METABOLISM AND FOOD 79 



or the decomposition of the protein. This result 

 was repeatedly supported by further investigations 

 with sheep, fattening oxen, and geese, and also 

 with carnivorous animals, so that it has been 

 proved that domestic animals form large quantities 

 of fat from carbohydrates. The question then 

 arose whether by this transformation the carbo- 

 hydrate portion of the food protein played a 

 direct or indirect part. On the false assumption 

 that it is necessary to give a large supply of protein 

 in a feeding ration, many believed that the forma- 

 tion of fat from carbohydrates could not take place 

 completely without the help of protein. A case 

 is seen on page 72, Experiment III, where a con- 

 siderable quantity of fat was formed when no pro- 

 tein at all was given. The small amount of pro- 

 tein matter came from the body tissue, the food 

 consisting only of carbohydrates with a little fat. 



In other investigations carried out with the help 

 of the respiration chamber, it was shown that the 

 formation of fat took place whether the relation of 

 digestible protein in the food was i : 2-4 of nitrogen- 

 free substance or i : 12-14 of the latter. With 

 oxen it was proved in the same way that from each 

 kilogram of digestible nutrients above the mainten- 

 ance ration, the following quantities of body fat, 

 202, 202, 217 grams, were obtained. In these three 

 cases the relation of digestible protein to nitrogen- 

 free extract was i : 4, i : 10-11, i : 16 respectively. 



