428 Anatomy Applied to Medicine and Surgery. 



fossa, and because it is bound down by the tentorium 

 cerebelli. The slow pulse and the vomiting, when present 

 in tumor of the brain, are probably dependent on disturb- 

 ance of the pneumogastric nerve. Convulsions may be 

 the result of the increased cerebral pressure and, so also, 

 is optic neuritis. In the latter case, since the optic nerve 

 is surrounded by two sheaths at its entrance into the 



Sensory Tract. 



Fibres connecting 

 Occipital & Tern pore 

 lobes with Pons 

 ( Cerebellum. 



Pyramidal fibres. 

 From Lenticular, 

 Nucleus & Frontal 

 Convolutions, including 

 Tracts for Face and 

 , Tongue. 



(Fig. 13.) 

 Diagram showing Tracts in Crus Cerebri. 



sclerotic one, a continuation of the dura mater, and the 

 other, from the pia mater, it follows that, when the pres- 

 sure in the brain is increased, the cerebro-spinal fluid is 

 forced into and distends these sheaths and thus causes com- 

 pression and resultant inflammation of the nerve. Double 

 optic neuritis is present in about 80% of cases of cerebral 

 tumor. When the neuritis affects one eye only, it is pos- 



