Chap. XX[.] 



OF /THE HUMAN BRAIN. 



405 



been otherwise, the altogether subordinate importance 

 of this organ in regard to Mind would quite justify us in 

 dealing much more briefly with its external anatomy.* 



The whole external surface of the Cerebellum is scored 

 by a very large number of ' fissures/ some of which are 



Fig. 149.— Upper Surface of the Cerebellum. (Sappey, after HirscMeld.) 1, 1, 

 Fuperior ' vermiform process ' (middle lobe) wliose anterior extremity bas been pushed 

 backwards in order to show the Corpora Quadrigemina ; 2, posterior extremity of 

 the superior and inferior ' vermiform processes,' and of the median fissure of the 

 Cerebellum ; 3, great circumferential fissure ; 4, great fissure of the upper surface 

 which divides it into two principal segments ; 5, posterior of these segments in the 

 form of a crescent ; 6, 6, G, 6, 6, anterior segment, quadrilateral, and composed of 

 five secondary curved segments like the preceding — each of these segments being 

 composed of closely packed 'laminai' of different sizes, separated by fissures of 

 varying depths ; 7, 7, sections of the Cerebral Peduncles; 8, ' posterior commissure' 

 of the Cerebrum ; 9, Corpora Quadrigemina. 



much deeper than others. These deeper fissures are 

 comparatively few in number, and they constitute the 

 boundaries of the several ' lobes ' and ' lobules ' of this 

 organ. Between them are others more or less concentri- 

 cally arranged, which vary much in length and depth. 



* A very elaborate work on the CerebeUum ('" Ban cles kleinen 

 Gehirus)," richly illustrated, has been issued by StilHng. 



