108 



Cerebrum. 



VZ. N. FACIAL. 



VI. N. ABDUC.- 



Pyramis- 



r. N. HYPOGLOSS: 



Corp. genie, 

 poster. 



BracJi. anter. 

 Brack, poster: 



Corpiis 

 guadrigem. 



Lemniscus 



Proc. cerebelli 

 d corp. quadrig. 



FunicuL 

 gracil. 



X. N. VAC 



XL. N. ACCESSOR/ 



449. Lateral View of the Pons- Varolii and the 

 Medulla Oblonyata. Natural size. 



The Corpora guadrigemina are situated immediately behind the third 

 ventricle and posterior commissure; they are two pairs of rounded emi- 

 nences, the anterior, larger, being called the nates, the posterior, smaller, 

 the testes. 



Laterally the eminences are prolonged into prominent white tracts, 

 the Braclua carports quadrigemini, of which the Braclua anteriora on both 

 sides are connected with the Corpus ymiculatum anticiun, and enter the optic 

 thalami, and the Braclua posteriora with the Corpus ymiculatum posticum, 

 and partly reach the optic thalami, partly the tegmentum. 



The pineal gland, Glandula pimalis s. Penis cercbri s. Conarium, 

 consisting mostly of grey matter, lies upon the anterior eminences of the 

 Corpus quadriyeminum, the nates; it sometimes contains the Ventriculus 

 conarii. The peduncles, Pedunculi conarii, arise from the anterior extremity 

 of the pineal gland ; they pass forwards and downwards upon the inner 

 margin of the optic thalami, to the anterior pillars of the fornix, as Taeniae 

 meditllares (see Fig. 448). 



Above the Corpora quadrtgemina is the Splwiium coiporis callosi 

 (see Fig. 447), and between the two, the transverse fissure of the 

 cerebrum ; through this fissure the pia mater passes inwards into the 

 third ventricle, as Tcla choroldea media; the fissure is prolonged along 

 the Pes hippocampi major (Cornu ammonis) to the base of the lower cornu 

 and contains a continuation of the pia mater to the Plexus choroideus lateralls. 



