OF THE NERVOUS SYSTEM, 



107 



by impressions on the organs resides in it; and it would 

 seem, from Flourens' experiments, to reside more especially 

 in the hemispheres of the cerebrum, to which the sensations 

 are transmitted by the nerves. 



200. Neither ought it to be forgotten that each nervous 

 fibril is quite distinct from one extremity to another ; and to 

 this must be ascribed the distinctness in our sensations, and 



Fig. 71. Brain of the Korqual (Balsenoptera rorqual). Figure A 

 gives the upper surface j figure B the lower. 



the referring them always to their peripheral extremities. 

 After amputation, the pains which occasionally continue are 

 constantly referred to the foot or hand which is no longer 

 present. 



201. Nerves of Sensibility or Sensation. All nerves 

 have not the power of transmitting sensations to the brain ; 

 some, on the contrary, are clearly nerves of motion, whether 

 acted on by our will or excited by other means. Some nerves, 

 as the optic, transmit only the impressions received from 

 colours ; to other stimulants this nerve is insensible. 



202. Modifications of the Sensibility. To these modi- 

 fications of the sensibility we owe the five senses ; 'the senses 

 of touch, taste, smell, hearing, seeing, are so many distinct 

 faculties putting us in relation with the various qualities of 

 the external world. To the first pair of nerves belongs the 

 sense of odours ; by the second pair we perceive coloured 

 bodies ; the portio mollis of the seventh pair, by some called 



