To attach, in relation to a curve f(x, y) = 0, a geometrical significance to the value of f(x, y) at an arbitrary point of the plane, it is necessary to impose a condition which has the effect of standardising the function f(x, y) by means of some divisor independent of the variables. This article, another outcome of Mr. Durell’s query on the semi-cubical parabola, is concerned with normalisation of the equation of an algebraic curve, and with Laguerre’s interpretation of a standard form of f(x, y). The axes are rectangular throughout.