Shelterbelt zone, 477, 576, 



577 

 Shelterers of soil fauna, 465 

 Shock, mechanical, 139 

 Shore(s), breezes, 145 



rocky, populations, 160, 161 



sandy, littoral, marine, 457, 

 458. See also Littoral. 

 populations, 181 

 Shrub stratum in forests, 481, 



488-495 

 Side winder, 164 

 Sign, reaction to, 126, 127 

 Silicates, 202, 204 

 Silicon, 167, 204 

 Silphidae, 534, 550, 551, 631, 



665 

 Silurian, 81 

 Simond, P. S., 28 

 Simplicity. See Complexity, 



Parsimony. 

 Simuliidae, 157, 671, 708 

 Simulium, \^T\■a, streamlining, 



157, 671 

 Sitotroga cerealella, 335, 351, 



383, S84 

 Size, aquatic animals, 132 



temperature and, 119, 120 



vertical distribution in wa- 

 ter and, 134 

 Skeletal support, gravity and, 



132. See also Bones. 

 Skin permeability, 169, 170, 



171 

 Sky radiation, 89, 90, 91 

 Slavery among social insects, 



424, 634, 685 

 Sleep, 553 



Stenobathic animals, 139 

 Slope of land, temperature re- 

 lations, 79 

 Smith, Harry S., 271 

 Snails, 20, 50, 148, 223, 341, 



409, 410, 531, 609, 610, 



612, 618, 619, 626, 702 

 Snakes, 164, 226. 227, 466, 



467, 471, 492, 604, 659, 



660, 668, 669, 677, 707 

 Snow, 179 



line, 180 



locomotion on, 163, 164, 

 180 



overwintering and, 180, 181 



soil relations, 220 

 Snowshoes, natural, 163, 164, 



180 

 Social animals, environmental 

 control, 215. See also 

 Homeostasis. 



facilitation, 395, 410 



hierarchy, 413. See also 

 Hierarchy. 



SUBJECT INDEX 



Social insects, 561, 645, 672, 

 698, 701, 713, 717, 

 719, 721. See also 

 Societies. 

 castes, 419-435, 599, 635, 

 636, 676, 678, 687, 

 690, 691, 692, 693, 

 722, 727. See also 

 Polymorphism. 

 colonies, 431, 685, 692, 



714, 717, 722 

 nutrition, 423 

 slavery among, 424, 634, 

 685 

 integration, 426-435, 633, 

 663, 664, 672, 676, 688, 

 693, 694, 701, 717, 718 

 parasitism. See Parasitism, 



social. 

 populations, 393, 419-435, 



722 

 science, 693. See also Man, 



Societies, Sociology. 

 status, quaUties determin- 

 ing, 413, 414 

 Societies, 684, 687 



complexity in, 632, 634, 



635 

 human, 420, 432, 435, 561, 

 632, 640, 672, 683, 691, 

 693, 694 

 insect, 561, 599, 632, 683, 

 685, 686, 687, 693, 

 694, 717, 718-721, 

 722. See also Social 

 insects 

 organization, 419-435 

 Sociology, general, 59, 729. 

 See also Aggregations. 

 human, 2, 435, 729. See 

 also Man, Societies. 

 Sodium, soil, 222 

 Soil, 80, 216-227 

 adaptation to, 226 

 adsorption, 176 

 alkali, 221 

 arthropods, tropical, dry 



season, 537 

 bacteria, 497, 498, 499, 



711 

 biota, 225 



forest, 484, 485 

 chemistry, 220, 705, 711 

 cUmate, 219 



consistency, 219, 697, 715 

 cycles, 216 

 ecological relations, 216- 



227 

 fauna, overwintering move- 

 ments, 537 

 forest, 224, 225 

 formation, 216, 705 



relation of mammals to, 

 484ff. 



831 



Soil, horizons, 217, 218, 219, 

 225 

 humus, 224, 697 

 hydrolysis, 219 

 iron in, 498 

 limestone, 221 

 macrobiota, 455 

 macrofauna, 465 

 mesobiota, 465 

 mesofauna, 465 

 microbiota, 465 

 microfauna, 52 

 moisture, 219, 220, 652 



656, 697 

 organisms, 52, 164, 225, 

 226, 227, 465, 466, 484, 

 485, 497, 498, 499, 537, 

 696, 705, 711 

 partial equivalence in, 223 

 pU, 221, 222, 223, 224 

 phosphorus in, 498 

 plant relations, 16 

 porosity, 218, 219 

 prior probability and, 222 

 profile, 217, 218 

 Protozoa, 52 

 saline, 221, 222 

 temperature, 79, 98, 109, 

 230, 474, 475, 671 

 gradient, 219 

 trace chemicals, 221 

 types, 225 



water, 219, 220, 656 

 Solar constant, 88 

 Solubility of gases in water, 



191, 192 

 Solution, molar, normal, 167 

 Songs. See Sound. 

 Sound, 139, 140, 429, 554, 

 619, 620, 621, 643, 665, 

 722. See also Calls, Ears, 

 Isolation, psychological. 

 Space, 22, 434, 435, 607, 608, 

 722, 729. See also Dis- 

 tance; Isolation, spatial: 

 Territoriality. 

 variations in, 78, 627 

 Spallanzani, I., 140 

 Sparrow(s), English, 724, 

 726, 727 

 habitat, 724 

 Specialization, 238, 634, 639, 

 645, 682, 683, 685, 705, 

 726, 728. See also Adapta- 

 tion, Host specificity. 

 Speciation, 600, 607, 610, 

 616, 621, 624, 628, 629, 

 641, 648, 663, 689, 720, 

 725, 728. See also Evolu- 

 tion. 

 of fishes, 61 Iff. 



