Origin of birds, 181. feathers, 102. flight, 122. hair, 102. life, 159. lungs, 177. milk glands, 212. placenta, 210. variations, 50. "Origin of Species" published, 41. Orthogenesis and Eimer, 243. Oxford meeting of British Association, 41. P Palaeozoic era, 170. Paley's Natural Theology, 87. Pangenesis, 236. Patagonia and its terraces, 29. Phenacodus, 185. Physical evolution of man, 254. Pithecanthropus, 188. Planetesimal theory, 155. Playing dead, 107. Playing 'possum, 107. Polygamy in animals, 137. Pond-snail, development of, 46. Potato worm, 142. Protective coloration, 109. Protoplasm, 164. Pterodactyl, 180. Puff adder, 107. Purpose and adaptation, 89. Purpose in nature, 88. Q Quiet and escape, 105. R Raining toads, 113. Religion and evolution, 74. Reptiles of Mesozoic, 179. Reproduction, asexual and sexual, 194. in fishes, 196. in frogs, 199. in reptiles, 202. Rhinoceros horn, 123. Romanes and isolation, 242. Rooster finer than hen, 132. S Saint Augustine and evolution, 11. Salamanders, 176. Sargent's picture, 289. Science and the book, 274. Science and theology, 280. Science, definition, 280. Seals and polygamy, 139. Sealskin and fur, 100. Sedgwick and Darwin, 24. Selection and evolution, 56. Sexual selection, 126, 128. Skunk's odor, 117. Sloth and megatherium, 29. Song and mating, 133. Sparrow, English, adapted to town, 66. and hawks, 69. and winter, 73. eat varied food, 71. eye-minded, 78. feed young on insects, 72. good qualities, 85. has reached limit, 85. in Philadelphia, 63. introduction, 62. lives near houses, 70. nests early, 81. nests often, 82. once migratory, 80. quarrels without animosity, 75. sociable, 74. spread of, 65. stays over winter, 79. successful, 83. transported in cars, 67. unafraid of man, 69. wintering, 73. Sparrow, House, 62. Sphex wasp, 143. Spider cocoons, 139. Spider, young, 140. Spontaneous generation, 159. Stone lilies, 171. Story of the horse, 220. Struggle against enemies, 104. for food, 91. for shelter, 92. for the individual, 90. for the species, 91, 125. Sunfish and young, 196. T Taste of toad, 118. Teeth of mammals, 98. Temperature of mammals, 99. Tertiary era, 185. Thayer, concealing color, 115. Theology and science, 280. Theology, definition, 280. Thomas Aquinas and evolution, 12. Three-toed horse, 227. Toad, bad taste, 118. color, 112. enemies, 113. short tadpole stage, 112. Tomato worm, 142.