Story of University's lost Darwin letter has happy ending.

A letter from Charles Darwin was lost for a hundred years before being rediscovered by chance by Professor Tim Birkhead at the University of Sheffield. Now it is among those that appear in the 13th volume of Darwin's correspondence, which has just been published. Darwin was a prolific correspondent, and many of his letters are of great significance in the history of both his own intellectual development and scientific discovery in general.

Professor Birkhead, of the University's Department of Animal and Plant Sciences, who is himself on the management committee of the huge and highly-acclaimed Darwin Correspondence Project, explained how the lost letter was discovered.

"I knew that the University owned one of Darwin's letters and I'd decided to make a poster explaining our links with Darwin. So I took the letter from our safe, where it's kept. I then discussed the poster with a colleague, who to my surprise said he had the letter in his filing cabinet. When I disputed this we looked at each other, simultaneously realising that for almost a hundred years the University had assumed that it had one Darwin letter, when in fact it had two."

The two letters, dating from January 1865, are part of a correspondence with Henry Denny, an entomologist at Leeds City Museum. In his first letter Darwin wonders whether Denny is aware of any evidence that body lice have developed into different species on the bodies of different races of humans. In his reply Denny cannot commit himself to a firm view, so in the second letter Darwin extends his line of enquiry to species of lice observed on different species of domestic mammals and birds.

Henry Denny's son, Alfred, was subsequently the University of Sheffield's first Professor of Zoology, from 1884 to 1925. In a satisfyingly symmetrical coincidence, Professor Birkhead is honorary curator of the Alfred Denny Museum, the University's zoology collection.

Notes for Editors: A picture of Professor Birkhead reading one of the letters next to the skeleton of a gorilla is available on request by e-mail from Jon Pyle.

The Darwin Correspondence Project exists to publish the definitive edition of letters to and from Charles Darwin, the most influential naturalist of the 19th century: when complete the series will comprise approximately 30 volumes

Please contact Jeanette Newcombe on 0114 2221032 or email mediateam@sheffield.ac.uk.