CHAPTER V

THE PACES OF THE HORSE 282

LIST OF ILLUSTRATIONS

FIG. PAGE

1. A HUMAN SKELETON IN THE ATTITUDE OF A QUADRUPED, TO GIVE A GENERAL IDEA OF THE POSITION OF THE BONES IN OTHER VERTEBRATES 5 2. SIZE OF THE ATLAS COMPARED WITH THE TRANSVERSE DIMENSIONS OF THE CORRESPONDING PARTS OF THE SKULL IN MAN 7 3. SIZE OF THE ATLAS COMPARED WITH THE TRANSVERSE DIMENSIONS OF THE CORRESPONDING REGIONS OF THE SKULL IN A DOG 8 4. LUMBAR VERTEBRÆ OF A QUADRUPED (THE HORSE): SUPERIOR SURFACE 9 5. A TRANSVERSE SECTION OF THE THORAX OF A MAN PLACED VERTICALLY--THAT IS TO SAY, IN THE DIRECTION WHICH IT WOULD ASSUME IN A MAN PLACED IN THE ATTITUDE OF A QUADRUPED (A DIAGRAMMATIC FIGURE) 13 6. A VERTICAL SECTION OF THE THORAX OF A QUADRUPED (DIAGRAMMATIC) 14 7. STERNUM OF A BIRD (THE COCK): LEFT SIDE, EXTERNAL SURFACE 17 8. ANTERIOR LIMB OF THE BAT: LEFT SIDE, ANTERIOR SURFACE 20 9. ANTERIOR LIMB OF THE SEAL: LEFT SIDE, EXTERNAL SURFACE 21 10. SITUATION AND DIRECTION OF THE SCAPULA IN THE HUMAN BEING, THE TRUNK BEING HORIZONTAL, AS IN QUADRUPEDS. VERTICAL AND TRANSVERSE SECTION OF THE THORAX (DIAGRAMMATIC FIGURE) 22 11. POSITION AND DIRECTION OF THE SCAPULA IN QUADRUPEDS. VERTICAL AND TRANSVERSE SECTION OF THE THORAX (DIAGRAMMATIC FIGURE) 22 12. LEFT SCAPULA OF THE HUMAN BEING, POSTERIOR SURFACE, PLACED IN THE POSITION WHICH IT WOULD OCCUPY IN THE SKELETON OF A QUADRUPED 23 13. LEFT SCAPULA OF A HORSE: EXTERNAL SURFACE 23 14. VERTICAL AND TRANSVERSE SECTION, AT THE SITE OF THE SHOULDERS, OF THE THORAX OF THE HORSE (DIAGRAMMATIC FIGURE) 24 15. VERTICAL AND TRANSVERSE SECTION, AT THE PLANE OF THE SHOULDERS, OF THE THORAX OF THE DOG (DIAGRAMMATIC FIGURE) 24 16. LEFT CLAVICLE OF THE CAT: SUPERIOR SURFACE (NATURAL SIZE) 26 17. CLAVICLE OF THE DOG (NATURAL SIZE) 26 18. SKELETON OF THE SHOULDER OF A BIRD (VULTURE): ANTERO- EXTERNAL VIEW OF THE LEFT SIDE 27 19. INFERIOR EXTREMITY OF THE LEFT HUMERUS OF A FELIDÆ (LION) 31 20. INFERIOR EXTREMITY OF THE LEFT HUMAN HUMERUS, SHOWING THE PRESENCE OF A SUPRATROCHLEAR PROCESS 31 21. SKELETON OF A BIRD (VULTURE): LEFT SURFACE 33 22. THE HUMAN HAND RESTING FOR ITS WHOLE EXTENT ON ITS PALMAR SURFACE: LEFT SIDE, EXTERNAL SURFACE 35 23. THE HUMAN HAND RESTING ON ITS PHALANGES: LEFT SIDE, EXTERNAL SURFACE 36 24. THE HUMAN HAND RESTING ON THE TIPS OF SOME OF ITS THIRD PHALANGES: LEFT SIDE, EXTERNAL VIEW 36 25. SUPERIOR EXTREMITY OF THE BONES OF THE HUMAN FOREARM: LEFT SIDE, SUPERIOR SURFACE 39 26. SUPERIOR EXTREMITY OF THE BONES OF THE FOREARM OF A DOG: LEFT LIMB, SUPERIOR SURFACE 39 27. SUPERIOR EXTREMITY OF THE BONES OF THE FOREARM OF THE HORSE: LEFT LIMB, SUPERIOR SURFACE 40 28. INFERIOR EXTREMITY OF THE BONES OF THE FOREARM OF A MAN: LEFT SIDE, POSTERIOR