704 



INDEX 



Smell, location of, 438 ; olfactory cells, 

 938 



Snakes, feeding habits of, 258-259 ; 

 locomotion of, 258 ; value of, 543-544 



Social inheritance, 607-608 



Social parasitism, cause of, 637 ; remedy 

 for, 637-638 



Societies, plants and animals, 298-300 



Society, cost of parasitism to, 637 



Soil, composition of, 137-139 ; condi- 

 tions of, affect life, 297 ; mineral salts 

 in, 139; relation to plants, 137-140; 

 water held in, 139 



Sound, character of, 439-440 



Sound stimuli, how received, 427-428, 

 430 



Span of life, 600 



Sparrow, English, 559, 560, 595 ; song, 

 554-555 



Spawning, habits of fishes, 588-589 ; 

 need of conservation during, 589- 

 591 



Species, 177, 179 



Sperm, 617 ; in Vaucheria, 615 



Spermatophyta, 180; angiosperms, 206- 

 213 ; classification of, 207 ; examples 

 of, 205-213 ; gymnosperms, 205-206 



Spiders, 238-239 



Spinal cord, 429 ; function of, 433, 434 



Spines, in seed dispersal, 109 



Spiracles, of insects, 58, 63 



Spirillum, kind of bacteria, 183 



Spirogyra, 201 ; conjugation of, 201- 

 202, 615 



Split proteins, 462, 476 



Sponges, economic value of, 542 ; struc- 

 ture of, 223-224 



Spongy tissue, of leaf, 153 



Spore, of bacteria, 183 



Sporophyte, of moss, 203 



Sprengel, on adaptation of flowers, 56 



Stamen, of flower, 83, 84 



Starch, effect of heat and digestion on, 

 339; test for, 118 



Starch-making. See Carbohydrates. 



Starfish, discussed, 226-228 ; harm done 

 by, 544-545 



Statocysts, in shrimps, 428-429 



Stem, dicotyledonous, 166-169 ; growth 

 in, 167; modified, 172-173; mono- 

 cotyledonous, 169-170 ; rise of water 

 in, 170-171 ; used as food, 520-521 



Sterilization, and bacteria, 458 



Stigma, of flower, 83, 84 



Stimulants, effect on body, 350-351 



Stimuli, how simple animals receive, 422, 

 425-426 ; how simple plants receive, 

 422, 424-425 ; light, 427, 429 ; mean- 

 ing of, 37 ; Paramecium responds to, 

 425-426 ; pressure. 430 ; reaction of 

 living things to, 39-42; sound, 427- 

 428, 430 ; touch, 427, 428 



Stomach, digestion of food in, 369-372 



Stomata, 152-153 



Storage, cold, 458; of food, in plants, 



171-172 

 Stored products, insects harmful to, 



565-566 

 Struggle, for existence, 111 

 Sturgeon, 534, 590 

 Style, of flower, 83, 84 

 Succession, ecological, 300-305 

 Sugar, as a preservative, 459 ; storage 



in liver, 375-376; test for grape, 128- 



129 

 Sun, source of energy, 157 

 Sunlight, necessary for carbohydrate 



making, 157-158, 160-161 

 Survey, value of city, 14 

 Swallow, barn, 556 ; food of, 548 

 Sweat glands, 316, 317 ; function of, 415 

 Swim bladder, of fish, 246 

 Swimmerets, of crayfish, 233 

 Symbiosis, 287-288 

 Synapse, 431 

 System, circulatory, 395-401 ; digestive, 



367-369 ; excretory, 412-415 ; nerv- 

 ous, 429-435 

 Systemic circulation, 397 



Tadpole, 252-253, 254 



Tapeworm, 228, 493 ; harm done by, 



545 ; in bass, 493 

 Taste, buds, 437 ; location of, 437-438 

 Taxonomy, 178 

 Tea, a stimulant, 350-351 

 Teaching, profession of, 651 

 Teeth, care of, 366-367 ; effect of decav. 



365-366; kinds, 365 ; number of , 365 ; 



structure of, 365, 366 

 Teleosteans, bony fish, 247-248 

 Temperature, 291-293 ; effect on plants 



and animals, 41-42 

 Tentacles, of hydra, 224, 225 

 Tertiary roots, 140 

 Testa, seed coat, 117 

 Tetanus, cause of, 470 

 Thallophyta, 180 ; bacteria, 181 ; classi- 

 fication of, 200; fungi, 193-197; 



molds, 198-199 ; yeasts, 190-193 

 Thoracic dust, 399 

 Thorax, of insects, 58, 62, 237 

 Throat, common diseases of, 407-408 ; 



septic sore, 470 

 Thrombus, in blood, 388-389 

 Thymus gland, 394 

 Thyroid gland, 392, 393 

 Tissue building, 328-329 

 Tissues, 47-48 

 Toad, an amphibian, 254; usefulness 



of, 543 

 Toadstools, 193-194 

 Tobacco, use of, 354 

 Tonsils, enlarged, 408 

 Touch, how stimuli received, 427, 428 ; 



organ of, lobster, 428 





