Analysis of Rate of Regeneration 405 
TABLE III 
Data for Experiment II. Same explanation as for Table I 
APRIL MAY 
Dates of measurement...........---+++ee0+: 27 | 30 7 a i Ig | 21 | 27 
Amounts of regenerationinmm......---..--| 14 ON Ne ee ed ee Dy | 6.2 | 6.5 
Days in period between measurements ....... | BP als esau |e Ke 4 6 6 
Gain duringeach period .........-+++++++++- | | 1.4 | 0.2 | 0.9 | 0.9 o.3 0.7 +1 0.3 
Rate during each period.........-++++++4+5- ite | 0.46 | 0.50 0.30 | 0.25 | 0.07 | 0.12 | 0.05 
material in the regenerating tail on the fifth day after operation 
and two others four days later, individual variation probably 
has a large influence upon the average results after the ninth 
day from the time of the operation. The average results for this 
series are given in Table IV. 
TABLE IV 
| 
| OCTOBER 
| 
Dates of measurements........------ Keg el | Gal, -% (keGe aka wi A ee 20 
mm. of regeneration..........--+++-- | | 0.23 | 1.31 | 3-34 | 5-35 ze 55 9.07 | 9.17 | 9.60 
Days in periods between. measure- | 
lhl Baobab aren I00 Dooonciour fomaes 2 7 Nee? 2 3 2 3 3 
mm. gains during each period.......--| 0.23 | 1.08 | 2.03 2.01 | 2.20 | 1.52 | 0.10 | 0.43 
mm. per day during each period....... | | 0.12 | 0.54 | 1.02 | 1.05 | 0.73 | 0.76 | 0.03 | 0.14 
| | | | | 
Experiment IV was planned for a study of the histology of 
regenerations in relation to the changes in the rate. On October 
17, 1908, the series containing thirty-five individuals was operated 
upon. The average amount removed was 14.8 mm., the extremes 
of operation were 14 mm. and 15.9 mm. A control series of five 
individuals was maintained. The animals were 45-50 mm. long, 
the complete set having an average length of 49.1 mm. Ten 
measurements were made in the thirty days following the opera- 
tion and three individuals selected at random from the operated 
series were killed each time a measurement was made. Thus 
the last few measurements are influenced by the individual varia- 
