Butterfly metamorphosis inside its chrysalis. This sequence was produced from reconstructed computed tomography (CT) scan data, which shows the internal detail of a caterpillar's transformation into a butterfly within its chrysalis. Initially the caterpillar's internal organs are seen, mainly its digestive tract and the network of breathing tubes along its length. As the metamorphosis progresses, the internal structures become increasingly complex. New organs appear in red, including the wings, which appear first, and the eyes (far left), limbs and the hard exoskeleton. When the adult butterfly emerges, it expands its wings to their familiar form by pumping in haemolymph (insect \blood\).