THE CEREBELLAR CORTEX 37 



THE MOLECULAR LAYER OF THE CEREBELLUM 



The cells of the molecular layer of the cerebellum are of two varieties. First, the small 

 stellate cells (S)\ secondly, the cells with fibres which enter into the basket-like formation 

 about the Purkinje cell (B) (Korbzellen). 



Plate XVII. shows the small stellate cells of the molecular layer. They have irregular 

 polygonal bodies with three, four, or more dendrites, and an axis cylinder. The size of these 

 cells is only 10 to 15/u,. The long axis of the body is horizontal in the deeper portion of 

 the molecular layer, but may be directed in any direction in the more superficial part. The 

 dendrites are comparatively short. They divide and subdivide, the majority taking a horizontal 

 direction. The neuraxon is long and gives off numerous collaterals. It appears to pass ver- 

 tically in the molecular layer only, not entering the granular layer. Its final destination is 

 uncertain. It is impossible to distinguish between the dendrites and the neuraxon in the plate, 

 but a higher magnifying power shows that the longest of the fibres is the neuraxon. Some 

 of the collaterals of the neuraxon can be traced. They usually take a horizontal course after 

 leaving the neuraxon. There are numerous horizontal and vertical fibres shown whose cells 

 are not visible. These together make up a complex interlacing mass of fibres in this molec- 

 ular layer. 



The second variety of cells in the molecular layer is the cell with basket expansion (It). 

 These lie chiefly in the deeper part of the layer. They are small cells, polygonal in shape, 

 which give off numerous dendrites and a long neuraxon. This differs from the neuraxon 

 of other cells in being thick and irregular in size. From it there arise numerous collaterals, 

 which take a downward course and end in brush-like expansions, which appear to surround 

 the body of a Purkinje cell. The name " basket cell " is given to these cells because the 

 ends of their collaterals appear to enclose the body of the Purkinje cell as in a basket. It 

 would be erroneous to suppose that the fibres intertwine as do the straws of a basket. The 

 size of these cells is about 20 /u,. A doubt has arisen that the basket fibres are true neu- 

 raxons; in fact, some authorities have supposed the basket to be a glia structure. Cajal, Golgi, 

 Van Gehuchten, and Kolliker, 1 however, agree with the view that the baskets are made up 

 of fine nerve fibres. 



1 Kolliker, Handbuch d. Gewebelehre des Menschen, 6te Aufl., 1893. II. Bd., iste Halfte. 



