The nature of Life and its power of reproduction—The stuff of which Life is made—The Emotions—The simplest living things—Where is neither Birth nor Death yet the Population increases—The First Marriage—The beginning of sex—The two dominating instincts—The conditions of survival—The Oyster’s narrow world—“Fiddling work”—Amorousness—The superior Male—Where Death begins—“Germ-plasm” and what it means—Sex and “Secondary sexual Characters”—Some theories—“Hormones” what are they?

The use of the term “Courtship”—Primitive Man and the Foundations of Society—“Amorousness” as a motive force—Polygamy—Our half human ancestors—Standards of Beauty—Disquieting signs

The Man-like Apes and their mode of Life—Their “Courtships”—Musical Chimpanzees—How the Orang-utan improves his voice—His likeness to Caliban—The truculent visage of the Gorilla—“Ornament” in the lower Apes—The Concerts of the Howler Monkeys

The Birth of Weapons—All Flesh is Grass—Utility and Ornament—The Fever of Love—The “Challenge” of the Deer—What it means-More about “Hormones”—“Hummel” Stags—The Age of Deer—The “Courtship” of the Moose—Types of Antlers—Antlered Females—Fighting Topi—The Lance of the Oryx in the Lion’s Flanks—Happiness and Hartebeestes—Odoriferous Suitors—The Bloody Sweat of the Hippopotamus—The Elephant in Love—Concerning Tusks—Polygamy

A Surprising Relationship—The Lion’s Mane—The Sabre-toothed Tiger—Some Theories about Origins—Sea-lions in Love—Some Strange Ornaments—Whales and Weapons

Generalities—Darwin v. Wallace—The Peacock in his Pride—The “Display” of the Peacock Pheasant—The Splendour of the Argus Pheasant and the Marvel of its Eyes—The Frill of the Amherst Pheasant—Birds of Paradise in the Toils of Love—Inflated Suitors-Ruffs and Reeves—Fearsome Weapons and their Uses—Birds which dance-Musical Birds—The Bird’s Voice-box—The “Lek” of the Capercaillie—Instruments of Percussion—The Curious Performance of the Woodpecker

Where the RÔle of the Sexes is reversed—Polygamy and how it is brought about—Coloration and Courtship—Instinctive Actions—The Importance of Landed Possessions—The Meaning of “Display”—The Springs of “Behaviour”—A New Light on the Wild-duck—The “Display” of the Great-crested Grebe—Some xiiiNeglected Factors

The Courtship of the Crocodile—Amorous Lizards—Horned Chameleons—A Flagellating Terrapin—The Frog that would a-wooing go—Some Musical Frogs—Some marvellous instincts in Newts

Germinal variations—Fishes and Mate-hunting—Some Remarkable Sexual Differences displayed by the Teeth of “Rays”—The Double-eyed Fish—The Coloration of the Dragonet—Some Curious Facts about Salmon—The Strange Use of the Kidney in the Stickle-back—The Stickle-back and Parental Duties—Siamese Fighting-fish

Butterflies and Moths, and the Coloration of their Wings—Female Choice and “Fine Feathers”—When Male Butterflies are Dominant—Sexual Selection among Butterflies—Abortive Experiments—Wallace and the Sexual Selection Theory—The Sense of Smell in Butterflies and Moths—Fragrant Butterflies—Wingless Moths and their Lures to Lovers—Methods of Pairing among Butterflies and Moths—More Experiments

The Coloration, and other Forms of Ornament in Beetles, and the Significance thereof in regard to the Sexual Selection Theory—The Courtship of Grasshoppers and their Kin—The Remarkable Ears of Locusts and Grasshoppers—The Field-cricket and the Katydid as Troubadours—The Wonderful Performances of the Cicadas—The Duels of Long-horned Locusts—Dragon flies—The May-flies’ “Dance of Death”—The Jaws of the Giant Alder-fly and their Strange Use—Some Curious Facts xivabout Stone-flies

Musical Lovers among Spiders and Scorpions—Colour among Spiders, and its uses—The Spiders’ Dance of Death—Spiders and Conjugal Bliss—How Pairing is accomplished—Scorpions in Love—Musical Crabs—Quarrelsome Fiddler-crabs—Crabs and Courtship in the Deep Sea-Amazons among Prawns—Brine-shrimps and Water-fleas—“Natural” v. “Sexual” Selection

The Courtship of the Cuttle-fish—The Sumptuous Cradle of the Argonaut—The Love-darts of the Snail—Hermaphrodites and the Dangers of Self-fertilization—Oysters and Beauty—Sex reduced to its Lowest Terms—Parthenogenesis and Virgin Birth—The Story of the Hive-Bee—The Departure of the Queen—The New Queen and her Marriage-flight—The Celebration of the Nuptials and its Surprising Sequel—The Widowed Queen turns Executioner—The Queen as Mother—The Queen’s Daughters—Nursemaids’ Duties—Change of Work—The Drones and their Career—Food and Sex—The Bumble-bee and its Life-story

Courtship among the Ants—The Great Renunciation—Maternity carried to Extremes—Where Males are Superfluous—Degenerate Males—Keeping Death at Bay—Where Females are Unknown