834 THE CENTRAL NERVOUS SYSTEM 



Sometimes in high lesions of the cord there is anesthesia at the cor- 

 responding level, but the area supplied by the lower spinal roots, espe- 

 cially the skin in the region of the anus, is sensitive to one or other 

 kind of stimulation. In recovery, too, there may be an early reap- 

 pearance of sensations in isolated caudal areas. The explanation given 

 for these results is that the fibers carrying different kinds of sensation 

 have a lamellar arrangement in the cord, the longest fibers being on the 

 outside (see page 813). When a partial lesion affects the mesial fibers 

 more than the lateral, there will accordingly be recovery of the caudal 

 skin areas before those higher up. 



