WATER EELATIONS OF OTHER SPECIES 



125 



for any other species {± 5.2 CA). The consistency among rates 

 of intake is partially related to the regime of green food, but dif- 

 fers greatly among ten individuals on the same diet (Gompel et 

 ah). The concurrent urinary output is somewhat more variable 

 (± 11.8 CA daily in HI), as though drinking is of greater concern. 

 In water content the daily variability of HI (15 days) appears to 

 be CA ± 1.53; of individual Z4 (80 days), CA ± 1.49. The varia- 

 tions are greater than in dog and man by about the same ratio as 

 the turnover rates. 



-4 -2 +2 



Total Water Load 



Fig. 74. Eate of total water exchange (% of Bo/liour) in relation to water load 

 (% of B„). Equilibration diagram for rabbit. In deficits, gain by voluntary ingestion 

 in first 1.0-hour, and loss by all paths, together with turnovers, are measured in two in- 

 dividuals supplied with food ; new data. Dash line =: theory that intake equals deficit. 

 In excesses, loss is from the animals of series B in figure 72, but is limited to the first 

 1.0 hour after loading and has 0.3% of Bo/hour as evaporative loss added to the urinary 

 loss; gain is oxidative alone, from data of Heilner ( '07). 



The rabbit is characterized, therefore, by rapid rates of water 

 intake, like the dog's, in recoveries from deficits; and by elimina- 

 tion of small excesses at rates proportional to loads, but of ex- 

 tremely large excesses at a uniform maximal rate. In 24-hour 

 periods the variability of body weight is somewhat greater than 

 that of the larger species dog and man. Eates of intake are gen- 

 erally less variable than in other species observed. Equilibration 

 of water content involves all the processes present in the other two 

 species of mammals, at rates that relative to body weight are as 

 high as in the dog. 



