THE LATERAL VENTRICLES 25 



a flattened band of white fibres and its narrow anterior 

 extremity divides into the two columns (anterior pillars] 

 (p. 15). The posterior extremity of the fornix divides into 

 two crura, which pass downwards and forwards in the floor of 

 the inferior (descending) horn of the lateral ventricle to 



Septum pellucidum 

 Corpus callosum ^ \ Fornix 



Interventricular foramen- *"" 



Lamina terminalis 



Oculo-motor nerve 



-. Middle commissure 



- Pineal body 

 __ _ -Corpora qnadrigemina 



^ Cerebral aqueduct 

 (of Sylvius). 



_ Fourth 

 ventricle 



_ __ Central canal of 

 ~" spinal medulla 



FIG. 14. Median Sagittal Section through the Brain-Stem, showing the 

 third and fourth ventricles and their connexions. 



terminate in the uncus (p. 16). Superiorly, the fornix is 

 attached to the septum pellucidum in front and to the corpus 

 callosum behind (Fig. 14). Inferiorly, it is in contact with 

 the tela chorioidea, which separates it from the superior surface 

 of the thalamus on each side and from the third ventricle in 

 the median plane. 



