English: Filamentous bacteriophage fd (Inovirus), shadowed on an electron microscope grid. The phages are not aligned and are in their natural state as flexible worm-like chains. The phage dimensions are about 6 nm width and 900 nm contour length. The electron micrograph grids were prepared and shadowed as described by Marvin and Hoffmann-Berling 1963, Z. Naturforsch. B18, 884-893. The date of this unpublished electron micrograph is 7 November 1962.