Influence of temperatures corresponding to those of the host animals on Tahyna virus.

The influence of temperature of 36.5 and 39.2 degrees C on uncloned low passage Tahyna virus in chick embryo cell cultures was studied in the course of 10 passages. At a high multiplicity of infection, the virus titres showed a considerable variability, especially at 39.2 degrees C. The cytopathic effect (CPE) apparent at both temperatures started later and was of lower intensity at 39.2 degrees C than at 36.5 degrees C. The temperature of 39.2 degrees C intensified the thermostable character of the virus. Changes in plaque size and virulence were connected mainly with the cultivation substrate of the virus.