431 



Skeleton, of leaf, 85 



of man, 268. 

 Skin, 268 ; 



hygiene of, .'111. 

 Skunk, 20."). 

 Sleep, need of, 356. 

 Small intestine, 307, 308. 

 Smell, sense of, 358. 

 Snail, 185. 

 Snakes, 189 ; 



food of, 212. 

 Soft palate, 301. 

 Soil, composition of, 77 ; 



how water is held in, 77, 78. 

 Sound, character of, 3(50. 

 Sour bread, 139. 

 Soy beans, 152. 

 Sparrow, 246. 



Spawning habits, economic impor- 

 tance, 239. 

 Species, 175, 194. 

 Sperm, 177. 



Spermaries of frog, 243. 

 Spermatophytes, 176. 

 Spinal cord of fish, 237. 

 Spiracles, 29. 

 Spirillum, 142. 

 Sponge, 180, 182, 183, 206. 

 Spore, 131, 173; 



plants, 174. 

 Sporozoa, 182. 

 Sprengel, Conrad, 40. 

 Squash bug, 215. 

 Stables, clean and filthy, 388. 

 Stamens, 36. 

 Starch, action of diastase, 69 ; 



digestion, 299 ; 



grains, 60 ; 



in bean, 61 ; 



made by green leaves, 90, 92 ; 



test for, 61. 



Starch making and milling, 92. 

 Starfish, 184; 



food of, 216. 

 Stegomyia, 221. 

 Stems, as food, 118; 



passage of fluids up, 84 ; 



structure of, 97. 

 Sterilization, 145. 



Sterilizer, 140. 

 Stigma, 36. 

 Stimulants, 289. 

 Stirrup, 359. 

 Stomata, 86, 88. 

 Stomach, 297 ; 



digestive experiments, 304 ; 



of frog, 243 ; 



of man, 303. 



Street cleaning department, 387. 

 Structure, colorless corpuscles, 315; 



of leaf, 85 ; 



of red corpuscle, 314 ; 



of root, 73 ; 



of root hairs, 74. 

 Sturgeon, 186. 

 Style, 36. 



Sublingual glands, 299. 

 Submaxillary glands, 299. 

 Suffocation, 340. 

 Sulphur, 149. 

 Sun, source of energy, 88. 

 Sundew, 102. 

 Sunlight in home, 374. 

 Sweat glands, 342. 

 Sweeping and dusting, 336. 

 Swim bladder of fish, 236. 

 Symbiosis, 163. 

 Sympathetic nerves, 352 ; 



nervous system, 304, 350. 

 Syphilis, 152, 156. 

 Systemic circulation, 320. 



Table of cost of food, 276, 283. 

 Tactile corpuscles, 357. 

 Taenia solium, 227. 

 Tapeworm, 227. 

 Taproot, cross section, 74. 

 Taste buds, 301, 358. 

 Teeth, 301. 

 Teleosts, 187. 

 Temperature, 417 ; 



of blood, 318. 

 Tern, 190. 

 Testa, 59. 

 Test, for carbon dioxide, 64 ; 



nutrients, 61, 68. 

 Thallophytes, 176. 

 Thoracic duct, 324. 



