorsal view of brain and cranial nerves. 



V. Trigeminal. This nerve originates in a large ganglion, 

 the Gasserian ganglion. Its nerves enter the medulla at its 

 anterior end. Distally the ganglion gives off two branches, 

 the lower of which bifurcates into two. The ophthalmic 

 branch (V 1 ) passes over the eye muscles in the orbit, becomes 

 united with the ophthalmic branch of the Vllth and is supplied 



