The Demise of the Preformed Embryo: Edinburgh, Leiden, and the Physician-Poet Mark Akenside's Contribution to Re-Establishing Epigenetic Embryology.

Seventeenth-century advances in microscopy prompted a shift in the dominant theory of human reproduction from one of epigenesis, derived from such ancient authorities as Aristotle, which posited that the mixing of male and female reproductive material generated a being which had not existed before, to one of preformation, whereby embryologists argued that the offspring of an animal already existed in miniature in the reproductive material. This chapter reveals that the poet, Mark Akenside, anticipated the Enlightenment's challenge to the prevailing preformationist orthodoxy when a medical student at Edinburgh in the late 1730s, as evident in his May 1744 thesis entitled De ortu et incremento foetus humani ('On the Origin and Growth of the Human Foetus'). What prompted Akenside to take such a bold step? Faced with a scarcity of biographical sources, Akenside's major poem on The Pleasures of Imagination (1744) suggests how the poet had been thinking about reproductive processes in innovative contexts and that his medical research informed his concept of poetic creation.