February 9, 1849 (a Friday)

On this date, Richard Owen gave a public lecture entitled “On the Nature of Limbs,” at an evening meeting of the Royal Institution of Great Britain in London. This lecture laid out to a general audience Owen’s notion of homology in general, and his account of vertebrate limbs in particular. Earlier, in 1843, Owen had defined a homology as the “same organ in different animals under every variety of form and function” (Owen 1843, p.379). The 1848 book On the Archetype and the Homologies of the Vertebrate Skeleton had introduced his sophisticated theoretical and observational framework in comparative morphology. Now in the 1849 lecture, Owen forcefully argued for fins as found in different groups of fish and limbs as occurring in different tetrapod taxa being homologous, by pointing to homologies among the individual skeletal parts of fins and limbs. Published in the same year under the title On the Nature of Limbs, this lecture, together with On the Archetype, marks Owen’s most innovative contribution to comparative biology, which made him the most prominent naturalist in Britain before Darwin.