Coloured scanning electron micrograph (SEM) of fruit fly (Drosophila melanogaster) emerging from a puparium. The puparium (green) has split open to enable the adult fly to leave; a process known as eclosion. The puparium consists of the hardened outer skin of the final larval instar. Inside, the larva undergoes metamorphosis; most of its cells die, but some (in regions called imaginal discs) develop the adult structures such as compound eyes (orange), legs, antennae and wings. The fly inflates its head so as to open the puparium; still with a soft exoskeleton, it then thrusts its head forwards and performs a series of pulsed contractions of its body to free itself. D. melanogaster is a model organism for research due to its short life cycle and simple genetic makeup. Many varieties exist, with differing eye and body colours; this fly is Oregon R: the colours are false. Magnification: x60 at 10x8.