Sixteen-week-old dogs were inoculated with 20,000 tissue culture doses (TCD50) of infectious canine hepatitis virus. Four days after inoculation, liver cells examined in the electron microscope contained both virus particles and nonviral paracrystalline formations. Tissue culture cells also contained virus particles and nonviral paracrystalline formations 48 hr after inoculation with virus. When Epon-embedded sections were treated for 1 hr with 0.5% pepsin in 0.1 N HCl, a selective extraction of the viral coats and of the nonviral paracrystals was observed.