 There are at least three ways in which the change in embryological theory instituted by Maupertuis, and subsequently elaborated by Buffon, proved to be relevant to the broader question of the historical transformation of species. First, this new account of the embryological origin of the individual organism meant that it actually is organized in historical time rather than pre-existing and simply unfolding at an opportune moment. Second, it involved a theory of material inheritance that explained the passing on of physical traits from one generation to the next through the transmission of particles of matter. Third, the conservation of the identity of the species is guaranteed only by the accurate transmission of this material inheritance. If this transmission is affected by external circumstances in any way, significant historical change in the lineage of ancestor and descendant is possible. These options, opened up by Maupertuis’s speculations, were subsequently developed within an institutional setting by Buffon.