CEREBELLUM. 295 



(b) The large granular cells are large rnultipolar celU whose 

 dendrites and axones run in quite the opposite direction to that 

 taken by the processes of the small granular cells. The axone 

 extends in the granular layer toward the medullary substance, 

 giving off numerous collaterals which end around the small 

 granular cells. The dendrites run, on the contrary, into 

 the molecular layer (Figs. 220 and 221). 



In the granular layer we find between the cells described 

 a network of medulated fibres which pass through the layer, 

 partly from the white substance outward, and partly from the 

 cells of the ganglionic layer to the medulla. 



2. The middle or ganglionic layer is made up of the so- 

 called cells of Purkinje. These are arranged in a single layer. 

 Each cell consists of a large pyriform cell body giving off one 

 or two dendrites in the direction of the molecular layer. These 

 dendrites break up into numerous branches which reach almost 

 to the surface of the cortex. They resemble a very richly 

 branched tree, whose branches spread out in a single plane at 

 right angles to the long axis of the cerebellar convolutions. 

 Thus in a cross-section of the convolution the whole extent of 

 the arborization may be seen, while in a longitudinal section 

 this is not the case (cf. Figs. 221 and 222). The profuse 

 branching and general relations of these cells can be made out 

 especially well in Golgi preparations. 



The axone which emerges from the opposite side of the cell 

 runs in the medullary substance, and sends out collaterals in 

 its course through the granular layers, which branch and run 

 back in part to the molecular layer (Fig. 221). 



3. The outermost, so-called molecular layer, shows two kinds 

 of nerve cells: large cells lying in the deeper layers, and small 

 cells more superficially situated. The former are multipolar 

 cells with many dendrites directed mainly toward the periphery, 

 and an axone running transversely to the long axis of the con- 

 volution. The axone lies parallel to the border between the 

 granular and the molecular layers, and gives off at intervals 

 many branches which surround the bodies of the Purkinje 

 cells in a sort of basket-work. One axone thus joins together 



