PLATE 10.
FIG. 16.
TRANSITIONAL PATTERNS—Loops and Whorls (enlarged three times).
The chief theoretical objection to this threefold system of classification lies in the existence of certain compound patterns, by far the most common of which are Whorls enclosed within Loops ([Plates 7], [8], Fig. 12, 15, 18, 19, and Fig. 13, 20-23). They are as much Loops as Whorls, and properly ought to be relegated to a fourth class. I have not done so, but called them Whorls, for a practical reason which is cogent. In an imperfect impression, such as is made by merely dabbing the inked finger upon paper, the enveloping loop is often too incompletely printed to enable its existence to be surely ascertained, especially when the enclosed whorl is so large (Fig. 13, 23) that there are only one or two enveloping ridges to represent the loop. On the other hand, the whorled character of the core can hardly fail to be recognised. The practical difficulties lie almost wholly in rightly classifying a few transitional forms, diagrammatically and roughly expressed in Fig. 11, 4, 5, and Fig. 12, 8, 18, 19, with the words “see” so and so written below, and of which actual examples are given on an enlarged scale in [Plates 9] and [10], Figs. 15 and 16. Here Fig. 15, a is an undoubted arch, and c an undoubted nascent loop; but b is transitional between them, though nearer to a loop than an arch, d may be thought transitional in the same way, but it has an incipient curl which becomes marked in e, while it has grown into a decided whorl in f; d should also be compared with j, which is in some sense a stage towards k. g is a nascent tented-arch, fully developed in i, where the pattern as a whole has a slight slope, but is otherwise fairly symmetrical. In h there is some want of symmetry, and a tendency to the formation of a loop on the right side (refer back to [Plate 7], Fig. 11, 4, and Fig. 12, 12); it is a transitional case between a tented arch and a loop, with most resemblance to the latter. [Plate 10], Fig. 16 illustrates eyed patterns; here l and m are parts of decided loops; p, q, and r are decided whorls, but n is transitional, inclining towards a loop, and o is transitional, inclining towards a whorl. s is a nascent form of an invaded loop, and is nearly related to l; t and u are decidedly invaded loops.
The Arch-Loop-Whorl, or, more briefly, the A. L. W. system of classification, while in some degree artificial, is very serviceable for preliminary statistics, such as are needed to obtain a broad view of the distribution of the various patterns. A minute subdivision under numerous heads would necessitate a proportional and somewhat overwhelming amount of statistical labour. Fifty-four different standard varieties are by no means an extravagant number, but to treat fifty-four as thoroughly as three would require eighteen times as much material and labour. Effort is economised by obtaining broad results from a discussion of the A. L. W. classes, afterwards verifying or extending them by special inquiries into a few of the further subdivisions.
PLATE 11.
Fig. 17.
ORIGIN OF SUPPLY OF RIDGES TO PATTERNS OF PRINTS OF RIGHT HAND.
Of the two letters in the left upper corner of each compartment, the first refers to the source of upper boundary of the pattern,
the second to the lower boundary. For patterns on the prints of left hands, Ii and Oo must be interchanged.