io88 HUMAN ANATOMY. 



In recapitulation, the foregoing cerebellar lobes, with their component worm-segments and 

 associated hemisphere-tracts, and the intervening fissures may be followed in order, from the 

 anterior and superior end of the worm to its front and lower pole. Although not agreeing 

 with a morphological division, such grouping ' is convenient as applied to the adult human 

 cerebellum. 



THE LOBES OF THE CEREBELLUM. 



WORM HEMISPHERE LOBE 



Lingula (Vinculum lingulae) Lobus lingulae 



Sulcus precentralis 

 Lobulus centralis Ala lobuli centralis Lobus ccntralis 



- Sulcus postcentralis - 



Culmen monticuli Lobulus lunatus anterior Lobus culminis 



- Sulcus preclivalis 

 Clivus monticuli Lobulus lunatus posterior Lobus clivi 



Sulcus postclivalis 

 Folium cacuminis Lobulus postero-superior Lobus cacuminis 



Sulcus horizontalis 



Tuber vermis Lobulus postero-inferior Lobus tuberis 



Sulcus postpyramidalis 

 Pyramis Lobulus biventer Lobus pyramidis 



Sulcus prepyramidalis 

 Uvula Tonsilla Lobus uvulae 



- Sulcus postnodularis - 



Nodulus Flocculus Lobus noduli 



Architecture of the Cerebellum. With the exception of where the robust 

 peduncular collections of nerve-fibres' enter the hemispheres and immediately above 

 the dorsal recess of the fourth ventricle, the cerebellum is everywhere covered by a 

 continuous superficial sheet of cortical gray matter which follows and encloses the sub- 

 divisions of the white core. The latter, as exposed in sagittal sections of the hemi- 

 sphere, is seen to be a compact central mass of white matter, from which stout stems 

 radiate into the various lobules. From these, the primary stems, secondary branches 

 penetrate the subdivisions of the lobules, and from the sides of these, in turn, smaller 

 tracts of white matter, the tertiary branches, enter the individual folia. Over these 

 ramifications of the white core, the cortical gray matter stretches as a fairly uniform 

 layer, about 1.5 mm. thick, that follows the complexity of the folia and fissures. 

 The resulting arborization and the contrast between the white and gray matter are 

 particularly well shown in sections passing at right angles to the general direction of 

 the folia. This disposition is especially evident in median sagittal sections (Fig. 938), 

 where the less bulky medullary substance of the worm, also known as the corpus 

 trapezoideum, and its radiating branches produce a striking picture, to which the 

 name, arbor vita 1 cerebelli, is applied. 



The Internal Nuclei. In addition to and unconnected with the cortical 

 layer, four paired masses of gray matter, the internal nuclei one of considerable 

 size and three small lie embedded within the white matter. 



The dentate nucleus (nucleus dentatusX or corpus dentation, the largest and 

 most important of the internal nuclei, consists of a plicated sac of j^ray matter 

 (Fig. 951) and resembles in many respects the inferior olivary nucleus. Like the 

 latter, it is a crumpled thin lamina of gray matter which is folded on itself into a 

 pouch, enclosing white matter, through whose medially directed mouth, termed the 

 hilitm, emerge many fibre-constituents of the superior cerebellar peduncle. The 

 dentate nucleus never encroaches upon the core of the worm, but lies embedded 

 within the anterior part of the median half of the hemisphere, with its long axis 



'Modified from Schafer and Thane in Quain's Anatomy, Tenth Edition. 



