FROM the naturalist's point of view, the sole purpose of all forms of life in this world, man included, is to beget more life, and secure the perpetuity of the species. The master instinct in every living creature is to increase and multiply and fill the world with its progeny. Our dream that every living thing was made to serve some namable purpose apart from itself, or was designed in some way to serve man, is a notion that has survived from the childhood of the race.

Many forms, in both the animal and the vegetable worlds, are the enemies of man and the enemies of one another. Other forms play into one another's hands, but only to help forward the scheme of propagation of one or both sides, as when vines and trees incase their seeds in tempting fruit-pulps which the animals eat and thus drop the undigested germs far and near. All our fruits, from the apple down to the wild berries, are plotting to get their seeds scattered and planted, and they offer edible morsels as a wage to any creature that will perform this service. In many cases the wage is a very small one, as with the red cedar, the hardback (Celtis), the sumac, the poison-ivy, and the like; but it serves the purpose; the hungry birds are quick to lend a hand. If the plants and vines and trees had minds and could answer our question as to what is passing in them, they would say: "We are thinking how best to perpetuate our species – how to attract the insects to visit the flowers, and thus secure a hardier race by cross-fertilization; how to tempt the birds and four-footed creatures to come and sow our seeds; how to protect these seeds and nuts till they are ripe and ready to pass along the precious heritage of life; hence some of us trust to the winds and the waters to secure fertilization, in which cases we do not need to develop bright or showy flowers, but a superabundance of pollen; for sowing our seeds, some of us devise wings and balloons; others devise hooks and hands that seize upon passing animals; others make use of the tension of springs and other mechanical devices. We heavy-nut-bearing trees enter into partnership with squirrels and crows and jays; they carry OUT nuts to distant woods and fields; some they carelessly drop by the way, some they hide under the leaves or in the grass, and we find our account in each. They unwittingly plant more oaks and chestnuts and hickory-trees."

Nearly all the animal orders below man are equally obsessed with the idea of perpetuating their species; for this they live, for this they die. It is a kind of madness; it leads to all kinds of excesses and extravagances: bizarre colors and ornaments, grotesque forms and weapons, fantastic rites and ceremonies. The sexual instinct emboldens the timid, and spurs the sluggard; it sharpens the senses, it quickens the wits, it makes even the frogs and toads musical, and gives new life to the turtle. In fact, the drama of all life revolves around the breeding-instinct. It is this that fills the world with music, color, perfume. The nuptials of the vegetable world are celebrated with lovely forms, brilliant hues, and sweet incense. With the birds they are attended by joyous songs, gay plumes, dances and festive reunions, and striking, if at times grotesque, forms. With the insects, music and gay colors mark the day; with the human race, how much of our song and art and pursuit of beauty has grown out of the instinct to please and win the opposite sex! Without this incentive the mating instinct, the love of children, and of home and fireside could we ever have attained to our present civilization?

What is the meaning of the spring and summer chorus of bird-songs – the ecstasy of larks and finches, the madness of nightingales, the melody of thrushes, the intoxication of bobolinks and mocking-birds – the jewels in the plumage, the fantastic in behavior – but sexuality, the innate desire for offspring? How Nature surrounds this passion with the gay, the festive, the hilarious! how she aids it with color and form! how she lavishes upon it all her arts to charm and persuade and entice! Her creatures forget their staid and quiet ways; there is a sound of music and gayety on the one hand, and a noise of strife and battle on the other. The stag bugles and tosses his horns, the bull bellows and tears and paws the earth, the grouse drums and booms, the woodpecker beats a spring reveille on a dry limb, the insects fiddle and shuffle and snap their wings – indeed, nearly all forms of life assume new activity and intensity.

It is the sex principle that gives the beard to the man, the antlers to the stag, the mane to the lion, the spurs and comb to the cock, and the strange fashions and coloration to the male birds. Reproduction is the one thing Nature has most at heart and is intent on securing at all hazards – at the hazard of pain, hunger, strife, and self-destruction.

Just to keep up the game of life, to keep the measure full to overflowing – has Nature any other purpose than this? Think of the swarms of the living that come and go, especially in the insect world, and leave no trace behind! Yes, and at times, in the higher-animal world. Think of the hordes of lemmings that at intervals appear in northern Europe, and move through the land devastating the farmers' crops, till they reach the sea, into which they plunge and are drowned. Ships are said to sail at times through miles of lemmings, swimming they know not whither.

