Notebooks that belonged to Charles Darwin that were thought to have been lost now seem to have likely been stolen, CNN reports.
These notebooks include the one with his famous sketch of the 'Tree of Life,' it adds. It notes that the notebooks were removed from Cambridge University Library's special collection to be photographed back in September 2000 and while logs recorded the photographs were completed by November 2000, a check in January 2001 found the box had not been returned to its spot.
According to BBC News, librarians initially thought the notebooks may have been misfiled, but searches of the collection, including one this year, have come up empty. Jessica Gardner, the university's librarian, tells the BBC that they have had to conclude the notebooks were stolen. She adds that they won't stop looking and encourages anyone who might have any information to get in touch with the library or the Cambridgeshire police.
While the notebooks have been digitized, Cambridge's Jim Secord tells the BBC that those versions are not a replacement for the real thing, which he says is "almost like being inside Darwin's head."