548 



THE CEREBRUM. 



middle of the white substance of the hemisphere of the brain, whilst a 

 part comes to the surface in the body and anterior coruu of the lateral 

 ventricle. This ■intraventricular portion of the corpus striatum (nuchiis 

 caiidatus) is of a pyriform shape, its larger end being turned forwards, 

 and its narrow end being directed outwards and backwards, so that the 

 optic thalami of the two sides are received between the diverging corpora 

 striata. On cutting into it, there may be seen at some depth from the 

 surface white tibres, which are prolonged from the corresponding cere- 

 bral peduncle, and give it the streaked appearance from which it has 

 received its name. 



The extraventricular portion of the corpora striata, nuclear hniiculans, 

 is separated from the intraventricular part by a layer of white substance. 



Fig. 38-1. 



Fig. 384. — Right Half of the Encephalic Peduncle and Cerebellum as seen fkom 

 THE INSIDE OF A MEDIAN SECTION (Allen Tlioiuson after Reicliert). 



n, right optic nerve ; II' optic commissure divided ; III, right tliird nerve ; VI, 

 sixth nerve ; V 3, third ventricle ; Th, back part of the thalamus opticus ; 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 ; I c, lamina cinerea ; i, infundibulum (cavity) ; t c, tuber cinereum ; /, mark 

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

 commissure mollis; s p, sti'ia pinealis or peduncle of pineal gland ; c_p, posterior com- 

 missure, above it the peduncle of the pineal gland, and below it the upper end of the 

 pa-.sage to the fourth ventricle ; Q, corpora quadrigemina (section) ; a s, aciueduct of 

 Sylvius near the fourth ventricle ; P V, pons Varolii divided in the middle ; M, medulla 

 oblongata ; p a, right anterior pyi-amid ; p d, decussating bands cut across ; p p, posterior- 

 pyramids ; c, central canal, divided, with grey substance surrounding it. In the cerebel- 

 lum, a V, stem of white substance in the centre of the middle lobe of the cerebellum, 

 ramifying towards the arbor vit;e ; s 2', 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 lamimB of the square lobe ; 2, posterior sui)erior lobe ; 3, pos- 

 terior inferior lobe ; 4, lobulus gracilis ; f>, biventral lobe ; G, amygdaloid lobe. 



