Abstract
The particles of measles and distemper viruses have been examined in the electron microscope and the technique of negative staining was used. The diameter of virus particles varies from 120mμ to 600mμ and the structures of the viruses are very similar for each other. The particles have an internal herical component about 18-20mμ diameter, enclosed in the outer membranes with the spikes. The virus particles are pleomorphic.
