Nail base. Coloured scanning electron micrograph (SEM) of the base of a finger nail. The nail (grey) is composed of a hard translucent form of the protein keratin. The top layer of the skin is composed of dead keratinised cells that are continuously sloughed off and replaced with new cells from below. Magnification: x30 when printed at 10 centimetres wide.
(I am both disgusted and interested by this picture)