XVIII.--Arrangement of the Papillary Ridges 157 XIX.--Flexures of the Palm and Sole 170 XX.--The Evolution of a Bursa 178 XXI.--The Plantar Arch 192 XXII.--Muscles 200 XXIII.--Innervation of the Human Skin 218 XXIV.--The Building of Reflex Arcs 231 SUMMARY 257 INDEX 259 LIST OF ILLUSTRATIONS. FIG. PAGE 1 Arrangement of hair on the forearm 42 2 Diagrams of hair-patterns 51 3, 4, 5 Neck of horse, showing muscles and tendons 53, 54 6–19 Side of neck of various horses, showing varieties of hair-patterns 56–62 20–29 Illustrations of human eyebrows, showing muscular action and hair-direction 70–73 30 Front view of horse, showing pectoral pattern 76 31 Side view of horse showing hair-direction 77 32, 32a Frontal region of horses, showing muscles and hair-pattern 78 33 Side view of horse, showing chief superficial muscles 79 34, 35 Side and back views of cow, showing hair-patterns on back 88 36 Lioness, showing direction of hair-streams on muzzle 93 37 Back of lion, showing hair-pattern 95 38–40 Gluteal region, foreleg and chest of domestic dog, showing hair-direction 99, 101 41 Arrangement of hair on back of lemur, chimpanzee and man 105 42 _Idem_ chest 109 43 Giraffe, showing hair-patterns of neck 116 44 Giraffe in attitude of drinking or browsing off the ground 117 45 Bongo, showing hair-patterns of chest 119 46 Kiang. Side view showing inguinal and axillary patterns 121 47 Forefoot of llama, showing hair-direction 122 48 Two-toed sloth, showing action of gravity on hair 123 49 Domestic horse, fully harnessed 128 50 Side view of domestic horse, showing reversed hair due to harness 129 51–58 Necks of various horses, showing reversed hair due to collar 132–135 59 Right hand, drawing of papillary ridges, made from impressions 158