266 THE NERVOUS SYSTEM 



occupy the anterior two-thirds of the posterior division of 

 that tract. Furthermore, fibers from the posterior cortical 

 area pass through the posterior one-third of the posterior 

 division of the internal capsule to the optic thalamus, from 

 which fibers pass through the tegmentum to the pons and 

 medulla and are continuous with fibers from the sensory 

 tracts of the cord. The decussation of all these fibers has 

 been mentioned. 



FIG. 85. Diagram of the motor areas on the outer surface of a 

 monkey's brain. (Landois after Horsley and Schafer.) 



Fig. 84 taken in conjunction with Fig. 77 illustrates the 

 most recent ideas of the motor and sensory connections be- 

 tween brain and cord and the motor and sensory paths in 

 the cord. 



(b) Fibers from the anterior portion of the frontal lobe 

 pass through the anterior limb of the internal capsule and 

 seem to end in the gray matter of the pons and there to com- 

 municate with the cerebellum through the middle peduncles. 

 Fibers also pass from the temporo-sphenoidal lobes and 

 from the caudate nuclei of the corpora striata to the cere- 

 bellum on the opposite side. The connection is crossed in all 

 these cases. 



(r) Transverse fibers in the corpus callosum connect all 

 parts of the two lateral hemispheres. Besides these com- 



