The oribatid integument is well known for a number of porose organs. The distribution of these organs has taxonomic importance, especially in Brachypylina. Until recently, the function of these organs was conflictingly interpreted. It is now known that porose organs may represent either respiratory or secretory porose organs. According to Norton et al. (1997), in adult Poronota the porose organs may be grouped into several series. In addition to the octotaxic system of the notogaster, a marginoventral series of the ventral plate, an apodemato-acetabular system of tracheae, and a humerosejugal series of the sejugal and lateral podosomal region can be recognized. In juveniles the lateral parts of the bodies are usually not provided with porosities. However, in some taxa, predominately belonging to Ceratozetoidea, the juveniles possess a rather conspicuous humeral organ (oh). We have studied this organ for the first time with TEM and SEM in Edwardzetes edwardsii (Ceratozetidae). It evidently represents a secretory porose organ, probably homologous to the humeral porose organ Ah of the adults, which may be modified into a conspicuous vesicle in Ceratozetoidea (and some other taxa).