METABOLISM DURING STARVATION 



339 



Metabolism with Excess of Protein. When an animal excretes in 

 the urine daily the same amount of nitrogen as it is receiving in the 

 diet, it is said to be in a state of nitrogenous equilibrium. If the 

 amount of the nitrogen taken in be suddenly increased (for example, 

 an animal is put on to a lean meat diet), the nitrogen output goes up; 

 but at first the amount of nitrogen excreted lags behind that ingested, 



B 



FIG. 189 A. 



Chick A, weight 162 gms. ; Chick B, 342 gms., are birds of same age (81 days). A re- 

 ceived corn gluten food, B received lactalbumin in addition. Chicks C and D 

 also (81 days old) received corn gluten and cottonseed flour. A gained 52 gms. 

 in 55 days ;'/?, 283 gms. in 55 days ; C, 284 gms. in 53 days ; D. 322 gms. in 53 days. 

 (Osborno and Mendel.) 



so that nitrogen equilibrium is not attained for several days 

 generally three to five, the time varying according to the nature of the 

 protein fed. During these days the animal is storing up nitrogen 



