218 FUNCTIONS OF THE NERVOUS SYSTEM. 



performed without any idea of a purpose, and without any direction of the 

 will, being frequently in opposition to it (258 265). 



IV. The Cerebral Hemispheres, or Ganglia, which are evidently the instru- 

 ments or organs of the intellectual faculties. These are connected by fibres 

 of communication with almost all parts of the body ; and from their propor- 

 tional size in Man, it seems probable that many of the nervous trunks are 

 principally composed of such fibres. It is probably by them alone that ideas 

 or notions of surrounding objects are acquired, and that these ideas are made 

 the groundwork of mental operations. They would seem, also, to be the 

 exclusive seat of Memory. The results of these operations are manifested on 

 the bodily frame, through the Will, which is capable of acting, in greater or 

 less degree, on all the muscles forming part of the system of Animal life 

 (279292). 



V. The Cerebellum, which appears to be concerned in the regulation and 

 harmonization of Muscular movement, whether instinctive or voluntary ( 266 

 278). 



Tabular View of the Nervous Centres. 



Cerebral Ganglia, 



the centres of the operations 



of Intelligence and Will. 



Nerves of Special sensa-^i Ganglia of Snerial SPHSP fNerves of Special sensa- 



tion.-Motor fibres min- ( \**> I tion.-Motor fibres min- 



. ^- the centres of Consensual, -^ , , ., 

 " 5tinctive,and Emotional actions. ! f t gj em 



Cerebellic Ganglia, 



for harmonization of general 



muscular actions. 



Afferent and Motor Nerves J Respiratory I Afferent and Motor Nerves 



of Respiration, Deglutition, > and stomato-gastric 2 of Respiration, Deglutition, 

 &c. > Ganglia. f &c. 



Trunks of Spinal nerves, composed""! o g ^ f Trunks of Spinal nerves, composed 

 of fibres from true Spinal Cord, and | c o ^ g g | of fibres from true Spinal Cord, and 

 from Cerebrum, Cerebellum, and I T?;= '& *s \ from Cerebrum, Cerebellum, and 

 Medulla Oblongata; each group f c c g ] Medulla Oblongata; each group 

 containing afferent and efferent $^ >~ T containing afferent and efferent 

 fibres. J 5 S'oJ = U 



295. The distinctness of the operations of these several centres is shown in 

 various ways : but especially by conditions of the bodily system, in which 

 one or more of them is in a state of inaction, whether temporary or perma- 

 nent ; or is prevented, by the interruption of the usual channel of communi- 

 cation, from operating on particular parts. Thus, in ordinary profound Sleep, 

 which is a state of complete unconsciousness, it is evident that the Cerebral 

 Hemispheres, and the Ganglia of Special Sense, are at rest ; as the Cerebel- 



