In January 1867, Charles Darwin’s closest friend Joseph Hooker wrote to Darwin – tired of being his photographic intermediary. Requesting a Carte de Visite of Darwin for Prof. Miquel of Utrecht, Hooker laments “I grieve to bother you on such a subject— I am sick & tired of this Carte Correspondence.” This paper looks to tease apart what a photographic portrait meant for Darwin, the quintessential 19th century man of letters. When we think of Darwin’s correspondence, we often talk about how he created, maintained, and used written letters to reinforce his scientific credibility and to motivate his correspondence to bring the experimental field to his house at Down. While his writing was certainly essential to this aim, when examining his letters what is also evident is just how important his photographs were to maintaining his scientific network. Darwin’s photographs and his carte de visites circulated around the European continent and across the Atlantic Ocean, and ended up on the walls of many well-known scientists and he equally requested and collected photographs of his scientific friends. This paper will therefore bring together concerns in the history of letter writing and in photographic history to address what it meant for a nineteenth century scientist to exchange photographic objects, and how the collection and exchange of these objects developed into a form of scientific practice.