DISEASES OF THE NERVOUS SYSTEM. 



281 



Table indicating the weight of the encephalon and 

 spinal cord as compared with that of the body (Colin). 



The anterior portion of the surface of the brain appears 

 to be the supreme organ of the cerebro-motor processes or 

 impulses, whereas the posterior portion of the cerebrum 

 is similarly related to sensation. The part of the cerebrum 

 anterior to the motor tract is chiefly concerned with the 

 manifestation of intelligence. 



Besides the ganglia already mentioned at the base of 

 the brain, which include the corpora striata, the optic 

 thalami, the corpora geniculata, and the corpora quadri- 

 gemina, there are collections of grey matter constituting a 

 series of subordinate centres, closely succeeding each other, 

 from the corpora quadrigemina above to the termination of 

 the cord below, each either giving origin to motor or re- 

 ceiving sensory fibres. Each centre is also capable of 

 independent action in connection with reflex or automatic 

 movements. The most important function of tlie cere- 

 bellum is the co-ordination of voluntary movements. It 

 has been held that it presides over the reproductory 

 functions, but several facts oppose this view. M. Leuret 

 showed, by taking the averages in ten stallions, twelve 



