2 5 o AGE, GROWTH, AND DEATH 



say that we have established the following four laws 

 of age : 



First, rejuvenation depends on the increase of the 

 nuclei. 



Second, senescence depends on the increase of the 

 protoplasm, and on the differentiation of the cells. 



Third, the rate of growth depends on the degree of 

 senescence. 



Fourth, senescence is at its maximum in the very 

 young stages, and the rate of senescence diminishes 

 with age. 



As the corollary from these, we have this natural 

 death is the consequence of cellular differentiation. 



