Reverting once more to the singularly interesting phenomena whereby in certain conditions of cerebral disease, or local injury, the correlation between articulate speech, writing, and even the unconscious expressiveness of gestures, used certain specific convolutions of the left hemisphere, Dr. Pye-Smith says: “The opinion that some difference between the two sides of the brain has to do with our preference for the right hand over the left may, perhaps, be supported by two very interesting cases of aphasia occurring in left-handed persons, recorded by Dr. Hughlings Jackson and Dr. John Ogle. In both these patients there was paralysis of the _left_ side; so that it seems likely that in these two left-handed people the right half of the brain had the functions, if not the structure, which ordinarily belong to the left. To these cases may be added a very remarkable one published by Dr. Wadham (_St. George’s Hospital Report_, 1869). An ambidextrous or partially left-handed lad was attacked with left hemiplegia and loss of speech; he had partly recovered at the time of his death, twelve months later, and then the right insula and adjacent parts were found softened.” The remarkable difference in the convolutions of different brains, and the consequent extent of superficies of some brains over others apparently of the same size, have been matter of special observation, with results lending confirmation to the idea that great development of the convolutions of the brain is the concomitant of a corresponding manifestation of intellectual activity. But the complexity in the arrangement of these convolutions, and the consequent extent of superficies, often differ considerably in the two hemispheres of the same brain. The variations in shape and arrangement of the convolutions in either hemisphere may be no more than the accidental folds of the cerebral mass, in its later development in the chamber of the skull; and within ordinary limits they probably exercise no appreciable influence on physical or mental activity.