INDEX 



565 



Racial betterment, 553; character- 

 istics, hormones in relation to, 

 177 



Radiant energy, 39 



Radio, 549 



Rainfall, distribution of, 109 



Random assortment of chromo- 

 somes, 313 



Ratio, 1:2:1, 352; 9:3:3:1, 362; 

 gametic, 383; genotype, 385; 

 phenotype, 385; recombination, 

 352 



Rats, hooded pattern, 398 



Rattan, 432 



Raw materials of plant foods, 39 



Rays, active in photosynthesis, 40; 

 invisible but chemically active, 

 39 



Realms, Australian, 456, 477; Ethi- 

 opian, 477; Holarctic, 457, 477; 

 Neotropical, 478; Oriental, 479; 

 plant 456; subdivisions, 480 



Reason, 186 



Reassortment, law of, 351; mecha- 

 nism of, 360 



Receptors, 124; contact, 136, 153; 

 distance, 136, 142, 157; distance, 

 advantage of, 157 



Recessive, 356 



Recombination, 350; ratio, 352 



Red corpuscles, 88 



Reducing division, 310 (fig.), 343 

 (fig.) 



Reflex action, 153, 161; complex, 

 156, 531; simple, 153 



Regeneration, 295 



Regulation, chemical, 169, 327; of 

 motion, 123 



Relative achievement, 529 



Release, energy in metabolism, 260 



Repair, 17 



Reproduction, 8, 19, 292, 316; ad- 

 justment of, 115; asexual, 116, 

 316; asexual, results of, 295; 

 sexual, 116, 295, 316; typ«s of, 

 316; vegetative, 345 



Reproductive instinct, 168 



Resemblance, family, 518; pro- 

 tective, 441; of twins, 518 



Resistance, disease, 394; frost, 395 



Respiration, 98; organs of, 99; pig- 

 ments, 102 



Resting nucleus, 285; spore, 117, 

 320 



Results, mechanical of root struc- 

 ture, 55; of asexual reproduc- 

 tion, 295; of evolution, 431; of 

 fertilization, 299 



Retina of eye, 145 (fig.) 



Retting, 266 



Rheumatism, 223 



Rhodesia man, 499 



Rivalry, adaptations for, 437; 

 among plants, 438 



Root hairs, 54, 276; tubercles, 212 



Roots, 117; adjustment of, 110; as 

 excreting organs, 61: structure 

 of, 53 (fig.); tropisms of, 112 



Rotting of wood, 265 



Royal families, 520 



Rudimentary organs, 414 



Rusts, 204, 210 



Sage brush plains, 466 (fig.) 



Saliva, 75, 93 



Sanitation, government, 245 



Sap, ascent of, 57; nuclear, 285, 

 289 



Saprophytic fungi, 210 



Saunders, Dr. Charles E., 341 



Scarlet fever, 225 



School, new Lamarckian, 428 



Scientific names, 413 



Scrofula, 220 



Sea floor, animals of the, 490; tem- 

 perature of the, 483; weeds, 272 



Secondary sexual characters, 174, 

 309 



Secretion, 61; glands, 93 



Security of life, 545 



Seed, 334, 339 (fig.); dormancy of, 

 341; germination of, 69; plants, 

 342; reproduction by, 334 



Segregation, 345; law of, 351 (fig.); 

 of genes, 354; of linked genes, 

 370 



Selection, 392; artificial, 418; ef- 

 fects of, 397; natural, theory of, 

 421; pure line, 392; sexual, 426 



Self-defense, adaptations for, 436; 

 in plants, 437 



Semicircular canals, 139 



Sense, chemical, 139 (fig.); organs, 

 classes of, 136; organs, internal, 

 136; perception, motions of, 

 133; temperature, 140 



Senses, contact, 139; external, 136; 

 internal, 136 



