CORRELATIVES OF WATER CONTENT IN OTHER SPECIES 



247 



were replaced in water ; they fully recovered their water contents 

 before analysis. Volume of collectable blood, whether measured 

 by washout (Griirber, 1889) or by drainage (Smith and Jackson, 

 '31), decreases relatively more than the partially desiccated body 

 as a whole. When the same tissues manifest both losses of weight 

 and changes of composition (dilution of dry residue), it is possible 

 to compare the increments of tissue volume as found by the two 

 independent methods (table 26, columns 3 and 7) ; actually they 

 yield similar values in all organs except liver. 



+30 



+ao 



*\0 



I- 



-ti -}0 



-ao 



-30 



Froc 



Liver ^ A 



Blood/' ij 



/ A j Muscle 

 ^—■^ IStomach 



-30 -20 



-\0 +10 +10 +30 



Water Lood 



Fig. 132. Increment in dilution of tissue (% of control) in relation to water load 

 (% of Bo). Frog, Dilutions are measured by ascertaining dry residue in weighed 

 samples, whence AE = 100(Do/Di) - 100. In negative loads each point is the average 

 of 4 individuals of ^ana esculenta (Eey, '37, p. 1120) ; in positive loads each point is 

 the average of 12 individuals of Eana pipiens (new data). 



It is evident that in extreme desiccation the interstitial fluid 

 (= the non-collectable juice) of the frog suffers greatest reduction. 

 The blood is next greatest. Perhaps the circulating tissues of the 

 body, therefore, change most. Other measures of dilution are 

 modified similarly to dry residue (specific gravity, enumeration of 

 blood erythrocytes, Durig, '01, p. 414). In general (fig. 132 and 

 table 27) the relative dilutions differ among various tissues at 

 similar water loads of the body. If there are any depots for water, 

 they are the blood and lymph. Since with water load the dilutions 



