CORRELATIVES OP WATER CONTENT IN OTHER SPECIES 



251 



TABLE 29 



Increments in dilutions (^E) of tissues, in per cent of Eg, computed from analyses of dry 

 residues (A/O), in various species 



by restriction of food intake. The long period of time that elapsed 

 during water restriction marks a type of water deficit unlike that 

 by more temporary water restriction. Water here appears to have 

 the same role as any other indispensable food ; its continued deficit 

 in the body automatically inhibits the taking of all other foods 

 (anorexia), with inevitable deficit of total substance in the body. 

 That is a restatement of the above facts in the language of incre- 

 ments. 



"§ 92. Comparisons 



Other species than mammals and frogs have been studied only 

 in isolated respects. A few observations of tissue concentrations 

 exist upon pigeons (Schuchart, 1847; Falck and Scheffer, 1854a) 

 and chickens (Pernice and Scagliose, 1895; Korr, '39). Measure- 

 ments of oxygen consumption and carbon dioxide production in 

 desiccation have been extended to several insects and molluscs 

 (Caldwell, '25; Thompson and Bodine, '36). Only by confusing 

 diverse types of water load could a considerable body of compara- 

 tive data be aligned. Among the meagre materials already men- 

 tioned, what uniformities and what contrasts are found? 



What measurements could conceivably be made upon all kinds 

 of organisms whose water contents are modified? None would be 

 suitable that depend on morphological similarity; hence besides 



