While the integument of oribatid mites bears many interesting features and their nature and distribution is well known, primarily from studies by Grandjean conducted between 1928 and 1970 and acarologist following in his footsteps, the functions of the integument are still poorly understood Three contributions in this volume try to elucidate the integument. The first paper introduces the know types of integuments based on observations of the nature of the cuticular component and summarizes the distribution of cuticular component types among oribatid mite taxa. The second paper illustrates and discusses the fine structure of a selection of porose organs and their cellular components and presents a discussion of the function of porose organs comparing it to the more voluminous literature on cuticular structures of other insects and arachnids. Finally, the third paper synoptically interprets these data from an evolutionary perspective looking at the systematic value of and the ecological correlations between porose organs.