Plate 20 from the paper 'On the double organs of generation of the lamprey, the conger eel, the common eel, the barnacle, and the earthworm, which impregnate themselves; though the last from copulating, appear mutually to impregnate one another', by Everard Home, Philosophical Transactions of the Royal Society, vol.113 (1823), pp.140-151. Fourteen figures showing details of the head, jaws, pedicle, penis, eggs and other internal structures of the barnacle. Signed in ink lower left 'Franz Bauer' Royal Society stamp verso.Original: watercolour on board. 1823