172 



A NEURAL METAMERE. 



[BOOK i. 



FIG. 25. SCHEME OF THE NERVES OF A SEGMENT OF THE SPINAL CORD. 



Gr grey, W white matter of spinal cord. A anterior, P posterior root. G ganglion 

 on the posterior root. N whole nerve, N' spinal nerve proper, ending in M skeletal 

 or somatic muscle, S somatic sensory cell or surface, X in other ways. V visceral 

 nerve (white ramus communicans) passing to a ganglion of the sympathetic chain 

 S, and passing on as V to supply the more distant ganglion <r, then as V" to the 

 peripheral ganglion a' and ending in m splanchnic muscle, s splanchnic sensory 

 cell or surface, x other possible splanchnic endings. 



From S is given off the revehent nerve r. v (grey ramus communicans), which 

 partly passes backward towards the spinal cord, and partly runs as v. m, in con- 



