INDEX

Alcock, Colonel, on courtship of crabs, 255

Alder-flies, claspers of, 233

Amorousness, a factor in evolution, 24

— power of, 6, 9

— where absent, 6

Andrews, Dr. C. W., on display of Frigate-bird, 111

Antelopes, battles of, 64

— horns of, 63

— scent glands of, 67

Antennæ, sense of smell in, 199

Antlers, branching of, 61

— eaten when shed, 58

— in female deer, 62

— shedding of, 53

— types of, 60

— use of, 55

Ants, nuptial flight of, 297

— dismal fate of queen, 298

Apes, brilliant colours of, 45

— — — use of, 46

— family relations of, 43

— polygamy in, 48

— power of voice in, 42

— related to man, 41

Aphides, appalling fertility of, 301

— parthenogenesis in, 301

Argonaut, remarkable egg-cradle of, 269

Armature in birds, 117

Argus Pheasant, display of, 96

— — ocelli of, 97

Baboons, mane of, 44

Bailador, dances of, 121

Barrett Hamilton, Major, on Fur-seals, 85

Bee, Bumble, life of, 292

— drone, life of, 281, 289

— queen, as executioner, 279

— — execution of, 286

— — nuptial flight of, 279

— worker, evolution of, 290

Beetles, fighting between, 214

— stridulating organ of, 217

— vivid coloration in, 209

“Behaviour,” specific character of, 157

Birds, secondary sexual characters of, 94

Birds-of-Paradise, display of, 101

Bower-birds, coloration of, 158

— — origin of “bowers,” 160

— — singular behaviour of, 157

Brine-shrimp, vitality of, 304

Bug, extraordinary armature of, 216

Bustard, Australian, display of, 108

Bustard, Great, display of, 107

Butterflies, courtship of, 195

— excess of males in, 192

— experiments on, 205

— and female choice, 193

— females larger than males, 193

— fighting between, 194

— fragrance of, 200

— males mobbing females, 196

— methods of pairing, 204

— scent scales of, 199

Butterfly, Small-blue, method of folding wings of, 187

Caiman, Dr. W. T., on A pus, 306

Campbell on courtship of spiders, 247

Cassowary, roar of, 112

Castration, effects of, 144

Chamæleons, armature of, 167

Cicada, music of, 222

Cockles, blindness of, 274

Coloration, cause of iridescent, 189

— forms of, 186

Conger-eel, huge size of females in, 178

Cooke, Mr. John, and the behaviour of sheep, 69

Courtship, meaning of, 21

Crabs, courtship of, 258

— seizing mates, 260

— stridulating organs of, 255

Crane, dances of, 120

Crocodile, courtship of, 164

Cunningham, J. T., and secondary sexual characters, 14

Dancing in birds, 119

Darwin, his theory of Sexual Selection, 12

Darwin on coloration of beetles, 210, 211

— on coloration of mollusca, 275

— on “horns” of beetles, 212

— on mane of baboons, 44

— on sexual selection in butterflies, 194

Deer, antlers of, 53, 62

— courtship of, 53

— fatal encounters of, 55

“Diathetic” types, meaning of, 50

“Display,” function of, 183

— in birds, need of, 147, 149

Double-eyed fish, 176

Dragon-flies, antiquity of, 227

Dragonet, courtship of, 177

Eland, horns of, 65

— strange habits of, 68

Elephant, courtship of, 71

— remarkable scent glands of, 69

— use of tusks in, 70

Elephant-seal, courtship of, 87

Emotions and human evolution, 32

— and sexual selection, 17

Emu, air-sacs of, 112

Eunuchs, peculiar features of, 145

Extinction, causes of, 17

Fabre on courtship of scorpions, 252

Fashions among savages, 33 et seq.

Fighting-fish, ferocity of, 182

Fish, disparity in size of sexes 178

Forbes, Dr. H. O., on deceptive coloration in a spider, 240

Frigate-bird, air-sacs in display of, III

Frilled-lizard, courtship of, 165

Frogs, concerts of, 171

— courtship of, 169

— singing like a Greenfinch, 173

Fur-seals, courtship of, 81

— polygamy of, 81

— precocious sexual instincts in, 86

Germ-plasm, nature of, 11

Giraffe, kick of, 73

— strong smell of, 68

Grasshopper, air-bladder of, 219

— stridulating organs of, 218, 221

Grebe, Great-crested, courtship of, 151

Groos, Professor, on emotions, 18

Hippopotamus, bloody sweat of, 69

— teeth of, 72

Hooded-seal, air-sac of, 88

Hormones, nature of, 16

— part played by, 146, 147

Horns, evolution of, 51

Hottentots, remarkable peculiarities of, 31

Howard, H. E., on importance of “territory” 140

— on play in warblers, 121

— on sexual selection, 138

Huxley, Mr. Julian, on the behaviour of Mallard, 149

— on the Great-crested Grebe, 151

Hypertely, meaning of, 125, 127

Image, Professor Selwyn, on Vapourer Moth, 201

Impotency, possible consequences of, 155

Ingram, Sir William, on display of King Bird-of-Paradise, 102

Insects and sexual selection, 192

Katydid, song of, 222

Kinetogenesis, meaning of, 80

Leptodora, olfactory sense of, 262

Life, lowest forms of, 3 et seq.

Lion, mane of, 77

— polygamy in, 81

Lizards, courtship of, 165 et seq.

