 We can conveniently date these developments from the speculations of Pierre de Maupertuis, put forth in two treatises, the better known the Physical Venus (Vénus physique) published in 1745. To deal with the difficulty of explaining how atomistic seeds derived from the male and female could be formed into the complexity of the embryo, Maupertuis drew upon a kind of Newtonian attraction inherent in these seeds which also included elements of Leibnizian monad theory. In his last formulation of 1751 he expanded on this with the claim that the particles themselves were endowed with an internal principle that led them to arrange themselves to form specific parts of the fetus. Maupertuis’ dynamic “epigenesis” incorporated both mechanism and dynamic materialism (Terrall 2002: chp. 7; Hoffheimer 1982).