Behold the birds building their nests in spring; how absorbed, how persistent they are! How almost impossible it is to defeat or discourage them! Any one who has tried to prevent English sparrows from breeding on his premises soon learns what a difficult task he has undertaken. Equally, any one who charges himself to see to it that no burdocks or red-root, or other troublesome weeds, mature their seeds on his farm or about his grounds, finds out what enterprise and hardihood he is trying to thwart. Cut the plebeian burdock down within a few inches of the ground and keep it cut down, shorn of all its big leaves, and yet in August or September, without the support of any foliage, it will push out and develop burs in the axils of its old leaves. I have seen masses of burs thus form about the stem half as large as one's fist. The plant was making a last and supreme effort to perpetuate itself. Most garden weeds behave in the same way. As the summer nears its end, and their earlier efforts to form seeds have been thwarted, they seem to become alarmed, and to make a last heroic effort, probably drawing upon the last grain of material stored in the root and stalk to develop the precious germ.

Fruit-trees, starved or in an unhealthy condition, seem to be seized with the same alarm and overload themselves with small, inferior fruit. Is it not notorious that men and women suffering from certain slow, wasting diseases are exceptionally prolific? On the other hand, plants and animals overfed or exceptionally prosperous seem to forget the primal command.

The birds, I repeat, are not easily discouraged. In April of the past year a pair of phœbe-birds built their exquisite mossy nest in a niche in the rocks at the entrance to my natural cellar at Slabsides. It was a nest in the best style of the phœbe's art, built unhurriedly, as all first nests of the season usually are. Like the plant, the bird does not hurry till the season gets late. One snow-white egg was laid, when, on a visit to me of some schoolboys, the nest accidentally came to grief; it was detached from the rock upon which the bird had so carefully masoned it. I replaced the nest, but its foundations had been loosened, and the winds dislodged it. The phœbes then began a nest on a timber under the little shed. One day I found this dislodged and its material pulled apart on the ground beneath. Who or what Vandal or Hun of the woods did it, whether a red squirrel or an owl or other violator of its neighbor's rights, I know not. But the phœbes did not lose heart. When I discovered the second calamity that had befallen them, they were already at work building the third nest, and – what was very unusual – were using the material of the nest just destroyed. Bit by bit the mother bird was gathering it up and reconstructing her "procreant cradle." I hoped a third disaster would not befall the pair, and it did not, but if it had, not later than June, they would probably have built still another nest. The phœbes usually rear two broods in a season when all goes well with them. It is to build the nest and rear the young that they have made the long and hazardous journey from our Southland, or even from Central America, and it is this that will cause them to make it every spring as long as they live. It is this that impels myriads of other small birds and water-fowl to make the same trip from the Far South, braving storms and winds and other perils by land and sea. To beget progeny that will in time reproduce themselves is the unconscious and unquenchable motive that actuates them all. This same motive impels the golden plover to make its marvelous flight from the plains of Patagonia to the Arctic Circle in Alaska, a distance of nearly half the circumference of the globe, crossing oceans without a rest. It sends the European migrants across the Mediterranean from Africa to France, many of them so fatigued on reaching land that they fall an easy prey to man and beast.

It is the impelling force of this motive or instinct that sends the fish up the streams and rivers in the spring, making the waters alive with denizens from the sea, impelling the salmon to leap falls, or, failing to scale them, to keep up the effort till they die from exhaustion. The breeding-instinct is the ruler of life. It asks no questions, it requires no guarantee, it pauses at no obstacles. It sends races of men and animals to seek new lands; it fills nations with the desire for expansion, kindles in them the earth-hunger, and is often the chief factor in devastating wars.

In man the sexual passion is stronger than all others; it rules his life, it has made his history. Consciously or unconsciously, he lives for his posterity. He wages wars to plant colonies or to conquer territory from his enemies, in which his race may expand and increase. His eye is ever on the future; he is looking out for his children and his children's children. Nine tenths of the life of woman centres around the idea of making herself attractive to the opposite sex. This is the meaning of all the modes and fashions – of the monstrous hats, the hobble-skirts, the preposterous shoes, the paint, the jewelry, the feathers, the frippery and the furbelows, the immodest exposures, the exaggerations and accentuations, and all the bewildering arts and devices by which woman seeks to enhance her feminine charms.

The social dances, old and new, though the participants may be all unconscious of it, are as literally sexual, and have as direct reference to the old command to be fruitful and multiply and replenish the earth, as do the dances and aerial evolutions of the birds and the wild fowl. Fine clothes, like fine feathers, all point in the same direction. Male pride and female pride do not differ in their genesis or natural history from the pride displayed in barnyards and in the fields and woods – it is all the outcome of the old command to increase and multiply – it is the masterful desire of one sex to make itself attractive to the opposite.

