CHAP. XXI.] 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 Hirschfeld.) 1, 1, 

 Superior 'vermiform process' (middle lobe) whose anterior extremity has 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, 6, 6, 6, anterior segment, quadrilateral, and composed of 

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

 composed of closely packed 'laminae' 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 Cerebellum (" Bau des kleinen 

 Gehirns)," richly illustrated, has been issued by Stilling. 



