Preface

Abstract

Modular organisms are those that grow by the repeated iteration of units of structure. This manner of growth is characteristic of many invertebrates, and of higher and most lower plants. Modular organisms almost inevitably iterate their units of construction by branching. The modules may then separate from each other to become physiologically independent parts of a clone ( Hydra and duck­weeds) or remain attached to each other in more or less physiologically integrated wholes (trees, corals, salps, etc.). The ways in which the attached modules of a genet are arranged relative to each other gives the whole an often characteristic form that may, as in the species-specific outline of trees or corals, defy accurate description in words yet be modelled effectively by computer graphics. Modular growth normally constrains organisms to a fixed immobile life, though there are exceptions among free-floating aquatics. Most of the properties associated with mobility in unitary organisms are expressed through the form or architecture of modular organisms, e. g. the capture of resources, mating, competition, defence.