526 



ELEMENTARY BIOLOGY 



Regeneration, 268 ; in earthworm, 

 268 ; of the eye, 268 ; and growth, 

 265; in Hzard, 270; in plants, 47, 

 269-270 ; in starfish, 269 



Registration of vital statistics, 395 



Regulators, 50 



Reproduction, 291 ; in animals, 327 ; 

 asexual and sexual, 299, 328 ; among 

 batrachians, 328 ; in fern, 322 ; in 

 fishes, 327 ; in insects, 329; in ver- 

 tebrates, 330 



Reptiles, egg of, 330 



Reptilia, 485 



Research, organization of, 509; scien- 

 tific, 511 



Resemblances, protective, 354 



Respiration, 144; artificial, 170-171; 

 blood and, 146; calorimeter, 92- 

 and energesis, 261 



Respirator, 161 



Rest and work, 214 



Resuscitation, 170 ff. 



Reversal of physiological effects, 136 



Rexford food tables, 97, 98 



Rickets (rachitis), 108 



Rockweed, 298 



Roots, 32, 42, 300, 477 ; adventitious, 

 47, 49; as binding agents, 46, 47; 

 climbing, 48, 49 ; and elimination 

 of refuse, 261 ; forms of, 44, 45 ; 

 prop, 47, 49 ; structure of, 42, 43 ; 

 tap-, 45; tubercles, 62; uses of, 46-49 



Root hairs, 42, 44 



Root pressure, 45 



Ross, Sir Ronald, 404 



Rotation of crops, 62-63, 4^3 



Rotting of flax, 396 



Roundworm, 482 



Salamander, regeneration in, 268 



Saliva, 78, 81, 82 



Salivary glands, 83 



Salts, and life, 339 ; relation to pro- 

 teins, 556; relation to protoplasm, 

 52, 339 ; in soil, 30, 66 



Sand dunes, 46 



San Jose scale, 419 



Sap in plants, 46, 176 ff. 



Sapsucker, yellow-bellied, 427 



Scale, San Jose, 419 



Scales of fishes and reptiles, 350 



Scholarship and smoking, 165 



School lunches, 128 



Science, and agriculture, 67 ; and cost 

 of living, 124, 129, 506 ; and natural 



resources, 69 ; origin of, 509 ; and 

 research, 511 ; social nature of, 507 



Scion, 271 



Screening against flies, 403 



Seedless fruit, 303, 454 



Seedling, 35, 36 



Seeds, 32, 315; and alternation of 

 generations, 324, 325 ; distribution 

 of, 317 ff. ; embryo in, 33; escape 

 of, 316; food reserve of, 34, 35, 

 301-302; and fruit, 301, 302, 315; 

 origin of, 301, 303; protection of, 

 315, 316; size of, 36, 319 



Segregation, law of, 445, 446, 447, 449, 



450'.455. 

 Selection, improvement through, 439, 



440, 441 ff. ; natural, 472 

 Self-pollenation, 304 

 Semen, 327, 329 



Sensation, sound, 238 ; and stimula- 

 tion, 228 

 Sensitive plant, 361 

 Serum, 181 



Sewage, 60 ; and bacteria, 397 

 Sex, 296 ff., 320 ff., 331 ff. See also 



Reproduction 

 Shedding of leaves, 375 

 Shellac, 413 

 Shelter, making of, 371 

 Shelter, primitive, of man, 500 

 Shoot (plant axis), 32 

 Sickness, control of, 194 ff., 395, 



507 

 Sieve plates, 176 

 Skeletons of primates, 491 

 Skin, 345, 347, 351 ; hygiene of, 206; 



temperature regulation by, 155 

 Skulls of primates, 292 

 Skunk, 374 

 Sleep, 118, 215 

 Sleeping sickness, 341 

 Smell, organs of, 227 ; sense of, in 



man, 502 

 Smoke, and health, 162 ; and plants, 



162 ; tobacco, 162 

 Smoking, and school standing, 165; 



effects of, 163, 164 ff. 

 Snoring, 151 

 Sociability, in animals, 432 ff. ; in man, 



138, 435. 504-505 

 Society, and air, i58ff. ; alcohol and, 

 137; and birds, 425 ff. ; and evolu- 

 tion, 473-474; and food, 122 ff. ; and 

 the forest, 378 ff. ; and health, 

 388 ff., 394 ff., 399 ff. ; and insects, 



