DEOXYPENTOSE NUCLEIC ACIDS 59 



There is little doubt that these fractions should not be con- 

 sidered as individuals. If we are dealing with a continuous 

 spectrum, as I have suggested, it may, in fact, be impossible to 

 isolate what could be considered as a rigorously homogeneous 

 specimen; it is not easy even to imagine a proper criterion for 

 such a decision. Conceivably, no two nucleic acid molecules, 

 within the same nucleus, are entirely identical. But here we clash 

 against the definition of a macromolecule; and seeking refuge in 

 statistics, the science of reconcihng the parallels, we may con- 

 clude that it is hard to fight on a front where friend and enemy 

 wear the same uniform. 



References p. 60 



