THE CEREBELLUM 609 



irbances gradually subside, and in the course of a few months the equilibra- 

 )ry power is so far regained that standing and walking at least become 

 ossible. In this condition, however, the coordinating power is directly de- 

 endent on visual impulses, for with the closure of the eyes all the previous 

 lotor disturbances at once recur. These and similar facts indicate that the 

 gmicircular canals are the peripheral sense-organs from which come the 

 erve impulses most essential to the excitation of the cerebellar coordina- 

 te centers in their control of equilibrium and of progression. 



The cerebellum may therefore be regarded as the essential, most highly 

 ifferentiated portion of the coordinating mechanism concerned in the main- 

 enance of equilibrium, during both station and progression. The manner 



which the cerebellum accomplishes this result is unknown, though it is 

 ertain, from the foregoing facts, that its special mode of activity is dependent 

 to the excitatory action of nerve impulses transmitted from a variety of 

 Peripheral sense-organs. 



