CH. XLV11I.] 



STRUCTURE OF THE CORTEX 



695 



Histological Structure of the Cerebral Cortex. 



The possibility of differentiating the cerebral cortex in relation 

 to its functions took origin in the work of Bevan Lewis and Henry 

 Clarke in 1878, and the subject has in recent years received attention 



Fin. 432. The layers of the conical grey 

 matter of the cerebrum. (Mey nert. ) 



H 



Fio. 433. Principal types of cells in the 

 cerebral cortex. 



A, medium-sized pyramidal cell of the 

 second layer. 



B, large pyramidal cell. 



C, polymorphic cell. 



D, cell of which the axis- cylinder process is 



ascending. 



E, neuroglia cell. 



F, cell of the first layer, forming an inter- 



mediate cell-station between sensory 

 fibres and motor cells. Notice the 

 tangential direction of the nerve- 

 fibres. 



G, sensory fibre from the white matter. 

 11, white matter. 



1, collateral of the white matter. (Ramon 

 y Cajal.) 



at the hands of A. W. Campbell, Brodmann J. S. Bolton, and others. 

 Certain main features have been established, although unanimity on 

 the interpretation of all the facts has not yet been reached. 



