144 



THE RATE OF GROWTH 



[CH. 



to this question depends on whether, in the days following the 

 first actual measurement, we can or cannot detect a daily increment 

 in velocity, before that velocity begins its normal course of diminu- 

 tion. Now this preUminary ascent to a maximum, or point of 

 inflection of the curve, though not shewn in the above-quoted 

 experiment, has been often observed : as for instance, in another 

 similar experiment by the author of the former, the tadpoles bein^ 

 in this case of larger size (average 49-1 mm.)*. 



The acceleration curve is drawn in Fig. 39. 



Here we have just what we lacked in the former case, namely 

 a visible point of inflection in the curve about the seventh day 

 (Figs. 38, 39), whose existeiice is confirmed by successive observa- 

 tions on the 3rd, 5th, 7th and 10th days, and which justifies to 

 some extent our extrapolation for the otherwise unknown period 

 up to and ending with the third day; but even here there is a 

 short space near the very beginning during which we are not 

 quite sure of the precise slope of the curve. 



We have now learned that, according to these experiments, 

 with which many others are in substantial agreement, the rate of 

 growth in the regenerative process is as follows. After a very 

 short latent period, not yet actually proved but whose existence 

 is highly probable, growth commences with a velocity which very 



* Op. cit. p. 406, Exp. IV. 



