89] RATE OF REGENERATION— ZELENY 89 



in the present experiment were made on killed individuals so that only 

 a single regeneration measurement is made in a single individual. This 

 procedure also tends toward a greater variability in the data. The 

 number of individuals in any particular measurement also is less than 

 for the second regeneration of frog tadpoles. 



Notwithstanding all these unwelcome factors the general features 

 of regeneration are similar to those for the tadpole experiment. The 

 regenerated length at any time is approximately proportional to the 

 removed length. It is true even in the earliest measurements. As 

 for frog tadpoles the shorter removals have proportionately a larger 

 regeneration than the others at practically each time of measurement. 

 The approach to equality in specific lengths is true only of the lengths 

 of removal equal to one-fifth or more of the tail length. 



At two days the regenerated lengths are respectively 0.10, 0.15, 

 0.15, 0.47 and 0.53 mm. for the five levels of removal. They give specific 

 lengths of 0.07, 0.07, 0.04, 0.08 and 0.06 as shown Table 45 and Figures 

 36 and 37. 



At four days the regenerated lengths are 0.12, 0.15, 0.30, 0.41 and 

 0.40 mm. and the specific lengths 0.11, 0.07, 0.07, 0.07 and 0.05 as shown 

 in Table 46 and Figures 38 and 39. 



At six days the regenerated lengths are 0.32, 0.47, 0.62, 0.70 and 

 1.02 mm. and the specific lengths 0.30, 0.20, 0.16, 0.12 and 0.11 as shown 

 in Table 47 and Figures 40 and 41. 



At eight to nine days the regenerated lengths are 0.40, 0.65, 0.80, 

 1.40 and 1.52 mm. and the specific lengths 0.44, 0.28, 0.23, 0.23 and 

 0.19 as shown in Table 48 and Figures 42 and 43. 



At ten to eleven days the regenerated lengths are 0.50, 0.63, 1.54, 

 2.22 and 2.22 mm. and the specific lengths 0.62, 0.26, 0.43, 0.41 and 

 0.27 as shown in Table 49 and Figures 44 and 45. 



At thirteen days the regenerated lengths are 0.78, 0.92,- 1.74, 2.40 

 and 3.60 mm and the specific lengths 0.74, 0.43, 0.48, 0.44 and 0.48 as 

 shown in Table 50 and Figures 46 and 47. 



At fifteen to sixteen days the regenerated lengths are 0.80, 1.30, 

 1.37, 2.80 and 3.80 mm. and the specific lengths 0.67, 0.61, 0.40, 0.48 and 

 0.54 as shown in Table 51 and Figures 48 and 49. 



At seventeen to eighteen days the regenerated lengths are 0.70, 

 1.40, 1.60, 3.80 and 4.67 mm. and the specific lengths 0.67, 0.62, 0.41, 

 0.66 and 0.57 as shown in Table 52 and Figures 50 and 51. 



A summary of regenerated lengths is given in Table 53 and of 

 specific regenerated lengths in Table 54. 



Since the experiment was closed at eighteen days and since the 

 measurements at different times were made on different individuals it 

 is not possible to make as accurate a comparison of completeness of 



