Widely respected by contemporaries for his work in natural history, Leonard Jenyns (1800–93) combined research with his duties as an Anglican clergyman. He published and lectured extensively on zoology and botany. Having recommended Darwin for the Beagle voyage, he later produced a paper, 'On the Variation of Species', which Darwin personally requested to see. This 1835 work catalogues five classes of vertebrates: mammals, birds, reptiles, amphibians and fish. Native, introduced and extinct species of the British Isles are included, with binomial and common names given, along with the dimensions and a description. An improvement on previous works which had overly relied on secondary sources, Jenyns's manual also provides information on location, diet and propagation. The catalogue testifies to the diligent work being carried out in natural history in the era prior to Darwin's revolution. Jenyns's Observations in Natural History (1846) and Observations in Meteorology (1858) are also reissued in this series.