G. J. R.

Christ Church, Oxford,
April 19th, 1892.

CONTENTS

PAGE
[CHAPTER I.]
Introductory[1]
[CHAPTER II.]
Classification[23]
[CHAPTER III.]
Morphology[50]
[CHAPTER IV.]
Embryology[98]
[CHAPTER V.]
Palæontology[156]
[CHAPTER VI.]
Geographical Distribution[204]
[CHAPTER VII.]
The Theory of Natural Selection[251]
[CHAPTER VIII.]
Evidences of the Theory of Natural Selection[285]
[CHAPTER IX.]
Criticisms of the Theory of Natural Selection[333]
[CHAPTER X.]
The Theory of Sexual Selection, and Concluding Remarks[379]
[Appendix to Chapter V.][421]
[Note A to Page 257][443]
[Note B to Page 295][445]
[Note C to Page 394][448]
[Index][451]

LIST OF ILLUSTRATIONS

Fig.PAGE
1. Successive forms of Paludina, from the Tertiary deposits of Slavonia[19]
2. Skeleton of Seal[52]
3. Skeleton of Greenland Whale[53]
4. Paddle of Whale compared with Hand of Man[54]
5. Wing of Reptile, Mammal, and Bird[56]
6. Skeleton of Dinornis gravis[61]
7. Hermit crabs compared with the cocoa-nut crab[64]
8. Rudimentary or vestigial hind-limbs of Python[67]
9. Apteryx Australis[69]
10. Illustrations of the nictitating membrane in various animals named[75]
11. Rudimentary, or vestigial and useless, muscles of the human ear[76]
12. Portrait of a young male gorilla[78]
13. Portrait of a young male child[79]
14. An infant, three weeks old, supporting its own weight[81]
15. Sacrum of Gorilla compared with that of Man, showing the rudimentary tail-bones of each[82]
16. Diagrammatic outline of the human embryo when about seven weeks old[83]
17. Front and back view of adult human sacrum[84]
18. Appendix vermiformis in Orang and in Man[85]
19. The same, showing variation in the Orang[85]
20. Human ear[86]
21. Fœtus of an Orang[87]
22. Vestigial characters of human ears[88]
23. Hair-tracts on the arms and hands of Man, as compared with those on the arms and hands of Chimpanzee[90]
24. Molar teeth of lower jaw in Gorilla, Orang, and Man[93]
25. Perforation of the humerus (supra-condyloid foramen) in three species of Quadrumana where it normally occurs, and in Man, where it does not normally occur[95]
26. Antlers of stag, showing successive addition of branches in successive years[100]
27. Fission of a Protozoön[107]
28. Hydra viridis, partly in section[111]
29. Successive stages in the division of the ovum, or egg-cell, of a worm[113]
30. Ovarian ovum of a Mammal[121]
31. Amœboid movements of young egg-cells[122]
32. Human ovum, mature and greatly magnified[123]
33. Stages in the formation of the polar bodies in the ovum of a star-fish[125]
34. Fertilization of the ovum of an echinoderm[126]
35. Fertilization of the ovum of a star-fish[127]
36. Karyokinesis of a typical tissue-cell (epithelium of Salamander)[129]
37. Study of successive changes taking place in the nucleus of an epithelium-cell, preparatory to division of the cell[131]
38. Formation and conjugation of the pronuclei in Ascaris megalocephala[132],
[133]
39. Segmentation of ovum[135]
40. The contents of an ovum in an advanced stage of segmentation, drawn in perspective[135]
41. Formation of the gastrula of Amphioxus[137]
42. Gastrulation[138]
43. Gastrula of a Chalk Sponge[139]
44. Prophysema primordiale, an extant gastræa-form[140]
45. Ideal primitive vertebrate, seen from the left side[143]
46. The same in transverse section through the ovaries[144]
47. Amphioxus lanceolatus[145]
48. Balanoglossus[148]
49. A large Sea-lamprey (Petromyzon marinus)[148]
50. Adult Shark (Carcharias melanopterus)[149]
51. Diagram of heart and gill-arches of a fish[150]
52. One gill-arch, with branchial fringe attached[150]
53. Diagram of heart and gill-arches in a lizard[150]
54. Ideal diagram of primitive gill-or aortic-arches[151]
55. The same, modified for a bird[151]
56. The same, modified for a mammal[151]
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 different 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. Horns of C. matheronis[168]
64. Horns of C. pardinensis[168]
65. Horns of C. issiodorensis[168]
66. Horns of 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 fin (diphycercal)[170]
71. Tail of Archæopteryx[171]
72. Tail of modern Bird[171]
73. Archæopteryx 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 primævus[184]
81. Bones of the foot of four different forms of the perissodactyl type[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. Palæotherium. (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]
90. Transformation of Strombus[202]
91. Pigeons. Drawn from life[298]
92. Pigeons (continued). Drawn from life[299]
93. Fowls. Drawn from life[300]
94. Fowls (continued). Drawn from life[301]
95. Pair of Japanese Fowls, long-tailed breed[302]
96. Canaries. Drawn from life[303]
97. Sebastopol, or Frizzled Goose[304]
98. The Dingo, or wild dog of Australia[304]
99. Dogs. Drawn from life[305]
100. Dogs (continued). Drawn from life[306]
101. The Hairless Dog of Japan[307]
102. The skull of a Bull-dog compared with that of a Deer-hound[307]
103. Rabbits. Drawn from life[308]
104. Horses. Drawn from life[309]
105. Sheep. Drawn from life[310]
106. Cattle. Drawn from life[311]
107. Wild Boar contrasted with a modern Domesticated Pig[312]
108. Seasonal changes of colour in Ptarmigan (Lagopus mutus)[317]
109.Œdicneus crepitans, showing the instinctive attitude of concealment[320]
110. Imitative forms and colours in insects[322]
111. The larva of Puss Moth (Cerura vinula)[325]
112. The larva of Puss Moth in disturbed attitude[326]
113. Three cases of mimicry[328]
114. Two further cases of mimicry; flies resembling a wasp in the one and a bee in the other[329]
115. A case of mimicry where a non-venomous species of snake resembles a venomous one[330]
116. A case of mimicry where a homopterous resembles a leaf-cutting ant[332]
117. Feather-footed pigeon[359]
118. Raia radiata[368]
119. Electric organ of the Skate[369]
120. Electric cells of Raia radiata[370]
121. The Garden Bower-bird (Amblyornis inornata)[382]
122. Courtship of Spiders[388]
123. Courtship of Spiders (continued)[389]
124. The Bell-bird (Chasmorhynchus niveus)[396]
125. C. tricarunculatus[397]