CODE-SCRIPT OF BIOLOGICAL HIGH POLYMERS 119 



have alluded before. In all our following discussions we must 

 keep in mind that the nucleic acids are devoid of any perceptible 

 periodicity or of recognizable repeating subunits. They are high 

 polymers of a largely arrhythmic nucleotide sequence which is, 

 however, not random. 



Until our first results were pubHshed in 1948 and 1949 

 (Refs. 16, 17) the nucleic acids, within their two known sugar 

 categories, were considered as analytically indistinguishable; the 

 problems posed by their analysis were not even seriously dicussed. 

 Now, the great diversity in the composition of the nucleic 

 acids is recognized generally. I limit myself here to two exam- 

 ples (Tables 20, p. 87, and 26). Although occasionally nucleic 

 acids from widely distant cellular sources are encountered that 

 cannot be distinguished by constituent analysis, it is safe to 

 assume that different species never produce identical nucleic 

 acids. 



But do the same cells always produce the same nucleic acids; 

 in other words, do the nucleic acids exhibit the property of 



TABLE 26 



NUCLEOTIDE RATIOS IN RIBONUCLEOPROTEINS* 



* Taken from previous papersi8-22^ Abbreviations: A, adenylic acid; G, 

 guanylic acid; C, cytidylic acid; U, uridylic acid; Pu, purine nucleotides; 

 Py, pyrimidine nucleotides; 6-Am (6-amino nucleotides), A + C; 6-K 

 (6-keto nucleotides), G + U. 



References p. 125 



