RECENT WORK UPON VISCERAL AND 

 ALLIED NERVES. 



WITHIN the past few years our knowledge of the 

 physiology" and anatomy of the complicated tangle 

 of nerve fibres and cells forming the sympathetic system 

 has been making great advances ; advances which are due 

 to a very great extent to the active work of Langley and 

 his co-workers, Dickinson and Anderson. 



In the following account of our present knowledge of 

 this subject I will first confine myself to the question of 

 efferent fibres, leaving the discussion of the afferent fibres, 

 upon which our knowledge is much scantier, for a later 

 paper. Our proper appreciation of the true anatomical and 

 physiological status of the sympathetic system may be said 

 to date from 1885 when Gaskell's important paper on vis- 

 ceral innervation appeared in the Jo2t,rnal of Physiology. 



For the purposes of this paper I have not referred back 

 to earlier work than this, except in a few instances where it 

 was necessary to make the account a little more complete. 

 In most cases, however, the papers utilised have been 

 published within the past five years. The whole has been 

 divided up into sections, each giving an account for the 

 different organs, and I have placed that for the pilo-motor 

 nerves first as giving in many ways a more complete picture 

 than any other, of the general arrangement of fibres and cells 

 in the sympathetic system. 



PHILO-MOTOR NERVES. 



The nerves which Langley and Sherrington have de- 

 signated "pilo-motor," and which on stimulation cause con- 

 traction of the erectores pilorum and erection of the hairs, 

 have been shown to form a constituent part of the sym- 

 pathetic system. 



Schiff ^ showed that electrical stimulation of the spinal 



^ Quoted by 'L^.ngXey, /oitrn. of Physiol., vol. xv., p. 241, 1894. 



