INDEX 



313 



scale form, 162 

 sciophytes, 183 

 Scirpus, 163 

 scutellum of grains, 100 

 Scutellaria, 178, 193 

 secondary species, 222 



succession, 275, 278 

 sedimentation, 283 

 Sedum, 160, 162 

 Sedwn stenopetalum , 160 

 seed -distributed plants, 241 

 seed, in ecesis, 263 



production, influence of, 243 

 selection, 196 

 self-pollination, 124, 127 

 Senecio, 160, 228, 242 



taraxacoides, 179 

 sensit ive plant , 1 42 

 sensory area of tendrils, 141 

 serotinal flowers, 1 30 

 sexual reproduction, 115 

 shade leaves, 178 



plants, 165, 183 



tents, 181 

 shock, 142 

 Sicyos, 141 

 Sieversw., 243 

 sieve tissue, 53, 84 

 Silene, 243 

 silicle, 132 

 silique, 132 



Silphium laciniatum, 145 

 simple agsiregation, 237 

 _ law of,'"239 

 simultaneous readings, 30, 31, 36 

 size and thickness of leaves, 179 

 sling psychrometer, 27, 28 

 slope, 22, 27 



influence of, 23 

 snowfall, 21 

 society, 225, 226 

 soil, air-content of, 19 



can, 10 



chemical nature of, 18 



influence on water content, 15 



mechanical analysis of, 20 



properties, determination of, 19 



samples, 10; depth of, 12 



"sourness" of, 19 



structure, 16, 20 



temperatures, 92 



texture, 15, 20 



thermometer, 92 

 soils, origin and structure, 16, 17 

 Solidago, 227, 260 



canadensis, 258 



decumbens, 191 



oreoppila, 191 

 soluble salts, 18 



absorjjtion of, 48 



soluble salts, influence of, 47 

 solutes, 18 

 Sparganium, 126 



angustifolium, 152 

 sparse, 205 



Spartina cynosuroides, 301 

 spiny disseminules, 243 

 Spirodela, 167 

 sponge cell, 172 



leaf, 183 



tissue, 57, 151 , 174 

 spongophyll, 183, 184 

 spore-distributed plants, 241 

 Sporobolus, 162 

 six)rophore, 113, 115 

 sports, 189, 196 

 spring aspect, 224 

 stability, 170, 1S5 

 stabilization, 285 

 stable forms, 186 

 standard, comparison with, 75 



making a, 73 

 Stapelia, 164 

 Staphylea, 242 

 starch, 82, 84, 85, 100, 103 



determination of, 83 



stations, 31 

 staurophyll, 183, 184 

 stems, form of, 179 



functions of, 54 



of monocotyledons, 53 



of shade plants, 180 



structure of herbaceous dicoty- 

 ledons, 52 



structure, types of, 51 



xerophytes, 162; t'V'pesof, 162 

 Stipa, 45, 162, 226, 244 



consocies, 226 

 stimulatory action, 2 

 stimuli, external, 3 



internal, 3 



kinds of, 3 



nature of, 1, 2 



nature of light, 72 

 stimulus of gravity, 137 



of shock, 143 

 stolon, 114 

 stomata, 52, 57, 153 



functions, 61 



in sun and shade leaves, 178 



modifications of, 148 



structure and position, 60 

 storage leaves, 58 



of food material, 84 



of water. 151 

 structure of formations, 219, 221 



of leaf, 56 



of woody stems, 53 

 struggle for existence, 251 

 subcopious, 205 



