244 



THE NERVOUS SYSTEM 



body of the corpus callosum (truncus corporis callosi), arching somewhat dor- 

 sally, extends toward the occiput and terminates in the splenium, a thickened 

 rounded border situated dorsal to the pineal body and corpora quadrigemina. 

 Related to the concave or ventral side of the corpus callosum are the fornix, 

 septum pellucidum, lateral ventricles, tela chorioidea of the third ventricle, and 

 the pineal body (Fig. 170). 



Genii of corpus callosum 



Cingulum (cut) ~^pF 



Corpus callo-... 

 sum 



Centrum semi- 

 ovale 



Medial longi-.. 

 ludinal stria 



Cingulum (cut) J 



Splenium of _,, 

 corp. callosum" 



Frontal part of 

 ' radiation of 

 corp. callosum 



Intersection of 

 fibers from cor- 

 . pus callosum 

 and corona 

 radiata 



.Superior longi- 

 tudinal fas- 

 ciculus 



Radiation of 

 corp. callosum 



^Transverse tem- 

 poral gyri 



Optic radiation 



Occipital part of 

 radiation of 

 corp. callosum 



Fig. 174. Dissection of the human telencephalon to show the radiation of the corpus callosum. 



Dorsal view. 



Turning again to the dorsal aspect of the corpus callosum, a careful inspec- 

 tion will show that at the bottom of the great longitudinal fissure it is covered 

 by a very thin coating of gray matter, continuous with the cerebral cortex in 

 the depths of the sulcus of the corpus callosum (Figs. 174, 175). This is a rudi- 

 mentary portion of the hippocampus and is known as the supracallosal gyrus or 

 indusium griseum. In this gray band there are embedded delicate longitudinal 



