632 



THE NEEVOUS SYSTEM. 



In frontal sections through the occipital and posterior temporal regions the tapetum 

 stands out very distinctly (Fig. 559, p. 631 ; see also Figs. 565, p. 636, and 567, 

 p. 638). 



Septum Pellucidum. The septum pellucidum is a thin vertical partition which 

 intervenes between the two lateral ventricles. It is triangular in shape, and 

 posteriorly it is prolonged backwards for a variable distance between the body of 

 the corpus callosum and the fornix, to both of which it is attached. In front it 

 occupies the gap behind the genu of the corpus callosum, whilst below, in 

 the narrow interval between the posterior edge of the rostrum of the corpus 

 callosum and the fornix, it is prolonged downwards in the paraterminal body 

 towards the base of the brain. The septum pellucidum is composed of two 

 thin laminae in apposition with each other in the median plane (Fig. 562 ; Fig. 

 564, p. 635). 



Cavum Septi Pellucidi. This name is applied to the median cleft between the 



Sulcus cinguli 

 Gyrus cinguli paracentral area 



Commissura fornicis 

 Corpus fornicis 

 Corpus callosum 

 Septum pellucidum 

 Sulcus cinguli 



Paracentral sulcus 

 ! Sulcus centralis 



Hippocampal rudiment 

 Incisura sulci cinguli 



Gyrus frontalis superior 

 Lamina chorioidea 



Foramen 

 interventriculare's 



Rostrum of 



corpu 

 callosum 



Sulcus_^3H 

 genuali 

 Anterior 

 commissure" 



Olfactory bulb 

 Corpus paraterminale' / 



Columna fornicis .,/ 

 Olfactory tract 

 Stria olfactoria lateralis - 

 Nucleus amygdalae 



Piriform area 



Thalamus (cut surface) 



Rhinal fissure 

 Cauda fasciae dentatse 



Hippocampus 



'Sulcus prsecunei 

 .Praecuneus 

 ^..Sulcus subparietalis 



parieto- 

 ''occipitalis 



Sulcus paramediali 

 .,-A.rea striata 



iV J3ulcus 



"sagittalis cunj 



Sulcus 

 retrocalcarim 



Area striata 



Sulcus polaris inferior 

 Sulcus calcarinus 



> Sulcus sagittalis gyri lingualis 



\ JSulcus collateralis 

 Hippocampus 



j Splenium of corpus callosum 

 Fascia dentata 



| Cms fornicis 

 Gyrus paradentatus 

 mbria 



FIG. 560. THE MEDIAL ASPECT OF THE RIGHT HALF OF THE BKAIN EXPOSED BY A MEDIAN SAGITTAL SECTION. 



two laminae of the septum pellucidum. 

 brains. 



It varies greatly in size in different 



VENTRICULUS LATERALIS. 



The cavity in the interior of the cerebral hemisphere is called the lateral 

 ventricle. It is lined throughout by ependyma continuous with the ependymal 

 lining of the third ventricle. In some places the walls of the cavity are in 

 apposition, whilst in other localities spaces of varying capacity, and containing 

 cerebro- spinal fluid, are left between the bounding walls. 



The lateral ventricle communicates with the third ventricle of the brain by 

 means of a small foramen, just large enough to admit a crow-quill, which is 

 termed the foramen interventriculare. This aperture is placed in front of the 

 anterior end of the thalamus and behind the column of the fornix. 



The highly-irregular shape of the lateral ventricle can be best understood by the 



