Negatively-stained transmission electron microscopic (TEM) images revealed some of the ultrastructural morphology exhibited by a number of different microorganisms. Panel "A" represents a composite micrograph, created for the purpose of comparing the size difference between a poxvirus at the top, a bacillus in the middle, and a herpesvirus at the bottom. Panels "B", "C", and "D" are TEMs depicting the sequential degeneration of variola virus particles.