List of Illustrations. xiii 



PAGE 



Fic. 57. A scries of embryos at three comparable and progressive 

 stages of development, representing each of the classes 

 of vertebrated animals below the Mammalia . . 153 



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



progressive stages of development, representing four dif- 

 ferent divisions of the class Mammalia . . . J5J 



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. issiodoremis . . . . . . 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 Archaopteryx 171 



73. Tail of modern Bird 171 



73. Archaopteryx macura, restored 17 J 



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 strpentina . 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 186 



83 Bonet of the foot of four different forms of the artiodactyl 



type 187 



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



84. Palaeotherhtm. (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 



