NERVE 129 



from side to side. (2) These irritative symptoms soon pass 

 off, and the animal then manifests inadequacy or weakness 

 in the Hmbs of the affected side, so that it droops to that side, 

 and, if a quadruped, may circle to that side. (3) After some 

 weeks these symptoms disappear, compensation for the loss 

 of one side of the cerebellum being established. 



When compensation is completed in the dog, destruc- 

 tion of the cerebral cortex of the opposite side leads to a 

 reappearance of the muscular inadequacy. 



In some cases in man, when slowly progressing disease 

 has destroyed the organ, no loss of equilibration appears. 

 In other cases the cerebellum has been congenitally 

 almost absent, and yet the individual has not shown any 

 sign of want of power of maintaining his balance. Evidently, 

 therefore, in such cases the cerebrum compensates for the 

 absence of the cerebellum. 



4. Stimulation of the cerebellum has yielded results some- 

 what difficult of interpretation, but the most recent investi- 

 gations seem to show that stimulation of the cortex with 

 currents strong enough to produce movements when applied 

 to the discharging part of the cerebral cortex in the monkey 

 (see p. 192), does not produce manifest effects. On the 

 other hand, comparatively weak currents applied to the 

 basal nuclei do produce movements, the most manifest of 

 which are conjugate movements of the eyes, and of the 

 eyes and head to the side stimulated. If the nucleus of 

 Deiters is stimulated, the movements are rather in the 

 muscles of the limbs of the same side. 



It has been further found that powerful stimulation may 

 also cause flexion of the elbow of the same side and 

 extension of the opposite elbow with extension of the trunk 

 and lower limbs. This may be associated with the main- 

 tenance of the body in the erect position and with the 

 alternate movements of the legs in the act of progression. 



Although stimulation of the cerebellar cortex has failed 

 to reveal any localisation of function, a study of the relative 

 development of different parts in different groups of animals, 

 and a study of the effects of local removal, seem to indicate 

 that the median part is connected with the movements of 

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