498 THE FUNCTIONAL RELATIONS OF THE 



Baid, ** takes no part in cerebral functions proper. It 

 appears to have nothing at all to do with the manifesta- 

 tions of Instinct, of Intelligence, or of Will.'* Whether 

 absolutely correct or not, this is a notion commonly enter- 

 tained. On the other hand, that certain ataxic disorders 

 of movement are caused by lesions of the Cerebellum, 

 Vulpian felt compelled to admit ; though he rejected the 

 commonly entertained hypothesis of Flourens, that it is 

 ** a centre by which the co-ordination of voluntary and 

 other movements is eiFected." 



The great uncertainty that has always prevailed in 

 regard to the functions of the Cerebellum is due to 

 various causes. It is attributable partly to the com- 

 plicacy of the connections of this organ with other regions 

 of the central Nervous System, as well as to the obscurity 

 w^hich reigns as to the several sources of its 'ingoing,' and 

 the destination of its ' outgoing,' fibres — for to suj)pose 

 with Luys that the peduncles of the Cerebellum are com- 

 posed of * outgoing ' fibres only seems to the writer as 

 opposed to fact as it would be to the plan of Nerve 

 Centres generally. But the uncertainty as to the real 

 functions of this organ, is due also to the variety and 

 obscurity of the symptoms resulting from its injury in 

 any of the lower animals, and from a like variability of 

 relation between symptoms and lesions, revealed to those 

 who study the effects of diseases of the Cerebellum in Man. 



These latter variations are attributable partly to the intimate 

 connection of the Cerebellum with other important portions of the 

 Brain. This makes it difficult to experiment with the organ in tlie 

 lower animals without great risk of irritating or injuring, now one, 

 now another of these adjacent parts; and equally difficult, on the 

 other, to get nncomplicated disease of the (Cerebellum — disease that 

 is limited to this organ and unassociated with symptoms resulting 

 from pressure on, or irritation of, other important parts, such as the 

 Medulla or * pons Varolii.* 



