Small white butterfly egg. Coloured scanning electron micrograph (SEM) of an egg of the small white butterfly (Pieris rapae). Eggs are laid singly on the underside of leaves of Brassica plants (cabbage, broccoli) and nasturtiums. The sculpted shell is made of a protein called chorionin and has central aeropyles, breathing pores (brown), that allow air to flow to the developing embryo. Magnification: x160 when printed at 10 centimetres tall.
