Bird song, 135. Blowing viper, 107. Blue birds and frost, 61. Bradbury, Dean, 43. Buffon and evolution, 15. Bumble bees, 125. Butterfly colors, 129. Butterfly's mouth, 95. C Carboniferous age, 174. Carnivorous teeth, 124. Caterpillars on leaves, 110. Cave man, 188. Cells live in water, 166. Cenozoic age, 185. Cicada killer, 143. Circular nest of bird, 147. City life in man, 256. Clothing of birds, 101. Coal plants, 174. Cold-blooded animals, 99. Color, concealing, Thayer, 115. Concealing appearance, 105. Cope and Lamarckianism, 244. Cope on taste of toad, 118. Coral reef formation, 32. Country life in man, 256. Cretaceous period, 180. Cricket song, 134. Crinoids, 171. Crossing and variation, 53. Cuvier criticises Lamarck, 19. D Darwin, Charles, along La Plata, 28. at Buenos Ayres, 28. at Keeling Atoll, 31. at Galapagos, 30. father of evolution, 21. in Brazil, 27. in Patagonia, 29. in Peru, 30. on Beagle, 26. persuaded world of evolution, 21. studies Lyell's Geology, 26. studies Malthus, 35. Darwin, Erasmus, and evolution, 16. Darwin's ancestry, 22. birth, 23. burial in Abbey, 43. death, 43. education, 23. narrative of voyage, 33. patient mind, 45. purity of mind, 29. return to England, 33. short sketches, 39. study of barnacles, 34. work double, 233. Deer horns, 138. Descartes and evolution, 12. Descent of man, 189. Determinants in nucleus, 238. Development of chick, 204. Development of pond-snails, 46. Devonian age, 173. Devonian fish, 173. DeVries and mutation, 246. Duckmole, 208. E Early marriage, 272. Earth's age, 155. Ecstatic flight, 136. Egg-laying mammals, 208. Eimer and orthogenesis, 243. Elements of Geology, Lyell, 26. Emanuel Kant and evolution, 13. Embryo of chick, 203. Emerson and nature, 48. Empedocles and evolution, 8. English sparrow (see Sparrow, English). Environment in man, 258. Eugenic program, 269. Evening primrose and mutation, 246. Evolution since Darwin, 233. F Feeble-mindedness, 264. Feet of mammals, 122. First living things, 165. Fish eggs, 145. Fish may freeze, 104. Fitz-Roy, Capt., and Beagle, 25. Freedom of teaching, 291. Fright paralysis, 108. Frog's long tadpole stage, 112. Frost and bluebirds, 61. Fur of seal, 100. Future evolution of man, 249. G Galapagos Islands and evolution, 30. Geological periods, 158. Glyptodon and armadillo, 29. Goethe and evolution, 20. Graphite from plants, 168. Grasshopper's mouth, 93. Grasshopper song, 133.