CHAP. V] 



rfstto-Sennort/ Arrangement of Nerve Fibres 



113 



Supraradiary Layer. 



The supraradiary layer is m-ciipied by a comparatively dense plexus of fibres most of 

 which are of delicate calibre, but, heiv and there, fibres of Martinotti of coarser type are seen 

 running up to end in the zonal layer. It is also to be observed that this is one of the 

 regions in which the fibres composing the radiary fasciculi pierce the line of Baillarger 

 (Gennari) and project well into the supraradiary layer; in some measure this accounts 

 for the fact that the plexus in the upper half of the layer is much sparser than it is in 

 the lower. 



The Line of Gennari. 



This line is composed of an extremely dense network of fibres of fine calibre, interlacing 

 and intertwining in all directions, mingled with which are a few long, horizontal, or oblique 

 fibres of medium calibre. In the same network, especially in the lower part, spaces are left 

 which correspond in size with the small stellate cells seen at this level, for the accommodation 

 of which the lacunae are evidently intended. 



FIG. 10. Kacliary zone in the calcarine or Yisuo-sensory area, x 4JJ>. 



The drawing has been made from a part deep down, next the white substance, in order to bring in some of the large 

 obliquely or transversely directed fibres to which special reference is made in the text. These are probably the 

 optic fibres of Ramon y Cajal. It will be noticed that for cortex having such important functional attributes the 

 radiations are not strong, and the interradiary plexus not particularly rich. 



c. 15 



