190 



PHYSIOLOGY OF CENTRAL NERVOUS SYSTEM. 



interpretations of the sensations of pressure, temperature, and 

 muscular conditions. The part of the cortex, if any, concerned 

 in the primary conscious mediation of the sense of pain has not 

 been definitely localized. 



The Histological Evidence. Course of the "Fillet." On 

 the histological side there is very strong corroborative evidence for 

 the view that the cortical centers for the sensory fibers of the body 



Fissure of Rolando 



Internal or Median fillet" 



3& 



nal CorcL 



Fig. 85. Schema representing the origin and course of the fibers of the median fillet, 

 the intercentral paths of the fibers of body sense. 



in general lie in the parietal lobe in the region indicated above. 

 This evidence is connected with the path taken by the sensory 

 fibers in the cord, especially those of the posterior columns, after 

 ending in the nucleus gracilis and nucleus cuneatus of the medulla. 

 This path is represented in a schematic way in the accompanying 

 diagram (Fig. 85). The second sensory neurons arise in the nuclei 

 mentioned. Some of them pass into the cerebellum by way of the 



