A monograph on left-handedness, ultimately printed in the _Proceedings of the Royal Society of Canada for 1886_, was long delayed, in the hope of meeting with some response to appeals I had repeatedly addressed to medical friends, in the expectation that, sooner or later, some strongly-marked case of left-handedness among hospital or other patients might afford an opportunity for securing an autopsy of the brain. But unless the fact has been previously noted, there is little occasion in the passive condition of mortal disease to give prominence to the left-handed action of a patient, and I had to rest content with inviting attention to the subject when a favouring opportunity presented itself. But my anticipations of the result to be looked for were very definite, could the required organ of exceptionally developed nerve-force be got hold of. There was indeed one very suitable brain close at hand, and available for many curious speculative researches; but wholly beyond reach of ocular investigation by me. I could therefore only draw attention to it as possibly accessible to some future investigator, since even vivisection must needs defeat my aim. I accordingly remarked: “My own brain has now been in use for more than the full allotted term of threescore years and ten, and the time cannot be far distant when I shall be done with it. When that time comes, I should be glad if it were turned to account for the little further service of settling this physiological puzzle. If my ideas are correct, I anticipate as the result of its examination that the right hemisphere will not only be found to be heavier than the left, but that it will probably be marked by a noticeable difference in the number and arrangements of the convolutions.”