List of Illustrations. 



xui 



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 



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



progressive stages of development, representing four dif- 

 ferent divisions of the class Mammalia 



59. Dingram of geological succession of the classes of the 



Animal Kingdom 

 Skull of Oreodon Culbertsoni 

 62. Horns of Cervus dicroccru- 



C. mathej-onis . 



C. pardinensis . 



C. issiodorensis . 



60. 

 61, 



63- 

 64. 



65- 

 66. 



67. 



68. 

 69. 



70. 



71 



72. 



73 



74- 



75- 

 76. 



77- 

 78. 



79- 

 80. 

 81. 



82 



83- 

 84. 



85- 

 86. 



87. 

 88. 

 89. 



» 



Sedgznickii 



n existing Deer' 



Successive stages in the development of 



Antlers ..... 

 Homocercal tail .... 

 Heterocercal tail .... 

 Vertebrated but symmetrical fiu (diphycercal) 

 Tail of ArchiEOpteryx 

 Tail of modern Bird 

 Ai-chc£Optery'X macura, restored 

 Skeleton of Polar Bear . 

 Skeleton of Lion .... 

 Anterior limb of Man, Dog, Hog, Sheep, and Horse 

 Posterior limb of Man, Monkey, Dog, Sheep, and Horse 

 I'osteiior limb of Baptanodon discus, and anterior limb of 



Chelydra serpentina ...... 



Paddle of a Whale 



Yo%%S\. '^€i&'ioVi oi Phenacodus primcEvus 



Bones of the foot of four different forms of the perisso 



dactyl type ....... 



bonei of the foot of four different forms of the arliodacty 



type 



Feet and teeth in fossil pedigree of the Horse 



FalcEoiherium. (Lower Tertiary of Paiis Basin) 



Hipparion. (New World Pliocene) 



Comparative series of Brains ..... 



Ideal sectii n through all the above stages 



Skulls of Canadian Stag, Cervalces Aniericanus, and Elk 



Transmutations of Planorbis ...... 



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