564 



INDEX 



Reticular theory, of nature of protoplasm, 

 54 



Rhinoceros, prehistoric, 378 



Rhizoda, classified, 521 



Rhizoid, of mold, 251 



Rhizomes, plants with, 261 ; propaga- 

 tion by, 261 



Rhythmic segmentation, of small intes- 

 tine, 130 



Rickets, cause, 102-103 ; prevention and 

 cure of, 100, 103 



Rodentia, classified, 527 



Rootstock, plants with, 261 ; propaga- 

 tion by, 261 



Root hairs, of plants, 69 



Ross, Major R., investigation of malaria, 

 481-482 



Rotation of crops, need for, 409-411 



Round worms. See^ Nematheliminthes 



Roux, isolation of diphtheria toxin, 451 



Runners, use of, in propagating, 260-261 



Saliva, composition of, 121-122; diges- 

 tive action of, 121-122; enzymes of, 

 121 ; factors influencing secretion of, 

 121 ; functions of, 120-121 ; secretions 

 of, 121 



Salivary glands, position of, 120; func- 

 tion of, 120-121 



Saponification, in the digestive process, 

 131 



Saprophytes, group of bacteria, 251, 394, 

 499 



Scarlet fever, probable cause of, 458 ; 

 test to determine susceptibility to, 458 ; 

 transmission of, 459 



Schleiden, knowledge of cells, 28 



Schultze, contribution to cell theory, 29 



Schwarin, Theodore, work on cells, 28 



Science, age of, 1-3 ; aim of, 6 ; and 

 health, 417-419 ; contributions by 

 Greeks, 10-12; growth of, 10-11; of 

 primitive man, 10 



Scientific method, modern, 13-15 * 



Scurvy, 97; cause of, 100, 102; treat- 

 ment for, 100, 102 



Scyphozoa, 522 



Secretagogues, 128 



Secretin, 133 



Secretions, internal, 191-192 ; of green 

 cell, 40 



Seed, appendages, 294 ; differ from eggs, 

 281 ; dispersal of, 294-295 ; food re- 

 serve of, 294-295 ; formation of, 278- 

 279 ; protection of, 294 



Segmentation, rhythmic, of small intes- 

 tine, 130 



Segregation, of genes during maturation, 

 325, 328 ; Mendel ian law of, 324-326 



Selection, artificial, importance in plants, 

 352 



Self-acting nervous system. See Au- 

 tonomic nervous system 



Self-pity, as trait of personality, effect of, 

 236 



Serum of blood. See Blood 



Sexual characters, secondary, 281-282 



Sexual reproduction, in higher plants and 

 animals, 264, 268, 273-291 ; in mold, 

 264-265 ; meaning of, 264 ; in Parame- 

 cium, 267-268 ; in Spirogyra, 265-267 



Shick test, application of, 457 ; of sus- 

 ceptibility to diphtheria, 453 



Side-chain theory, of immunity, 506 



Sieve tubes, of plants function of, 68 



Simiidae, 527 



Simon, Theodore, tests by, 228 



Sirenia, animals of Order, 527 



Skin, functions of, 173-174 ; hygiene of, 

 174-175 ; laboratory study of the, 170- 

 171 ; organ of elimination, 170, 173- 

 174 ; sense organ, 173 ; structure of, 

 172-173 ; thickness of, 172 



Slant, agar, 397 



Slips, method of vegetative propagation, 

 255-256 



Small intestine, absorption from, 136- 

 137; adaptations of, 136-138; diges- 

 tion in, 130-131,132-133, 135; diges- 

 tive juices of, 132-133 ; folds in, 136 ; 

 glands of, 131 ; movements of, 130 ; 

 villi of, 136, 137 



Smallpox, cases and deaths in United 

 States, 424 ; epidemics of, 420 ; history 

 of, 420 ; history of inoculations against, 

 420-421 ; nature and symptoms of, 

 423, 425 ; preparation of vaccine for, 

 426 ; prevention, 425-426 ; spread, 

 425 ; value of vaccination, 426-427. 

 See Vaccination 



Soil, bacteria of, 405-411 ; conservation 

 of, 411 



Somatic cells, 269 



Somatic variations, not transmitted, 310 



Spallanzani, on spontaneous generation, 

 241 



Spawning, of fish, 283-284; of frogs, 

 282-283 



Species, production of new, 347-349 ; in 

 taxonomy, 517 



Species and Varieties, by De Vries, 376-377 



Species, Origin of, by Darwin, 373 



Specialization, in higher plants, 69-72 



Sperm cell, characteristics of, 268 



Spermatogenesis, meaning of, 269 



Spermatophyta, 520 



Sperms, production of frog, 285 



Sphincters, 125 



Spillman, production of hardy wheat by, 

 350 



Spinal cord, description of, 207-208; 

 diagram of cross section, 208 ; func- 



