ioo ANIMAL LIFE 



generous and ungrudging is the renewal, so serenely 

 is the new man made, that we forget that all balance 

 is complex adjustment and all progress hardly won. 

 We mark, not the loss that energy entails, but its sus- 

 tained and transforming activity. Artists by nature, 

 we rightly overlook the pains of effort. But if we 

 are to comprehend the working of that mysterious 

 life the activities of which arrest us, then we must 

 be possessed by the conception of the downfall which 

 precedes every uplifting in the transformation of living 

 tissues. The more thorough the burning, the more 

 complete will be the reconstruction, and health is as 

 dependent on the one as on the other. We rise 

 Phoenix-like out of our own ashes. As we obtain 

 explosion by confining the area and increasing the 

 rate of expanding activity, so a muscle gives out in one 

 convulsive movement a force which at other times is 

 spent in gentle and repeated efforts. But whether 

 gentle or explosive, muscular action is only sustained 

 by oxygen, and the more vigorous the effort, the greater 

 the demand. 



As for muscles, so for other tissues. Our very 

 bones are constantly being renewed. Where the 

 seeming waste is greatest, there the new growth is most 

 active ; and should this new growth be no reproduction 

 of the preceding part, but an addition or new develop- 

 ment, then it is subjected still more fiercely to the 

 alternate tides of waste and repair. Breakdown by 

 oxygenation, reconstruction by feeding, is the rule by 

 which we live and move and work out our being. 



