From all this, then, we have seen that the connections which render possible the _accurate_ localizing functions of the manubrium are almost, though not quite, exclusively radial. We have also seen that between accurate localization and mere random movements on the part of the manubrium there are numerous gradations, the degree of decline from one to the other depending on the topographical relations between the point of stimulation and the end of the section (the section being of the form represented by A B in the figure). These relations, as we have seen, are the more favourable to correct localization: (_a_) the greater the radial distance between the point of stimulation and the end of the section; and (_b_) the less the circumferential distance between the point of the stimulation and the radius let fall from the end of the section. But we have seen that the limits as regards severity of section within which these gradations of localizing ability occur, are exceedingly restricted--a cut of only a few millims. in length, even though situated at the greatest radial distance possible, being sufficient to destroy all localizing power of the manubrium as regards the middle point of the corresponding arc of the margin, and a stimulus applied only a few millims. from the attached end of a severed marginal strip entirely failing to cause localizing action of the manubrium. Lastly, we have seen that even after all localizing action of the manubrium has been completely destroyed by section of the kinds described, this organ nevertheless continues actively, though ineffectually, to search for the seat of irritation. [Illustration: Fig. 23.]