ABSTRACT
The part of the brain which is of importance to the mani festation of mental functions is the outer rind, or cortex, of grey matter, which is in contact with the inner surface of the skull. This outer rind is thrown into a series of tortuous folds or convolutions separated by slits or fissures, and both combine to give it an appearance of great complexity. These convolutions were long considered to present no definite arrangement, but to be thrown together in meaningless disorder. During the latter half, or rather more, of the last century, it has, however, been shown, by the many eminent men who have given their attention to the subject, that the pattern which is assumed by the convolutions-though showing many subsidiary differences, not only in different races and different individuals, but also in the two hemi spheres of the same person-is yet arranged on a consistent and uniform plan in every human brain, and that any decided deviation from the plan results in an imperfect performance of the cerebral function.
