INDEX 



521 



Glare, 236 



Glucose as adulterant, 123 



Gluten, 51 



Glycogen, 189 



Gonococcus bacteria, 237 



Grackle, bronzed, 427 



Grafting, 270, 271, 272 



Grains, 34, 78, 217 



Gravity, responses to, 38, 241 



Great blue heron, 428 



Green slime, 76 



Growing period of various animals, 



^335 



Growth, 17 ; as cause of movement, 

 38 ; discontinuous, 269, 292 ; limits 

 of, 265 ; and regeneration, 265 ; in 

 roots, 43; and smoking, 165; in 

 stems, 347 



Guano, 60, 66, 429 



Guard cells, 71, 72 



Gudernatsch, Dr. J. F., 285 



Gullet, 82, 87 



Gut, 84, 101-104. See also Intestine 



Gymnosperms, 481 



Gypsy moth, 419, 422 



Habit, 248 ff. ; formation of, 150 ; for- 

 mation of, by protoplasm, 131 



Habit-forming drugs, 255-257 



Habits, eating, 89, 114; feeling, 250; 

 health, 114-119; kinds of, 249; 

 selection of, 250; thinking, 249; 

 tobacco, 163 ff. ; value of, 251 



Habituation, 131, 163 



Haddock, breathing of, 147 



Haemocyanin, see Hemocyanin 



Haemoglobin, see Hemoglobin 



Hairs, of mammals, 349, 350 ; of 

 plants, 347, 348 ; root, 42 



Happiness, biology and, 4 



Headache, 1 18 



Headache powders, 118 



Health, alcohol and, 133 ; and bacte- 

 ria, 386; and biology, i ; fatigue and, 

 215; food and, 89; habits for con- 

 trol of, 114-119; public, 394, 410, 510 



Healing, 266 



Hearing, 238 ; in fishes, 239 



Heart, 185, 186; beat of, 190; care 

 of, 190; effect of smoking upon, 

 164; leaky, 190; training of, 191 



Heat, 9, II, 27, 54, 72, 143, 155, 156, 

 157, 206, 348, 359, 363 {see also Tem- 

 perature) ; and living matter, 337- 

 338, 391 (see also Frontispiece); 



measurement of, 91 (.f^^aAc? Calorie); 

 from organism, 92 



Hemocyanin, 179 



Hemoglobin, 179, 183, 184 



Heredity, 443 ; in animals, 444 ; appli- 

 cations of, 450 ; and disease, 200 ; 

 in man, 454, 455; of modifications, 

 461 , 492, 504 (see also Frontispiece) ; 

 in plants, 444 ; and protoplasm, 

 457 ; and theory of evolution, 473, 

 492 (see also Frontispiece) 



Hermit crab, 363, 364 



Heroin, 257 



Heron, great blue, 428 



Hessian fly, 419 



Heterospory, 324 



Home-finding instinct, 363 



Home-making, 368, 371 



Homo, 488, 495, 496 



Homology, 365 



Honey, 313, 413, 433 



Honey-pot ant, 433 



Hookworm, 341, 510 



Hormones, 52, 188-1S9 



Horns, 315 



Horse, evolution of, 466 



Horse botfly, 421 



Horse power, 91 



Horsefly, 398 ff. 



Human race, 455, 488, 501 



Humus, 75 



Huxley, Thomas H., 489 



Hybrid, 445 



Hybridizing, 450 



Hydrotropism in plants, 38-39 



Hypocotyl, 33 



Illumination, 362. See also Light 



Imitation, 494, 499; learning by, 504 



Immunity to disease, 198, 452 ; ac- 

 quired and natural, 199; active and 

 passive, 200; breeding for, 451 



Indigestion, 115, 118, 135, 138 



Individual differences, iio-iii, 198, 

 234, 258 (see also Variation); in 

 digestion of food, 106; in size of 

 stomach, 115; in susceptibility to 

 alcohol, 134 ; in susceptibiUty to 

 tobacco, 163 



Individuality, 437 



Industrial dangers, 169, 171, 214, 236 



Industrial hygiene, 128 



Industrial poisons, 158 ff. 



Industry, biology and, 4 



Infancy and parental care, 331 ff. 



