**A.** UV-sensitivity of lysogens. Strains: wild type non-lysogen, AB1157; Lambda lysogen, EL104; Lula lysogen, EL103. The data points are means of 3–4 independent measurements, done on different days, ± SEM. **B.** Phage titer in saturated cultures of wild type (EL103 and EL104) and Δ*recA* lysogens (Lula, EL105; Lambda, EL106). The data points are means of five independent measurements, done on the same day, ± SEM. **C.** Cell titer versus Lula titer in the culture of a Lula lysogen (EL103) as a test for possible quorum sensing. Note that X axis is in log scale, as the left Y axis, but the right Y axis (for the lower curve) is linear. **D.** Stability of Lambda in saturated cultures of Lambda lysogen (EL104) and non-lysogen (AB1157). The data points are means of 3 independent measurements, done on different days, ± SEM. **E.** Stability of Lula in saturated cultures of Lula lysogen (EL103) and non-lysogen (AB1157). The data points are means of 3 independent measurements, done on different days, ± SEM. **F.** Stability of Lambda and Lula against aerosolation. The loss of phage titer in either stationary or rapidly shaking (to generate frothing) 1% NaCl suspensions was determined at two time points.