Eggs, of the crocodile, 110; of fish carried in the father’s mouth, 65; of frogs, 71; of ostriches cracked by the father, 139; of fish, modes of transport of, 66; of shark, 28, 42; of snake, 116. Eider-duck, range of the, 142. Elastic band in front of snake’s jaw, 111. Elephant, affinity to rodents, 276; _the Indian_, 277; intelligence of the, 278; structure of the, 276–279; tooth and tusk of, found in Australia, 194; -seal, 314. Emus, pairing birds, 139. Enamel-scaled fish, 33. _Eohippus_, 209; ancestor of the horse, 213, 261. _Europe in the age of ice_, 299. Evolution, of sympathy and self-sacrifice, 352; taught by Darwin, 345. _Exocœtus, the flying-fish_, 54. Eyelid, third, in reptiles and birds, 109, 136. Eyelids, absence of, distinguishes snakes from legless lizards, 110. Falcon, swooping of the, 176. _Fangs of poisonous snakes_, 119. Feather, number of threads in an eagle’s, 133. Feathers of birds, their growth and importance, 133, 134. Feet, grasping of perching birds, 155. Felines, highest type of flesh-feeder, 290; kill by a blow, 288; retractile claws of, 289. Fins of the minnow, 24. Fish, affection shown by, 69; age of the gristly, 333; air-bladder of, 25; ancient forms of, 33, 37–42; blind, of Kentucky caves, 68; come to the coast to spawn, 57; deep-sea, 47–50; lowest type of, 11; limbs of, 25; mammals which imitate, 318; muscular power of, 24; ocean home of the, 21; of the old or gristly type, 27; parental care in, 349; skeletons of deep-sea, 49; small ancient, 20, 34–42; varieties of modern, 46; weapons of, 29, 40, 42, 48, 52, 58, 59, 64, 68. _Fishing frog, Lophius_, 59. Fish-life, general sketch of, 67. Fish-lizards of olden times, 92. _Flamingo, half-way between waders and swimmers_, 150. Flat-fish, structure of, 61. Flint tools of early man, 343. Flying-fish, 53–55. Flying-gurnards, 55. Food of land-birds, 155. Fowls and their relations, 157. Fox, a solitary hunter, 285; range of the, 286. France, tree-frogs of, 87. Freshwater fish, 65. Frigate-bird, perches on trees, 148. Frog, a recent form of amphibian, 84; carrying young in a pouch, 87; carrying eggs and tadpoles, 87; _metamorphosis of the_, 72–76; lungs of, 76; more nearly allied to fish than reptiles, 129; mouth and tongue of, 77; respiring skin of, 77; spawn described, 71; _tree-, of New Guinea_, 86. _Fruit-bats_, 238. Fur-seals, history of, 310. Gadow, Dr., on number of threads in an eagle’s feather, 133. Galagos or lemurs of Africa, 243. Galapagos, tortoises of, 101. _Galeopithecus or Colugo_, 231. Gaudry cited, 212. Gautier, M., on snake poison, 119. _Gecko or wall lizard_, 105. Geese, range of wild, 142. Geography, changes in physical, 340.