A mere variety can never establish a sticking-point in the forward course of evolution, but each new sport affords one. A substantial change of type is effected, as I conceive, by a succession of small changes of typical centre, each more or less stable, and each being in its turn favoured and established by natural selection, to the exclusion of its competitors. The distinction between a mere variety and a sport is real and fundamental. I argued this point in _Natural Inheritance_, but had then to draw my illustrations from non-physiological experiences, no appropriate physiological ones being then at hand: this want is now excellently supplied by observations of the patterns on the digits. INDEX AH, number of ridges in, 200 Allix, 60 A. L. W. system, 80 Ambiguities in minutiae, 91, 111 America, 163 Anthropometric laboratory, 4, 35 Arches, 7, 75, 78; interpretations of, 114, 193 Artisans, 59 Artists, 58 Assyrian bricks, 25 Atkinson, R. F., 192 Author, the, finger prints of, 8, 58, 73 Axis of pattern, 68 Ball for inking, 42 Ball of thumb, 96 Basques, 18, 192 Bearings as by compass, 84 Beech, Dr. Fletcher, 197 Benzole, 36, 41 Bertillon, 2, 15, 154, 169; _Bertillonage_, 155, 164, 167 Bewick, 26 Bible, the, 22 Bifurcations, 91 Binomial law, 11, 112 Bird's nest, 34 Blacklead, 49 Blood as ink, 45 Bowditch, H. P., Professor, 47 British Museum, 25 Brobdingnags, 1 Brothers, 171 Burns of finger, 59 C. set of standard patterns, 177 Callosities, 59 Cambo, 18, 192 Camera lucida, 52, 104 Cards, 38; keeping in order, 145 Casts, 49 Centesimal scale, 12, 17, 124, 129, 182 Cheiromancy, 1, 26; creases, 56 Chequer-work, 106 Chess board, 106 Chinese deed, 24; money, 25; cheiromancy, 26; registration of Chinese, 26, 152 Cicatrix, 59 Circular patterns, optical illusion, 77 Collins, F. H., 17, 21, 177, 190, 193 Collodion, 51 Colour-blindness, 71 Comparison of prints, 90, 167 Compass bearings, 84 Compasses, test by the points of, 61 Copper sheeting for inking, 42; for smoking, 48 Cores, 6, 76, 145 Correlation, 158 Couplets of digits, 119; of A and B brothers, 172 Creases, 1, 56; in infant, 57 Criminals, 149 Crosse, Dr., 192 Cylinder, revolving, 49 Dabs by the finger, 40, 90, 153 Darenth Asylum, 19, 197 Demography, Congress of, 163 Deserters, 149, 164 Development, 58 Digits, peculiarities of, 114 Direction of twist, 78 Divergence of ridges, 68 Drawing master, 48 Ducts, 57 Dyes, 44 Ear-marking the A, B sets of brothers, 172 Embryology, 58 Enclosures within ridges, 92 English, the, 17, 192 Enlargements, 51 Envelopes to rods or staples, 76 Error, law of, 19, 198; "probable," 199 EVIDENTIAL VALUE, Chap. VII., 100 Evolution, 20, 60 Eyes in patterns, 143 Fauld, Mr., 26