Introduction

This is a story about dynamics: about change, flow, and rhythm, mostly in things that are alive. My basic outlook is drawn from physical chemistry, with its state variables and rate laws. But in living things, physical and chemical mechanisms are mostly quite complex and confusing, if known at all. So I’m not going to deal much in mechanisms, nor even in cause and effect. Instead I will adopt the attitude of a naturalist-anatomist, describing morphology. The subject matter being dynamics, we are embarked upon a study of temporal morphology, of shapes not in space so much as in time. But by introducing molecular diffusion as a principle of spatial ordering, we do come upon some consequences of temporal morphology for the more plainly visible shapes of things in space.