THE PHYSIOLOGY OF REGENERATION 



323 



the basis of the average data for a number of tadpoles with an 

 average body length of 49.1 mm. The average amomit of tail 

 removed was 14.8 mm. and the average amount of regenerated 

 tail was determined for a period of 38 days at intervals of about 

 four days each. 



Comparing the two curves we observe, first of all, that even in 

 organisms so widely apart in the scale of classification as are the 



III- 



24 days 



Fig. 1 Curve showing the rate of regeneration of the tail of Podarke obscura, as 

 expressed in the number of segments regenerated during the first twenty-four days 

 following operation, based on the data of tables 2 and 3 in Morgulis, '09. 



annelids and the amphibians, the rate of posterior regeneration 

 obeys apparently the same natural law, which therefore trans- 

 cends specific and generic and even greater differences. In both 

 instances we find that the bulk of regeneration is accomplished 

 within a fortnight, between the second and fourteenth day succeed- 

 ing the operation, — during which time regeneration reaches its 

 climax and suddenly declines ; subsequently the rate of regenera- 

 tion continues to decrease slowly but steadily. 



