12 CHEMICAL SPECIFICITY OF NUCLEIC ACIDS 



TABLE 2 

 COMPOSITION OF DEOXYRIBONUCLEIC ACID OF OX 



(in moles of nitrogenous constituent per mole of P) 



TABLE 3 



COMPOSITION OF DEOXYPENTOSE NUCLEIC ACID OF MAN 



(in moles of nitrogenous constituent per mole of P) 



organs, the composition of two deoxyribonucleic acids of micro- 

 bial origin, namely from yeast^^ and from avian tubercle bacilli^^, 

 is summarized in Table 4 (Ref. 31). 



The very far-reaching differences in the composition of 

 deoxypentose nucleic acids of different species are best illustrated 

 by a comparison of the ratios of adenine to guanine and of 

 thymine to cytosine as given in Table 5. It will be seen that in 

 all cases where enough material for statistical analysis was 

 available highly significant differences were found. The ana- 

 lytical figures on which Table 5 is based were derived by com- 

 paring the ratios found for individual nucleic acid hydrolysates 

 of one species regardless of the organ from which the preparation 



