Infection of owl monkey cells with Herpesvirus saimiri (HVS) induces the formation of a new DNA-dependent DNA polymerase with biochemical properties different from the normal DNA polymerase-beta of the host cell. The viral DNA polymerase can be detected within 1 day of infection, but shows its highest specific activity in the cell nucleus when the cytopathic effect is advanced. Neither the virus-induced DNA polymerase nor the thymidine kinase were susceptible to inhibition by the herpesvirus DNA polymerase inhibitor, phosphonoacetic acid. Murine leukemia cell lines produce hemoglobin in vitro when exposed to a variety of biological agents including butyric acid, DMSO, DNA inhibitors, and certain antibiotics. Other inducers of selected lines are SeO2, methylethylketone, ethyleneglycolmonomethyl ether, acetone, methanol, and ethanol. Butyrate both triggers hemoglobin synthesis and becomes incorporated into hemoglobin. Incorporation of butyrate does not occur with other inducers and appears to be metabolized via the propionate pathway to succinyl-CoA, by-passing the tricarboxcylic acid cycle.