noted 137 carry the burden on the left shoulder to 81 on the right; in another case 76 to 45; and in the case of loading cordwood, where the natural action of the right hand is to place the burden on the left shoulder, so that the use of the right shoulder necessarily implies that of the left hand, the numbers were 65 using the left shoulder and 36 the right. Here, therefore, a practical test of a very simple yet reliable kind fails to confirm the idea of any such mechanical cause inherent in the constitution of the human frame, tending to a uniform exertion of the right side and the passive employment of the left in muscular action. While thus questioning some of the assumptions and deductions set forth by Dr. Buchanan, it must be acknowledged that his later theory has this great advantage over other attempts to account for right-handedness, that it equally meets the cases of deviation from prevalent usage. No theory is worthy of serious consideration which deals with left-handedness as an exceptional deviation from habitual action; as where, in his earlier treatise, Dr. Buchanan expressed the belief that many instances of left-handedness are “merely cases of ambidextrousness, when the habit of using the left side, in whatever way begun, has given to the muscles of that side such a degree of development as enables them to compete with the muscles of the right side, in spite of the mechanical disadvantages under which they labour.” “There is an awkwardness,” he added, “in the muscular efforts of such men which seems to indicate a struggle against nature.” But for those indisputable cases of “men who unquestionably use their left limbs with all the facility and efficiency with which other men use their right,” he felt compelled either to resort to the gratuitous assumption of “malformations and pathological lesions in early life, diseases of the right lung, contraction of the chest from pleurisy, enlargement of the spleen, distortions of the spine,” etc.; or to assume a complete reversal of the whole internal organic structure.