Exhibition curator Dr Donald Kerr says he was surprised and thrilled to receive a letter two weeks ago from Darwin's great-grandson, retired physiology professor Richard Darwin Keynes, wishing him all the best for the exhibition and enclosing a copy of his own book about Darwin's discoveries aboard the Beagle in the 1830s.
"He heard about the exhibition through [Dunedin lichen researcher] Dr David Galloway. I had no idea that they were acquainted."
Prof Keynes' letter is one of a series of fortunate connections Dr Kerr has encountered since he began searching for material for the exhibition two months ago.
All but three items come from the university's various collections, but Dr Kerr was able to match two contributions lent by other libraries.
The Dunedin Public Library provided a large caricature of the Rev Samuel Wilberforce (son of slave trade abolitionist William Wilberforce), who wrote a scathing review of Darwin's 1859 book On the Origin of Species.
A Christchurch library provided a book containing a copy of Samuel Wilberforce's review.
Even the poster advertising the exhibition was the result of a fortunate connection, Dr Kerr said.
"I saw a sketch of Darwin drawn by Harriet Lubbock in a book and discovered her husband was a friend of Darwin's and that they had a descendant called Lyulph Lubbock.
"So I googled him, found him, and emailed him to ask if we could reproduce the sketch as our poster.
"Within 24 hours he had replied, wishing us all the best and attaching a scan of the sketch for us."
Among the treasures in the exhibition are three letters written by Darwin, one to noted Dunedin doctor and collector Thomas Hocken and the others to English geranium breeder John Denny.
The Hocken letter and thousands of other items were donated to the university by Dr Hocken 100 years ago, while the Denny letters were donated by the late Prof Geoff Baylis, long-serving head of the university's botany department.
He had been given them many years earlier by Dr Denny's godmother, Miss Connie Sedge.
The exhibition also contains a third edition and a sixth edition of On the Origin of Species.
Dr Kerr said the university would dearly love to own a first edition, but with a copy selling last year for 89,000 ($NZ217,0000), that was unlikely.
"We're waiting for a generous benefactor."
•Beetles, Barnacles, Orchids and the Origin of Species: Charles Darwin and his Legacy. Exhibition on display in the University of Otago special collections exhibition area, first floor, information services (central library) building, until July 3.
