GENERAL INDEX 
veg., 21, 84 ; warm, 87 ; water in, 
28, 84 ; water-capacity, 86 ; water- 
retaining capacity, 87 ; xerophytic 
factors of, 35 
Solanum Dulcamara, _ incipient 
climber, 116 ; nigrum, 216 
Solar energy, 4, 9, 65 ; spectrum, 66 
Sonchus, latex, 216 ; arvensis, 216 
Sorghum vulgare, 148 
Sorrel, wood. See Ozxalis 
Sow-thistle. See Sonchus 
Spadix, *175, 178 
Sparganium natans, leaf, 51 
Spathe, *175, 178 
Species, 218, 219, 224; elementary, 
205, 221 ; origin of, 202 
Spectrum, solar, 66 
Spermaphytes, 183 
Sphagnum, 89, 253 
Sphagnum-bog, 231, 250, 252, 253 
Spices, 150, 151 
Spike, 178, *180 
Spinach (Spinacea oleracea), 150 
Spindle-tree : aril, 196; honey, 172; 
structure of seed, 146 
Spines : of holly. 104 ; origin of, 139 ; 
as a protection, 136, 140, *141; 
in xerophytes, 44 
Spirea, pollen-fl., 169 
Spiranthes Romanzoviana, 214 
Spirits, 20, 151 
Sports, horticultural, 153 
Spurge, 216, 218; latex, 142 
Stachys arvensis, 57, 216 
Stamen, 162 
Starch: formation of, 5, 66 ; reserve-, 
145 
Starchy seeds, 147 
Stellaria media, fertilization, 165 
Stems : assimilating, 44, *45 ; edible, 
150; stunted growth of, 36; 
-tubers, 111 
Steppes, 19, 23, 35 
Stigma, 162 ; of wind-pollinated fls., 
167 
Stinging hairs, *141; nettle, 167, 
216 
Stipules : as bud-scales, 61; hollow, 
133; as spines, 140, *141; as 
tendrils, *118 
Stitchwort, 217; cleistogamous fis. 
165 
Stolons, 155 
Stomata, *{26, *27; in aquatics, 
49 ; regulating transpiration, 32 ; 
in xerophytes, 38, 39, 40, *41, 
*43 
315 
Stonecrop, *39, 41, 218; honey, 
172 
Stones, xerophytic factors of, 35 
Storage of food-reserves, 145 
Stork’s-bill, 217. See Hrodium 
Strand-vegetation, 277, 279 
Stratification of plants in woods, 228 
Strawberry : acids in, 143; fr., 184, 
187, *193 ; stolons of, *155 
Strawberry-tree. See Arbuius Unedo 
Streams, veg. of, 235 
Struggle for existence, 203, 208, 210 
Strychnin, 143, 148 
Strychnos Nux-vomica, 143, 148 
Stunted growth of stems, 36 
Style, 162 
Sub-alpine pastures, 230 ; rocks, veg. 
of, 290 
Subdominant plants, 227 
Submerged leaves, 50 
Subularia, 55 
Succulent plants, *39, *41,*42, 58,88 
(see Halophytes) ; fruits, 136, 192 
Suckers, 155, 161 
Sueda maritima, 58, 59 
Sugar, 5, 146; -cane (Saccharum 
officinarum), 150, 151; -maple 
(Acer saccharum), 150 
Sumach, 212 
Summer-annuals, 107 
Summit-heath, 251 
Sun, the source of energy, 4, 65 
Sundew, 89. See Drosera 
Sunflower : fr., 187 ; seed, 146 
Sunlight, 4, 65 ; duration of, 10, 67 ; 
influence on veg., 67 ; intensity of, 
67. See Light 
Sun-plants, *72 
Survey-maps, ecological, list of, 231 
Surveys, ecological, 229 
Survival of the fittest, 203 
Swamp-eypress, 212 
Swamps: bush-, 243; 
See Bogs and Marshes 
Swede, 111, *112, 150 
Sweet chestnut, 23, 61, 136, *137, 
*187 ; cicely, 216 ; potato, 150 
Switch-plants, 44, *45 
reed-, 241. 
| Syeamore, fr., 190, *191; dispersal 
of fr., 195 
Symbiotic insects, 133, 144 ; pls., 132 
Symbiosis, 132 
Syncarpous ovaries, 7183 
Tamus communis, 214 ; berries, 149 ; 
climbing pl., 116. See Black 
Bryony 
