The Dutch scientist Jan Swammerdam was one of the first researchers to study insect metamorphosis. Using the recently-invented microscope, he proved that metamorphosis was the life cycle of a single insect rather than the rebirth of different animals. Swammerdam’s Historia Insectorum Generalis (1669) was known to Merian. This English translation of the Historia, published in 1758, was edited by the influential botanist Sir John Hill (c.1714–1775), who owned the Merian drawings in the Royal Collection before they were acquired by George III.