Several years ago, in an address to the American Neurological Association, I ventured the statement that the human race had not as yet developed more than a fifth of its potential brain power. With other evidence in support of this view, I1 offered certain deductions based on the history and achievements of Helen Keller. Since that time, I have had the opportunity and privilege to study Miss Keller personally. It is now my purpose to assemble the results of this study in their fuller bearing on the potential development of the human brain and also to present a comparative sensory analysis of Helen Keller and Laura Bridgman. Such an analysis in itself must needs be a contribution to that partially written chapter in the annals of the sensorium which records the adaptive successes of the deaf and dumb and blind.
HEAD'S THEORY OF SENSIBILITY
Before I discuss Miss Keller's