Correlation Centres axd Tracts 55 



The latter usually decussate and convey their impulses up 

 to the cerebellar hemisphere on the opposite side. The pons 

 is to be regarded as a structure which has been added to the 

 primitive hindbrain coincident with the development of the 

 cerebellar hemispheres, for the purpose, primarily, of putting 

 these into communication with the cerebral cortex. Hence 

 it is very much smaller in the rat than in man, where both 

 the cerebral cortex and the cerebellar hemispheres are much 

 more largely developed. 



