ANATOMY AND PHYSIOLOGY OF NERVOUS SYSTEM. 721 



iin in the skin is due to the segment of the spinal cord from which 

 ;he organ concerned receives its sensory fibers, there being a spread 

 >f it through the nerve-centers, and thus causing an error in its 

 localization. 



Blows on the solar plexus reflexly cause arrest of the heart, 

 'he splanchnics also have sensory nerves for the intestine, and in 

 itestinal cramp may give rise to extremely painful sensations. In 

 he colic due to lead-poisoning, we have an affection of the sympa- 

 thetic ganglia. 



Reflex Action of the Sympathetic Ganglia. Sokownin has found 

 ill at when in the cat the nervous connections of the inferior 

 lesenteric ganglion are divided, with the exception of the hypogas- 

 tric nerves, and when the central cut end of one hypogastric is stim- 

 ."lated, contraction of the bladder ensues on the opposite side, 

 iccording to Langley, this is not a true reflex, but an axon reflex. 



