Fig. 4. Small printing roller, used in the pocket apparatus, actual size. It may be covered either with india-rubber tubing or with roller composition 40
III.--Fig. 5. Diagram of the chief peculiarities of ridges, called here _minutiæ_ (the scale is about eight times the natural size) 54
Fig. 6. The systems of ridges and the creases in the palm, indicated respectively by continuous and by dotted lines. Nos. 2, 3, 4, and 5 show variations in the boundaries of the systems of ridges, and places where smaller systems are sometimes interpolated 54
IV.--Fig. 7. The effects of scars and cuts on the ridges: _a_ is the result of a deep ulcer; _b_ the finger of a tailor (temporarily) scarred by the needle; _c_ the result of a deep cut 59
Fig. 8. Formation of the interspace: filled in (3) by a loop; in (4) by a scroll. The triangular plot or plots are indicated. In (1) there is no interspace, but a succession of arches are formed, gradually flattening into straight lines 67
V.--Fig. 9. Specimens of rolled thumb prints, of the natural size, in which the patterns have been outlined, p. 69, and on which lines have been drawn for orientation and charting 68
VI.--Fig. 10. Specimens of the outlines of the patterns on the ten digits of eight different persons, not selected but taken as they came. Its object is to give a general idea of the degree of their variety. The supply of ridges from the _inner_ (or thumb side) are coloured blue, those from the _outer_ are red (the scale is of the natural size) 70
VII.--Fig. 11. Standard patterns of Arches, together with some transitional forms, all with their names below 75
Fig. 12. As above, with respect to Loops 75
VIII.--Fig. 13. As above, with respect to Whorls 75
Fig. 14. Cores to Loops, which may consist either of single lines, here called _rods_, or of a recurved line or _staple_, while the ridges that immediately envelops them is called an _envelope_ 76
IX.--Fig. 15. Transitional patterns, enlarged three times, between Arches and either Loops or Whorls 79
X.--Fig. 16. Transitional patterns, as above, but between Loops and Whorls 79
XI.--Fig. 17. Diagram showing the nine genera formed by the corresponding combinations of the two letters by which they are expressed, each being _i_, _j_, or _o_ as the case may be. The first two diagrams are Arches, and not strictly patterns at all, but may with some justice be symbolised by _jj_ 80