STRUCTURE OF THE CORPUS STRIATUM. 



255 



FIG. 28(>. -SECTION ACROSS THE OPTIC THALAMUS AND CORPUS STRIATUM IN THE 



REGION OF THE MIDDLE COMMISSURE. (Natural size. ) 



dh., thalmus ; a, e, i, its anterior, external, and internal nuclei respectively ; w, its external 

 white layer ; m.c., middle commissure ; v. 3, third ventricle ; a small part is also seen 

 below the middle commissure; c.c., corpus callosum ; /, fornix, separated from the 

 third ventricle and thalamus by the velum interpositum. In the middle of this are 

 seen the two veins of Galen and the choroid plexuses of the third ventricle ; and at its 

 edges the choroid plexuses of the lateral ventricles, v.l. ; t.s., stria pinealis ; cr., 

 forward prolongation of the crusta passing laterally into the internal capsule, i.e. ; 

 s.t.r., subthalamic prolongation of the tegmentum, consisting of (1) the dorsal layer, 

 (2) the zona incerta, and (3) the corpus subthalamicum ; s.n., substantia nigra ; n.c., 

 nucleus caudatu s of the corpus striatum ; n.I.., nucleus lenticularis ; e.c., external cap- 

 sule ; cl., claustrum ; 7, island of Reil; h, hippocampus; d, fascia dentata. 



FIG. 287. HORIZONTAL 

 SECTION THROUGH THE 

 OPTIC THALAMUS AND 

 CORPUS STRIATUM. (Na- 

 tural size. ) 



;\ I. , lateral ventricle, anterior 

 cornu ; e.c., corpus callo- 

 sum; s.l., septum luci- 

 dum ; a.f. , anterior pillars 

 of the fornix ; v. 3, third 

 ventricle; th., thalamus 

 opticus ; s. t. , stria pine- 

 alis ; n.c. ,iiucleus caudatus, 

 and n.I., nucleus lenticul- 

 aris of the corpus stria- 

 tum ; i.e., internal capsule ; 

 g., its angle or genu ; n.c., 

 tail of the nucleus caudatus 

 appearing in the descend- 

 ing cornu of the lateral 

 ventricle ; cl, claustrum ; 

 /, island of Reil. 



