296 



PLATE III. 



FIGURE 1. 



Type of fibre arrangement in the precentral or motor area. Drawn from a section through 

 the precentral or ascending frontal gyms, at a point 15 nun. from the upper border of the hemisphere. 



Z, zonal layer, dense and well-detined. 8, supraradiary layer. B, position of line of Baillarger, 

 its position obscured by surrounding fibre wealth R, radiary zone. Note the general superiority 

 in fibre representation in comparison with the cortex in any other area. The numbers refer to 



FIGURE 2. 



Type of cell lamination in the precentral area ; drawing taken from a section passing through 

 the paracentral lobule. 



The plexiform layer (1) is slightly deeper than it is in most other parts of the cortex. The 

 layers of small and medium-sized pyramidal cells (2 and 3) exhibit nothing remarkable. The number 

 and shape of the large external pyramidal cells (4) are worth nothing. There is an exceedingly 

 indistinct lamina of stellate cells (5), but it may be seen that elements pertaining to this category 

 encroach upon the layers above and below. The poor development of this lamina and the enormous 

 cells of Betz (6) are the most important cytological guides to the differentiation of this area. 

 The layer of fusiform cells (7) shows nothing of special interest. Low power, x $; high power, x i|^. 



