WATER EELATIONS OF FROG 121 



are more rapid than net losses. No data are available in steady 

 states of water excess or deficit. 



Eandom variations preserve water content with a CA of ±: 2.22% 

 of Bo in 24-hour periods. This indicates the accuracy with which 

 intake equals output, for 40% of Bq of water is turned over in each 

 of these periods. 



Desiccated dead frogs exchange water initially at rates equal 

 to living ones. Frogs kept out of water recover from excesses 

 more slowly than those in water. Water is not lost (excreted) 

 through the skin, when evaporation is prevented, in response to 

 water excesses. 



With an entirely different path of water intake (the skin) from 

 that present in mammals, a qualitatively similar diagram is present 

 except that intake through the skin persists when water contents 

 are already excessive. Quantitatively, recoveries occur at rates 

 roughly similar to those in man, and much slower than in dog. 

 Recoveries from deficits exceed in rate the recoveries from ex- 

 cesses, even as they did in man and dog. Quantitative comparisons 

 with other animals will be shown later (chapter IX). Living in 

 an aqueous medium does not mean that fewer or slower compen- 

 sations are provided for the recovery of usual water contents, nor 

 that the organism is careless of what the content is. 



