432 Max Mapes Elhs 
Length of regenerated tail in millimeters 
6 9 12 15 18 
Days since operation 
Fig. 1. The curves represent the amount of regeneration for Series O, P, R, S, and T, Experi- 
ment 4. The abscissa represents time, and the ordinate, the length of the part regenerated in milli- 
meters. The dotted lines are the paths of regeneration, had the amount of regeneration been laid 
down at a uniform rate, throughout the period of regeneration. They give a standard to which 
the curve of amount may be compared. 
Tables 9, 10, 11, 12 and 13 give the individual records for the tadpoles of series O, POR WS; 
Experiment 4. 
Table 13 gives the average percentages regenerated for all of the series of Experiment 4, through- 
out the period of regeneration. 
32 
