EQUILIBRATIONS IN PARTS OF ORGANISMS 167 



mainder of the body, and between arm and remainder through 

 transport in plasma, are more rapid than exchanges in isolated 

 muscle that has no vascular circulation. All recoveries are without 

 measurable lag. 



Whatever divisions of labor there may be between individuals 

 and their component parts, both kinds of units (whole and part) 

 undergo, each in its own way, adjustments of water content. The 

 vicissitudes of existence may often be diverse for each kind, but 

 also sometimes not. Hence it is possible to select like tasks of regu- 

 lation for rabbit, for rabbit blood, and for rabbit leucocyte; for 

 example, each might recover from a deficit of water of like magni- 

 tude. Roughly, to return half its deficit, the whole body requires 

 0.02 hour (fig. 74), the blood requires perhaps 1.3 hours (fig. 94), 

 and the leucocyte requires 0.008 hour (fig. 100). Data are not 

 available for comparing recoveries from deficits of one identical 

 type and size that in fact proceeded simultaneously. 



A protection to the part is afforded by the fact that it keeps its 

 place in the whole body, just as the whole organism's water content 

 is regulated to some degree by keeping itself in certain environ- 

 ments. For, the body limits the loads to which the part is exposed. 

 And, the body facilitates the exchanges of water by which the part 

 recovers. The relations between the organism and its constituent 

 cells and tissues, therefore, may be equivalent, in part, to those 

 between the environment and the whole individual. 



