Earthworm, anatomy of, *126; alimentary canal of, *126; cross-section of, *131; reproductive organs of, *130; structure and life of, 127. Earthworms, 136. Echinoderm, development of, 119; structure of, 117; shape of, 116. Echinodermata, 108; classification of, 120. _Echinodoris_ sp., *254. Echinoidea, 121, 122, 123. _Eciton_, 225. Ecology, animal, 403. _Ectopistes migratorius_, 351. Eel, 284. Eft, green, 297; western brown, *299. Eggs of birds, collecting, 469. Eider, 347. Elasmobranchii, 279. _Elassoma_, 271. Elk, *394, 396. Epeiridæ, 236. Ephemerida, 194. _Epialtus productus_, *153. Equipment of laboratory, 450. Equipment of pupil, 447. _Erethizon dorsatus_, 391. _Erethizon epixanthus_, 391. _Eretmochelys imbricata_, 215. _Erismatura rubida_, 347. _Eumeces skeltonianus_, *316. _Eupomotic gibbosuc_, dissection of, (facing) *263; life of, 270; structure of, 263. _Exocætus_, 285. Eye, cornea of compound, of horse-fly, *186; section through compound, of blow-fly, *185. Eye of vertebrate, *378. _Falco sparverius_, 353. Family, defined, 72. Fauna, 440. Feather-stars, 121, 125, *126. Feet of birds, 362. _Felis concolor_, 398. Feræ, 397. Fever, yellow, and mosquitoes, 205. _Fiber zibethicus_, 391. Fire-flies, 209. Fishes, 263; body form and structure of, 271; classification of, 277; development and life-history of, 276; habits and adaptations of, 285. Fish-hatcheries, 288. Flat-worms, 137. Flea, house, *204. Flickers, 355. Flies, 201; chalcid, 214; ichneumon, 212. Flight of birds, 366. Flying fishes, 285. Food-fishes, 288. Food of birds, 370. Foraminifera, 80. Fox, 398. _Fregata aquila_, 346. Frogs, 299. _Fulica americana_, 349. Fulmars, 345. Function, defined, 14. Functions, essential, 15. Fur-seals, 398, *399. Fur-seals, parasitized, *422. _Gadus callarias_, 284. Galley-worm, *227. Gall-flies, 214. Gallinæ, 350. Gastropoda, 246. _Gavia imber_, 347. Gavial, 326. Generation, spontaneous, 58. Genmules, 85. Genus, defined, 70. _Geococcyx californianus_, 354. Gephyrean, *134. Girdler, currant stem, *215. Glass-snake, 317. Glires, 391. Goat, Rocky Mt., 397. _Gonionema vertens_, *101. Goose, Canada, 347. Gophers, pocket, 391. _Gordius_, 140. _Grantia_, *47. _Grantia_ sp., 85. Grayling, 284. Grebe, horned, 343; pied-billed, 343. Green, methyl, 351. Greensnake, 320. Gregariousness, 410. Grouse, ruffed, 350. _Grus americana_, 348. _Grus mexicana_, 348. Guillemot, 345. Guinea-pig, 391. Guinea-worm, 140. Gull, great black-backed, 345. Gulls, 345. Gymnophiona, 302. Gyrinidæ, 206. Habitat, 441. Hag-fishes, 279. Hair-worms, 140. _Haliætus leucocephalus_, 352. _Halictus_, 216.