332 



PLATE XXI. 



FIGURE 1. 



Type of fibre arrangement in the intermediate precentral area. From a section through the 

 superior frontal gyrus, 4 cm. anterior to the fissure of Rolando. Compare with Plate III., figure 1. 



Z = zonal layer ; much less distinct. S = supraradiary layer. B = position of line of Baillarger. 

 R = radiary zone. The arrangement resembles that of the precentral area but the fibre wealth 

 is obviously less. 



The right-hand figures and brackets refer to, and indicate the position of, the various cell- 



FlGURE '2. 



Type of cell-lamination in the intermediate precentral area. From a section showing the cortex 

 of the base or posterior end of the middle frontal gyrus. 



Layers 1, 2 and 3 call for no special comment. The external layer of large pyramidal cells 

 (4) is remarkably well-developed and quite equal to what was seen in the precentral or motor 

 area. As in the precentral area the stellate cells (5) do not form a distinct lamina. At 6 a 

 considerable number of cells can be seen equal in size to those at 4, but there is an entire 

 absence of "giant" cells. The fusiform layer (7) is uninteresting. 



Low power drawing, x -^ ; high power, x --. 



