Using a combination of structural techniques, we propose to seek possible histological substrates for cerebral dominance in human cerebral cortex. The program is predicated on the already well established fact that one cerebral hemisphere in man, usually the left, is critical to higher symbolic activities, and particularly to language function. While evidence now exists documenting the fact that this functional asymmetry can be demonstrated as early as the fourth postnatal week, and that this is accompanied by structural asymmetry of parts of the temporal lobe, we are not aware of qualitative or quantitative descriptions of the relevant histological matrix. Through the use of several histological methods and computer programs developed for analysis of this type of data, we hope to specify certain structural and connectional differences related to the phenomenon of hemispheric dominance and lateralization of cortical function.