UNIFORMITIES AND COMPAEISONS AMONG COMPONENTS 375 



omy quotient was not illustrated by quantitative data, and states 

 in which it varies were not ascertained. 



The most efficacious recovery might be defined as that which 

 exists when the economy quotient becomes infinity or zero ; in which 

 case either loss or gain is completely suppressed, and net exchange 

 equals total exchange. That rarely occurs, and with some excuse. 

 Perhaps it can be supposed that complete suppression appears only 

 where cessation of exchange can be managed without interfering 

 with any other component (as, when ingestive gain of water ceases 

 in the dog's positive water load). But for one exchange to con- 

 cern only one component is the exception; further physiological 

 properties are modified by the continued production of heat in posi- 

 tive heat loads, and by the continued gain of carbon dioxide in posi- 

 tive loads of carbon dioxide. Other cases of unforeseen interrela- 

 tions give rise to more elaborate and less widely accepted excuses, 

 with little descriptive foundation, such as could be given for the 

 continued intake of water by the frog in positive water loads. To 

 illustrate how unforeseen combinations arouse unwitting excuses, 

 I quote a careful observer. "The Corixidae are air breathing," 

 says Krogh ( '39, p. 118), "and one would expect their integuments 

 to be practically water impermeable. Is it possible that they take 

 up water and salt in such quantity with the food that an osmotic 

 regulation becomes necessary?" In this one expression of sur- 

 prise it is implied that oxygen exchange is highly correlated with 

 water exchange through any one surface, that impermeability is 

 less trouble than exchange, that every property of an organism has 

 fitness, and that a physiologist knows what to expect more often 

 than not. Yet no biologist mixes his data and his "derivations" 

 to a less degree; most scramble them more. 



Not only is it difficult to discover a rate of exchange that cor- 

 rects one component without affecting others; it is also apparent 

 that the relative rates of exchange among components are compati- 

 ble one with another. Heat loss by evaporation would be impossible 

 in a steady state (fig. 48) if water gain were slower than water loss 

 by this path. Even decelerations fit together ; a man would readily 

 undercool (fig. 143) if his water and heat loss by vaporization did 

 not decelerate before the heat load was entirely dissipated. 



Components that are loaded slowly also recover (unload) 

 slowly in most instances. Thus, rectal temperature and heart beat 



