Charles Darwin: a life in pictures
Barnacles. Darwin made a major contribution with his eight-year study of the group. He finished in 1854 and then turned full-time to his species theory.
See an introduction to the barnacle research by Marsha Richmond here.
See Darwin's Catalogue of the appendages and other parts of Cirripedes, mounted as microscopical slides. (1854-5)]. [barnacles] Introduction
Some of Darwin's barnacle specimen slides now on display at the Zoology Museum, Cambridge:
Photograph: John van Wyhe.