Autopsy findings and examination of histological sections from 12 schizophrenic patients and from age-matched, non-schizophrenic controls were enlarged and confirmed our previous study. Four subgroups were differentiated with gross abnormalities, in most cases with asymmetry of the temporal sulcal gyral pattern. Two types of macroscopical deviations are described. Different periods of developmental termination, concerning the sulcal gyral pattern of the temporal lobe, suggest a period in which the disturbance of the development originated which coincides with a probably genetically-induced disturbed migration in the entorhinal region toward the end of the fifth month. It is thought that the parahippocampal or entorhinal area develops differently, space- and time-wise. This may explain why migratory disturbances particularly occur in this precisely limited area. The findings in the ventral insular area are discussed, together with factors which also suggest a developmental disorder.