oyo GROWTH AND THE AGING PROCESS I4 



a whole is showing a loss or deficit. Studies with radioactive isotopes indicate that 

 living tissue is constantly exchanging some of the amino acids, its building blocks, 

 for new ones acquired from the intake of food and resynthesis. In this sense, growth 

 continues its struggle throughout the life span and finally "sinks outwearied rather 

 than o'ercome"*. 



* Byron — The Corsair, Canto the Second, VI. 



