Effects of Metabolic Disturbances in Infants 155 



(4) Partly due to the interrelationships (2) and (3) kidney 

 function is readily impaired by stress. 



Thus the high incidence of body fluid disturbances is 

 partly due to the occurrence of disease and partly to relatively 

 inefficient homeostatic defence mechanisms. The latter is well 



Fig. 1. Lability of osmotic regulation in 



10-day-old puppies. 

 Left column : salt- and protein- 



free diet 

 Central column : normal 

 Right column : concentrated milk 



illustrated by the observation that diets such as milk evapor- 

 ated to one-quarter of its original volume, or salt- and protein- 

 free food, bring about great changes in the tonicity of the 

 body fluids (Csapo and Kerpel-Fronius, 1933; Kerpel- 

 Fronius, 1933). After the first, the osmolarity of the blood 

 plasma in puppies rose to 526 m-osm. /I., 457 m-osm. being 

 accounted for by " hyperelectrolytaemia " ; after the second, 

 the electrolytes decreased to 232 m-osm./l. (Fig. 1). There 



