INDEX 



549 



Rods, vision, 354 

 Root crops, 286 



formation of, 284 

 Root-forming hormones, 284 

 Root-nodule bacteria, 255 

 Rooting. 285 

 Roots, 249, 275 



Rothamsted Experiment Station, 7 

 Rubber, (203) 

 Rubidium, 195, 390 

 Rumen, 429, 430 

 Ruminants, 68, 429 



stomach, (429) 

 Rutabagas, 415 



Saccharic acids, 71 

 Safflower, 411 

 SafHower meal, 413 

 Salicin, 73 

 Saliva, 10, 424 



composition of, 424 

 Salivary amylase, 424 

 Salivary glands, 424 

 Saltpeter, 4, 6 

 Salts, 327, 328, 400 



balance of, 392 



formation of, 112 



inorganic, 13, 295, 417 



mercury, 237 

 Sand, 257 



Saponification, (83), 92, 93 

 Saponification number, (86), 87 

 Saponins, 73 

 Saturated fatty acids, 82 

 Scleroproteins, 114 

 Scurvy, 327, 328, 347-349 

 Secondary forces, 44, 45 

 Secretin, 312, 313.433 

 Seeds, 75. 233, 242, 245 



chemical composition of, 233 ff 



coats of, impervious, 235 



germination of, 229. 2? 5 (f 

 age and, 236 



lettuce, 237 



metabolism of germinating, 238 ff 



proteins of, 114, 237. 2.39 



treatment of, 237 

 Selenium, 195, 590 ff 



toxicity of. 391 

 Semesan, 237 



Semiacetals. 55-57, 59, 65, 72 

 Semipermeable membrane, 108. 262 

 Sequence of bases in nucleic acids. 123 

 Serine, (90), (98), 112. 115, 466. 468. 493 



metabolism of, (469) 

 Serotonin, 467 



Serum. 295. (295) 



Serum albumin. 298, 493 



Sesquiterpene, 201 



Sex hormones, 316, 321, 323, 421 



synthetic, 421 

 Shikimic acid, (467) 

 Shock, 321, 390 

 Shortenings, 84, 191 

 Silage, 410 

 Silica, 251,252. 259 

 Silicates, 249 

 Silicon, 195, 250, 257, 397 

 Silt, 257 

 Sitosterol, 94 

 Skatole, 440, 467 

 Skeletal structure, 401 

 Skeletal tissues, 369 

 Skeleton, 371,383, 392,403 

 Skin, 301 



Small intestine, 420 

 Soap, 77, 78, S3, 86. 87. 93. 245 



calcium. 83 



zinc, 83 

 Sodium, 195, 249-251, 258-260, 263, 295, 

 306, 315, 369, 373, 389, 390, 392, 

 402-404, 408 



allowance of, 393 

 Sodium chloride, 380 

 Sodium nitrates, 227, 264, 265 

 Sodium palmitate, (78) 

 Sodium stearate (soap). (83) 

 Sodium taurocholate, (94) 

 Soil, 4-6, 8. 26, 2-/9 ff 



acid, 251 



alkaline, 251 



colloids of, 257 ff. 261 



composition of. 250 ff 



fertility of, 254. 279 



formation of, 2-f^ 

 Soil solution, 261 

 Solids, 31 ff 



Solubility, 101, 114, 116 

 Solute, 34, 45 

 Solutions, 26, 27, 33 ff, 43, 249 



solid, 33 

 Solvent, 34, 137 



fat, 235 

 Sorbitol, 72 

 Sorghum, 410 



silages, 414 

 Sorption, 45 

 Soybeans, 45 

 Specific heat, 15, 30 

 Specificity, 102, 132 

 Spermatozoa, 449 

 Sphingomyelins, 87, 88, 90, (91), 306 



