Addendum to Parts I, II and III

Abstract

Since completion of these three papers our attention has been drawn to a publication by L. Silvestri (1949 Boll. 1st. sieroter. Milano , 28, 326). This work reports results which are relevant to all three papers now submitted. In particular Silvestri has shown that the inactivation of T 2 treated with HN 2 is not complete until 2 h after removal from the agent, although the conditions which he employed did not permit an accurate assessment of this nor reveal its cause. He also claims to have found an increased proportion of host-range mutants in the progeny of cells of E. coli infected with HN 2-treated T 2 at multiplicities greater than 1; this demonstration also involved incidental evidence of multiplicity reactivation of the treated phage. We have been unable, however, to obtain convincing evidence of an increase in the proportion of cells yielding host-range mutants following infection with HN 2-treated T 2. We are indebted to Dr David R. Krieg of the Oak Ridge National Laboratory for drawing our attention to the above publication.