SURFACE, POSITION OF SUPINATION 41 29. INFERIOR EXTREMITY OF THE BONES OF THE FOREARM OF A DOG: LEFT SIDE, ANTERIOR SURFACE, NORMAL POSITION--THAT IS, THE POSITION OF PRONATION 41 30. INFERIOR EXTREMITY OF THE BONE OF THE FOREARM OF THE HORSE: LEFT SIDE, ANTERIOR SURFACE 42 31. SKELETON OF THE SUPERIOR LIMB OF A BIRD (VULTURE): LEFT SIDE, EXTERNAL SURFACE 47 32. SUPERIOR LIMB OF THE HUMAN BEING, THE DIFFERENT SEGMENTS BEING PLACED IN THE ATTITUDE WHICH THE CORRESPONDING PARTS OCCUPY IN BIRDS: LEFT SIDE, EXTERNAL SURFACE 48 33. SKELETON OF THE BEAR: LEFT LATERAL SURFACE 50 34. SKELETON OF THE DOG: LEFT LATERAL SURFACE 52 35. SCAPULA OF THE DOG: LEFT SIDE, EXTERNAL SURFACE 53 36. LEFT SCAPULA OF THE CAT: EXTERNAL SURFACE 53 37. SKELETON OF THE FINGER OF A FELIDE (LION): LEFT SIDE, INTERNAL SURFACE 57 38. SKELETON OF THE PIG: LEFT LATERAL SURFACE 58 39. SKELETON OF THE OX: LEFT LATERAL SURFACE 61 40. SKELETON OF THE HORSE: LEFT LATERAL SURFACE 64 41. FLEXION OF THE HUMERUS: RIGHT ANTERIOR LIMB OF THE HORSE, EXTERNAL SURFACE (AFTER A CHROMOPHOTOGRAPHIC STUDY BY PROFESSOR MAREY) 74 42. EXTENSION OF THE HUMERUS: RIGHT ANTERIOR LIMB OF THE HORSE, EXTERNAL SURFACE (AFTER A CHROMOPHOTOGRAPHIC STUDY BY PROFESSOR MAREY) 74 43. THE LEFT ILIAC BONE OF THE HUMAN BEING: EXTERNAL SURFACE, PLACED IN THE POSITION WHICH IT WOULD OCCUPY IN THE SKELETON OF A QUADRUPED 79 44. LEFT ILIAC BONE OF A QUADRUPED (HORSE): EXTERNAL SURFACE 79 45. PUBIC REGION OF THE PELVIS OF A MARSUPIAL (PHALANGER, FOX) 81 46. PELVIS OF A BIRD (THE COCK): EXTERNAL SURFACE, LEFT SIDE 82 47. POSTERIOR LIMB OF THE HORSE PLACED IN THE POSITION WHICH IT SHOULD OCCUPY IF THE ANIMAL WERE A PLANTIGRADE: LEFT LIMB, EXTERNAL SURFACE 89 48. SKELETON OF THE FOOT OF A BIRD (THE COCK): LEFT SIDE, EXTERNAL SURFACE 90 49. PELVIS OF THE DOG, SEEN FROM ABOVE 91 50. PELVIS OF A FELIDE (LION), VIEWED FROM ABOVE 92 51. PELVIS OF THE OX: SUPERIOR SURFACE 95 52. TARSUS OF THE OX: POSTERIOR LEFT LIMB, ANTERO-EXTERNAL SURFACE 97 53. PELVIS OF THE HORSE: SUPERIOR SURFACE 101 54. TARSUS OF THE HORSE: LEFT POSTERIOR LIMB, ANTERIOR SURFACE 104 55. EXTENSION OF THE LEG: RIGHT POSTERIOR LIMB OF THE HORSE, EXTERNAL SURFACE (AFTER A CHRONOGRAPHIC STUDY BY PROFESSOR MAREY) 107 56. HUMAN SKULL: MEASURE OF THE FACIAL ANGLE BY THE METHOD OF CAMPER. ANGLE BAC = 80° 110 57. SKULL OF THE HORSE: MEASURE OF THE FACIAL ANGLE BY THE METHOD OF CAMPER. ANGLE BAC = 13° 110 58. SKULL OF ONE OF THE FELIDÆ (JAGUAR): LEFT LATERAL ASPECT 113 59. SKULL OF THE LION: LEFT LATERAL ASPECT 113 60. SKULL OF THE DOG: LEFT LATERAL ASPECT 115 61. SKULL OF THE PIG: LEFT LATERAL ASPECT 117 62. SKULL OF THE OX: LEFT LATERAL ASPECT 119 63. SKULL OF THE HORSE: LEFT