NERVE 



I 



NERVE FIBER 



DEGENERATING TIBER 



REGENERATING 

 NERVE FIBER 



PATHWAY 



< 



GAP 



FROZEN DRIED 

 NERVE 



TUBE' PLASMA CLOT 



Fig. 85. Regeneration of a nerve. A: The nerve is cut and the individual 

 nerve fibers degenerate in the section to the right, the distal stump. The nerve 

 fibers on the left are attached to the cell bodies and they undergo degeneration 

 for a short distance from the cut surface but soon begin to regenerate. B: Cones 

 of growth form at the end of each nerve fiber and migrate along pathways pro- 

 vided by the degenerating nerve fiber. C: A relatively large section of the nerve 

 is removed and a gap separates the newly regenerating fibers from the pathways 

 in the degenerated portion of the nerve. The nerve fibers grow in a nondirected 

 fashion. D: A piece of frozen, dried nerve is placed in the gap and the regen- 

 erating nerve fibers follow the pathways in this dead nerve. E: The two ends of 

 the cut nerve are connected by means of a tube. The tube contains blood plasma. 



146 



