468 | THE NERVOUS SYSTEM. 
or notch. The posterior notch (incisura cerebelli posterior) is smaller and narrower 
than the anterior notch. It is bounded laterally by the lateral hemispheres, whilst 
its bottom is formed by the median lobe or vermis. It is occupied by a fold of 
dura mater, called the falx cerebelli. The anterior notch (incisura cerebelli anterior) 
is wide and shallow, and, when viewed from above, it is seen to be occupied by the 
Pons Varolii 
Mesencephalon 
Anterior crescentic lobule 
Posterior cres- 
Central lobule centie lobule 
Culmen 
monticuli 
Postero- 
superior lobule 
Clivus 
monticuli 
Folium eacuminis : F 
Postero-interior lobule 
Tuber valvule Posterior notch 
Fia. 348.—UPprer SURFACE OF THE CEREBELLUM. 
inferior quadrigeminal bodies and by the superior peduncles of the cerebellum. 
As in the case of the hinder notch, its sides are formed by the lateral hemispheres 
and the bottom by the vermis. 
On the superior surface of the cerebellum there is little distinction to be noted 
between the median lobe and the upper surface of each lateral hemisphere. On 
this aspect the median lobe receives the name of superior vermis, and it forms a 
high median elevation, from which the surface slopes gradually downwards on each 
side to the margin of the hemisphere. The superior vermis is highest in front, 
immediately behind the anterior notch, and from this it inclines downwards towards 
the posterior notch. This elevation of the superior worm is frequently called the 
monticulus cerebelli. The folia on the surface of the superior vermis are thicker 
and fewer in number than those on the upper surface of the lateral hemisphere. 
It is this which gives it the worm-like appearance from which it derives its 
name. 
On the inferior surface of the cerebellum the distinction between the three 
constituent parts of the organ is much better marked (Fig. 349). On this aspect 
the lateral hemispheres are full, prominent, and convex, and are separated by a 
deep mesial hollow, which is continued forwards from the posterior notch. This 
hollow is termed the vallecula cerebelli, and in its fore-part is lodged the medulla 
oblongata. When the medulla is raised and the lateral hemispheres are pulled 
apart, so as to expose the bottom of the vallecula, it will be seen that this is 
formed by the vermis inferior, and, further, that the latter is separated on each 
side from the corresponding lateral hemisphere by a distinct furrow, termed the 
sulcus vallecule. 
Sulci Cerebellii—Certain of the fissures which traverse the surface of the 
cerebellum are deeper and longer than the others, and they map out districts which 
are termed lobes. The most conspicuous of all these clefts is the great horizontal 
fissure. ' 
The great horizontal fissure (sulcus horizontalis cerebelli) of the cerebellum 
begins in front and passes continuously round the circumference of the organ, 
cutting deeply into its outer and posterior margin. In front, its lips diverge to 
enclose the three cerebellar peduncles as they pass into the interior of the 
cerebellum. The great horizontal fissure divides the organ into an upper and a 
lower part, which may be studied separately. 
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