I092 



HUMAN ANATOMY. 



several richly branched dendrites pass in various directions, but largely into the 

 molecular layer. The axone is most distinctive, as very soon after leaving the cell it 

 splits up into an arborization of unusual extent and complexity, which, however, is 

 confined to the granular layer. These cells, therefore, belong to those of type II 

 (page 998). Since by their processes they are brought into intimate relation with 

 a number of other neurones, the elements under consideration are probably of the 

 nature of association cells. 



The nerve-fibres encountered within the cerebellar cortex (Fig. 945) comprise 

 three chief varieties, (i) The lirst of these includes the axones of the cells of Purkinje 

 which contribute an inconsiderable portion of the fibres passing from the cerebellar 

 cortex to other parts, either of the cerebellum itself or of the cerebrum and brain-stem. 

 (2) The moss-fibres destined especially for the granular layer, which upon enter- 



FiG. 945. 



Molecular layer 



Granule layer 



White matter 



Moss-fibres 



Axones of Purkinje cells 



Climbing fibres 



Diagrammatic reconstruction of part of fclimn, illustrating relations of nerve-cells and fibres of cerebellar cor- 

 tex ; folium is shown cut transverseh- and longiludmally ; a, Purkinje cells ; d, granule cells; c, small cortical cells; 

 d, basket cells ; e, large stellate cells. 



ing the latter break up into a number of branches, that bear, either at the points of 

 division or at their ends, thickenings from which bundles of short diverging twigs are 

 given of?. By this arrangement each moss-fibre ends in relation with a large number 

 of granule cells. (3) The climbing-fibres, so named (Cajal) on account of their 

 tortuous and vine-like course, ascend through the granular to the molecular layer, 

 to which they are chiefly if not e.xclusively distributed, where they entwine and 

 cling to the primary and secondary dendritic processes of the Purkinje cells. 

 Additional fibres encountered within the granule layer are, evidently, the axones of 

 the granule cells and the collaterals of the cells of Purkinje, whilst a large propor- 

 tion of the fibres within the molecular layer are formed by the ramifications of the 

 axones of the granule cells and of the basket cells. 



The neuroglia forms a supporting framework of considerable density both 

 within the white matter and the cortex. As seen in preparations colored with the 

 usual nuclear stains, the neurogliar elements are conspicuous within the granule 

 layer, to whose numerous small nuclei they contribute no small part. The cells 

 occupying the outer zone of the granule layer exhibit a peculiar arrangement of their 

 processes that in a measure recalls the disposition of those of the Purkinje cells. In 



