144 University of California Publications in Zoology ["^ol. 18 



SUMMARY 



1. After transverse section of nerve cord, locomotor transmission 

 fibers regenerate before giant fibers. 



2. The period of regeneration after a simple transection is very 

 short, from three to four days. 



3. Removal of short pieces of the cord gives the same results as 

 simple transverse section, except that the period of regeneration is 

 prolonged. 



4. The effect of drugs, such as stovaine, on the cord shows that 

 the transmission fibers may be active, while the giant fibers are still 

 under the anesthetic. Recovery is in the same order as is shown in 

 regeneration. 



5. The general result of this study shows that the giant fibers are 

 concerned with other functions than locomotion, and that locomotor 

 transmission fibers lie deep in the cord. 



LITERATURE CITED 



BlEDERMANN, W. 



1904. Studien zur vergleichenden Physiologie der peristaltisehen Bewegun- 

 gen. I. Die peristaltisehen Bewegungen der Wiirmer und der Tonus 

 glatter Muskeln. Arch. ges. Physiol., 102, 475-542, 1 figure in text. 

 BOVARD, J. F. 



1918. The transmission of nervous impulses in relation to looomotion in the 

 earthworm. Univ. Calif. Publ. Zool., 18, 103-134, 14. 



BUDINGTON, R. A. 



1902. Some physiological characteristics of annelid muscle. Am. J. Physiol., 

 7, 155-179, 16 figures in text. 

 Friedlander, B. 



1894. Beitriige zur Physiologie des Centralnerven systems und des Bewe- 

 gungsmechanismus der Regenwurmer. Arch. ges. Physiol., 58, 

 168-206. 

 Straub, W. 



1900. Zur Muskelphysiologie des Regeuwurms. Arch. ges. Physiol., 79, 

 379-399, 15 figures in text. 



