> XXX.] THE BRAIN-. 315 



olivary body. (Their superficial origin is 

 different in man.) 



f. The eighth pair of nerves just outside the 

 seventh ; they cling to the lateral surface of 

 the medulla, they will be seen on the dorsal 

 surface passing over the restiform bodies. 

 Note the small bundles of fibres (strise 

 acusticae) passing over the restiform bodies 

 into the fourth ventricle. 



g. The ninth, tenth and eleventh pairs of nerves 

 each arising by several roots which form a 

 line on the lateral part of the medulla ; this 

 line in its lower portion is continuous with 

 the line of the posterior roots of the cervical 

 nerves; the eleventh pair has origin also 

 from the spinal cord, it may be traced down- 

 wards on the surface of the cord to about the 

 sixth cervical nerve. 



A. The twelfth pair of nerves arising by several 

 roots between the anterior pyramids and 

 olivary bodies. 



10. Observe again the ventral surface of the brain 

 (§ 5), removing the pia mater. 



11. Separate the hemispheres and observe the 

 corpus callosum, noting its curve in front 

 (genu) and its curve behind (splenium). 



12. Cut away in thin slices the dorsal surface of the 

 hemispheres, nearly down to the level of the 

 corpus callosum, noting the outer grey substance 

 and. the innei: Fhite substance, 



