io6 THE SPINAL CORD AND CEREBELLUM 



some physiologists to follow a direct path to the bulb, 

 the question again presents itself, What may be the 

 function of the remainder which are connected with 

 cells in and around the posterior horn ? The anterior 

 horn is, one may believe, mainly motor. Is the posterior 

 horn merely a centre of co-ordination, or is it mainly 

 sensory ? If it be sensory, are not the fibres which, 

 proceeding from the posterior root, end in it also 

 sensory? Again, if they be sensory, what form of 

 sensation can we allot to the coarse and what form 

 to the very fine fibres ? Does it not seem likely that 

 the latter are connected with some of the more delicate 

 chemical processes of metabolism ? The visceral nerves 

 in general are remarkable for their delicacy of calibre, 

 and if a portion of their fibres are connected with 

 vaso-motor functions, and a portion with secretory 

 or chemical processes, those belonging to the latter 

 category might be supposed to be of very fine structure. 

 The circulation of the abdominal region is remark- 

 able, not only because of the plentiful supply of blood- 

 vessels, but because the variations to which it is subject 

 are probably greater than in any other part of the 

 body. The nerves of the intestines must for this 

 reason include many vaso-motor fibres, and their 

 distribution on reaching the cord must correspond, 

 one would suppose, in some measure to the position 

 occupied by these organs. Although the distribution 

 in the spinal cord of the abdominal splanchnics or 

 vaso-motor nerves to the intestines is a matter of 

 great complexity, one may probably assume that they 



