1340 



BIOLOGICAL EFFECTS OF RADIATION 



Schumann region, 15 



Screens, colored, in re growth of seed 



plants, 763 (.see Filters) 

 Seed, effect of light on utilization of food, 

 731 

 germination (see Germination), effects 

 of, ultra-violet on, 853; X-rays on, 

 963 

 plants, under artificial illumination, 

 867; daylight minus ultra-violet, 

 863; ultra-violet, 853-887 

 Seedlings, in re ultra-violet, 853 

 Segmental interchange, 1169, 1177 

 Self-reversal, in emission spectra, 30, 31 

 Senders, of mitogenetic radiation, 940; 

 bacteria as, 922, 941; onion root tips 

 as, 922; yeast as, 941 

 Senescence, in re photoperiodism, 691 

 Sensitive spot hypothesis, 1312, 1317- 

 1323; gene number, 1321, 1322; gene 

 size, 1323; mechanism of action, 

 1317, 1320 

 Sensitivity, to irradiation, of bacteria, 

 1133; biological variation of, 1316, 

 1325; significance of variation of, 

 1324; in embryonic development, 

 401 

 of plants, to radium, 993; to X-rays, 



970 

 in phototropism, 1081; base response 

 to light, 1081; tip response to 

 light, 1081 

 Skin, irradiation of, 477 

 Solar radiation, 126, 171-180, 211-226 

 intensity, at normal incidence, 212 

 intensity variations, with air mass, 

 213, 215; with altitude, 213; with 

 seasons of year, 214; with geo- 

 graphical position, 222, 223 

 pyrheliometric standard of, 211 

 Spark lines, 31 



Spectra, band, 258; types of, 258; con- 

 tinuous, discontinuous, 273 

 Spectral analysis, mitogenetic, 938 

 Spectral regions (visible), absorption, 

 etc., by leaves, 779 

 effects on, seed plants, 763-790; ab- 

 sorption of inorganic salt.s, 778; 

 anthocyanin formation, 777; chem- 

 ical composition, 771; growth and 

 development, 764; stomatal be- 

 havior, 775; transpiration, 773 



Vol. 1 contains pp. 1 to 676 



Spectrum, gamma ray, 15; regions of, 14 



Spores, of fungi, 898, 908 



Standard deviation, defined, 233; of 

 difference, 230, 237; of frequency 

 constants, 238; of point binomial, 

 229 



Standard error, of coefficient of variation, 

 238; of mean, 237; of standard devia- 

 tion, 237 



Stationary spates, 16-19 



Statistical treatment, of irradiation prob- 

 lems, 227 



Stele, effect of light on, 830, 832 



Stems, of green plants, effects of X-rays 

 on, 974 



Stentor, response to light, 581 



Sterols, activation of, 324, 333 



Stimulation, mitogenetic, 919 



radiation and, with fungi, 893, 899, 905, 



908 

 by radium rays, 995 

 by X-rays, with green plants, 962-968 



Stokes' law, 33 



Stomatal behavior, in re regions of 

 spectrum, 775 



Structure, of plants, and light intensity, 

 728 



Sun, 171 {See also Solar radiation); 

 luminous equivalent of energy, 180; 

 spectral distribution from, 126, 174, 

 175; total radiation, variability of, 

 172, 173; ultra-violet radiation from, 

 176, 177, 179 



Sunlight, continuous, effects on green 

 plants, 715, 722 

 effects on bacteria, 1120 



Suprasterol, 330, 332 



Survival curves, fungi and, 891-893, 

 905-907 



Suspensoids, 303; irradiation and, 308 



Tachysterol, 329-331 

 Temperature, anthocyanin formation 

 and, 1113; photochemical reactions 

 and, 271 

 radiation and, with fungi, 893, 894, 900, 

 903 

 Temperature coefficient, 268; of ultra- 

 violet inactivation of bacteria, 1128 

 ; Vol. 2, pp. 677 to 1330. 



