Covington continued to correspond with Darwin, who sent him a gift of a replacement ear-trumpet to help with Covington's increasing deafness. His deafness may have been the result of exposure to guns used in collecting specimens. In response to Darwin's request for specimens, Covington and his eldest son collected a large number of barnacles at nearby Twofold Bay. Darwin's letter of 23 November 1850 expressed his delight at having just received the box, which included particularly unusual species. This contributed to the extensive studies of barnacles which established Darwin as a biologist.