The demonstration of the basic brain mechanism through studying the partially commissure-sectioned case appears to be a most prom ising enterprise. The work with animals of HAMILTON and others in elucidating psychological brain process heretofore not imagined are mere indications of what the potential seems to be. Study of the partially disconnected patient seems equally revealing and productive in showing how many high level cognitive activities are managed in the cerebral flow of information. With respect to the issue of localization of function, it would seem clear that those cerebral...