Intranuclear Changes in the Polyhedrosis of Tipula paludosa (Diptera)

Abstract

THE technique of cutting ultra-thin sections for electron microscopy has made it possible to follow the behaviour of certain viruses in the cell, and this is particularly true of the nuclear virus diseases of insects. The present note describes the remarkable behaviour in the nucleus of the polyhedral virus which causes a blood disease in the larva of the fly, Tipula paludosa ¹. Sections through blood cells in the early stages of infection show an apparent condensation of the chromatic material in the centre of the nucleus in which the virus rods can be seen developing (Fig. 1). Most of the virus rods at this stage are concentrated in the centre though some occur scattered throughout the nucleus. The virus rods are never observed on the outer side of the nuclear membrane.