1918] 



Bovard: Giant Fibers in Earthworms 



141 



Experiment 191 — Regeneration of Nerve Cord After Removal of Short 



Sections of Cord 



Worm 

 A 

 B 

 C 

 D 

 E 

 F 

 G 

 H 

 I 

 J 

 K 

 L 

 N 



A P refers to locomotor impulses passing from anterior to posterior. 

 P A refers to locomotor impulses passing from posterior to anterior. 







- int. epith. 



n. sJi. 

 9-f. 



ctx. 



I. m. 



■ cr. VI. 



■ ch. sh. 



spi. 



Fig. 1 — A camera lueida drawing showing the union of the cut ends of the 

 ventral nerve cord. X 42. Experiment 191, line 1. In this worm two ganglia 

 had been removed and nine days given for regeneration. Normal locomotor 

 transmission and giant fiber action had returned, ch. sh., chaeta sheath; cir.m., 

 circular muscle; ctx., cicatrix tissue; epi., epidermis; g.f., giant fiber; int. epith., 

 intestinal epithelium; ?. m., longitudinal muscle; n.c, nerve cord; n.sh., nerve 

 sheath. 



