CONTRIBUTIONS FROM THE ZOOLOGICAL LABORATORY OF THE MUSEUM OF 

 COMPARATIVE ZOOLOGY AT HARVARD COLLEGE, E. L. MARK, Director, No. 215 



CONTRIBUTIONS TO THE PHYSIOLOGY OF 

 REGENERATION 



III. FURTHER EXPERIMENTS ON PODARKE OBSCURA 



SERGIUS MORGULIS 

 CONTENTS 



A. Relation between degree of injury and rate of regeneration 7 



B. Relation between frequency of injury and rate of regeneration 15 



C. Relation between sex and rate of regeneration 18 



D. Relation of the amount of removed to the amount of regenerated tissue. 19 



Conclusions 20 



Bi bliography 22 



A. RELATION BETWEEN DEGREE OF INJURY AND RATE 

 OF REGENERATION 



The amount of discussion aroused within the last two or three 

 years over the question as to whether or not an additional muti- 

 lation of an organism exerts an accelerating influence upon its 

 regeneration testifies to the great significance and interest of 

 the question, especially from the point of view of the regenera- 

 tive energy. But unfortunately w^e are unable to give the final 

 verdict in favor of either alternative. The idea that by increas- 

 ing the number of injuries to the organism each injured part is 

 caused thereby to regenerate more rapidly, received recently 

 elaborate evidence from Zeleny ('09a), who was also the first to 

 propound the idea ('03). The researches of other investiga- 

 tors, however, have more or less failed to accord with his conclu- 

 sions. Emmel ('06) observed in the case of the young lobster 

 that the rate of regeneration diminishes with increased mutila- 

 tion; Scott ('07) found that the rate of regeneration of the fins of 

 Fundulus is independent of the degree of injury; in the brittle- 



