172 



PHYSIOLOGICAL KEGULATIONS 



only in those living units whose total gains and total losses are 

 known. 



(2) Modification ratios. The responses to change in load, in 

 terms either of total exchanges or of various paths, may be mea- 

 sured by comparing the maximal and minimal rates of exchange 

 found (table 10). Proficient adjustment calls for very rapid move- 

 ment of water at one time, little at another. At a glance it is 

 apparent that oxidative gain is no factor in recovery. Nor is 

 either fecal or evaporative loss greatly concerned in restoring 

 water balance in any species studied, or under any conditions 



TABLE 10 



Bates of water exchange {per cent of Bq, in first 1 Jiour of recovery) when water load 



and at 



TABLE 11 



Modification ratios, augmentation ratios, and partitions of 



