WATER RELATIONS OP FROG 



113 



being retained in the cloaca) always increases, at diverse rates that 

 climb with the deficit. When these initial rates are studied indi- 

 vidually (Adolph, '39b), the standard deviations of rates among 

 members of each group of ten are quite uniformly about ± 27 per 

 cent of their arithmetical means. 



Urine formation is measurably present only in positive incre- 

 ments of water content, and in negative increments down to - 10% 



2 3 4 5 6 



Waier Output 

 Fig, 68. Water intake (% of BoAour) in relation to water output (% of Bo/hour) 

 under varying water loads, within the initial 0.5 hour and the initial 1.0 hour of recovery. 

 Each point represents the mean for 10 individuals, as in the same data of figure 66. The 

 dash line represents the state in which intake and output are equal; this occurs only 

 at water balance. 



of Bo (fig. 66). The initial rates are approximately proportional 

 to the water contents of the body above - 10%. Measurements of 

 urine production made over half -hour periods are less accurate than 

 those made over longer periods ; nevertheless at each load the aver- 

 age rate of urine production during the first 0.5 hour of recovery 

 is found to equal the rate during 1.0 and 2.0 hours. Hence the 

 intact frog shows no measurable lag in onset of diuresis following 

 intraperitoneal injection of water. 



