This book considers the interaction of morphological and phonological determinants of linguistic form and the degree to which one determines the other. It considers the operation of canonical forms, the invariant syllabic shapes of morphemes and the defining characteristic of prosodic morphology. Dr Downing presents an original theory which she tests on data from a wide variety of languages. Her book will be of central interest to scholars and advanced students of phonology and morphology, and of linguistic theory more generally.