A Correlation between the Compositions of Deoxyribonucleic and Ribonucleic Acids

WE have shown that the composition of the ribonucleic acid of bacterial cells does not depend upon the very considerable changes in composition of deoxyribonucleic acid found when profound reorganizations of the hereditary nature of intestinal bacteria occur1,2. The composition of deoxyribonucleic acid in different bacterial species belonging to various systematic groups was shown to vary widely (from the extreme AT-type to the highest GC-type); whereas that of ribonucleic acid from these species was shown to vary slightly, small differences being noted only between very diverse species3,4. Thus the greater part of the ribonucleic acid of the cell appeared to be independent of the deoxyribonucleic acid.