CHAP. XXIII.] 



OT THE HUMAN BRAIN. 



447 



ment of the constituents of these layers, as seen in a 

 section through the 

 ' third frontal ' con- 

 volution (fig. 359). 

 Quite recently, 

 moreover, Bevan 

 Lewis and H. Clarke 

 have described a 

 very similar arrange- 

 ment of nerve ele- 

 ments in the * as- 

 cending frontal' and 

 other adjacent Con- 

 volutions. Their pa- 

 per is accompanied 

 by excellent illus- 

 trations.* 



They give the follow- 

 ing description of the 

 five layers of the 'as- 

 cending frontal' be- 

 ginning with the most 

 superficial. The first 

 is a delicate friable stra- 

 tum containing no real 

 nerve elements. It is 

 made up of the usual 

 network of 'neuroglia' 

 with finely granular 

 matrix, in which are 

 distributed numerous 

 small nuclei and 



FIG. 160. Large Pyramidal Cell, with its processes, from fourth layer of Cortical 

 Grey Matter so-called 'Giant Cell.' (Charcot.) a, Body of the Cell tapering away 

 into a branched pyramidal prolongation ; b, Its basal prolongation which come into 

 relation with (c), the white fibres of the Convolution (highly magnified). 



* Proceed, of Eoyal Society, 1878, p. 38. 