LATERAL ASPECT 121 64. SKULL OF THE HARE: LEFT LATERAL ASPECT 123 65. SKULL OF THE COCK: LEFT LATERAL SURFACE 128 66. MYOLOGY OF THE HORSE: ANTERIOR ASPECT OF THE TRUNK 132 67. MYOLOGY OF THE HORSE: INFERIOR ASPECT OF THE TRUNK 135 68. MYOLOGY OF THE DOG: SUPERFICIAL LAYER OF MUSCLES 141 69. MYOLOGY OF THE OX: SUPERFICIAL LAYER OF MUSCLES 143 70. MYOLOGY OF THE HORSE: SUPERFICIAL LAYER OF MUSCLES 146 71. MYOLOGY OF THE HORSE: PANNICULUS MUSCLE OF THE TRUNK 148 72. MYOLOGY OF THE HORSE--SHOULDER AND ARM: LEFT SIDE, EXTERNAL SURFACE 166 73. MYOLOGY OF THE DOG: LEFT ANTERIOR LIMB, EXTERNAL ASPECT 178 74. MYOLOGY OF THE OX: LEFT ANTERIOR LIMB, EXTERNAL ASPECT 180 75. MYOLOGY OF THE HORSE: LEFT ANTERIOR LIMB, EXTERNAL ASPECT 182 76. MYOLOGY OF THE DOG: LEFT ANTERIOR LIMB, INTERNAL ASPECT 190 77. MYOLOGY OF THE HORSE: ANTERIOR LIMB, LEFT SIDE, INTERNAL ASPECT 192 78. LEFT ANTERIOR LIMB OF THE HORSE: INTERNAL ASPECT 194 79. LEFT ANTERIOR LIMB OF THE HORSE: EXTERNAL ASPECT 196 80. LEFT ANTERIOR LIMB OF THE HORSE: EXTERNAL ASPECT 196 81. DIAGRAM OF THE POSTERIOR PART OF A TRANSVERSE SECTION PASSING THROUGH THE MIDDLE OF THE LEFT FORE-LIMB OF THE DOG: SURFACE OF THE INFERIOR SEGMENT OF THE SECTION 198 82. DIAGRAM OF A HORIZONTAL SECTION OF THE MIDDLE OF THE FOREARM OF THE LEFT LEG OF THE HORSE: SURFACE OF THE INTERIOR SEGMENT OF THE SECTION 198 83. MYOLOGY OF THE HORSE: THE ANTERIOR TIBIAL MUSCLE (FLEXOR OF THE METATARSUS), LEFT LEG, ANTERIOR VIEW 214 84. MYOLOGY OF THE DOG: LEFT HIND-LIMB, EXTERNAL ASPECT 216 85. MYOLOGY OF THE OX: LEFT LEG, EXTERNAL ASPECT 218 86. MYOLOGY OF THE HORSE: LEFT HIND-LIMB, EXTERNAL ASPECT 220 87. MYOLOGY OF THE DOG: LEFT HIND-LIMB, INTERNAL ASPECT 222 88. MYOLOGY OF THE HORSE: LEFT HIND-LEG, INTERNAL ASPECT 223 89. MYOLOGY OF THE DOG: MASTICATORY MUSCLES (A DEEPER DISSECTION THAN THAT SHOWN IN FIG. 90) 233 90. MYOLOGY OF THE DOG: MUSCLES OF THE HEAD 235 91. MYOLOGY OF THE OX: MUSCLES OF THE HEAD 237 92. MYOLOGY OF THE HORSE: MUSCLES OF THE HEAD 239 93. CLAW OF THE DOG: INFERIOR SURFACE 249 94. LEFT HAND OF THE DOG: INFERIOR SURFACE, PLANTAR TUBERCLES 249 95. VERTICAL ANTERO-POSTERIOR SECTION OF THE FOOT OF A HORSE 250 96. THIRD PHALANX OF THE HORSE: LEFT ANTERIOR LIMB, EXTERNAL SURFACE 251 97. LEFT ANTERIOR FOOT OF THE HORSE: ANTERIOR ASPECT 253 98. LEFT ANTERIOR FOOT OF THE HORSE: EXTERNAL ASPECT 254 99. VERTICAL AND TRANSVERSE SECTION OF A LEFT HUMAN FOOT: OUTLINE OF THE SURFACE OF THE POSTERIOR SEGMENT OF THIS SECTION (DIAGRAMMATIC FIGURE) 255 100. INFERIOR SURFACE OF A FORE-HOOF OF THE HORSE: LEFT SIDE 256 101. THIRD PHALANX OF THE HORSE: LEFT ANTERIOR LIMB, INFERIOR VIEW 257 102. THIRD PHALANX OF THE HORSE: LEFT POSTERIOR LIMB, INFERIOR VIEW 