RECOMBINATION IN VIRUSES AND BACTERIA 



117 



Intact phages 



Star pattern 





Average of 

 25 arms 



DNA released from 

 phage coat 



Average of 

 10 arms 



First-cycle 

 phages 



Average of 

 5 arms 



Second-cycle 

 phages 



Average of 

 5 arms 



FIGURE 5.2. Diagram of the results of the star experiment which traces DNA during 

 phage development (after Levinthal, 1957, in: McElroy and Glass, The Chemical Basis 

 of Heredity, p. 737, Baltimore, The Johns Hopkins Press)." 



"Recent evidence (Rubenstein, Thomas 6i Hershey, 1961, Proc. Nat. Acad. Sci., Wash., 

 47:1113), which shows that the DNA in bacteriophage is a single intact molecule, requires 

 that this experiment be reinterpreted. 



