ml REGENERATION, OR C4R0WTH AND REPAIR 145 



rapidly increases to a maximum. The curve quickly, — almost 

 suddenly, — changes its direction, as the velocity begins to fall; 

 and the rate of fall, that is, the negative acceleration, proceeds 

 at a slower and slower rate, which rate varies inversely as some 

 power of the time, and is found in both of the above-quoted 

 experiments to be very approximately as 1/T'^. But it is obvious 

 that the value which we have found for the latter portion of the 

 curve (however closely it be conformed to) is only an empirical 

 value ; it has only a temporary usefulness, and must in time give 



2 4 6 8 

 Fig. 39. Daily increment, or amount regenerated, corresponding to Fig. 38. 



place to a formula which shall represent the entire phenomenon, 

 from start to finish. 



While the curve of regenerative growth is apparently different 

 from the curve of ordinary growth as usually drawn (and while 

 this apparent difference has been commented on and treated as 

 valid by certain writers) we are now in a position to see that it 

 only looks different because we are able to study it, if not from 

 the beginning, at least very nearly so : while an ordinary curve 

 of growth, as it is usually presented to us, is one which dates, not 



T. G. 10 