257 103. INFERIOR SURFACE OF A HIND-HOOF OF A HORSE: LEFT SIDE 258 104. LEFT POSTERIOR FOOT OF A HORSE: EXTERNAL ASPECT 259 105. FOOT OF THE OX: LEFT SIDE, ANTERO-EXTERNAL VIEW 260 106. THE PROPORTIONS OF THE HORSE (AFTER BOURGELAT) 265 107. PROPORTIONS OF THE HORSE (AFTER COLONEL DUHOUSSET) 270 108. PROPORTIONS OF THE HEAD OF THE HORSE, VIEWED IN PROFILE (AFTER COLONEL DUHOUSSET) 274 109. THE SAME DESIGN AS THAT OF FIG. 108, ON WHICH WE HAVE INDICATED, BY SIMILAR LINES, THE PRINCIPAL CORRESPONDING MEASUREMENTS 275 110. PROPORTIONS OF THE HEAD OF THE HORSE, SEEN FROM THE FRONT (AFTER COLONEL DUHOUSSET) 276 111. THE SAME FIGURE AS FIG. 110, ON WHICH WE HAVE MARKED, BY SIMILAR LINES, THE PRINCIPAL MEASUREMENTS WHICH CORRESPOND THERETO 277 112. HORSE OF WHICH THE LENGTH CONTAINS MORE THAN TWO AND A HALF TIMES THAT OF THE HEAD, AND OF WHICH THIS DIMENSION (A, B) EXCEEDS THE HEIGHT 279 113. HORSE OF WHICH THE LENGTH CONTAINS MORE THAN TWO AND A HALF TIMES THAT OF THE HEAD, AND OF WHICH THIS DIMENSION (A, B) EXCEEDS THE HEIGHT 280 114. HORSE OF WHICH THE LENGTH CONTAINS MORE THAN TWO AND A HALF TIMES THAT OF THE HEAD, AND OF WHICH THIS DIMENSION (A, B) IS INFERIOR TO THE HEIGHT 281 115. EXPERIMENTAL SHOES, INTENDED TO RECORD THE PRESSURE OF THE FOOT ON THE GROUND 284 116. RUNNER FURNISHED WITH THE EXPLORATORY AND REGISTERING APPARATUS OF THE VARIOUS PACES 285 117. TRACING OF THE RUNNING OF A MAN (AFTER PROFESSOR MAREY) 286 118. NOTATION OF A TRACING OF THE RUNNING OF A MAN (AFTER PROFESSOR MAREY) 287 119. NOTATION OF VARIOUS MODES OF PROGRESSION OF A MAN (AFTER PROFESSOR MAREY) 287 120. SWING OF THE RAISED ANTERIOR LIMB (AFTER G. COLIN) 289 121. SWING OF THE ANTERIOR LIMB ON THE POINT OF PRESSURE (AFTER G. COLIN) 290 122. POSTERIOR LIMB, GIVING THE IMPULSE (AFTER G. COLIN) 291 123. NOTATION OF THE AMBLING GAIT IN THE HORSE (AFTER PROFESSOR MAREY) 292 124. THE AMBLE: RIGHT LATERAL PRESSURE 293 125. NOTATION OF THE GAIT OF THE TROT IN A HORSE (AFTER PROFESSOR MAREY) 294 126. THE TROT: RIGHT DIAGONAL PRESSURE 295 127. THE TROT: TIME OF SUSPENSION 295 128. NOTATION OF THE PACE OF STEPPING IN THE HORSE (AFTER PROFESSOR MAREY) 296 129. THE STEP: RIGHT LATERAL PRESSURE 297 130. THE STEP: RIGHT DIAGONAL PRESSURE 297 131. THE GALLOP: FIRST PERIOD 298 132. THE GALLOP: SECOND PERIOD 298 133. THE GALLOP: THIRD PERIOD 299 134. THE GALLOP: TIME OF SUSPENSION 299 135. NOTATION OF THE GALLOP DIVIDED INTO THREE PERIODS OF TIME (AFTER PROFESSOR MAREY) 300 136. NOTATION OF THE GALLOP OF FOUR PERIODS IN THE HORSE (AFTER PROFESSOR MAREY) 300 137. LEAP OF THE HARE (AFTER G. COLIN) 301 138. THE LEAP 302 139. THE LEAP 302 140. THE LEAP 303 141. THE LEAP 303 142. THE LEAP 305 143. THE LEAP 305

