In order to see how the triangles would be seized by worms, some in a damp state were given to worms kept in confinement. They were seized in three different manners in the case of both the narrow and broad triangles: viz., by the margin; by one of the three angles, which was often completely engulfed in their mouths; and lastly, by suction applied to any part of the flat surface. If lines parallel to the base and an inch apart, are drawn across a triangle with the sides three inches in length, it will be divided into three parts of equal length. Now if worms seized indifferently by chance any part, they would assuredly seize on the basal part or division far oftener than on either of the two other divisions. For the area of the basal to the apical part is as 5 to 1, so that the chance of the former being drawn into a burrow by suction, will be as 5 to 1, compared with the apical part. The base offers two angles and the apex only one, so that the former would have twice as good a chance (independently of the size of the angles) of being engulfed in a worm’s mouth, as would the apex. It should, however, be stated that the apical angle is not often seized by worms; the margin at a little distance on either side being preferred. I judge of this from having found in 40 out of 46 cases in which triangles had been drawn into burrows by their apical ends, that the tip had been doubled back within the burrow for a length of between 1/20 of an inch and 1 inch. Lastly, the proportion between the margins of the basal and apical parts is as 3 to 2 for the broad, and 2½ to 2 for the narrow triangles. From these several considerations it might certainly have been expected, supposing that worms seized hold of the triangles by chance, that a considerably larger proportion would have been dragged into the burrows by the basal than by the apical part; but we shall immediately see how different was the result.