The Charles Darwin archive in the University Library contains not only letters, manuscript material, photographs, books and articles but also all sorts of small, dry specimens. Many of these enclosures have become separated from letters or lost altogether, but editors on the Darwin Correspondence Project always try to track them down. Seeds, butterfly wings, flowers and other plant samples are standard fare. However, a few of the enclosures are a little stranger.

Darwin solicited samples from his scientific colleagues, but some readers of his works also sent him items speculatively. For instance, a pig’s foot with an extra toe was dispatched from Germany in response to Darwin’s work on inheritance of polydactylism. Human hair, pony hair and photographs of a correspondent’s ears were amongst other deliveries. These bizarre enclosures provide a fascinating insight into how Darwin used the observations of his readers and correspondents as evidence to make changes to subsequent editions of his works.