INDEX 



705 



Tourniquet, how to use, 401-402 

 Toxin, formed by bacteria, 462 

 Toxin-antitoxin treatment, 478 

 Trachea, of man, 364 ; of insects, 63 

 Trades, abilities needed for, 648 

 Traits, inherited, 638-639 

 Transfusion, of blood, 391 

 Transients, bird, 551 

 Transpiration, factors in, 164 

 Trees, cause of growth, 31 ; city's need 



of, 586 ; injured by insects, 565 ; ma- 

 terials found in, 28, 29 ; position of 



leaves, 21-22 ; prevent erosion, 574 ; 



repair of, 586-587; skeleton, 21, 22; 



uses of wood, 577-578 ; values of, 574- 



579 

 Tree surgery, 586-587 

 Trial and error, method of response, 425- 



426 

 Triangle, factors in life, 608 

 Trichina, 494 ; harm done by, 545 ; life 



history of, 494 

 Trichocysts, of Paramecium, 220 

 Trichoptera, order of insects, 238 

 Tropisms, 420, 423; meaning of, 37; 



value of, 42 

 Trypanosomes, diseases caused by, 486- 



487 

 Trypsin, an enzyme, 374 

 Tsetse fly, diseases carried by, 486-487 

 Tuberculosis, and Koch, 662, 663 ; care 



of persons having, 509-510 ; cause of, 



465-466 ; effect of, 464-465 

 Tumble weed, dispersal of seeds of, 102, 



103 

 Turtle, adaptations of, 256-257 

 Tussock moth, 565 

 Tympanum, in frog, 250 

 Tyndall, John, apparatus and experiment 



to disprove spontaneous generation, 



658 

 Typhoid fever, carriers of, 469 ; cause of, 



467 ; Widal test for, 390-391 



Ungulates, 269-270 



Unit characters, 621 



Urea, 413 



Urine, excreted by kidneys, 413 



Useful bacteria, 183-189 



Vaccination, against smallpox, 475-476, 

 479-480 ; against typhoid fever, 481 ; 

 and Jenner, 659-661 ; to acquire im- 

 munity, 475-476 



Vacuole, of amoeba, 218-219 ; of Para- 

 mecium, 220 



Van Leeuwenhoek, 38, 658-659 



Variation, continuous, 632 ; Darwin on, 

 605 ; discontinuous, 632-633 ; mean- 

 ing of, 605 ; types of, 632-633 



Varieties, production of, new animal, 

 632-635 ; new plant, 632-635 



Vaucheria, reproduction of, 615, 616 



Vegetables, used as food, 526-527 ; uses 

 of fibers of, 529 ; uses of oils of, 529 



Vegetation areas, in United States, 306 



Vegetative propagation, 612-616; bud- 

 ding, 614 ; grafting, 613-614 ; regen- 

 eration, 612, 614 



Veins, 395 ; structure of, 398 ; valves of, 

 399 



Venae cavae, 398 



Ventilation, methods of, 410 ; need of, 

 410; of bedroom, 411, 497-498 



Ventricles. See Heart. 



Vertebrates, 242 ; groups of, 243 



Vessels, blood, 395, 398 ; lymph, 399 



Villi, 377-378 ; where found, 149-150 



Virginia creeper, 106 



Virus, filterable, 479-480 



Vitality, of weeds, 103-104 



Vitamins, 31, 330; diseases caused by 

 deficiency of, 334 ; list of foods con- 

 taining, 336-337; names of, 333; 

 sources of, 333-335, 336-337; use to 

 body, 333-335 



Vocation, biology prepared for, 649-654 ; 

 choosing a, 646-648 



Wallace, A. R., on progressive develop- 

 ment, 667 



Warbler, 559 ; yellow, 555 



Wasp, 60 ; life history of solitary, 69 



Waste disposal, in community, 505-507 ; 

 in home, 500 



Water, 294-297; absorbed by root 

 hairs, 149 ; cause of rise in stem, 170- 

 171 ; composition of sea, 20-21 ; dem- 

 onstration on electrolysis of, 24-25 ; 

 effect on plants, 39-40 ; evaporation 

 from plant, 164 ; given off by leaf, 163 ; 

 held by soil, 139 ; in living things, 27 ; 

 necessary for germination, 120-121 ; 

 value to body, 330-331 ; 



Water supplies, and diseases, 467; in 

 home, 500; regulated by trees, 574- 

 577 



Wealth, man controls environment for, 

 518-569 



Weeds, eradication of, 108 ; harmful, 

 105 ; methods of protection, 104 ; 

 place of growth, 105 ; poisonous, 106- 

 107; seed dispersal of, 102-103; 

 seeds of, eaten by birds, 549-550 ; use- 

 ful, 107; vitality of, 103-104; what 

 are, 101-102 



Weissman, August, work on germ cells, 

 670 



Wheat, rust, 101, 105, 195-196, 197; 

 mutant, 633 ; uses, 525-526 



White corpuscles, 387-388 



Widal test, for typhoid fever, 390-391 



Willow, girdled twig of, 168 ; family, 211- 

 212 



Windpipe, of man, 364 



Winged seeds, 110 



