Plate signed by the artist, G. Porter (under the supervision of William Hamilton); and by the engraver, W. Skelton. Dated: 9th July 1789.
Part of the book: Denman, Thomas, 1733-1815. A collection of engravings, tending to illustrate the generation and parturition of animals, and of the human species. London: Sold by J. Johnson, 1787.