Ill] 



RATE OF REGEXERATIOX—ZELENY 



111 



depart considerably from the others in specific rate. There is how- 

 ever no essential difference in the two sets of values as regards the form 

 of the rate curve. 



The change in rate of regeneration or acceleration of rate from any 

 period to the succeeding one is shown in Table 57 in which the period 

 of change is represented by the middle days of the two periods which 

 are being compared. The average of all the levels shows the acceler- 

 ation to be +0.095 mm. from the 2 to the 5 day period, — 0.015 for 5 to 

 7 days, —0.030 for 7 to 9 days, —0.058 for 9 to 11% days, —0.028 for 

 11% to 1514 days and — 0.001 for 15% to 37 days. It is only between 

 the first two periods that acceleration of rate is a plus quantity. Dur- 

 ing all the others it is minus, the most rapid rate of decrease coming 

 between 9 and 11% days. 



The accelerations of specific rate are more reliable measures for 

 obtaining averages including the different periods. Such values are 

 given in Table 58 and in graphic form in Figure 54. They give a result 

 in the relation of the periods to each other essentially similar to that 

 above. The average accelerations of specific rate are -f 0.014 for the 



6 8 10 13% 26 



— >■ Days after the operation 

 Figure 54 . Acceleration of specific rate First and second regenerations of the 

 tail in Rana clamitans Unbroken line=First regeneration Broken line= 

 Second regeneration. 



2 to 5 day periods, — 0.004 for 5 to 7 days, — 0.009 for 7 to 9 days, 

 —0.0085 for 9 to 11% days, —0.003 for 11% to 15% days and 0.000 

 for 15% to 37 days. The first period is the only one with a plus accel- 

 eration. The greatest minus acceleration comes between the 7 and the 

 9 day periods instead of 9 to 11% days. Averaging only the regener- 

 ations for the four deepest levels which show a constant specific rate 



