8o THE PHYSIOLOGY OF PROTEIN METABOLISM 



storage of nitrogenous material in the tissues. He suggested that 

 after liberal feeding with protein food there was an increase in 

 the functionating cell material in dogs, but that this increase of 

 active cell material did not last long. The only condition, which 

 altered this natural tendency to get rid of the stored material 

 rapidly, was when an increase in the amount of muscular work had 

 to be carried out at the same time as there was the increased supply 

 of protein. Bornstein (70) had previously reached much the same 

 conclusion. He could always get a marked retention of nitrogen in 

 the tissues, if simultaneously with the increased protein supply much 

 work was carried out. Thus, when he added to a ground ration of 13-21 

 grms. nitrogen per diem 6-75 grms. nitrogen in the form of caseinogen, 

 and at the same time did 17,000 mkg. of work daily, there was a defin- 

 ite retention of nitrogen, which he believed was in the form of flesh. 

 The nitrogen retained was equal to about 800 grms. flesh ; the calculated 

 increase of weight during the period of experiment (eighteen days) 

 amounted to 773 grms. ; the actual increase, ascertained by weighing, 

 was 800 grms. He concluded that if this " activity hypertrophy " were 

 to take place readily then there must be an abundant supply of protein 

 food. Seitz (368) has demonstrated by actual analyses of the liver that 

 storage of protein material took place in the hepatic cells. This worker 

 carried out two series of experiments on hens and ducks. Four birds 

 in each experiment were starved for eight days, then two were killed and 

 the livers immediately analysed, whilst the other two were fed on cod 

 flesh free from both fat and glycogen : 



These figures, although perhaps far from conclusive, show at least 

 that in the case of the livers of the fed birds there is a greater content 

 of nitrogen than in those of the starved ones. Of course this does not 

 settle in any way the form in which the protein is stored. Schryver 



