A keepsake box containing Charles Darwin’s shells is being returned to the family home.

The shells were gathered by Darwin on his famous Beagle Voyage, where his observations led him to develop his theory of evolution.

Darwin’s descendants have donated the red leather box and its “treasures” inside to English Heritage, who will display the object at what was Darwin’s home – Down House, in Kent.

The Victorian box belonged to Darwin’s daughters, who filled it with family mementos.

Darwin and his wife Emma gave the box to their eldest daughter Annie but when she died, aged 10 in 1851, the box passed to her sister Henrietta.

Henrietta (Etty) continued to fill it with souvenirs, including locks of hair belonging to members of the Darwin family, Darwin’s silk handkerchief and the shells.

His daughters carefully labelled the objects using scrap paper from the naturalist’s draft manuscripts.

The box has now been donated to English Heritage from the estate of Richard Darwin Keynes, great-grandson of Charles and Emma Darwin.

Speaking on behalf of the Keynes family, Simon and Randal Keynes, the great-great-grandsons of Darwin, said: “We are delighted to return this box, long treasured by Darwin’s daughter, Etty, and granddaughter, Margaret, to Down House for display among the other objects there which remind visitors of its many years as a family home.”

Darwin lived at Down House for 40 years until his death in 1882 and it was here that he wrote his groundbreaking masterpiece, On The Origin Of Species By Natural Selection (1859).

English Heritage said the box is a reminder that Darwin’s work and family life were “deeply intertwined”, with Henrietta helping him to edit The Descent Of Man (1871).

Its curator Olivia Fryman said: “This charming keepsake box gives us an intimate insight into Victorian habits of collecting, the life of Charles Darwin and how his scientific work and family life were intertwined.

“A treasured object, carefully preserved over the generations, the box will give visitors to Down House a valuable sense of Darwin’s work and the family who surrounded and supported him.

“We are incredibly grateful to the Keynes family for donating such a personal item.”

The donation has been announced on the 150th anniversary of the publication of Darwin’s book, The Descent Of Man And Selection in Relation to Sex (1871), in which he applied his theories of evolution to mankind.

The box will go on display later in the year.