442 



INDEX 



Gall-bladder, 362, 360. 

 Gametophyte, 152, 153, 155. 



in fern, 155 ; 



in moss, 162. 

 Ganglia, 399. 

 Ganoid, 283, 284. 

 Gastric juice, 358. 

 Gastric mill, 226. 

 Gastropods, 270, 273. 

 Gastrula, 200. 

 Genus, defined, 157. 

 Geotropism, 85. 

 Germination, defined, 74 ; 



factors in, 74 ; 



of bean, 78. 

 Gila monster, 294. 

 Gill rakers, 277. 

 Gills, fish's, structure of, 277. 

 Girdle, pectoral, in man, 327 ; 



pelvic, in man, 327. 

 Glands, gastric, 358 ; 



intestinal, 360 ; 



lymph, 377 ; 



mesenteric, 363 ; 



salivary, 356 ; 



structure of, 363 ; 



sweat, 391. 

 Glomerulus, 391. 

 Glottis of man, 354. 

 Glycogen, formation of, 360. 

 Grafting, 111. 

 Grain, 56. 



Grape sugar, tests for, 70, 71. 

 Guard cells, 120. 

 Gullet, 352, 354. 

 Gymnosperms, 157. 



Habits, formation of, 404 ; 



importance of right, 404. 

 Hemoglobin, 368. 

 Hair protection, in leaves, 129. 

 Hairs, development of, 321. 

 Halophytes, 161. 

 Hay infusion, life in, 188. 

 Health, and disease, 418 ; 



department of, 434, 436. 

 Hearing, organ of, 407, 408. 

 Heart, a force pump, 371. 

 Heart, in action, 371 ; 



nervous control of, 377 ; 



Heart, position of, 370 ; 



protection of, 370 ; 



structure of, 370 ; 



valves in, 370, 371. 

 Heliotropism, 116, 117. 

 Hemiptera, 242, 247. 

 Honeybee, 253. 

 Hookworm, 217, 218. 

 Hornets' nest, 254. 

 Horny fiber sponge, 201. 

 Horse, geologic history, 316. 

 Human blood, 367. 

 Human body a machine, 320. 

 Humus, 21, 92. 

 Hybridizing, 82. 

 Hydra, 202. 

 Hydrogen, 21. 

 Hydroid colony, 208. 

 Hydrophytes, 160. 

 Hygiene, personal, 418 ; 



public, 428. 



Hymenoptera, 245, 247. 

 Hypha, 149. 

 Hypocotyl, 65. 



Ichneumon fly, 267. 



Immunity, 430. 



Inorganic soil, relation to organic, 



92. 

 Insects, 233 ; 



and crustaceans compared, 246; 



beneficial, 264 ; 



communal life, 252 ; 



control of damage by, 265 ; 



disease-carrying, 258, 259, 260, 

 261; 



divisions of, 247 ; 



noxious, 262, 263, 264 ; 



relation to mankind, 258 ; 



winners in life's race, 233. 

 Inspiration, 384. 

 Instincts, 312. 

 Intestine, large, 363 ; 



small, structure of, 361. 

 Irritability, defined, 32. 

 Invertebrate, cross section of, 274. 



Joint, hinge, 324. 

 Key fruit, 56. 



