460 THE INTERNAL STRUCTURE 



tiguous Convolutions, the reader will not find it difficult 

 to believe what seems for many reasons probable, that 

 in the white substance of the Hemispheres, the mass of 

 which is so large, fibres of the Crus or from the Central 

 Ganglia on their road to or from the surface must, as 

 Broadbent points out, bear a small proportion to the 

 fibres passing from one part of the surface to another 

 either in the same or in opposite Hemispheres or, to put 

 it in the phraseology of Meynert, the fibres of the ' pro- 

 jection system ' are, in the aggregate, small, when com- 

 pared with those of the ' association system.' 



c. Commissures bringing tlw Cerebellum into relation 

 ivith the Cerebrum. These correspond with what are 

 known as the Upper Cerebellar Peduncles, though it is 

 possible that the Middle Peduncles ought also to be in- 

 cluded under this category. The distribution of these 

 parts will be referred to in the next section. The Lower 

 Peduncles, though they pass through a portion of the 

 Medulla, serve in the main to place the Cerebellum in 

 relation with the Spinal Cord. 



5. The General Structure of the Cerebellum, and its 

 Relations with other parts. 



The Cerebellum or ' Little Brain,' unlike the Cerebrum, 

 is a solid organ whose two halves are continuous with one 

 another. If a horizontal section be made through the 

 middle of the Cerebellum, there will be seen, in its interior, 

 on each side, a plicated bag-like nucleus of Grey Matter, 

 whose open extremity is directed forwards and inwards 

 (fig. 156, 14). 



The different Lobes of which the Cerebellum is composed 

 have been already referred to, as well as the manner in 

 which they are subdivided. But the extent and mode of 



