370 NEKVOUS SYSTEM. 



of the anterior white columns of the cord, which produces 

 any thing like the results of cerebellar injury. Certain im- 

 portant coordinate muscular movements are well known to 

 be dependent upon distinct nerve-centres. The acts of res- 

 piration are presided over exclusively by the medulla oblon- 

 gata. Deglutition probably has its distinct nerve-centre, as 

 well as the movements of the eyes. The centre regulating 

 the coordinate movements in speech is situated in the an- 

 terior cerebral lobes. None of these peculiar movements 

 are affected by extirpation of the cerebellum. 



If there be a distinct nerve-centre which presides over 

 the coordination of the general voluntary movements, ex- 

 periments upon the higher classes of animals show that this 

 centre is located in the cerebellum. It may be either in the 

 entire cerebellum or in a certain portion of this organ, but 

 if it be confined to a restricted part, this has not yet been 

 determined. If the cerebellum preside over coordination, 

 as a physiological necessity, the centre must be connected 

 by nerves with the general muscular system. If this con- 

 nection exist, a complete interruption of the avenue of com- 

 munication between the cerebellum and the muscles, we 

 would naturally expect, would be followed by loss of coor- 

 dinating power. From the anatomical connections of the 

 cerebellum, it appears that the only communication be- 

 tween this 'Organ and the general system is through the 

 posterior white columns of the spinal cord. TVe have seen 

 that these columns are not for the transmission of the gen- 

 eral sensory impressions, and there is no satisfactory evi- 

 dence that they convey to the encephalon the so-called mus- 

 cular sense. As regards general sensibility and voluntary 

 motion, we cannot ascribe any function to the posterior 



rium of the head, and thereby of the whole body ; that the pressure of the liquid 

 in these canals varies with the movements of the head, and that the brain re- 

 ceives from these, information with regard to the position of the head, and is 

 able to regulate the general movements accordingly ; and that this information 

 is inaccurate when the pressure of liquid in the canals is abnormal, the result 

 being disturbance of the general equilibrium. 



