THE CEREBRAL CORTEX 



657 



CFT. XLVL] 



from three up to nine. The most satisfactory division appears to 

 mo to be that into three. 



1. The molecular layer. Most superficially is a thin stratum of 



FIG. 478. The layers of the cortical grey 

 matter of the cerebrum. (Meynert.) 



FIG. 479. Principal types of cells in the 

 cerebral cortex. 



A, medium-sized pyramidal cell of the 

 second layer. 



B, large pyramidal cell. 



C, polymorphous cell. 



D, cell of which the axis-cylinder process is 



ascending. 



E, neuroglia cell. 



F, cell of the first, or molecular, layer, 



forming an intermediate cell-station 

 between sensory fibres and motor cells. 

 Notice the tangential direction of the 

 nerve-fibres. 



G, sensory fibre from the white matter. 

 H, white matter. 



I, collateral of the white matter. (Ramon 

 y Cajal.) 



medullated nerve-fibres largely derived from the dendrons of the 

 cells of the next layer. The nerve-cells (F in fig. 479) intermingled 

 with these are branched, and have several processes which lie 

 horizontally beneath the surface (tangential fibres). Neuroglia cells 

 are also present. 



2 T 



