GENERAL ANATOMY OF THE NERVOUS SYSTEM. 557 



to show the arrangement of the gray and fibrous substances 

 in profile, the course of the true spinal or excito-motory 

 nerves, and that of the true cerebral sensiferous and motorial. 

 A. Posterior surface of the cord. B. Anterior surface. C. The 

 cineritious or grey matter in the centre of the spinal marrow. 

 D, E. The true spinal or reflex nerves ; the incident or spinal 

 sensiferous nerve may be supposed to approach the spine at 

 D, the true motor spinal nerve leaving at E, which is capable 

 of producing contraction in the part to which its fibres are dis- 

 tributed when excited by the cineritious matter that receives 

 the stimulus brought by the incident spinal nerves at D. The 

 roots of the fibres of the two sides probably form some con- 

 nection in the cineritious matter. F. The cerebral sensiferous 

 fibres going to the brain. G. The motor cerebral fibres dis- 

 tributed to the muscles of volition. The respiratory nerves 

 of Sir C. Bell, will no longer then stand apart as a separate 

 system, but comes under the same category with the excito- 

 motory, to which the great sympathetic, as has been already 

 shown, in a measure belongs. 



47* 



