5 i6 



ELEMENTARY BIOLOGY 



Arrhenius, Svante, and the nitrogen 



problem, 63 

 Arsenic, becoming accustomed to, 



132 ; insecticide and fungicide, 131 

 Artemia, 289 



Artery, 185; pulmonary, 187 

 Arthropods, 280, 289, 432, 484 

 Arts, development of, 512 

 Ascent of sap, 176 

 Asexual reproduction, 299 

 Asphyxiation, 170 

 Assimilation, i8>, 50, 260, 265, 285 

 Associative neurons, 221, 499 

 Astigmatism, 235 

 Astringent, 192 

 Atwater, W. O., food doctrines of, 90, 



93> 99 



Auricle, 185 

 Aves, 485 

 Axon, 220, 498^ 



Bacteria, 61 ; in carbon cycle, 58 ; 

 control and use of, 394 ff. ; and 

 decay, 112, 1 18 ; destroyed by cook- 

 ing, 112; digestion in, 80 ; and 

 disease, 386; in food, 112, 120; in 

 industry 396 ; in life cycle, 63 ; and 

 nitrogen, 62, 67, 396 ; and soil, 396 ; 

 on teeth, 120; and wounds, 192 



Bacteriology, 388 



Balance of nature, 423 



Balancing organs, 242 



Bark, in roots, 43, 60 ; fibers and ves- 

 sels in, 176 



Bast, 79, 176 



Baths, after meals, 1 16 ; hot and cold, 

 206, 207 ; public, 396 



Batrachians, 485 ; reproduction 

 among, 328 



Becker and Hamalainen, nutritive 

 tables of, 101 



Bee, 329; and orchard, 313 ; sting of, 



373 



Beetle, calosoma, 422 ; ladybird, 423 ; 

 potato, 418, 462 



Behavior, as problem of biology, 5 ; 

 mechanical aspects of, 39, 217, 224 



Bends, 340 



Beriberi, 108 



Biennial plants, 44 



Bile, 86, 118, 184, 216 



Biology, 3; and cost of living, 129; 

 and efficient living, 4 ; and enjoy- 

 ment of life, 512-513; and food 

 supply, 130; and health, 3, 507; 



public protection, 126; applied to 

 saving of life, 393, 507 ; of the soil, 

 66 ; use of, 474 ; and wealth, 4, 506 



Birds, 485 ; destruction of, 425 ; diges- 

 tive system of, 87 ; economic value 

 of, 425, 429; eggs of, 330; food of, 

 425; and insects, 426; migration 

 of, 366, 426; nests of, 371 ; protec- 

 tion of, 426 ; undesirable, 429 ; 

 young of, 334 



Black Hole of Calcutta, 155 



Black hornet, 369 



Blackbird, red-winged, 429 



Bladder, 206, 262 



Bladder wrack, 298 



Blanching of plants, 73 



Blastophaga, 312 



Bleeding, 192 



Blood, 179; changes in, 188 ; circu- 

 lation of, 185 ; clotting of, 18 1 ; co- 

 ordination through, 434 ; ferments 

 in, 1 88; a living tissue, 193 ff. ; and 

 respiration, 146; a transportation 

 system, 262 



Blood pressure, 190 



Blood system, 264 



Blue jay, 427 



Bluebird, nest of, 370 



Blues, 118 



Bobolink, 429 



Bowels, see Intestines 



Brain, structure of, 498 



Brain food, 107 



Brain functions, localization of, 498 



Brains of vertebrates, 497 



Breathing, 144, 148, 149, 172-173; 

 control of, 149; and digestion, 116, 

 118; habits of, 151 ff . ; nose and 

 mouth, 150; in plants, 74 (see also 

 Oxidation) ; summary of hygiene 

 of, 172-173 



Breathlessness, 190 



Breeding, for immunity to disease, 

 450; for special points, 452 



Breeds, of plants and animals, 438 ; 

 variation in, 439 



Bristles, 350 



Bronchus, 148 



Bronzed grackle, 427 



Bryophytes, 481 



Bubonic plague, 410 



Buds, first, of seedling, 33 ; resting, 270 



Buffalo moth, 415, 417 



Burbank, Luther, 452, 453 



Burbank potato, 454 



