Two notebooks that once belonged to British naturalist Charles Darwin have been returned to Cambridge University's library, more than 20 years after they were reported missing.
The notebooks, which contain the origins of Darwin's theory of evolution, were found on March 9 inside a gift bag that was left on the floor in a public area of the library.
The bag also contained a printed message on a brown envelope that read: "Librarian Happy Easter X".
The librarian of Cambridge University Library, Dr Jessica Gardner, said little is known about how the notebooks were returned.
"We don't know a lot, but the facts are that the notebooks were left anonymously in a public place inside the university library and they were left inside a large pink gift bag," Dr Gardner said.
"Inside the gift bag was the original archive box, just a little larger than the notebooks themselves and also a plain brown office envelope which contained the notebooks themselves.
The contents of the notebooks were used by Darwin to piece together what would become the theory of evolution, and contained his first sketch about an "evolutionary tree" after a trip around the world in 1837.
The tree was later published as a fully developed tree of life in his book On The Origin of Species.
"They may be tiny, just the size of postcards, but the notebooks' impact on the history of science, and their importance to our world-class collections here, cannot be overstated," Dr Gardner said.
The notebooks are known as the Transmutation Notebooks because Darwin theorised in them for the first time how species might "transmute" from ancestral to later forms.
Closing the chapter on a 20-year search
The notebooks were first reported missing in January 2001, after they were removed from a strong room to be photographed in late 2000.
After an "exhaustive" search, Cambridge University Library concluded that the notebooks had likely been stolen, launching an extensive online appeal in November 2020.
The appeal was launched on November 24 to coincide with Evolution Day — the anniversary of Darwin's On the Origin of Species being published on November 24, 1859.
The university had estimated the the value of the notebooks would "probably run into millions of pounds".
"I'd like to say such a warm thank you to the public and to the police," Dr Gardner said.
The notebooks have since been returned to the strong room, but will soon be on display to the general public.
"They will be on show from July at a free exhibition called Darwin in Conversation," Dr Gardner said.
"We hadn't dreamt that we would be able to include these in the public exhibition when we were planning it, but now they're back we can, and everyone will have the chance to see them.
A police investigation into the disappearance of the notebooks remains ongoing.
ABC/Reuters
