47] 



RATE OF REGENERATION— ZELENY 



47 



average for the third regeneration at six days is due to a single excep- 

 tional individual it is more proper to put the third ahead of the second 

 at this time. 



A comparison of the three regenerations by individual cases is 

 shown in Table 32. At each of the six times taken the number of cases 

 showing a more rapid regeneration is greater for the third regeneration 

 than for the first and also greater for the second than for the first. The 

 third is ahead of the second at two times (more properly three times) 

 and equal to the third at four times (more properly three). 



When all the individual cases are taken together both third and 

 second regenerations are again distinctly ahead of the first as shown 

 by the totals in Table 32. The third is ahead of the second in twelve 

 cases (more properly thirteen) and the second ahead of the first in eight 

 cases (more properly seven). 



Each of the three comparisons shows that both second and third 

 regenerations are more rapid than first regenerations. The third regen- 

 eration shows a slight advantage over the second instance in all three 

 of the comparisons. In this instance the difference can not be due 

 to the presence of newly regenerated cells in the one case and not in the 

 other. 



TABLE 31 



Amblystoma punctatum Series 3967-3998 

 Comparison of lengths of first, second and third regenerations 



Age factor eliminated 



Regener- 

 ation time 

 in 

 days 



4 



Catalog 

 number 



3967 

 3968 

 3969 



Average 



3970 

 3971 

 3972 

 3973 



Average 



Regenerated lengths in mm. 



First 

 regeneration 



0.2 



0.25 



0.2 



0.22 



0.75 

 0.7 

 0.5 

 0.7 



0.66 



Second 

 regeneration 



0.25 



0.3 



0.2 



0.25 

 0.9 



0.75 

 0.6 



0.75 



Third 

 regeneration 



0.3 



0.27 



0.2 



0.26 



1.0 

 1.6 

 0.8 

 0.6 



1.00 