THE ARTISTIC ANATOMY OF ANIMALS

INTRODUCTION

GENERALITIES OF COMPARATIVE ANATOMY

Of the animals by which we are surrounded, there are some which, occupying a place in our lives by reason of their natural endowments, are frequently represented in the works of artists--either as accompanying man in his work or in his amusements, or as intended to occupy the whole interest of the composition.

The necessity of knowing, from an artistic point of view, the structure of the human body makes clear the importance we attach, from the same point of view, to the study of the anatomy of animals--that is, the study of comparative anatomy. The name employed to designate this branch of anatomy shows that the object of this science is the study of the relative position and form which each region presents in all organized beings, taking for comparison the corresponding regions in man. The head in animals compared with the human head; the trunk and limbs compared to the trunk and limbs of the human being--this is the analysis we undertake, and the plan of the subject we are about to commence.

Our intention being, as we have just said, the comparison of the structure of animals with that of man, should we describe the anatomy of the human being in the pages which follow? We do not think so. Plastic human anatomy having been previously studied in special works,[2] we take it for granted that these have been studied before undertaking the subject of comparative anatomy. We will therefore not occupy time with the elementary facts relative to the skeleton and the superficial layer of muscles. We will not dilate on the division of the bones into long, short, large, single, paired, etc. All these preliminary elements we shall suppose to have been already studied.

[2] Mathias Duval, 'Précis of Anatomy for the Use of Artists': Paris, 1881. 'Artistic Anatomy of the Human Body,' third edition, plates by Dr. Fau, text with figures by Édouard Cuyer: Paris, 1896. 'Artistic Anatomy of Man,' by J. C. L. Sparkes, second edition, text with 50 plates: Baillière, Tindall and Cox, London, 1900.

This being granted, it is, nevertheless, necessary to take a rapid bird's-eye view of organized beings, and to recall the terms used in their classification.

Animals are primarily classed in great divisions, based on the general characters which differentiate them most. These divisions, or _branches_, allow of their being so grouped that in each of them we find united the individuals whose general structure is uniform; and under the name of vertebrates are included man and the animals with which our studies will be occupied. The vertebrates, as the name indicates, are recognised by the presence of an interior skeleton formed by a central axis, the vertebral column, round which the other parts of the skeleton are arranged.

The vertebrate branch is divided into classes: fishes, amphibians or batrachians, reptiles, birds, and mammals.

The mammals--from the Latin _mamma_, a breast--are characterized by the presence of breasts designed for the alimentation of their young. Their bodies are covered with hair, hence the name _pilifères_ proposed by Blainville; and, notwithstanding that in some individuals the hairs are few, the character is sufficient to distinguish them from all other vertebrates.

We find united in this class animals which, at first, seem out of place, such as the whale and the bat; and, from their external appearance alone, the former would appear to belong to the fishes, and the latter to birds. Yet, on studying their structure, we find that, not only do these animals merit a place in the class which they occupy, because they possess the distinctive characters of mammals; but, still further, their internal structure is analogous to that of man and of the other individuals of this class.

Notwithstanding this similarity of structure, the whale is not without some points of difference from its neighbours the horse and the dog; therefore, in order to place each of these animals in a position suitable to it, mammals are divided into secondary groups called _orders_. The first of these orders includes, under the name _primates_, man and apes. The latter contain animals which approach birds in certain characters of their organism, forming a link between the latter and mammals.

We find, in studying the regions of the body in some of the vertebrates, that, while they present differences from the corresponding regions of the human body, they also offer most striking analogies. We can, for example, recognise the upper limb of man in the anterior one of quadrupeds, in the wing of the bat, in the paddle of the seal, etc. It is, so to speak, those variations of a great plan which give such a charm to the study of comparative anatomy.

The division of classes into orders, which we have just mentioned, being still too general, it was found necessary to establish subdivisions--more and more specialized--to which the names _families_, _genera_, _species_, and _varieties_ were given.