The science of life : fully illustrated in tone and line and including many diagrams

Sea-worms, 137, 137, 138

Secondary Era, 197, 465

Secretin, 102

Sedge-warbler, 748

Seed, 161; distribution of, 161, 162; evolution of, 432

Seed-ferns, 215, 435, 437, 443, 214, 420; evolution of, 420

Seeds, 158-162

Segmentation of the body, in animals, 123, 137, 407

— — egg, 93, 321

Segmented worms, 137, 145, 406

Selaginella, 431, 432

Selection, and change of race, 370 ; by man, 228-930, 287-290 ; in evolution (See Natural selection) ; sexual, 373, 738

Self-fertilization in plants, 160

Selous, Edmund, 738

Sematic colours, 569

Seminal vesicle, 91

Semfli-vertebrates, 117, 119

Semmelweis (1818-1865), 632

Senility, 88, 99, 330; of evolving races, 382 ; precocious, 330

Senility and races, 382 ; precocious, 330

Sensation, 71-75, 664; internal, 74; of position and movement,

1-82

Sense-organs, 71-84; evolution of, 664-670; irritability as common basis of, 664; limitations of, 690

Sepia, 133

Sequoia gigantea, 89

Sertularia, 151

Sex, and marriage in primitive man, 859-863; conduct in relation to, 834-837; control of, 338-339 ; determination of, 337-349, 338; evolutionary significance of, 362-363; importance in psychology, 812 ; intermediates, 347-349; mnormal causation of, 337-338; reversal of, 346. See Reproduction Sexes, proportion of the, 338-340, 340

Sex-hormones, 344-346

Sexless reproduction. duction

Sex-linked inheritance, 341-343, 342

Sex-mosaics, 343 ; butterflies produced by shock, 344

Sexual aberrations in fowls, 346

Sexual fetishism, 809

— selection, 373

Sexuality, evasions and replacements of, 274-275

Seymouria, 449

Shark, 116; basking, 116, 514

Shaw, George Bernard, 262, 263, 266, 384, 385

Sheep, 110, 140, 609, 610, 141, 564 ; an abnormally developed, 316

Shell-shock, 806

Shetland Islands; 374

“ Shine-by-Night,” 512

Shipworm, 529

Shock on pregnancy, influence of, 312

894

See Repro-

INDEX

Short-sightedness, cause of, 298

Shrew, flying, 565 ; jumping (brain of), 767

Shrew-mouse, I11

Shrimp, 124, 527

Siberia, 200, 233, 241, 590, 602

Sicily, 488, 494, 537 .

Sight, 78; in bees, 714; in dogs, 780; in fishes, 727. See also Eye

Silurian period, 197, 415, 416, 418, 424, 425, 429, 198, 420

Simocephalus, 408

Simpson, Sir James Young (18111870), 613

Sinai, 540

Sinanthropus, 251, 252, 485; skull of sub-man, 252, 859

Singer, Dr. Charles, 629

539; 549;

Single-celled life, 167-174, 176, 401, 402

Siphonophore, 150, 407, 415, 514, 520

Sirenians, 471

Sivatherium, 471

Sizes, of organisms, 562-568, 564, 565, 566, 567, 568; of ultramicroscopic particles, 396

Skate, 116

Skeleton, development of, 319; human, 24-28, 25, 26. 27: of dog, 106; of gorilla, 250: of

lobster, 121; of vertebrates, 108, 424, 220, 221; strength of, 566

Skin, 59-62, 649; and temperature regulation, 61-62, 649; of amphibians, 115, 671; of coloured races, 299-300, 354, 357; of fishes, 424; sunburn of, 357; 651

Skink, 114

Skua, 547, 548, 594

Skull, Broken Hill, 493

Skunk, 637

Sleep, nature of, 780-783

Sleeping-sickness, 172, 612, 625, 568

Sleepy sickness, 625

Slime-fungi (slime-moulds), 173, 178-180, 271, 179, 180

Slipper animalcule, 683, 683, 684 ; behaviour of, 683-686

Sloth, 111, 236, 383, 237, 238

Slow-worm, 114

Sludge-worms, 535

Slug, 131

Smallest living things, 185-186

Smallpox, 623, 625, 630-631, 653

Smell, 75 ; in bees, 715; in dogs, 780 ; in fishes, 727; in moths, 694; in primitive mammals, 766

Smelt, 536

Smilodon, 383, 384

Smith, Héléne, medium, 805

— Prof. Elliot, 766

— William (1769-1839), 195, 199

Snails, 130, 131, 671, 565, 566

Snakes, ancestral stock of, 449 ; extinct, 564

Snapdragon, 376

Snipe, 609, 739

Snow-leopard, 550

556, 609.

Solar disturbances and terrestrial life, relation between, 602

Solar plexus, 68

Soldanella, 548

Solenhofen, 201, 212

Solomon Islands, 870

Solomon’s seal, 586

Solutrean culture, 494

Soma, 281 ; germ-plasm and, 355

Somerville, Dr., 6, 7

Song-thrush, 565

Soot, and health, 646; amount deposited in modern towns, 646 ; defences against, 42

Soredia, 177

South Africa, 599

— America, 206, 209, 236, 237, 240, 241, 244, : 470; 472, 475, 476, 490, 534, 541, 544, 574; 599, 629; characteristic animals of, 238, 243

— American ungulates, primitive stock of, 471

— Georgia, 549

Spain, 488, 491, 494, 629

Spallanzani, Abbé, 613

Spanish Bayonet, 464, 692

— moss, 546

Sparrow, English, 364, 367, 610

— migration of the fox, 490

Spartina townsendii, 589

Species, chemical basis of, 21 meaning of, 105, 230-23 origin of. See Evolution

Speech, 792, 857; fundamental processes of, 773-774: parts of brain concerned in, 769

Sperm, human, 567, 568

Spermatophytes, 162

Spermatozoa, 90, 91, 92, 272, 340; of ferns and mosses, 163

Sperms. See Spermatozoa

Sperm-whale, 519, 471

Spherium, 535

Sphenodon, 114

Sphenophyll, 443

Sphex, 696

Spheerulia bombi, 140

Spider, 126, 566, 695, 420

Spider-crab, 524, 562, 511, 564; gamete of, 273 ; instinct of, 682

Spinal cord, 26, 108, 721, 24, 721

Spiracle, 107

Spirochetes, 182

Spirogyra, 174, 402, 403

Spirula, 514

Spisula, 527

Spitsbergen, 437, 442, 460, 3 490, 510, 547; 548, 549, 584; 591s 595

Spleen, 65

Sponge, reproduction of, 270, 270

Sponges, 152-153, 153, 270, 447

Spongilla, 270

Spontaneous generation, 5, 267, 268

Spores, 271 ; evolution of, in plants, 428-434; of bacteria, 181 ; of ferns and mosses, 162, 163, 164; of fungi, 180

Sporogonium, 164

Sporozoa, 172, 626, 402

Spring-tails, 584

Spurge, 541

Squat-lobster, gamete of, 273

DED.

234, 444,