Energy in Animals 49 



and that this accumulation is by volume 

 rather than by potential. There also comes a 

 time when further training will add nothing 

 to his endurance, but even this does not end 

 his dynamic development. If an animal has 

 been trained only a short time, his energy 

 will dissipate rapidly by idleness; if he has 

 been trained longer it will take longer for his 

 energy to dissipate to the same extent by the 

 same degree of idleness ; and if we examine the 

 matter carefully we will see that the time 

 required to dissipate accumulated energy 

 down to a given point by a given degree of 

 idleness is closely proportional, if not exactly 

 proportional, to the length of time involved 

 in its concentration. Also, that this propor- 

 tional relationship goes beyond the point 

 where individual endurance is increased by 

 additional work performed, and clearly indi- 

 cates that such additional work causes an 

 additional concentration of energy which is 

 apparent by observing the quantity dissi- 

 pated. There must be a concentration before 

 there can be a dissipation. Hence, old ani- 

 4 



