Japanese encephalitis virus was found to grow in vitro in a variety of tissues from the heron, an important avian host of virus in Japan. Cultures of heart, thigh muscle, lung, liver, spleen, stomach and intestine, and brain produced titers of virus similar to those which occur in blood of naturally infected herons. These findings suggest that viremia in herons results from virus proliferation in many tissues, and that if, like western equine encephalomyelitis virus16 JE virus remains dormant in birds, it might do so in a number of tissues rather than in a single tissue. However, no evidence was found of sequestered virus in 8 herons whose tissues were cultured first in vitro before inoculation of suckling mice.
Present address: Department of Bacteriology and Immunology, University of Minnesota, Minneapolis 14, Minnesota.