264 THE NERVOUS SYSTEM 



(c) the opposite cerebral hemisphere, and (d) different 

 parts of the same hemisphere. 



(a) Fibers converge from the anterior and middle (par- 

 ticularly the latter) parts of the cortex to pass by the corona 



FIG. 83. Scheme of the projection fibers within the brain. (Starr.) 



Lateral view of the internal capsule; A, tract from the frontal gyri to the 

 pons nuclei, and so to the cerebellum; B, motor tract; C, sensory tract for touch 

 (separated from B for the sake of clearness in the scheme); D, visual tract; E, 

 auditory tract; F, G, H, superior, middle, and inferior cerebellar peduncles; /, 

 fibers between the auditory nucleus and the inferior quadrigeminal body; K, 

 motor decussation in the bulb; At, fourth ventricle. The numerals refer to the 

 cranial nerves. The sensory radiations are seen to be massed toward the 

 occipital end of the hemisphere. (Am. Text-book.) 



radiata to the corpora striata, from which fibers are con- 

 tinued to the crusta, pons, pyramids of the medulla and 

 pyramidal tracts of the cord; most of these pass down 

 through the internal capsule to reach the corpora striata. 

 From the same regions also some fibers pass directly through 

 the internal capsule, without connection with the corpora 

 striata, to be actually continuous themselves with fibers 

 which, following the same course downward, are found in 

 the pyramidal tracts of the cord. All fibers passing from 

 these cortical areas mentioned through the internal capsule 



