124 



THE HUMAN -BODY. 



The lower surface or base of the brain presents an ex- 

 tremely complicated relief. In front, and on the sides, there 

 are numerdus convolutions. Towards the centre we find. 



Fig. 32. Lower surface of the brain. 



A. Anterior lobe. 



A'. Fissure of Sylvius. 

 A". Middle lobe. 

 A'". Posterior lobe. 



C. Cerebellum, or little brain. 

 M<7. Medulla oblongata. 

 PV. Pans Varolii. 

 T/. The pitrdtary body. 

 i-i. First pair, or olfactory nerves. 

 2-2. Second pair, or optic nerves. 

 3-3. Third pair, or common motor 



nerves of the eye. 

 4-4. Fourth pair, or pathetic nerves. 



5-5. Fifth pair, or trigeminal. 



6-6. Sixth pair, or abducent nerves of the 



eye. 

 7-7. Seventh pair a, Facial nerve. 



b, A uditory net ve. 



8-8. Righth pair- a.,. Glosso-pharyngcal 

 nerve. 



b, Pneumo-gastric 



nerve. 



c, Spinal-accessory 



nerve. 

 9-9. Ninth pair, or hypoglossal nerves. 



among other important details, the olfactory nerves on each 

 side of the great fissure ; the chiasma, or crossing of the optic 

 nerves; $h& pituitary body; the tuber cinereum, or ash-coloured 

 body; the corpora mammillaria, or mammillar bodies; and the 



