452 



PHYSIOLOGY 



of Purkinje's cells, apparently resting against the serrations on the 

 edges of these processes. The second kind of cell in the granular 

 layer is the so-called Golgi's cell a large cell with many dendrites 

 and an axon which terminates by frequent branches in the neigh- 

 bouring grey matter. 



The fibres making up the white matter are of three kinds two 

 afferent and one efferent. The moss fibres, so called from the curious 

 thickenings they present in the nuclear layer, pass up into the grey 



Molecular < 

 layer. 



Cells of / 

 Purkinje. I 



Nuclear , 

 layer. 



Central 



white 



matter. 



* ". 



FIG. 20lA. Schema of constituent elements'of cerebellum. (Modified from BOHM 

 and DAVIDOFF.) On the left is a section of the cortex as it appears when 

 stained by ordinary methods. The middle portion represents diagram- 

 matically a section at right angles to the laminae, while to the right of the 

 dotted line the section is taken in the same plane as the laminae. 



a, star-shaped cells of molecular layer ; &, 6, cells of Purkinje ; c, ' Golgi 

 cell ' ; d, small cells of nuclear layer ; e, ' tendril fibre ' ; /, ' moss fibre ' ; 

 g, axon of cell of Purkinje. 



matter and terminate by frequent branches in this layer. The 

 tendril fibres, also afferent, end in a rich arborisation which surrounds 

 the distal part of the bodies and the bases of the dendrites of the cells 

 of Purkinje. The efferent fibres are represented by the axons of the 

 cells of Purkinje, which acquire a medullary sheath and run down 

 into the white matter. 



This slight sketch of the anatomy gives us a conception of the 

 extreme complexity of choice presented to nervous impulses traversing 

 the cerebellar cortex. Thus a discharge along an axon of the cell 

 of Purkinje may be excited (1) by an impulse ascending the tendril 



