Description:
<jats:p>Cells of Salmonella typhi murium transduced by phage P 22 are mostly lysogenic. If the cells are infected at a low multiplicity and superinfection is excluded by antiserum, the transduced cells are not immune and no free phage is found in a culture of these cells. It is concluded that the transducing particle is a defective phage not able to establish lysogeny in the cell.</jats:p>
<jats:p>The differences between specialized transduction with phage λ and the transduction with phage Ρ 22 are discussed.</jats:p>