330 



PLATE XX. 

 FIGURE 1. 



Type of fibre arrangement in the parietal area. 



Drawn from a sagittal section through the superior parietal gyrus 4 cm. behind Rolando and 

 2 cm. from margin of hemisphere. 



Z = zonal layer. S = supraradiary layer. B = line of Baillarger. R = radiary zone. B 2 = redupli- 

 cated line of Baillarger. 



Compared with the postcentral arrangement, Plate V., there is an evident poverty of fibres, 

 especially in the radiary zone. 



The reduplication of the line of Baillarger runs in association with the well-marked inner 

 layer of large pyramidal cells. The same line is probably present in the postcentral cortex but 

 is obscured by the surrounding wealth of fibres. 



The numbers refer to cell-laminae. : ?--. 



FIGURE 2. 



Parietal type of cell-lamination. Drawing taken from a section of the precuneus 2 cm. 

 behind the upturned tail of the calloso-marginal fissure. 



Compared with the postcentral types, Plate VI., a difference is not observed until the fourth 

 layer is reached. Here the large external pyramidal cells do not form such a marked lamina, 

 because the individual members are smaller, paler and separated by wider intervals. The layer 

 of stellate cells continues well developed. 



Considerably fewer large cells are seen at 6 and those present have also suffered in relation 

 to size. 



Low power drawing, x -"j - ; high power, x f^.. 



