CEREBELLUM 533 



the three parts constituting the lobus semilunaris superior. As the folium 

 vermis is "traced laterally into the semilunar lobule of the hemisphere, 

 it is found to expand greatly. The result of this is that the lobus 

 semilunaris superior on each side forms an extensive foliated district 

 bounding the posterior part of the great horizontal sulcus superiorly. 



Lobes on the under surface of the Cerebellum. The connection 

 between the several portions of the inferior part of the vermis, and the 

 corresponding districts on the under surface of the two hemispheres is not 

 nearly so distinct as in the case of the superior part of the vermis and the 

 lobules on the upper surface of the hemispheres. 



Proceeding postero-anteriorly the following subdivisions of the inferior 

 part of the vermis are recognised (i) the tuber vermis, (2) the pyramid, 

 (3) the uvula, and (4) the nodule. 



On the under surface of the hemisphere there are five lobules mapped 

 out by intervening sulci. These are (i) && flocculus'^ a little lobule lying 

 on the brachium pontis ; (2) the biventral lobule ', which lies immediately 



Culmen Central lobule 



Declive 



Tuber vermis 



FIG. 225. Median section through the Vermis of the Cerebellum. 

 (From Gegenbaur. ) 



posterior to the flocculus, and is partially divided into two parts by a fissure 

 which traverses its surface ; (3) the tonsil, a rounded lobule, which bounds 

 the vallecula on the medial side of the biventral lobule ; (4) the inferior 

 semilunar lobule, placed posterior to the biventral lobule, and bounding the 

 great horizontal sulcus inferiorly. 



These lobules of the hemispheres, with the corresponding portions of 

 the inferior part of the vermis, constitute the lobes on the under aspect of 

 the cerebellum. 



Lobus Noduli. The lobus noduli comprises the nodule and the flocculus 

 of either side with an exceedingly delicate connecting lamina of white 

 matter, termed the posterior medullary vehim. 



The velum cannot be properly seen at present, but it will be exposed at 

 a later stage of the dissection. 



Lobus Uvulae. The uvula is a triangular elevation placed between the 

 two tonsils. It is connected across the sulcus valleculce with each tonsil 

 by a low-lying ridge of grey matter which is scored by a few shallow 

 furrows, and in consequence termed the furrowed band. The two tonsils 

 and the uvula form the lobus uviilce. 



To see the furrowed band it will be necessary to remove the tonsil on 

 one side, when the posterior medullary velum also will be exposed. 



