166 WHAT IS LIFE 



death occurs. Death may be "natural": Raymond 

 Pearl shows that "duration of life belongs in the 

 category of genetically definite and workable char- 

 acteristics."^ "For each organism," as Pearl says, 

 "there is a specific longevity determined by its 

 inherited physico-chemical constitution."^ Or death 

 may be due to any one of a number of other causes 

 (disease, injury, poisoning, starvation). However 

 caused, always death is nothing more and nothing 

 less than this rupture, or separation. 



This definition of death necessarily results from 

 my theory of life, and complements it. For if (as 

 theory asserts), the organism is a dual system, and 

 life, or the Z-system, is an intraatomic quantity, 

 then the cessation of the activities of the system (the 

 death of the organism) must mean the expulsion, or 

 separation, of the quantity life, since the elementary 

 units which (in peculiar organization) constitute the 

 Z-system, life, cannot he disposed of in any other way. 

 Though in the atoms that (in almost countless 

 numbers and of various kinds) make up the body, 

 there is superabundance of space to contain within 

 them an electrical system, yet the exquisitely exact 

 quantitative (numerical) relations of electrons that 

 determine the chemical atcm — every atom of mat- 



" American Naturalist, LVI, 187. 

 3 The Biology of Death, 49. 



