426 



INDEX 



Heredity, relation of alcohol to, 372. 



Hervey, William, 399. 



Hibernate, 22. 



Hides, 205. 



Hilum, 59. 



Honey and wax, 207. 



Hookworm, 183, 228, 229. 



Horse, ancestor of, 193, 260. 



How food is swallowed, 302. 



Human blood, 314. 



Human body, a machine, 267 ; 



composition of, 21. 

 Human physiology, definition, 15. 

 Humming bird, 43. 

 Humus, 79. 



Hundred calorie portions, 286. 

 Huxley, 398. 

 Hybridizing, 254. 

 Hybrids, 254. 

 Hydra, 179. 

 Hydrochloric acid, 303. 

 Hydrogen of water, 20, 20. 

 Hydrophobia, 392. 

 Hygiene, 27 ; 



of breathing, 338 ; 



of skin, 344 ; 



of mouth, 302 ; 



of muscles and bones, 268 ; 



outline, 415 ; 



personal, 261. 

 Hypocotyl, 59. 

 Hymenoptera, 30. 



Ichneumon fly, 208. 

 Illness of drinkers, 363. 

 Imperfect flowers, 44. 45. 

 Immunity, 157, 390. 

 Improvement, by selection, 253; 



of man, 261. 

 Impure water, 289. 

 Incisors, 301. 



Infectious diseases, 27, 363, 390. 

 Infusoria, 182. 

 Inner ear, 359. 

 Inoculation, 157. 

 Inorganic soil, 77 ; 



foods, 274. 

 Insects, 185 ; 



and foods, 376 ; 



Insects, as disease carriers, 225 ; 



as pollinating agents, 36 ; 



damage done by, 34, 214 ; 



diagram of, 29 ; 



food of, 33 ; 



of the house, 216 ; 



orders of, 30. 

 Inspection, of factories, 379 ; 



of raw food, 380. 

 Instincts, 195. 

 Internal secretions, 317. 

 Intestinal fluid, 306 ; 



glands, 308. 

 Intestine, large, 309. 

 Invertebrates, 185. 

 Iris, 360. 

 Isolation, 390. 



Jenner, Edward, 400. 

 Jimson weed, 128. 

 Jukes, 261. 



Kidney bean, 59, 63. 

 Kidneys, 181 ; 



human, 341 ; 



of frog, 243. 

 Kinetic energy, 267. 

 Knots, 112. 

 Koch, Robert, 403. 



Labor, division of, 178. 

 Laboratory equipment, 418. 

 Lacteals, 309, 324. 

 Lactic acid, 150. 

 Lactometer, 288. 

 Ladybug, 209. 

 Large intestine, 309 ; 



of frog, 243. 



Larva of milkweed butterfly, 32. 

 Latent energy, 267. 

 Lateral line, 234. 

 Leaves, as food, 117; 



evaporation of water from, 85 ; 



cell structure of, 85 ; 



mosaic, 90 ; 



respiration, 96 ; 



section, 49 ; 



skeleton of, 85 ; 



structure, 85, 86. 

 Length measures, 417. 



