In 1838 John Gould, the nineteenth-century ornithologist and publisher, arrived in Australia to record its natural history. When he left nineteen months later Gould had identified nearly 200 new bird species and gathered data for a major study of Australian mammals. Gould's voluminous Australian correspondence of more than 300 items in the British Museum (Natural History), is of immense importance for the light it throws on Gould's working methods. A selection of these letters is presented here, together with a catalogue containing detailed summaries of the contents of every item. The collection contains notable examples of Gould's own drawing in pencil, watercolour, crayon and chalk. Many of these, together with rare items privately owned, are published here for the first time.