THE CEREBRAL CORTEX 63 



chiefly by the basal or axis cylinder processes of the pyramid cells which sweep downward, 

 forming the mass of parallel fibres which make up the white matter under the cortex. But 

 it is quite evident that interlacing with these fibres, and passing at right angles to them, 

 are many other fibres ; and although the cells from which they arise are not here shown, it 

 can easily be believed that these cells and fibres form a fourth layer. After these plates 

 have been studied, some statements will be made regarding the arrangement of the cells in 

 different layers in the various regions of the brain. 