A great number of insect forms die as soon as they have fulfilled the Biblical injunction. This is true of all the ephemera, and at least one form of vertebrates, the lampreys; these perish as soon as they have spawned.

The cockchafer dies in a month after completing its metamorphosis. The seventeen-year locusts and the grasshoppers live but a short time after they have deposited their eggs. Nature has no further use for them. Many of the moths deposit their eggs within twenty-four hours after they escape from the chrysalis-case, and then very soon die. Many kinds of flies live only four or five hours – just long enough to lay their eggs. As soon as a drone of the hive-bee has fertilized the queen, the swarm has no further use for the whole tribe of drones and they are mercilessly killed or expelled from the hive. Nature displays the same superabundance of the fertilizing principle in such cases that she does in the trees and plants that cast their pollen upon the wind. This is to offset the element of chance. The services of only one drone is required, but the swarm develops scores of them to make sure that at least one male may meet the queen while she is coursing at random on her nuptial flight through the upper air.

Speaking of the queen of the hive-bee reminds me how literally the life of the hive revolves around her. The queen's moral support of the swarm, so to speak, is vital. If any accident befall her, in the case of a new swarm before it has established itself, the whole mass of worker bees instantly becomes demoralized; the swarm loses heart, and gradually perishes without making any attempt to start a new colony. The members seem to know instinctively that there can be no increase, and that their own lives are worthless.

I have seen the whole swarm, when it was suddenly discovered that the queen was missing, show the greatest agitation, every individual insect rushing about with quivering body and wings, in a panic of alarm. What one bee knew and felt, apparently the whole swarm knew and felt simultaneously.

It is worthy of note that though it costs the drone his life to fertilize the queen, dozens of them course through the air during the period that the mating-flight of the queen is due to take place, ready to sacrifice themselves in performing this duty. Alike with drone, worker, queen, the paramount instinct is the perpetuity of the race.

So careless of the male of most species is Nature, so solicitous for the well-being of the female! The function of the male is a brief one, that of the female a long and hazardous one. Among birds of prey the female is the larger, the bolder, and the more active. The parental instinct seems much stronger in her than in the male.

The breeding-instinct has developed among the birds, especially among the ground-builders, one of the most surprising traits or practices to be found in all animate nature. I refer to the tricks and the make-believe that birds will resort to in order to decoy one away from their nests or their young – feigning lameness, paralysis, suffocation, anything to fix the attention of the intruder upon the mother and lure him away from her precious eggs or young. I can recall nothing else so extraordinary in the whole range of animal instinct. The bird suddenly becomes a consummate actor and plays a role she probably never played before, and plays it in the best style of the art. Her behavior looks like the outcome of a sudden process of reasoning. "This creature," it seems to say, "wants my brood, but I will make him want me, and forget the brood. To do so, I have only to throw myself in his way and offer him an easy victim. By my feigned disablement I can draw him on and on, while my young hide, or the clue to my nest is lost."

Last spring in a low, wooded bottom in Georgia, my friend and I started a woodcock from her nest, in which were three eggs. The bird flew a few yards, at a height of ten feet or more, and then suddenly doubled up and fell fluttering to the ground, precisely as if she had been shot. It was a surprising performance. It is highly probable that it was the first time she ever did the trick, but she did it to perfection. Had we followed her, doubtless she would have given us another exhibition of her art of make-believe.

Strange to say, after all her concern for the safety of her eggs, the bird deserted her nest. My friend suggested that it was because we touched one of her eggs; but, as birds have little or no powers of smell, this reason seems inadequate. Rather am I inclined to believe that some accident befell the bird.

Equally surprising is it to see this stupid-looking mud-prober transformed into an ecstatic song-bird under the influence of the mating-instinct. Whoever has witnessed its hurried spiral flight in the March and April twilights, and heard its curious smacking, gurgling notes rain down out of the obscurity of a couple of hundred feet of air, has been present at one of the surprising incidents in the life of this bird.

