70 



ILLINOIS BIOLOGICAL MONOGRAPHS 



[70 



giving specific regenerations of 0.60, 0.27, 0.33, 0.31, 0.39 and 0.40. These 

 are shown in the graph given in figure 17. Because of the absorption 

 of regenerated tissue in the shorter removals and a slight growth in the 

 longer ones the latter show a comparative increase in specific lengths. 



1.6 2.6 4.9 8.2 



— >■ Lengths removed in mm. 



13.2 



17.9 



Figure 17 ' Rana clamitans Second regenerations Specific lengths Fifty- 

 six days 



For a comparison of completeness of regeneration it is better to 

 take the greatest lengths regenerated at each level rather than the 

 amounts regenerated at any particular time because the shorter levels 

 complete regeneration and begin to absorb the tissues sooner than do 

 the longer ones. On this basis the greatest regenerated lengths at each 

 of the six levels are, for the 1.5 mm. level 1.0 mm. reached at ten days, 

 for the 2.8 level 1.3 mm. reached at ten days, for the 4.9 level 1.6 mm. 

 reached at twelve and a. half days, for the 8.4 level 2.6 mm. reached at 

 twelve and a half days, for the 13.2 level 5.2 mm. reached at fifty-six 

 days, and for the 17.9 level 7.1 mm. reached at fifty-six days. These 

 data are given in tables 37, 38, 39 and 40 and in graphic form in figure 

 18. At the last two levels there was a slight increase from eighteen 

 to fifty-six days but this almost certainly came during the early part 

 of the period and the values are therefore completed values. Dividing 

 by the removed lengths the fractions obtained are 





and 



7.1 

 i7~9 



giving specific lengths of 0.67, 0.46, 0.33, 0.31, 0.39 and 0.40. The graph 

 is given in Figure 19. The high values for the two short levels are 

 probably due to the fact that the cells migrating to the cut surface form 



