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NEUROLOGY 



callosum. It is an irregularly curved cavity, triangular on transverse section, 

 with a roof, a floor, and a medial wall. The roof is formed by the under surface of 

 the corpus callosum; the floor by the following parts, enumerated in their order of 

 position, from before backward: the caudate nucleus of the corpus striatum, the 



Third ventricle 



Suprapineal recess 



FIG. 735. Drawing of a cast of the ventricular cavities, viewed from above. (Retzius.J 



stria terminalis and the terminal vein, the lateral portion of the upper surface of 

 the thalamus, the choroid plexus, and the lateral part of the fornix; the medial 

 wall is the posterior part of the septum pellucidum, which separates it from the 

 opposite ventricle. 



Interventricular foramen 



Ant. commissure 



Suprapineal recess 

 Cerebral aqueduct 



Optic recess 

 Infundibulum 



Lateral recess 

 Fio 736. Drawing of a cast of the ventricular cavities, viewed from the side. (Retzius.) 



The anterior cornu (cornu anterius; anterior horn; precornu) (Fig. 736) passes 

 forward and lateralward, with a slight inclination downward, from the interventric- 

 ular foramen into the frontal lobe, curving around the anterior end of the caudate 

 nucleus. Its floor is formed by the upper surface of the reflected portion of the 



