Professor van Biervliet has now completed his very careful study of right-sidedness and left-sidedness (already summarised in the Journal) by a still more careful investigation of ambidextrous persons. In the first place by photography, according to a special and uniform method, he finds that in the ambidextrous the two sides of the face, as well as the arms, are fairly alike, the face being slightly more developed on the right side, as among left-sided people, but not in so marked a degree. They occupy much the same position, indeed, throughout the investigation. When compared with right-sided and left-sided people as regards sensory acuteness, it is found that while the right-sided have predominant sensory acuteness on the right side, both the left-sided and the ambidextrous can see further, hear better, possess more acute tactile and muscular sense, on the left side, so that ambidexterity may be regarded as a variety of left-sidedness of more symmetrical anatomical type. In all respects the ambidextrous almost or quite resembled the left-sided.