228 PHYSIOLOGICAL KEGULATIONS 



etc.). It increases both when food is given with the water and 

 when not. The increased rate of secretion might be more closely 

 related to the water load either of the body or of the alimentary 

 tract (of the stomach itself). Whether the rate of juice output 

 from the walls of the stomach that are in contact with water given, 

 is the same as from pouch separated from the water, is not certain 

 (Sutherland, '21). While the stomach produces more fluid, it also 

 produces more acid and chloride (Ivy, '18). 



Bile output through a fistula is apparently not consistently 

 affected by water excesses (Bidder and Schmidt, 1852, p. 162; Snell 

 and Rowntree, '28). The composition of the bile is not signifi- 

 cantly changed. 



Intestinal juice, pancreatic juice, buccal mucus, and colonic ex- 

 cretion have probably not been measured in terms of output rates, 

 in water loads such as are being studied here. 



It has not been demonstrated that a quantitatively reproducible 

 correlation exists between water load and rate of any one alimen- 

 tary output. Many physiologists are confident that passage of 

 water into the alimentary tract "stimulates" the output of several 

 juices. Existing data show extreme irregularities of performance, 

 even with uniform procedure. On top of this is the uncertainty as 

 to what numerical water loads (of absorbed water) prevail during 

 and after the administrations and privations of water. The near- 

 est thing to a correlation at present is between salivary output and 

 size of water deficit. One of the motives in obtaining those mea- 

 surements was the hypothesis that shortage of saliva might be fur- 

 nishing a tangible signal to other organs and tissues of the dog, 

 leading to compensatory responses. But since shortages of water 

 have been observed in several diverse fluids and tissues, there is 

 less occasion to think of any single one of them as providing a 

 message. 



(2) Food intake is greatly reduced in water privation, as was 

 noted in early experiments {e.g., Pernice and Scagliosi, 1895). 

 This is not true on all diets nor at all loads, and quantitative studies 

 are needed. With the anorexia have been correlated qualitative 

 decreases of gastric motility (Rose et al., '31) originally on the 

 assumption that a ''direct connection" between them exists. No 

 criterion appears to have been proposed in physiological science for 

 distinguishing a direct connection from an indirect one. Perhaps 

 a useful statement of the situation is that by habitual mental associ- 



