The attribution to Lewis (later well-known for his pictures of oriental scenes) seems plausible, as the Dictionary of National Biography records that "the first bent of his art was towards animals, which he used to study at the menagerie in Exeter 'Change". The DNB also records that the Lewis family was familiar with the Landseers: at the date inscribed on this drawing, Charles Landseer was making anatomical drawings in red chalk as a pupil of Benjamin Haydon and Charles Bell, and in 1815/1816 Edwin Landseer borrowed Haydon's anatomical drawings (The diary of B.R. Haydon, ed. by W.B. Pope, vol. 1, p. 413)
