268 



ANATOMY OF THE CENTRAL NERVOUS SYSTEM. 



matter covering the mesial side of the thalamus. Yet its entire course is not to be 

 seen in this section. 



The fifth section {Fig. 174) is made directly anterior to the ehiasraa. This is 

 not divided, however, but is turned ventrally. The narrow, fissure-like ventricle is- 

 lengthened ventrally to form the infundibulum. In its inferior third it is crossed 

 by the commissura media. The thalami, covered by the stratum zonale and the 

 taenia, project into it, and it is closed above by the columns of the fornix, over which 



Cingulum 



Plexus chor. 

 ventr. lat. 



Nucl. ant. thai 



Nucl. lilt, thai 



Col. forri 



Capsula iiit 



Globus pallidn J, 



Comm. ant 



Subst. gngea cent 



Tract, olfact 



Fasc. arcnat. 

 Gyrus cent. ant. 



Fasc. fronto-oceip. 



rReg. of liypogl OS- 

 sal aiidspeeeh- 

 ( pathway 



asc. uncin. 



liob. olf. post. 



Lob. temporalis 



Fig. 173. 



lies the corpus callosum. The lateral end of each column is directly continuous, as 

 Fig. 173 shows, with the plexus chorioideus of the latlral ventricle. Close by the side 

 of the commissura mollis the descending columns of the fornix are seen, cut trans- 

 versely, in the central gray matter. Traversing the gray matter of the infundib- 

 ulum, they here turn posteriorly and ventrally to the corpus mamillare. 



Of the thalamus there is now visible the nucleus anterior, the nucleus medialis, 

 and the nucleus lateralis — also the latticed layer. From the first there develops the 

 tractus thalamo-mamillaris, the bundle of Vicq d'Azyr. The fibers from which it 



