PROJECTION FIBERS. 233 



lidus to the upper third of the central gyri, chiefly to the anterior 

 central. Origin is in doubt. 



/3. A large bundle from the posterior inferior part of the lateral 

 nucleus to the upper third of the central gyri, chiefly to posterior 

 central gyrus and adjacent part of the paracentral lobule. 



7. The gamma bundle is large. It runs from the globus 

 pallidus to same area as beta bundle. Origin is in doubt. 



8. Runs from the lateral nucleus of thalamus (from the central 

 of Luys and the arcuate nuclei) to the middle third of the central 

 gyri, principally to the posterior central. 



e. A bundle from the antero-inferior part of the lateral nucleus 

 to the lower third of the posterior central gyrus. 



f. The zeta bundle is last to be medullated. It rises in the 

 superior part of the lateral nucleus and terminates in the foot 

 (posterior end) of the superior frontal gyrus and in that 

 part of the gyrus cinguli which underlies the foot of the first 

 frontal. 



The cortical fillet conveys common sensory impulses to the 

 somaesthetic area of the cerebral cortex. If the cortical fillet be 

 severed, all common sensory impulses to that hemisphere are 

 interrupted; and complete loss of common sensation on the oppo- 

 site side of the body and hemiataxia result. 



Just where the fibers conducting taste impulses are located 

 in the tegmentum is unknown Auditory impulses run through 

 the lateral fillet and the brachium inferius to the medial geniculate 

 body; while optic impulses run directly to the lateral geniculate 

 body and the pulvinar without passing through the mid-brain 

 at all. Within the internal capsule the gustatory tract cannot 

 at present be located; but the acustic and visual paths are well 

 known. 



The acustic, or temporo-thalamic radiation (Figs. 70 and 54) 

 continues the auditory path from the medial geniculate body 

 through the retrolentiform part of the internal capsule, to the 

 transverse temporal gyri and the third and fourth fifths of the 

 superior temporal gyrus (Barker). Interruption of these fibers 

 produces deafness in the opposite ear, which is not complete 

 because the acustic path is not wholly crossed. There are some 



