368 



ELEMENTAL Y ANA TO MY. 



[LESS. 



medulla oblongata, a convex eminence formed of transverse 

 fibres running across from one lateral lobe of the cerebellum 



FIG. 324. THE BASE OF THE BRAIN. 



A , frontal lobe ; B, temporal lobe of the cerebral hemispheres ; CC, corpus 

 callosum ; Cb, cerebellum ; M, medulla oblongata ; P, the pituitary body ; 

 /. the olfactory nerve ; //. the optic nerve ; ///. IV. VI. the nerves of the 

 muscles of the eye ; V. the trigeminal nerve ; VII. the portio dura ; VIII. the 

 auditory nerve ; IX. the glosso-pharyngeal ; X. the pneumogastric ; XI . the 

 spinal accessory ; XII. the hypoglossal, or motor nerve of the tongue. The 

 number VI. is placed upon the pons Varolii. The crura cerebri are the 

 broad bundles of fibres which lie between the third and the fourth nerves on 

 each side. Between the crura cerebri and behind the pituitary body are placed 

 the rounded corpora inammillaria. S, sylvian fissure. 



to the other, somewhat like a bridge, and thence called fat pons 



Varolii. It lies upon the basilar surface of the occipital bone. 



Emerging from the front of the pons are two masses of 



longitudinal fibres (called the crura cerebri} which diverge 



