159] 



RATE OF REGEXERATIOX—ZELEXV 



159 



and 56 days respeetivel.y. The regenerated lengths at these times of 

 completion are respectively 61, 46, 39, 33, 42 and 41 per cent of the 

 removed lengths. It will be noted that the two shortest removals give 

 the highest per cents and the two medium ones the lowest per cents. 

 This difference is discussed in Part III on the effect of level of the cut. 



Experiment IV Rana clahitaxs Second regenerations 

 Series 3676-3765 



The data are given in Table 107. The tail was removed at different 

 levels approximating 6, 10, 18, 31, 49 and 67 per cent of the removed 

 lengths. Regeneration was completed for these levels at 10, 10, 12i/^, 



TABLE 104 



Rana clamltans Series 3557-3624 Completeness of regeneration 

 Successive regenerations in single individuals One-half of tail removed = 

 17 mm. on the average First operation Oct. 23. 1911 Second operation 

 Groups A and B Nov. 18 Group C Nov. 28 



Group 

 A 



Group 

 B 



Second 

 regener- 

 ation 



Jan. 3 



9.5 



9.8 

 10.0 

 11.9 



8.4 

 10.0 



8.7 



9.8 



8.3 

 8.2 

 11.9 

 9.7 

 8.3 



Third 

 regener- 

 ation 



Feb. 9 



8.5 

 11.4 

 9.3 

 9.5 

 9.9 

 8.7 

 8.1 



9.3 



9.0 

 8.1 

 7.3 

 8.0 

 12.8 

 7.4 

 9.5 



8.9 



Fourth 

 regener- 



7.3 



8.1 



8.0 



11.0 



8.0 



8.5 



5.8 

 11.3 

 6.9 

 7.6 

 7.4 

 5.0 

 6.4 



7.2 



Fifth 

 regener- 



April 24 



8.2 

 6.3 

 11.9 

 8.5 

 8.1 



8.6 



8.2 

 7.0 

 8.1 

 11.6 

 5.4 

 6.8 



