EXCHANGE OF MATERIAL. 463 



carbohydrates have a stronger sparing action on proteids than fats 

 (VoiT). This is apparent from the following table : 



TABLE X. 



Food. Flesh. 



Because of the great sparing action of carbohydrates on the 

 proteids, the herbivora, whose food generally contains large quanti- 

 ties of carbohydrates, easily increase in proteids (VoiT). 



While with the same amount of flesh increased amounts of fat 

 in the food do not continuously decrease the destruction of proteids, 

 according to VOIT the carbohydrates habitually decrease the 

 metabolism of proteids. This is seen from the previous table, but 

 is more apparent from the following : 



TABLE XL 



Food. Flesh . 



With the addition of carbohydrates to the food the destruction 

 of proteids increases with an increased amount of proteids. In the 

 presence of only small amounts of carbohydrates very large 

 amounts of proteids are necessary in the food to produce an increase 

 in the proteids of the body, while the result is more simply and 

 advantageously attained by considerably less proteids and propor- 

 tionally more carbohydrates. 



The action of the carbohydrates on the accumulation of fat 

 has been demonstrated by the investigations of VOIT and PETTEN- 

 KOFER showing that the carbohydrates not only decrease the 

 metabolism of fat and prevent its loss, but also cause its accumu- 



