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ILLINOIS BIOLOGICAL MONOGRAPHS 



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TABLE 40 



Rana clamitans Series 3676-3765 Summary Second regenerations 

 Lengths regenerated at different levels at different times 



First Regenerations 



The data for first regenerations are from a different set of indi- 

 viduals than those for second regenerations. The two kinds of opera- 

 tions were made on the same day. The general results obtained from the 

 first regenerations are in full agreement with those obtained from the 

 second regenerations but there is greater variability because of the 

 smaller number of individuals. The average per cents of the tail length 

 removed are respectively 6, 10, 17, 30, 48 and 62 for the six levels. 

 The first of these has two individuals averaging 1.5 mm. of removed 

 tail, the second five individuals with an average of 2.6 mm., the third 

 three individuals with an average of 4.6, the fourth eight with an average 

 of 8.2, the fifth five with an average of 13.0 and the sixth five with an 

 average of 16.7. The data for these experiments are given in Tables 

 41, 42, 43 and 44 and in Figures 20 to 35. 



The progress of a first regeneration is similar to that of a second 

 except that the maximum is reached later in the case of first regenera- 

 tions. In the present series the maximum specific rate for first regenera- 

 tions comes between the sixth and the eighth day after the operation. 

 A comparison of the two regenerations is made in the section on the 

 effect of successive removal. The change in rate during the process of 

 regeneration is also discussed in a separate section. 



