could help him with books, illustrations and notes, as well as specimens. He was a life-long friend of clergyman naturalist Leonard Jenyns, and a regular correspondent with the taxidermist John Gould, Sir William Jardine, the Earl of Derby, Edward Lear and Charles Darwin. Yarrell's knowledge of bird anatomy helped Lear develop his bird painting skill by teaching him that feather tracts follow the muscle contours, and he in return provided a drawing of a thicklip grey mullet for the fish book. Format Yarrell was a great admirer of Thomas Bewick (he named a new wildfowl species "Bewick's swan" after the engraver). Bewick's A History of British Birds, published in two volumes in 1797 and in 1804, had brought him nationwide fame, and since Yarrell owned several editions of Bewick's books, he naturally followed the older man's format for his own fish project. There was no established taxonomic sequence for arranging fish, so where possible Yarrell followed Cuvier and Valenciennes, otherwise using anatomical resemblances in features including fins, teeth, and head bones to order his species. Each entry started with an engraving of the species, followed by its scientific and English names and synonyms, and a lead section "Generic characteristics" summarising the key anatomical features. The main text described the fish in more detail, noted when it was recorded as a British species, mentioned interesting anatomical features, described its habits in terms of gregariousness and water depth, and where it could be found in Britain and Europe. Yarrell also ate many of the fish, so he could comment on their palatability. A typical example is Yarrell's first entry, for the perch. As well as the expected detailed anatomical and geographical information, in the five-page text he notes Production and publication Yarrell’s illustrations were woodcuts made using improved techniques pioneered by Bewick in which boxwood blocks were engraved on their ends using a burin, a tool with a V-shaped tip. The new illustrations for the fish book were drawn onto the blocks by Alexander Fussell and engraved by John Thompson, both of whom also worked on the later bird book. The most expensive part of producing illustrated books was the hand colouring of printed plates, mainly by young women. By using monochrome illustrations Yarrell could avoid this outlay and the associated costs of having to have the illustrations separate from the text and printed on a different grade of paper. The quality