THE THALAMI OPTICI. 



551 



and rest on the corresponding cerebral crura, which they in a manner 

 embrace. On the outer side each thalamus is bounded by the corpus 

 striatum and tsenia semicircularis. The upper surface, which is white, is 

 free and prominent, and is partly seen in the lateral ventricle, and partly 

 covered by the fornix. The part which is seen in the lateral ventricle is 

 more elevated than the rest, and is named the anterior tubercle. The 

 posterior surface, which is also white and free, projects into the descending 



Fig. 376. 



Fig. 



376. EIGHT HALF OF THE ENCEPHALIC PEDUNCLE AND CEREBELLUM AS 

 FKOJI THE INSIDE IN A MEDIAN SECTION (after Reichert). 



II, right optic nerve ; II', optic commissure divided ; III, right third nerve ; VI, 

 sixth nerve ; V 3, third ventricle ; Th, hack part of the thalamus options ; H, section of 

 the pituitary body ; A. corpus albicans ; P, pineal gland ; c a, points by a lower line to 

 the anterior commissure divided, and by an upper line to the divided anterior pillar of 

 the fornix ; Ic, lamina cinerea ; i, infundibulum (cavity); tc, tuber cinereum ; /, mark 

 of the anterior pillar of the fornix descending in the wall of the third ventricle ; c m, 

 commissnra mollis ; sp, stria pinealis ; cp, posterior commissure, above it the peduncle 

 of the pineal gland, and below it the upper end of the passage to the fourth ventricle ; 

 Q, corpora quadrigemina (section); as, aqueduct of Sylvius near the fourth ventricle ; 

 P V, pons Varolii divided in the middle ; M, medulla oblongata ; p a, right anterior 

 pyramid; pel, decussating bands cut across ; pp, posterior pyramids; c, central canal 

 with grey substance surrounding it divided. In the cerebellum, av, stem of white sub- 

 stance in the centre of the middle lobe of the cerebellum, ramifying towards the arbor 

 vitaa ; s v, superior vermiform process or vertical portion of the middle lobe ; s c, single 

 folium, which passes across between the posterior superior lobes; c', the folia, which 

 unite the posterior inferior lobes ; p, pyramid ; u, uvula ; n, nodule ; 1, part of the 

 laminae of the square lobe ; 2, posterior superior lobe ; 3, posterior inferior lobe ; 4, lob ul us 

 gracilis ; 5, bi ventral lobe ; 6, amygdaloid lobe. 



cornu of the lateral ventricle. The inner sides of the two thalami are in 

 contact one with the other. They present the grey substance of the inte- 

 rior of the thalami uncovered with white, and are generally partially united 

 together by a transverse portion, which forms the middle or soft commissure 

 of the third ventricle. 



