Metamorphosis has always been one of biology''s greatest wonders and toughest riddles. To emerge a butterfly, a caterpillar dissolves inside its chrysalis and builds a brand new brain, wings and legs. Why all this destruction and remodelling? Why all this wasted energy and time?Oren Harman beautifully unfurls the untold story of metamorphosis across two millennia, asking why it has obsessed and inspired us so profoundly. Along the way we meet poets, artists, philosophers, and a cast of scientists as colourful as the animals themselves: whether Aristotle determining cucumbers had souls, Sigmund Freud searching in vain for eel testicles, or a Japanese zoologist singing karaoke to a baby jellyfish.Taking us on an exhilarating journey through the creatures that metamorphose - a staggering three-quarters of all animal species - from starfish reproducing in reverse in ocean depths, to poison dart frogs on steaming rainforest canopies, to human adolescents struggling to control themselves, Metamorphosis is a new classic of natural history: a book that, by explaining a mystery of nature, causes us to relearn ourselves.