640 



STRUCTURE OF THE CEREBELLUM. [CH. XLV. 



Underneath the pia mater is the external layer of grey matter ; 

 it is formed chiefly of fine nerve-fibres with small nerve-cells 



p m 





iZc>* OrSVO.^oVo O^rfi & >> 



W w ,iV^'-v wW'rt-rK /;*-;. 'O o w *>v>-'v r\ 



' & 8?^ *fiS o^>^ ^<,%% 



* 





Fig. 474. Vertical section of dog's cerebellum; p TO, pia mater; p, cells of Purkinje, 

 which are branched nerve-cells lying in a single layer and sending single processes 

 downwards and more numerous ones upwards, which branch continuously and extend 

 through the external " molecular layer" towards the free surface ; g, dense (granular) 

 layer of small nerve-cells ; /, layer of nerve-fibres, with a few scattered nerve-cells. 

 This last layer (//) constitutes part of the white matter of the cerebellum, while the 

 layers between it and the free surface are grey matter. (Klein and Noble Smith.) 



scattered through it. Into its outer part, processes of pia mater 

 pass vertically ; these convey blood-vessels. There are also here 

 numerous long tapering neuroglia-cells. The internal or granular 



