Herpes-Type Virus Recovery from "Virus-Free" Frog Kidney Tumors

Abstract
Virus production was induced by low temperature treatment of the "virus-free" form of the frog renal adenocarcinoma (Lucke tumor). Virus recovered after this low temperature treatment fulfilled the morphological requirements of herpesvirus. Herpesvirus development was also Induced in eye chamber transplants from these "virus-free" primary tumors. The 2 naturally-occurring seasonal forms of this tumor are temperature-related states of the same tumor. The "virus-free" tumor may contain a relatively complete viral genome in masked or latent form.