Groundhog and winter, 103. Growth of North America, 167. H Haeckel advocates evolution, 42. Health certificates, 263. Henslow and Darwin's education, 24. Henslow suggests Darwin for Beagle, 24. Heredity and natural selection, 45. Heredity in man, 258. Homes, few animals have, 98. Homes, warm-blooded animals, 101. Horn of rhinoceros, 123. Horns of deer, 138. Horse and early man, 232. earliest, 223. neck, 229. story of, 220. three-toed, 227. Horseshoe crab, 171. How mammals developed, 192. Huxley at Oxford meeting, 42. I Ichneumon fly, 142. Image of God, 288. Improving the environment, 259. Improving the stock, 261. Inheritance of acquired characters, 238. Insect's biting mouth, 93. Interpretation of Genesis, 284. Isolation, Jordan, 242. Isolation, Romanes, 242. Isolation, Wagner, 241. J Java skull, 187. Jehovah confounding the nations, 289. Jordan and isolation, 242. Judgment, Michael Angelo, 289. Jukes family, 265. June-bug, 107. K Kallikak family, 265. Kant and evolution, 13. Katydid's color, 111. Katydid's song, 133. Keeling Atoll and Darwin, 31. King Crab, 171. L Lamarck and evolution, 17. Lampshells, 172. La Place's theory, 151. Leibnitz, and evolution, 13. Life from other planets, 162. Life in the past, 149. Life, its nature, 247. Linnaean Society and evolution, 40. Linnaeus and fixed species, 15. Locust's song, 135. Lucretius and evolution, 10. Lung-fish, 176. Lyell's Geology, 26. M Male birds brighter, 131. Male insects sing, 134. Malthus and population, 35. Mamma, significance of, 211. Mammals, egg-laying, 208. how developed, 192. Man and God's image, 288. early, and horse, 232. growing better, 255. Man's ancestry, 250. future evolution, 249. Mating and song, 133. Mating antics, 136. Meaning of Genesis, 284. Megatherium and sloth, 29. Mesozoic age, 178. Michael Angelo, Judgment, 289. Migration of birds, 103. Missing link, 187. Mizpah, 283. Modern teachers of biology, 291. Mongolian idiot, 265. Mosquito's bite, 97. Mosquito's mouth, 96. Mother-love, 217. Multiplication and evolution, 54. Mutation and DeVries, 246. N Nature of life, 247. Nature of milk, 214. Natural selection explained, 45. in brief, 36. Nebular hypothesis, 152. Neck of horse, 229. Neo-Darwinians, 237. Nests for warm eggs, 101. Number and position of breasts, 215. O Odor as protection, 117. Opossum playing dead, 107.