126 W. M. Wallace, W. B. Weil and A. Taylor 



magnesium, sodium, chloride and phosphorus than those fed 

 a high protein intake. 



B. By Electrolyte Intake. 



The high electrolyte diets led to increased calcium and 

 decreased chloride in all groups calculated on any basis. 



In the high protein groups the high electrolyte intakes also 

 resulted in more ash and less potassium when calculated on 

 any basis. 



In Table II the serum concentrations of sodium, potassium, 

 chloride and total protein are shown for the four experi- 

 mental groups. The only consistent significant difference is 

 for the concentration of total serum protein. Serum protein 

 concentrations are higher in the high-protein-fed groups. 

 The lower protein concentration may indicate protein de- 

 ficiency in the low protein group and other evidence for such 

 deficiency is given below. The validity of serum protein con- 

 centrations as a reliable index of protein malnutrition can be 

 questioned. In this connexion it is of interest that the serum 

 protein concentration of the breastfed infant is lower than 

 that of the infant fed cow's milk (Tudvad, Birch-Andersen 

 and Marmer, 1957). 



Animals in experimental groups No. 7 and No. 8 were fed 

 in such a manner as to allow accurate measurement of food 

 intake. The high protein group consumed 8 • 2 g. of ration per 

 animal per day in contrast to 9-3 g. per day for the low 

 protein group. The mean weights for the two groups at the 

 end of 23 days were 174 and 155 g. respectively. Calculation 

 of the caloric values for the whole bodies of these animals 

 shows that the high protein group contained 292 calories per 

 average animal (1,710 calories per kg.) and the low protein 

 group 263 calories per average animal (2,085 calories per kg.). 

 Calculation of the calories utilized for physiological activity 

 indicates that the low protein group expended 175 calories 

 more per animal for the period of observation than did the 

 high protein group. Increased spontaneous activity was 

 clearly evident in the low protein groups during the period of 



