70 NUCLEOPROTEINS AND NUCLEIC ACIDS 



Species and tissues and from different locations within the cell 

 has, moreover, demonstrated that while the differentiation 

 between species and organs on analytical grounds meets with dif- 

 ficulty, differences between nuclear and cytoplasmic nucleic acids 

 can be shown^^. 



6. REMARKS ON FUNCTIONS 



The spectator who has followed the development of our knowl- 

 edge of nucleic acids in the past few years cannot help feeling 

 that the stage is set for a grand finale. Many an acrobat has an- 

 nounced the salto mortale to a gasping audience (hoping to 

 change it into a salto immortale); and though often only a grace- 

 ful pirouette could be seen, tamen est laudanda voluntas. But I 

 beUeve that the deeper we get, the darker it becomes. It is true, 

 the temptation is almost overwhelming to pour all into one pot: 

 growth, and its change from benign to malignant; bacterial trans- 

 formations; the transmission of hereditary properties; the multi- 

 plication of virus and phage; the synthesis of inducible enzymes; 

 the differentiation of tissues; the formation of antibodies — every- 

 where an interplay between nucleic acids and proteins, a spin- 

 ning wheel in which the thread makes the spindle and the spindle 

 the thread. But if it is hard to recognize the similarities between 

 what is ostensibly dissimilar, it is even more difficult to make out 

 the differences between what appears so similar; and moderation 

 still is among the tools of our science. 



Brushing past, therefore, the heralds of immediate glory and 

 convinced, as I am, that we are not obliged to solve the secret 

 of life in 1955, I must conclude that the actual and established 

 evidence on direct biological functions of the nucleic acids is 

 rather meager. I should, furthermore, question whether a search 

 for functions, at any rate in the narrowly anthropomorphic 

 framework of a vulgar teleology, is what we need most at the 

 moment. 



The relevant information on the biological roles of the deoxy- 

 pentose nucleic acids^^ and the pentose nucleic acids^ has been 



