THE PONS AKD THE CEREBELLUM. 



317 



Upon the dorsal aspect of the hemispheres may be differentiated: — 



1. Lohus quadrangularis or anterior upper lobe on either side of the 

 monticulus. 



2. Lohus semilunaris superior or posterior upper lobe. The two pos- 

 terior upper lobes are connected by the folium cacuniinis. 



The lobes of the under surface of the cerebellum are shown in the next 

 figure (304). It presents a rather complicated picture. In order to prepare 

 specimens for this view the cerebellum must be severed from its connection 

 with the midbrain, — i.e., the anterior cerebellar peduncles must be severed, 

 — then from its connections with the pons and with the medulla and cord. 

 Thus on each side there are the three cross-sections of the cerebellar 

 peduncles. Between the anterior cerebellar peduncles lies a thin membrane, 



Fig. 204. — The cerebellum. (Ventral aspect.] 



the velum medullare anticum, which is a part of the roof of the meten- 

 cephalon. The cut surface of it is to be seen in the figure. 



The lobes on the ventral surface of the vermis are called; — 



1. Nodulus. 



2. Uvula. 



3. Pyramis. 



4. Tuier valvules, making the boundary between the ventral and dorsal 

 surface of the vermis (see Fig. 203). 



The lobes on the ventral surface of the hemispheres are: — 



1. Flocculus, on each side of the nodulus and moored by the slender 

 pedunculus flocculi. 



2. Tonsilla, on either side of the uvula. 