Love not only makes the songless woodcock vocal; it puts a new song into the throats of many of our birds. The oven-bird, the meadowlark, the purple finch, the goldfinch, and certain of the sparrows and warblers are keyed up to the point where the flight-song, or song of ecstasy, is the natural expression of the bird soul. The jays and crows also become musical, and the woodpeckers drum in varying keys on the resonant limbs. This marked contrast between their ordinary tones and their love-songs reminds one of Browning's lines: –

In the vegetable world the males of diœcious plants perish as soon as the period of bloom of the females, or pistillate plants, has passed. Our spring plant called mouse-ear and everlasting (Antennaria) is a familiar example. The two sexes are in separate groups, and show a marked difference in their appearance. The pistillate plants have a feminine look, they are more slender and graceful, and show more color; they differ in looks from the males as much as the queen bees differ from the drones. The males are short, stubby, freckled, and after they have shed their pollen they wither and perish, while the females continue to develop and grow in grace and beauty till their seeds are matured. The same is true with all shrubs and trees – hazels, chestnuts, oaks, beeches – which develop their pollen in catkins or aments; as soon as the pollen is shed upon the inconspicuous flowers the catkins wither and fall.

There is no case of love and mating among the plants more pleasing to me than that of our Indian corn. When I see the male blossom push its panicle up out of the top of the stalk, bold, rigid, conspicuous, rustic-looking, – "topping out," as the farmers say, – and then, following down the stalk with my eye, see among the leaves the female blossom timidly putting out her delicate silk fringe, like a lock of greenish-golden hair,  – one tender thread for each kernel of corn that is to be, – and awaiting the caresses through the agency of the wind of her suitor above, I am witnessing one of the most pleasing illustrations of Nature's great law that is to be seen in our fields and gardens.

In the case of no other tree in our Northern forests does the male principle assert itself so conspicuously as in the chestnut a tree that now, alas! seems in danger of extinction from some obscure fungus disease attacking its inner bark. In early summer its masses of creamy-white staminate flowers make the top of the woods gay, while its small, modest, greenish female flowers are seen only by him who closely searches for them. But the gala day of the males is brief, while the obscure mother-bloom goes forward and develops her polished triple nuts of autumn.

The odors of the blooming corn and blooming chestnut in some way suggest fruition and the sex passion.

In the hazel, masculine and feminine contrast in the same way as in the chestnut. The long, showy, pollen-yielding tassels are seen from afar, but the minute crimson stars of the nut-producing flowers you will not see without close inspection. Thus do sex characteristics run throughout organic nature. Whitman speaks of the sexuality of the earth, having in mind, no doubt, its fertility and the passive feminine relation it sustains to the orbs above.

Truly the breeding-instinct, with the whole train of subsidiary instincts that go with it, is close to Nature's heart, closer than the instinct of self-preservation. Life is conserved only that it may produce more life. In the insect world, certain forms utterly exhaust themselves in the art of reproduction; others in the act of providing housing and food for their unborn offspring. The May -fly develops into winged liberty, experiences the love-festival, deposits its eggs, when both sexes die, all within the compass of a few hours. Of some species of threadworms it is said that "the young live at the expense of the mother till she is reduced to a mere husk." Fabre tells us of a species of dung-beetle the male of which scours the fields for food for the young, which he carries home and, with his trident, reduces to a powder, till, after the labor of months, without nourishment himself, he becomes utterly exhausted and dies.

In eating up her lover after he has served her purpose, the female spider seems to be carrying domestic economy to unwarranted lengths. Yet generation after generation of male spiders court the female, though often with obvious signs of hesitancy and trepidation. Love overcomes the lover's fear of the ferocious jaws of his mistress. The same is true of the praying-mantis and the scorpion, as portrayed by the inimitable Fabre. After hours or days of love and nuptial bliss, the female turns and slays her lover, and makes a meal off him. The human, or, rather, inhuman, Bluebeard is matched on the other side of the house. Love and martyrdom go hand in hand with honey-bees, spiders, and scorpions. Eating up your mate is certainly a simple and primitive way out of matrimonial difficulties.

Is it not probable that in all such cases the female obtains some nutritive element, maybe in minute quantities, from the body of the male that is necessary for the complete development of her young? The purpose of Nature must be served in some way in such a tragedy, as it is when certain species eat the placenta and when the toad devours his cast-off skin.

Weismann has suggested that the bodies of animals are but appendages to the immortal chain of sex cells they are only the vessels in which the precious germs are nourished and conveyed, the body bearing the relation to them of host to parasite.

So solicitous is Nature for the well-being of the offspring that she will rob the mother's body, if insufficiently nourished, to feed the baby she is carrying in her womb. If the laying hen is not properly supplied with lime material, Nature will draw it from the bones of the hen herself to build the shell of the egg. The offspring is first always, and has the right of way over all else. In short, the struggle to live in the whole organic world resolves itself into the struggle to have and to rear offspring. This is