The integument plays an important role in the survival of metaÂ- zoans by separating and protecting them from a hostile environÂ- ment. Its function ranges from protection against injury and inÂ- fection; partlcipation in the regulation of body temperature and water balance, to respiratory activity, monitoring of the environÂ- ment and production of signals related to behaviour. All these result from specific structural, biochemical and physiological properties of intra-and extracellular components of the integuÂ- ment. Thus its characterization can be best accomplished by a multidisciplinary approach with authors specialized in different fields of science. This multi-author book, in two volumes, provides an up-toÂ- date survey of the literature. The first volume deals with the integument of invertebrates, the second with that of vertebrates, both organized primarily on a phylum basis. As the level of knowledge on the integument of phyla differs considerably, the information provided is correspondingly either limited or conÂ- densed. For some of the smaller groups of invertebrates little information is available, as often only a few electron micrographs are to be found in the literature; on the other hand, from the large body of knowledge existing for vertebrates, particularly for mammals, no complete overview can be provided, but publicaÂ- tions giving access to further information have been reviewed critically.