English: This image depicts a composite of two, highly-magnified, negative stain transmission electron micrographic (TEM) images of two forms of the monkeypox virus. On the left is an example o the C-form, or capsular-form, of a monkeypox viral particle, and on the right, a M-form, or mulberry-form of the virus. These two brick-shaped particles were discovered in a cell culture. The surface of the M-form virion is covered with short, whorled filaments, while the C-form virion, is penetrated by stain, and presents itself as a sharply defined, dense core surrounded by several laminated zones of differing densities.