Spinal nerves 



Vagus X 



Auditory VIII 

 Facial VII 



Trigeminal V 1 



Oculomotor III 

 Eyeball 

 Nasal sac 



Olfactory 

 Optic II 



Trochlear IV 

 Abducens VI — ' 

 Gasserian ganglion 



Tympanum — 

 Glossopharyngeal IX-* 

 Brachial enlargement — ' 

 Autonomic ganglion- 

 Brachial nerve 



Lumbar enlargement 

 ' — Autonomic nerve trunk 



Figure 233. Nervous system of the bullfrog, dorsal view. 



Olfactory nerve I 



Olfactory lobe 



Cerebral 

 hemisphere 



Optic II — 

 Optic chiasma 

 Pineal body 

 Diencepholon 



Optic lobe 



Ocufomofor 

 Trochlear IV 

 ■Trigeminal V 

 Cerebellum 

 Facial Vll 

 Auditory VllI 



Medulla 

 Vagus X 

 Glossopharyngeal IX 

 Spinal nenre I 

 Nerve (spinal) cord 



y^ oJi 



Olfactory lobe 



Cerebral 

 hemisphere 



First ventricle 

 Second ventricle 



Foramen of 

 Monro 



Third ventrici 

 Optic 

 ventricle 



. y Infundibulum 

 '^ — Pituitary body 



Cerebral aqued 



(aqueduct of 



Sylvius) 



Abducens VI 



Fourth ventricle 

 Medulla 



Centra! canal 



Figure 234. 



dorsal view. 



Brain of the frog. A, dorsal view. B, ventral view. C, ventricles (cavities) in 



351 



