The human eye is wired for Gestalt, for recognition rather than quantification. It is notoriously bad at apprehending population variance. A catalog or key setting forth a variety of typical forms for a phenomenon, such as that for leaf shape in Fig. IX-1, does not specify in any way how one might describe forms within a family (e.g. the growing leaf, its shape constantly changing) or assign particular specimens, always more or less idiosyncratic, to particular types. Such a classification should rather arise from a thoroughgoing quantification along the various lines I have pursued in this essay. The study of all form is the study of comparative or growing form, and the necessary quantifications are all based in the geometry of ordinary planes and space.