148 THE RATE OF GROWTH 



The Rate of Regenerative Growth in Tadpoles' Tails. 

 {After M. M. Ellis, J. Exp. Zool. vii, p. 421, 1909.) 



[CH. 



* Each series gives the mean of 20 experiments. 



removed 



Fig. 40. Relation between the percentage amomit of tail removed, the percentage 

 restored, and the time required for its restoration. (From M. M. Ellis's 

 data.) 



amount removed ; and my diagram is constructed from the four 

 sets of values thus obtained, that is to say from the four sets of 

 experiments which differed from one another in the amount of 

 tail amputated. To these we have to add the general result of a 

 fifth series of experiments, which shewed that when as much as 

 75 per cent, of the tail was cut off, no regeneration took place at 

 all, but the animal presently died. In our diagram, then, each 



