INDEX 



44:'. 



Snakes, feeding habits of, 289; 



locomotion in, 289; 



poisonous, 290. 

 Snails, activities of, 265; 



breathing in, 267; 



development of, 267 ; 

 . European, 266; 



feeding habits of, 266; 



forest, 266; 



lingual ribbon, 266; 



senses of, 267 ; 



variability in shell of, 265, 266. 

 Soils, composition of, 91; 



favorable to evaporation, 91 ; 



organic matter in, 92; 



water in (Exp.), 91; 



weathering of, 92. 

 Sorus, 153, 



Sound, character of, 422. 

 Sparrow, English, 301; 



white-throated, 303. 

 Speech, formation of sounds, 427. 

 Spermatophytes, defined, 151. 

 Sperm cell, in flower, 32; 



of fern, 155; 



of hydra, 197; 



of moss, 158; 



r61e in fertilization of egg, 33. 

 Spider, care of eggs and young, 258; 



structure of, 256. 

 Spider crab, 224. 

 Spider's web, forms of, 256, 257 ; 



use of, 256. 

 Spike, 48. 



Spines, in seed dispersal, 58. 

 Spiracle, 229. 



Spirogyra, formation of zygospore, 

 176; 



structure of, 175. 

 Sponge, glassy, 193 ; 



development of , 192; 



horny fiber, 193; 



limy, 191; 



relation to environment, 193; 



simple, 191. 

 Sponges, classification of, 193. 

 Sporangium, in fern, 153; 



in mold, 160; 



in moss, 157. 



Spore, defined, 152; 



in fern, \'hi; 



in molfl, 152, 160; 



in moss, 157. 

 Spore formation in yeaat, 167. 

 Spore print, 162 

 Sporidia, 165. 

 Sporophyte, of fern, 155; 



of moss, 157. 

 Sprains, 379. 

 Squid, 267 

 Stamen, 31, 38; 



diadeljjlKHi.-;, 36. 

 Staminute flower, of corn, 71; 



of squash, 45. 

 Standard, 36. 



Starch, non-osmosis of, 112 

 Starch grains, 67. 

 Starch test, 21. 

 Starfish, development of, 206; 



food of, 205 ; 



method of locomotion, 204; 



nervous system, 204; 



organs of breatlliIlL^ 205; 



regeneration in, 206; 



skeleton of, 203. 

 Stem, compared with root, 98; 



dicotyledonous, 105, 108; 



digestion in, 112; 



efi"ect of gravity on, 85; 



effect of light on, 98; 



form of food in, 112; 



heliotropism of, 99; 



monocotyledonou.^^. 1()(», 108; 



passage of fluid in, 110, 111; 



position of buds on, 102. 

 Stigma, 31, 33, 38: 



of wind-poUinatcd fl<twor, 44. 

 Stimulant, defined, 325. 

 Stinuili, response to, in paranurc-iuin. 



180. 

 Stipe, 162. 

 Stipule, 123. 124 



Stoma, 129,136; in transpiration. 136 

 Stomach, glands of, 336; 



movcnient of walls of. 337; 



of frog, 3.36; 



of man, 336. 

 Storage in st^Mus, 118. 



