Strands of hair believed to have fallen out of Charles Darwin's beard will go on show in public for the first time tomorrow in what is expected to be a blockbuster exhibition on the Victorian naturalist.
The wisps were discovered this summer by Randal Keynes, Darwin's great-great grandson, while he looked through the contents of a small leather box that had been kept by Darwin's daughter Etty.
They were wrapped in tissue paper marked "remaining hair" and placed in an envelope on which Etty wrote "Found after his death in my father's papers".
The small collection of loose hairs, which are going on display at the Natural History Museum, are thought to have fallen from Darwin's beard on to his writing desk, where they were collected when he died in 1882.
It is believed the women in Darwin's household wanted to keep a lock of his hair but had not managed to do so before his body was taken from their house for burial at Westminster Abbey.
Instead, it is thought that they looked in his study for loose hairs that had fallen from the long, wispy beard of the author of On the Origin of Species.
Darwin's wife, Emma, who was from the Wedgwood family, gave the box to her daughter Annie, who died at the age of 10, and it was then passed down to Annie's younger sister Etty.
The box, to be shown at the museum's Darwin exhibition, also contains shells that Darwin brought back from his famous five-year Beagle voyage to explore and map the oceans and islands of South America and the South Pacific.
It also contains shells collected by Darwin's children, which they labelled with scraps cut from their father's hand-written notes.
Other attractions in the exhibition include a live green iguana, a horned frog from South America and Darwin's personal notes debating whether to marry Emma.
Notebooks, artefacts, personal belongings, fossils and zoological specimens show how Darwin developed the idea of evolution by natural selection.
The exhibition also contains a reconstruction of Darwin's study at Down House, his home in Kent, where he refined his theory of evolution and completed On the Origin of Species.
Alex Gaffikin, exhibition developer at the Natural History Museum, said: "This is a truly remarkable collection of family heirlooms and specimens that brings us all just a bit closer to the great man himself, as well as his family.
"We can almost feel like we explored the Galapagos ourselves."
The exhibition is part of Darwin200, a national programme of events celebrating Darwin's ideas, impact and influence around the 200th anniversary of the Victorian naturalist's birth.