This article presents an explication of the references to the history of the calculus in the first few pages of Chapter 4 of Deleuze's _Difference and Repetition_. In those pages, Deleuze uses anachronistic readings of the calculus to explain his theory of ontogenesis, beginning with the differential, dx, that is strictly nothing by itself but that establishes singular points in relation to other differentials. He builds from the differential to power series, showing a corresponding process of determination in the ontogenesis (...) as the mathematics moves from derivative to the so-called original function. (shrink)