An exact correspondence between the _details_ of two minutiae is of secondary importance. Thus, the commonest point of reference is a bifurcation; now the neck or point of divergence of a new ridge is apt to be a little low, and sometimes fails to take the ink; hence a new ridge may appear in one of the prints to have an independent origin, and in the other to be a branch. The _apparent_ origin is therefore of little importance, the main fact to be attended to is that a new ridge comes into existence at a particular point; _how_ it came into existence is a secondary matter. Similarly, an apparently broken ridge may in reality be due to an imperfectly printed enclosure; and an island in one print may appear as part of an enclosure in the other. Moreover, this variation in details may be the effect not only of imperfect inking or printing, but of disintegration due to old age, which renders the impressions of the ridges ragged and broken, as in my own finger prints on the title-page. Plate 11, Fig. 18 explains the nature of the apparent discrepancies better than a verbal description. In _a_ a new ridge appears to be suddenly intruded between two adjacent ones, which have separated to make room for it; but a second print, taken from the same finger, may have the appearance of either _b_ or _c_, showing that the new ridge is in reality a fork of one or other of them, the low connecting neck having failed to leave an impression. The second line of examples shows how an enclosure which is clearly defined in _d_ may give rise to the appearance of broken continuity shown in _e_, and how a distinct island _f_ in one of the prints may be the remnant of an enclosure which is shown in the other. These remarks are offered as a caution against attaching undue importance to disaccord in the details of the minutiae that are found in the same place in different prints. Usually, however, the distinction between a fork and the beginning of a new ridge is clear enough; the islands and enclosures are also mostly well marked. [Illustration: PLATE 13. FIG. 20. V. H. H-D aet. 2-1/2 in 1877, and again as a boy in Nov. 1890.]