— fighting among, 167

Locusts, ear of, 220

— remarkable ornaments of, 225

Lucas, Dr. F. A., on sea-lions, 86

Males, degenerate, 307

— first to acquire new features, 9

— lead in new departures, 190

— where superfluous, 307

Mallard, remarkable behaviour of, 149

Man, evolution of, 22 et seq.

“Mate-hunger,” part played by, 147

— power, importance of, 5

Mating, preferential, 155

May-flies, dance of death of, 229, 232

— nuptial flight of, 232

— remarkable eyes of male, 231

May-flies, remarkable use of stomach in, 230

Mayer, Mr., experiments on moths, 205

Moina, claspers of, 262

Moose, peculiar habits of, 58

Morgan, Professor Lloyd, on emotions, 18

— on factors in selection, 19, 126

Moth, aquatic females in, 204

— Eyed-hawk, display of, 201

— Ghost, scent-bottle of, 200

— Kentish Glory, sexual differences in, 203

— Oak-eggar, remarkable sense of smell in, 202

— Vapourer, remarkable sense of smell in, 201

Moths, bright colours of, 188

— diurnal, 189

— males, sense of smell of, 199

— scent organs of, 200

Mouth, brilliant colour in birds, 142

Muller, Fritz, on fragrant butterflies, 200

Music in birds, 123 et seq.

Narwhal, tusk of, 90

Newts, courtship of, 170

— remarkable pairing habits of, 170

Ocelli in birds, nature of, 98

Octopus, courtship of, 267

— remarkable mating habits of, 268

Ornament, controlling factors of, 168

Orthogenesis, nature of, 17

Osborne, Professor, on factors in evolution, 17

Ostrich, roar of, 112

Oysters, helpless condition of, 274

— and social reformers, 275

Painted Terrapin, remarkable courtship of, 168

Parthenogenesis in Crustacea, 304

— occurrence of, 276

— significance of, 308

— types of, 300

Peacock, display of, 95

Peckham, Mr., on courtship in spiders, 241

Pheasants, display of, 100

Pigment intensification, cause of, 150

Plovers, fatal conflicts among, 117

— dances of, 119

Plumage, evolution of, 143

Polyandry, human, 29

— in birds, 134

— interpretation of, 136

Polygamy, human, 27

— in birds, 115, 135

— in ungulates, 75

— interpretation of, 76, 115, 135, 136

Poulton, Professor E. B., on animal coloration, 186

— on courtship of spiders, 245

— on sexual selection in spiders, 245

Prairie-hen, air-sacs in display of, 109

Pugnacity in birds, 116

Rays, remarkable teeth of, 176

Reproduction, forms of, 10

Rhinoceros, horns of, 75

Ruff, amorous instincts of, 115

— display of, 113

— variability of, 114

Sabre-toothed tiger, huge canines of, 80

— jaw-flanges of, 80

Salmon, coloration of, 180

— courtship of, 179

Sandpiper, Pectoral, air-sacs in display of, 108

Scent glands, 67

Scorpions, courtship of, 242

Secondary Sexual Characters, meaning of, 13

Selection, forms of, 7

Selous, Mr. F. C., on habits of moose, 59

— on the mane of the lion, 78

Sex, beginnings of, 4

— birth of, 12

Sex-antagonism, 9

Sexual instincts, dominance of, 162

— grades of, 183

— importance of, 27

Sexual selection, definition of, 20

— and human evolution, 38

— in the human race, 32

— instance of working of, 147

Sexual Selection Theory, modification of, 154

Sharp, Dr. David, on stridulating organs, 219

Sheep, scent of, 69

Skull, human, malformation of, 35

Smith Woodward, Dr. A., on factors in evolution, 17

Smynthurus, remarkable courtship of, 26

Snail, hermaphrodite state of, 271

— “love-darts” of, 271

— significance of coloration of, 272

Somato-plasm, nature of, 11

South, Mr., on Oak-eggar moth, 202

Spiders, courtship of, 242 et seq.

— dread sequel to nuptial rites, 246

— drumming of, 237

— nuptial rites in, 248

— remarkable coloration of, 239

— stridulating organs in, 237

Starling, Prof., on Hormones, 14, 16

State executions v. State pensions, 286

Stickle-back, paternal care in, 181

— remarkable nest of, 181

Stone-flies, degenerate wings in, 234

— nuptial rites performed in ice, 233

Stridulating organs of grass hoppers, 218

— nature of, 217

Sun-bittern, display of, 142

Syrinx in birds, 123

Termite, amazing fertility of queen, 302

“Territory,” importance of, 154

Thomson, Prof. J. A., on evolution of sex, 12, 309

Townsend, Mr., on sea-elephants, 87

Tragopans, display of, 100

Trimen, Dr., on deceptive coloration in a spider, 240

Turkey, display of, 99

Use, inherited effects of, 59

Virgin births, belief in, 296

Voice in birds, 123

Wallace, Alfred Russell, and Sexual Selection, 13, 137, 196

Warblers, play in, 121

Water-fleas, olfactory organs of, 261

Water-fleas, mating apparatus of, 226

Weismann, Professor, on coloration of butterflies, 187

Whales, armature of, 89

— battering-rams of, 179-89

Wheel-animalcule, vitality of, 307

Windpipes, where coiled, 128

Zebras, fighting among, 73

Printed at The Chapel River Press, Kingston, Surrey.