THE CEREBELLUM LAMINA AND SULCI. 



777 



UPPER SURFACE. On the upper aspect the cerebellum is raised No groove 

 in the centre, and sloped towards the sides (fig. 284). There is sur f ac e; 

 not any median sulcus on this surface ; and the hemispheres are halves 

 united by a median part the superior vermiform process. Separat- J u 

 ing the upper from the under surface, at the circumference, is the 

 horizontal fissure, which extends from the middle, or pontine, Horizontal 

 peduncle in front to the median notch behind. 



The UNDER SURFACE of the cerebellum is convex on each side, A hollow 

 where it is received into the lower fossae of the occipital bone ; and Jjjjj,j 

 the hemispheres are separated by a median hollow vallecula called 

 (fig. 285), which is widest in front where it lodges the upper end valley> 

 of the medulla oblongata ; the hinder end of the vallecula is con- 



Flocculus. 



Flocculus. 



Lobus 

 cacumiuis. 



Back part of the vallecula. 



FIG. 285. THE UNDER SURFACE OP THE CEREBELLUM WITH THE MEDULLA 



REMOVED. 

 The chief sulci are distinguished as in fig. 284. 



foliated. 



tinned into the notch at the posterior border, and receives the falx 

 cerebelli. At the bottom of the groove is an elongated mass named and 

 the inferior vermiform process, which corresponds to the central 

 part uniting the hemispheres above. The two vermiform processes 

 constitute the general commissure of the halves of the cerebellum. 



LAMIN.-E AXD SULCI. The superficial part of the cerebellum is Surface 

 composed of grey substance, and is marked by concentric laminae 

 or folia, which have their free edges towards the surface, and run 

 in a curved direction with the concavity turned forwards. The Between 

 laminae are separated by sulci, which are lined by pia mater, and su i c i. 

 are of variable depth. Only a small number of the laminae appear 

 on the surface, for many others are placed on the sides of the Many folia 

 larger processes, and are concealed within the deeper sulci. The are hl 



