624 THE CEREBELLUM. 



larger fissures, many of the folia are seen to lie concealed within them, and 

 do not reach the surface of the cerebellum. 



Certain fissures, which are deeper than the rest, and constant in their 

 position, have been described as separating the cerebellum into lobes, which 

 are named as follows. 



The central lobe, situated on the upper surface, consists of about eight 

 folia, immediately adjoining the anterior concave border. The superior and 

 anterior lobe, sometimes called quadrate, and the superior and posterior lobe, 

 are placed between the central lobe and the great horizontal fissure. On the 

 under surface are seen successively the inferior posterior lobe, the slender 

 lobe, the biventral lobe, the amygdala, and the subpeduncular lobe or flocculus. 

 This last-named lobule, lobule of the pneumo-gastric nerve (Vicq-d'Azyr), 

 subpeduncular lobe (Gordon), or flocculus, projects behind and below the 

 middle peduncle of the cerebellum. It is connected by a slender pedicle of 

 white fibres to the rest of the hemisphere ; but its exposed surface is grey, 

 and is subdivided into five or six small laminae. 



Fig. 356. 



Fig. 356. INFERIOR SURFACE OP THE CEREBELLUM WITH THE POSTERIOR MEDULLARY 

 VELUM (after Reil and Reichert, and from nature). f 



The medulla oblongata has been in great part removed by a cut passing through it 

 near the pons Varolii ; the two amygdaloid lobules have also been removed, and the 

 medulla and pons Varolii pulled downwards in order to bring into view the posterior 

 medullary velum. 



p s, posterior superior lobe of the cerebellum ; fh, horizontal fissure ; p i, posterior 

 inferior lobe ; g, lobulus gracilis ; b i, biventral lobe ; c, placed on the folia which pass 

 across between the hemispheres of opposite sides ; p, pyramid ; u, uvula ; n, placed in 

 the fourth ventricle immediately below the nodule ; p v, on each side, placed on the cut 

 surface where the amygdalae have been removed, points by a line to the posterior medullary 

 velum ; v, v, cavity of the fourth ventricle within the borders of the velum and behind 

 the inferior cerebellar peduncles; the cavity extends on each side into the pedicle of the 

 flocculus, /; m, section of the medulla oblongata, in which the posterior opening of the 

 olivary capsules of grey matter is shown ; VI, sixth nerves ; V, roots of the fifth nerves, 

 and above them, the facial and auditory roots. 



Within the vallecula, or on its borders, the following parts are seen. 



Commencing from behind, a conical and laminated projection named the 

 pyramid, is first met with. In front of that is another smaller projection, 

 called the uvula, which is placed between the two rounded lobes at the sides of 

 the vallecula, named the amygdala ; these terms having been suggested by 

 a comparison with the parts so named in the throat. Between the uvula 

 and amygdalse on each side, but concealed from view, is extended a ridge 



