CEREBELLUM 



487 



with the posterior crescentic lobule of the hemisphere, and the three parts 

 are included under the one name of lobus declivis. 



The two crescentic lobules on the upper surface of the hemisphere are 

 frequently described together as the quadrate lobule. 



Lobus Semilunaris Superior (O.T. Lobus Cacuminis). The folium 

 vermis forms the most posterior part of the superior portion of the 

 vermis, and it bounds the horizontal fissure, superiorly, at the posterior 

 notch. It is a single folium, the surface of which may be smooth 

 or notched with rudimentary secondary folia, and it is the connecting 

 link between the two superior semilunar lobules of the hemispheres 

 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 is that the lobus semilunaris 

 superior, on each side, forms an extensive foliated district bounding the 

 posterior part of the horizontal sulcus superiorly. 



Lobes on the Lower Surface of the Cerebellum. The connection 

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



Culmen Central lobule 



Declive 



Tuber vermis 



Py 



Lingula on the 

 anterior medul- 

 lary velum 



Nodule 



FIG. 198. Median section through the Vermis of the Cerebellum. 

 (From Gegenbaur. ) 



corresponding districts on the inferior 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. 



The following subdivisions of the inferior part of the vermis are 

 recognised, from behind forwards (i) the tuber vermis, (2) the pyramid, 

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



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

 out by intervening sulci. They are (i) \hzflocculus, a little lobule lying 

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

 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 

 horizontal sulcus inferiorly. 



The lobules of the inferior parts of the hemispheres, with the corre- 

 sponding portions of the inferior part of the vermis, constitute the lobes 

 on the inferior aspect of the cerebellum. 



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

 of each side, with an exceedingly delicate connecting lamina of white 

 matter, termed the posterior medullary velum. 



