216 
ZOOLOGY: C. ZELENY 
13.1 and 18.1 mm. from the tip or respectively 6, 10, 18, 31, 49 and 
67% of the tail length. 
Since the specific regenerated length or length regenerated per unit 
of removed length is a fair constant for all levels between 4.9 and 18.1 
mm. the most reliable data on change in rate are obtained by averaging 
the specific rates for all the individuals with these levels of injury. 
The average specific rates per day obtained in this manner are 0.010 
mm. for the 0-4 day period, 0.045 for the 4-6 day period, 0.042 for 6-8 
3.S 6 8 10 13.2 26 
Day» ilta the operation 
FIG. 4. ACCELERATION OF SPECIFIC RATE. FIRST AND SECOND REGENERATIONS OF 
THE TAIL IN RANA CLAMITANS. UNBROKEN LINE = FIRST REGENERATION. BROKEN 
LINE = SECOND REGENERATION. 
FIG. 5. PERCENTAGE INCREMENT PER DAY AT DIFFERENT PERIODS AFTER THE 
OPERATION. FIRST AND SECOND REGENERATIONS OF THE TAIL OF RANA CLAMITANS. 
UNBROKEN LINE = FIRST REGENERATION. BROKEN LINE = SECOND REGENERATION. 
days, 0.032 for 8-10 days, 0.025 for 10-12^ days, 0.002 for 12^-18 
days and 0.000 for 18-56 days (fig. 3). The specific rate reaches its 
maximum just before the end of the sixth day. 
The values for acceleration of specific rate are +0.011 mm. from the 
0-4 to the 4-6 day period, 0.000 from the 4-6 to the 6-8 day period, 
-0.005 from the 6-8 to the 8-10 day period, -0.006 from the 8-10 
to the 10-121- day period, -0.004 from the 10-12 J to the 12J-18 day 
period and 0.000 from the 12^-18 to the 18-56 day period (fig. 4). 
