List of Illustrations. xiii 



PAGE 



FIG. 57. A series of embryos at three comparable and progressive 

 stages of development, representing each of the classes 

 of vertebrated animals below the Mammalia . .152 



58. Another series of embryos, also at three comparable and 



progressive stages of development, representing four dif- 

 ferent divisions of the class Mammalia . . . 153 



59. Diagram of geological succession of the classes of the 



Animal Kingdom . . '. . . . . 165 



60. Skull of Oreodon Culbertsoni . ''. ... . 167 



61. 62. Horns of Cervus dicrocerus . . . . . 168 



63. ,, C. matheronis . . . . . . 168 



64. C. pardinensis ...... 168 



65. C. issiodorensis 168 



66. C.Sedgttiukii 168 



67. Successive stages in the development of an existing Deer's 



Antlers . . 169 



68. Homocercal tail . . . . .... .169 



69. Heterocercal tail , .170 



70. Vertebrated but symmetrical fin (diphycercal) . .170 



71. Tail of Archaopteryx . 171 



72. Tail of modern Bird 171 



73. Archaopteryx macura, restored 172 



74. Skeleton of Polar Bear 174 



75. Skeleton of Lion 175 



76. Anterior limb of Man, Dog, Hog, Sheep, and Horse . 176 



77. Posterior limb of Man, Monkey, Dog, Sheep, and Horse 177 



78. Posterior limb of Baptanodon discus, and anterior limb of 



Chelydra serpentina 179 



79. Paddle of a Whale . . . . . . . 180 



80. Fossil skeleton of Phenacodus primcevus . , . . 184 



81. Bones of the foot of four different forms of the perisso- 



dactyl type . . . .1 ". . . .186 



82. Bones of the foot of four different forms of the artiodactyl 



type 187 



83. Feet and teeth in fossil pedigree of the Horse . . 189 



84. PaloEotherium. (Lower Tertiary of Paris Basin) . .190 



85. Hipparion. (New World Pliocene) . . . .192 



86. Comparative series of Brains ...... 194 



87. Ideal section through all the above stages . . . 195 



88. Skulls of Canadian Stag, Cervalces Americanus, and Elk 198 



89. Transmutations of Planorbis . . . . . . 200 



