316 ELEMENTARY PHYSIOLOGY. [XXX. 



Make a shallow cut along each side of the corpus 

 callosum and pull up the cortex on the outside 

 of the cut; a space, the body of the lateral ven- 

 tricle, will be seen ; carefully cut away the roof 

 of this space, which will then be seen to run 

 forwards as the anterior cornu and backwards and 

 downwards as the descending cornu of the lateral 

 ventricle; on one side completely remove the 

 cortex above the cornua. Observe 



a. The nucleus caudatus of the corpus stria- 

 turn, seen as a large rounded projection into 

 the anterior cornu and continued backwards 

 as a tapering mass (tail of the nucleus) on the 

 outer side of the body of the ventricle. 



b. The hippocampus major, a rounded projec- 

 tion of the floor and medial wall of the 

 descending cornu. 



c. The floor of the body of the lateral ventricle 

 consisting of a thin lamina (cp. 15), the 

 fornix; continuous posteriorly with the 

 hippocampus. 



d. The choroid plexus of the lateral ventricle 

 covering the lateral edge of the fornix and of 

 the hippocampus. At the junction of the 

 body of the ventricle with the anterior cornu 

 the choroid plexus dips down underneath 

 the fornix. 



e. Turn laterally the choroid plexus and observe 

 the band of white substance running from the 

 fornix along the edge of the hippocampus 

 forming the fimbria of the hippocampus. 



