THE VACUOLATING VIRUS OF MONKEYS : II. VIRUS MORPHOLOGY AND INTRANUCLEAR DISTRIBUTION WITH SOME HISTOCHEMICAL OBSERVATIONS

Cells infected with the vacuolating virus, SV₄₀, respond by swelling to several times their normal volume. Within enlarged nuclei, virus-containing inclusions appear which are acidophilic and Feulgen-positive. The formation of nuclear inclusions is followed by the appearance of cytoplasmic vacuoles and then shrinkage of the cell. Inclusions were found to exhibit unique double staining when a light-green counterstain was used in the Feulgen reaction. The virus is of low electron density, round, and 300 A in diameter. It occurs in large numbers, singly and in short chains, and it appears to multiply at the expense of chromatin.