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 . . . 15^ 



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.Sedgwickii . . . . . .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 fill (diphycercal) . .170 



71. Tail of ArchcBOpteryx 171 



72. Tail of modern Bird 171 



73. Archceopteryx tnacura, restored 17 1 



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, Monk y, 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 primavus . . .184 



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



dactyl type 186 



82 Bonet of the fftot of four different forms of the artiodactyl 



type 187 



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



84. Palaolherium. (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 



